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Costa P, Pereira C, Romalde JL, Almeida A. A game of resistance: War between bacteria and phages and how phage cocktails can be the solution. Virology 2024; 599:110209. [PMID: 39186863 DOI: 10.1016/j.virol.2024.110209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 08/12/2024] [Accepted: 08/14/2024] [Indexed: 08/28/2024]
Abstract
While phages hold promise as an antibiotic alternative, they encounter significant challenges in combating bacterial infections, primarily due to the emergence of phage-resistant bacteria. Bacterial defence mechanisms like superinfection exclusion, CRISPR, and restriction-modification systems can hinder phage effectiveness. Innovative strategies, such as combining different phages into cocktails, have been explored to address these challenges. This review delves into these defence mechanisms and their impact at each stage of the infection cycle, their challenges, and the strategies phages have developed to counteract them. Additionally, we examine the role of phage cocktails in the evolving landscape of antibacterial treatments and discuss recent studies that highlight the effectiveness of diverse phage cocktails in targeting essential bacterial receptors and combating resistant strains.
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Affiliation(s)
- Pedro Costa
- CESAM, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Carla Pereira
- CESAM, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Jesús L Romalde
- Department of Microbiology and Parasitology, CRETUS & CIBUS - Faculty of Biology, University of Santiago de Compostela, CP 15782 Santiago de Compostela, Spain.
| | - Adelaide Almeida
- CESAM, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
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Grafakou A, Mosterd C, Beck MH, Kelleher P, McDonnell B, de Waal PP, van Rijswijck IMH, van Peij NNME, Cambillau C, Mahony J, van Sinderen D. Discovery of antiphage systems in the lactococcal plasmidome. Nucleic Acids Res 2024; 52:9760-9776. [PMID: 39119896 PMCID: PMC11381338 DOI: 10.1093/nar/gkae671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 08/10/2024] Open
Abstract
Until the late 2000s, lactococci substantially contributed to the discovery of various plasmid-borne phage defence systems, rendering these bacteria an excellent antiphage discovery resource. Recently, there has been a resurgence of interest in identifying novel antiphage systems in lactic acid bacteria owing to recent reports of so-called 'defence islands' in diverse bacterial genera. Here, 321 plasmid sequences from 53 lactococcal strains were scrutinized for the presence of antiphage systems. Systematic evaluation of 198 candidates facilitated the discovery of seven not previously described antiphage systems, as well as five systems, of which homologues had been described in other bacteria. All described systems confer resistance against the most prevalent lactococcal phages, and act post phage DNA injection, while all except one behave like abortive infection systems. Structure and domain predictions provided insights into their mechanism of action and allow grouping of several genetically distinct systems. Although rare within our plasmid collection, homologues of the seven novel systems appear to be widespread among bacteria. This study highlights plasmids as a rich repository of as yet undiscovered antiphage systems.
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Affiliation(s)
- Andriana Grafakou
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Cas Mosterd
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Matthias H Beck
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Philip Kelleher
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Brian McDonnell
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Paul P de Waal
- dsm-firmenich, Taste, Texture & Health, Center for Food Innovation, Delft 2613 AX, The Netherlands
| | - Irma M H van Rijswijck
- dsm-firmenich, Taste, Texture & Health, Center for Food Innovation, Delft 2613 AX, The Netherlands
| | - Noël N M E van Peij
- dsm-firmenich, Taste, Texture & Health, Center for Food Innovation, Delft 2613 AX, The Netherlands
| | - Christian Cambillau
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IMM), Aix-Marseille Université - CNRS, UMR 7255 Marseille, France
| | - Jennifer Mahony
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
| | - Douwe van Sinderen
- School of Microbiology & APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland
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Sheykholeslami N, Mirzaei H, Nami Y, Khandaghi J, Javadi A. Ecological and evolutionary dynamics of CRISPR-Cas systems in Clostridium botulinum: Insights from genome mining and comparative analysis. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024; 123:105638. [PMID: 39002873 DOI: 10.1016/j.meegid.2024.105638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/11/2024] [Accepted: 07/07/2024] [Indexed: 07/15/2024]
Abstract
Understanding the prevalence and distribution of CRISPR-Cas systems across different strains can illuminate the ecological and evolutionary dynamics of Clostridium botulinum populations. In this study, we conducted genome mining to characterize the CRISPR-Cas systems of C. botulinum strains. Our analysis involved retrieving complete genome sequences of these strains and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Subsequently, we performed an analysis of homology in spacer sequences from identified CRISPR arrays to investigate and characterize the range of targeted phages and plasmids. Additionally, we investigated the evolutionary trajectory of C. botulinum strains under selective pressures from foreign invasive DNA. Our findings revealed that 306 strains possessed complete CRISPR-Cas structures, comprising 58% of the studied C. botulinum strains. Secondary structure prediction of consensus repeats indicated that subtype II-C, with longer stems compared to subtypes ID and IB, tended to form more stable RNA secondary structures. Moreover, protospacer motif analysis demonstrated that strains with subtype IB CRISPR-Cas systems exhibited 5'-CGG-3', 5'-CC-3', and 5'-CAT-3' motifs in the 3' flanking regions of protospacers. The diversity observed in CRISPR-Cas systems indicated their classification into subtypes IB, ID, II-C, III-B, and III-D. Furthermore, our results showed that systems with subtype ID and III-D frequently harbored similar spacer patterns. Moreover, analysis of spacer sequences homology with phage and prophage genomes highlighted the specific activities exhibited by subtype IB and III-B against phages and plasmids, providing valuable insights into the functional specialization within these systems.
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Affiliation(s)
- Naiymeh Sheykholeslami
- Department of Food Hygiene, Faculty of Veterinary Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran
| | - Hamid Mirzaei
- Department of Food Hygiene, Faculty of Veterinary Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran; Department of food Biotechnology, Biotechnology Research Center, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
| | - Yousef Nami
- Department of Food Biotechnology, Branch for Northwest & West Region, Agricultural Biotechnology Research, Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran.
| | - Jalil Khandaghi
- Department of food Biotechnology, Biotechnology Research Center, Tabriz Branch, Islamic Azad University, Tabriz, Iran; Department of Food Science and Technology, Sarab Branch, Islamic Azad University, Sarab, Iran
| | - Afshin Javadi
- Department of Food Hygiene, Faculty of Veterinary Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran; Department of food Biotechnology, Biotechnology Research Center, Tabriz Branch, Islamic Azad University, Tabriz, Iran
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4
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Kutzer MAM, Cornish B, Jamieson M, Zawistowska O, Monteith KM, Vale PF. Mitochondrial background can explain variable costs of immune deployment. J Evol Biol 2024; 37:1125-1133. [PMID: 39145390 DOI: 10.1093/jeb/voae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Organismal health and survival depend on the ability to mount an effective immune response against infection. Yet immune defence may be energy-demanding, resulting in fitness costs if investment in immune function deprives other physiological processes of resources. While evidence of costly immunity resulting in reduced longevity and reproduction is common, the role of energy-producing mitochondria on the magnitude of these costs is unknown. Here, we employed Drosophila melanogaster cybrid lines, where several mitochondrial genotypes (mitotypes) were introgressed onto a single nuclear genetic background, to explicitly test the role of mitochondrial variation on the costs of immune stimulation. We exposed female flies carrying one of nine distinct mitotypes to either a benign, heat-killed bacterial pathogen (stimulating immune deployment while avoiding pathology) or to a sterile control and measured lifespan, fecundity, and locomotor activity. We observed mitotype-specific costs of immune stimulation and identified a positive genetic correlation in immune-stimulated flies between lifespan and the proportion of time cybrids spent moving while alive. Our results suggests that costs of immunity are highly variable depending on the mitochondrial genome, adding to a growing body of work highlighting the important role of mitochondrial variation in host-pathogen interactions.
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Affiliation(s)
- Megan A M Kutzer
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Beth Cornish
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Jamieson
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Olga Zawistowska
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Katy M Monteith
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Pedro F Vale
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Liaghat A, Yang J, Whitaker R, Pascual M. Punctuated virus-driven succession generates dynamical alternations in CRISPR-mediated microbe-virus coevolution. J R Soc Interface 2024; 21:20240195. [PMID: 39165171 PMCID: PMC11336687 DOI: 10.1098/rsif.2024.0195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/30/2024] [Accepted: 07/08/2024] [Indexed: 08/22/2024] Open
Abstract
The coevolutionary dynamics of lytic viruses and microbes with CRISPR-Cas immunity exhibit alternations between sustained host control of viral proliferation and major viral epidemics in previous computational models. These alternating dynamics have yet to be observed in other host-pathogen systems. Here, we address the breakdown of control and transition to large outbreaks with a stochastic eco-evolutionary model. We establish the role of host density-dependent competition in punctuated virus-driven succession and associated diversity trends that concentrate escape pathways during control phases. Using infection and escape networks, we derive the viral emergence probability whose fluctuations of increasing size and frequency characterize the approach to large outbreaks. We explore alternation probabilities as a function of non-dimensional parameters related to the probability of viral escape and host competition. Our results demonstrate how emergent feedbacks between host competition and viral diversification render the host immune structure fragile, potentiating a dynamical transition to large epidemics.
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Affiliation(s)
- Armun Liaghat
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
- Department of Biology, New York University, New York, NY, USA
| | - Jiayue Yang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Rachel Whitaker
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Mercedes Pascual
- Department of Biology, New York University, New York, NY, USA
- Department of Environmental Studies, New York University, New York, NY, USA
- Santa Fe Institute, Santa Fe, NM, USA
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Yu T, Huang J, Huang X, Hao J, Zhang P, Guo T, Bao G, Li G. Sub-MIC antibiotics increased the fitness cost of CRISPR-Cas in Acinetobacter baumannii. Front Microbiol 2024; 15:1381749. [PMID: 39011146 PMCID: PMC11246858 DOI: 10.3389/fmicb.2024.1381749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 06/04/2024] [Indexed: 07/17/2024] Open
Abstract
Introduction The escalating prevalence of bacterial resistance, particularly multidrug-resistant bacteria like Acinetobacter baumannii, has become a significant global public health concern. The CRISPR-Cas system, a crucial defense mechanism in bacteria against foreign genetic elements, provides a competitive advantage. Type I-Fb and Type I-Fa are two subtypes of CRISPR-Cas systems that were found in A. baumannii, and the I-Fb CRISPR-Cas system regulates antibiotic resistance in A. baumannii. However, it is noteworthy that a majority of clinical isolates of A. baumannii lack or have incomplete CRISPR-Cas systems and most of them are multidrug-resistant. In light of this, our study aimed to examine the impact of antibiotic pressure on the fitness cost of the I-Fb CRISPR-Cas system in A. baumannii. Methods and Results In the study, we conducted in vitro competition experiments to investigate the influence of sub-minimum inhibitory concentration (sub-MIC) on the CRISPR-Cas systems' fitness cost in A. baumannii. We found that the fitness cost of the CRISPR-Cas system was increased under sub-MIC conditions. The expression of CRISPR-Cas-related genes was decreased, while the conjugation frequency was increased in AB43 under sub-MIC conditions. Through metabolomic analysis, we identified that sub-MIC conditions primarily affected energy metabolism pathways. In particular, we observed increased carbon metabolism, nitrogen metabolism, and intracellular ATP. Notably, the CRISPR-Cas system demonstrated resistance to the efflux pump-mediated resistance. Furthermore, the expression of efflux pump-related genes was increased under sub-MIC conditions. Conclusion Our findings suggest that the I-Fb CRISPR-Cas system confers a significant competitive advantage in A. baumanni. However, under sub-MIC conditions, its function and the ability to inhibit the energy required for efflux pumps are reduced, resulting in an increased fitness cost and loss of competitive advantage.
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Affiliation(s)
- Ting Yu
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- Department of Laboratory Medicine, Affiliated Hospital, Yangzhou University, Yangzhou, China
| | - Jiayuan Huang
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
| | - Xinyue Huang
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
| | - Jingchen Hao
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
| | - Pengyu Zhang
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
| | - Tingting Guo
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- Department of Laboratory Medicine, Affiliated Hospital, Yangzhou University, Yangzhou, China
| | - Guangyu Bao
- Department of Laboratory Medicine, Affiliated Hospital, Yangzhou University, Yangzhou, China
| | - Guocai Li
- Department of Microbiology, Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- Department of Laboratory Medicine, Affiliated Hospital, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College/Guangling College, Yangzhou University, Yangzhou, China
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7
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Zeng X, Liang S, Dong J, Gao G, Hu Y, Sun Y. The trade-off of Vibrio parahaemolyticus between bacteriophage resistance and growth competitiveness. Front Microbiol 2024; 15:1346251. [PMID: 38919495 PMCID: PMC11196418 DOI: 10.3389/fmicb.2024.1346251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 04/10/2024] [Indexed: 06/27/2024] Open
Abstract
Vibrio parahaemolyticus is a food-borne pathogen, which is often isolated from various seafood products. In this study, two kinds of bacteriophages was isolated from the offshore sediments samples. The anti-phage mutant strain were obtained after seventeen rounds of co-culture of Vibrio parahaemolyticus and mixed bacteriophage, multigroup sequencing was carried out on spontaneous the anti-phage mutant strain and the wild-type strain. We used the Sanger sequencing to verify the accuracy of the mutation sites. Biolog GEN III MicroPlates were used to evaluate the metabolic capacity of wild-type strains and the anti-phage mutant strain. In this study, we found that with flaG gene (slight homology to N terminus of multiple flagellins) mutated, making the bacteriophage unable to absorb to the cell surface of the host. And, the growth competitiveness of the anti-phage mutant strain is lower than the wild-type strain. These results indicated that the fitness cost, including loss of the growth competitiveness, constitutes a barrier to the prevalence of these defense mechanisms. And the selection pressure on different anti-phage strategies depends on the trade-off between mortality imposed by bacteriophages and fitness cost of the defense strategy under the given environmental conditions. In conclusion, this study provides valuable insights into the phage-host interaction and phage resistance in Vibrio parahaemolyticus. Our study provided knowledge for the evolutionary adaption of bacteria against the bacteriophage, which could add more information to understand the phage resistance mechanism before applying in the industry.
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Affiliation(s)
- Xiuxiu Zeng
- Ningbo No.2 Hospital, Ningbo, Zhejiang, China
- Guoke Ningbo Life Science and Health Industry Research Institute, Ningbo, Zhejiang, China
| | | | - Jiayi Dong
- Guoke Ningbo Life Science and Health Industry Research Institute, Ningbo, Zhejiang, China
| | | | - Yaoren Hu
- Ningbo No.2 Hospital, Ningbo, Zhejiang, China
| | - Yuechao Sun
- Ningbo No.2 Hospital, Ningbo, Zhejiang, China
- Guoke Ningbo Life Science and Health Industry Research Institute, Ningbo, Zhejiang, China
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Pirnay JP, Djebara S, Steurs G, Griselain J, Cochez C, De Soir S, Glonti T, Spiessens A, Vanden Berghe E, Green S, Wagemans J, Lood C, Schrevens E, Chanishvili N, Kutateladze M, de Jode M, Ceyssens PJ, Draye JP, Verbeken G, De Vos D, Rose T, Onsea J, Van Nieuwenhuyse B, Soentjens P, Lavigne R, Merabishvili M. Personalized bacteriophage therapy outcomes for 100 consecutive cases: a multicentre, multinational, retrospective observational study. Nat Microbiol 2024; 9:1434-1453. [PMID: 38834776 PMCID: PMC11153159 DOI: 10.1038/s41564-024-01705-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 04/19/2024] [Indexed: 06/06/2024]
Abstract
In contrast to the many reports of successful real-world cases of personalized bacteriophage therapy (BT), randomized controlled trials of non-personalized bacteriophage products have not produced the expected results. Here we present the outcomes of a retrospective observational analysis of the first 100 consecutive cases of personalized BT of difficult-to-treat infections facilitated by a Belgian consortium in 35 hospitals, 29 cities and 12 countries during the period from 1 January 2008 to 30 April 2022. We assessed how often personalized BT produced a positive clinical outcome (general efficacy) and performed a regression analysis to identify functional relationships. The most common indications were lower respiratory tract, skin and soft tissue, and bone infections, and involved combinations of 26 bacteriophages and 6 defined bacteriophage cocktails, individually selected and sometimes pre-adapted to target the causative bacterial pathogens. Clinical improvement and eradication of the targeted bacteria were reported for 77.2% and 61.3% of infections, respectively. In our dataset of 100 cases, eradication was 70% less probable when no concomitant antibiotics were used (odds ratio = 0.3; 95% confidence interval = 0.127-0.749). In vivo selection of bacteriophage resistance and in vitro bacteriophage-antibiotic synergy were documented in 43.8% (7/16 patients) and 90% (9/10) of evaluated patients, respectively. We observed a combination of antibiotic re-sensitization and reduced virulence in bacteriophage-resistant bacterial isolates that emerged during BT. Bacteriophage immune neutralization was observed in 38.5% (5/13) of screened patients. Fifteen adverse events were reported, including seven non-serious adverse drug reactions suspected to be linked to BT. While our analysis is limited by the uncontrolled nature of these data, it indicates that BT can be effective in combination with antibiotics and can inform the design of future controlled clinical trials. BT100 study, ClinicalTrials.gov registration: NCT05498363 .
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Affiliation(s)
- Jean-Paul Pirnay
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium.
- European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Non-traditional Antibacterial Therapy (ESGNTA), Basel, Switzerland.
| | - Sarah Djebara
- Center for Infectious Diseases, Queen Astrid Military Hospital, Brussels, Belgium
| | - Griet Steurs
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Johann Griselain
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Christel Cochez
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Steven De Soir
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Tea Glonti
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - An Spiessens
- Center for Infectious Diseases, Queen Astrid Military Hospital, Brussels, Belgium
| | - Emily Vanden Berghe
- Center for Infectious Diseases, Queen Astrid Military Hospital, Brussels, Belgium
| | - Sabrina Green
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Jeroen Wagemans
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Cédric Lood
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | | | - Nina Chanishvili
- Eliava Institute of Bacteriophages, Microbiology and Virology, Tbilisi, Georgia
| | - Mzia Kutateladze
- Eliava Institute of Bacteriophages, Microbiology and Virology, Tbilisi, Georgia
| | | | | | - Jean-Pierre Draye
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Gilbert Verbeken
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Daniel De Vos
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Thomas Rose
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Jolien Onsea
- Department of Trauma Surgery, University Hospitals Leuven; Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Brieuc Van Nieuwenhuyse
- Institute of Experimental and Clinical Research, Pediatric Department, UCLouvain, Brussels, Belgium
| | - Patrick Soentjens
- Center for Infectious Diseases, Queen Astrid Military Hospital, Brussels, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Maya Merabishvili
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
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Xiao W, Weissman JL, Johnson PLF. Ecological drivers of CRISPR immune systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594560. [PMID: 38952799 PMCID: PMC11216370 DOI: 10.1101/2024.05.16.594560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
CRISPR-Cas is the only known adaptive immune system of prokaryotes. It is a powerful defense system against mobile genetic elements such as bacteriophages. While CRISPR-Cas systems can be found throughout the prokaryotic tree of life, they are distributed unevenly across taxa and environments. Since adaptive immunity is more useful in environments where pathogens persist or reoccur, the density and/or diversity of the host/pathogen community may drive the uneven distribution of CRISPR system. We directly tested hypotheses connecting CRISPR incidence with prokaryotic density/diversity by analyzing 16S rRNA and metagenomic data from publicly available environmental sequencing projects. In terms of density, we found that CRISPR systems are significantly favored in lower abundance (less dense) taxa and disfavored in higher abundance taxa, at least in marine environments. When we extended this work to compare taxonomic diversity between samples, we found CRISPR system incidence strongly correlated with diversity in human oral environments. Together, these observations confirm that, at least in certain types of environments, the prokaryotic ecological context indeed plays a key role in selecting for CRISPR immunity. Importance 2Microbes must constantly defend themselves against viral pathogens, and a large proportion of prokaryotes do so using the highly effective CRISPR-Cas adaptive immune system. However, many prokaryotes do not. We investigated the ecological factors behind this uneven distribution of CRISPR-Cas immune systems in natural microbial populations. We found strong patterns linking CRISPR-Cas systems to prokaryotic density within ocean environments and to prokaryotic diversity within human oral environments. Our study validates previous within-lab experimental results that suggested these factors might be important and confirms that local environment and ecological context interact to select for CRISPR immunity.
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Tadeu AD, Duarte J, Trindade D, Costa P, Venâncio C, Lopes I, Oliveira V, Gomes NCM, Almeida A, Pereira C. Bacteriophages to control Vibrio alginolyticus in live feeds prior to their administration in larviculture. J Appl Microbiol 2024; 135:lxae115. [PMID: 38710582 DOI: 10.1093/jambio/lxae115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/16/2024] [Accepted: 05/04/2024] [Indexed: 05/08/2024]
Abstract
AIMS This study aimed to evaluate the efficiency of two phages [VB_VaC_TDDLMA (phage TDD) and VB_VaC_SRILMA (phage SRI)] alone and in a cocktail to control Vibrio alginolyticus in brine shrimp before their administration in larviculture. METHODS AND RESULTS Phages were isolated from seawater samples and characterized by host spectrum, growth parameters, adsorption rate, genomic analysis, and inactivation efficiency. Both phages belong to the Caudoviricetes class and lack known virulence or antibiotic-resistance genes. They exhibit specificity, infecting only their host, V. alginolyticus CECT 521. Preliminary experiments in a culture medium showed that phage TDD (reduction of 5.8 log CFU ml-1 after 10 h) outperformed phage SRI (reduction of 4.6 log CFU ml-1 after 6 h) and the cocktail TDD/SRI (reduction of 5.2 log CFU ml-1 after 8 h). In artificial marine water experiments with Artemia franciscana, both single phage suspensions and the phage cocktail, effectively inactivated V. alginolyticus in culture water (reduction of 4.3, 2.1, and 1.9 log CFU ml-1 for phages TDD, SRI, and the phage cocktail, respectively, after 12 h) and in A. franciscana (reduction of 51.6%, 87.3%, and 85.3% for phages TDD, SRI, and the phage cocktail, respectively, after 24 h). The two phages and the phage cocktail did not affect A. franciscana natural microbiota or other Vibrio species in the brine shrimp. CONCLUSIONS The results suggest that phages can safely and effectively control V. alginolyticus in A. franciscana prior to its administration in larviculture.
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Affiliation(s)
- Amanda Dias Tadeu
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - João Duarte
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - David Trindade
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Pedro Costa
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Cátia Venâncio
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Isabel Lopes
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Vanessa Oliveira
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Newton C M Gomes
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Adelaide Almeida
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Carla Pereira
- Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
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11
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Özcan A, Yıbar A, Kiraz D, Ilıkkan ÖK. Comprehensive analysis of the CRISPR-Cas systems in Streptococcus thermophilus strains isolated from traditional yogurts. Antonie Van Leeuwenhoek 2024; 117:63. [PMID: 38561518 DOI: 10.1007/s10482-024-01960-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
Phage resistance is crucial for lactic acid bacteria in the dairy industry. However, identifying all phages affecting these bacteria is challenging. CRISPR-Cas systems offer a resistance mechanism developed by bacteria and archaea against phages and plasmids. In this study, 11 S. thermophilus strains from traditional yogurts underwent analysis using next-generation sequencing (NGS) and bioinformatics tools. Initial characterization involved molecular ribotyping. Bioinformatics analysis of the NGS raw data revealed that all 11 strains possessed at least one CRISPR type. A total of 21 CRISPR loci were identified, belonging to CRISPR types II-A, II-C, and III-A, including 13 Type II-A, 1 Type III-C, and 7 Type III-A CRISPR types. By analyzing spacer sequences in S. thermophilus bacterial genomes and matching them with phage/plasmid genomes, notable strains emerged. SY9 showed prominence with 132 phage matches and 30 plasmid matches, followed by SY12 with 35 phage matches and 25 plasmid matches, and SY18 with 49 phage matches and 13 plasmid matches. These findings indicate the potential of S. thermophilus strains in phage/plasmid resistance for selecting starter cultures, ultimately improving the quality and quantity of dairy products. Nevertheless, further research is required to validate these results and explore the practical applications of this approach.
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Affiliation(s)
- Ali Özcan
- Animal Originated Foodstuffs Department, Central Research Institute of Food and Feed Control, Bursa, Turkey.
- Food Hygiene and Technology Department, Faculty of Veterinary Medicine, Uludağ University, Bursa, Turkey.
| | - Artun Yıbar
- Food Hygiene and Technology Department, Faculty of Veterinary Medicine, Uludağ University, Bursa, Turkey
| | - Deniz Kiraz
- Animal Originated Foodstuffs Department, Central Research Institute of Food and Feed Control, Bursa, Turkey
| | - Özge Kahraman Ilıkkan
- Kahramankazan Vocational School, Food Quality Control and Analysis Program, Başkent University, Ankara, Turkey
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12
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Alseth EO, Custodio R, Sundius SA, Kuske RA, Brown SP, Westra ER. The impact of phage and phage resistance on microbial community dynamics. PLoS Biol 2024; 22:e3002346. [PMID: 38648198 PMCID: PMC11034675 DOI: 10.1371/journal.pbio.3002346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Where there are bacteria, there will be bacteriophages. These viruses are known to be important players in shaping the wider microbial community in which they are embedded, with potential implications for human health. On the other hand, bacteria possess a range of distinct immune mechanisms that provide protection against bacteriophages, including the mutation or complete loss of the phage receptor, and CRISPR-Cas adaptive immunity. While our previous work showed how a microbial community may impact phage resistance evolution, little is known about the inverse, namely how interactions between phages and these different phage resistance mechanisms affect the wider microbial community in which they are embedded. Here, we conducted a 10-day, fully factorial evolution experiment to examine how phage impact the structure and dynamics of an artificial four-species bacterial community that includes either Pseudomonas aeruginosa wild-type or an isogenic mutant unable to evolve phage resistance through CRISPR-Cas. Additionally, we used mathematical modelling to explore the ecological interactions underlying full community behaviour, as well as to identify general principles governing the impacts of phage on community dynamics. Our results show that the microbial community structure is drastically altered by the addition of phage, with Acinetobacter baumannii becoming the dominant species and P. aeruginosa being driven nearly extinct, whereas P. aeruginosa outcompetes the other species in the absence of phage. Moreover, we find that a P. aeruginosa strain with the ability to evolve CRISPR-based resistance generally does better when in the presence of A. baumannii, but that this benefit is largely lost over time as phage is driven extinct. Finally, we show that pairwise data alone is insufficient when modelling our microbial community, both with and without phage, highlighting the importance of higher order interactions in governing multispecies dynamics in complex communities. Combined, our data clearly illustrate how phage targeting a dominant species allows for the competitive release of the strongest competitor while also contributing to community diversity maintenance and potentially preventing the reinvasion of the target species, and underline the importance of mapping community composition before therapeutically applying phage.
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Affiliation(s)
- Ellinor O. Alseth
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, United Kingdom
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Rafael Custodio
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, United Kingdom
| | - Sarah A. Sundius
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Math, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Interdisciplinary Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Rachel A. Kuske
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Math, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Sam P. Brown
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Edze R. Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, United Kingdom
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13
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Agapov A, Baker KS, Bedekar P, Bhatia RP, Blower TR, Brockhurst MA, Brown C, Chong CE, Fothergill JL, Graham S, Hall JP, Maestri A, McQuarrie S, Olina A, Pagliara S, Recker M, Richmond A, Shaw SJ, Szczelkun MD, Taylor TB, van Houte S, Went SC, Westra ER, White MF, Wright R. Multi-layered genome defences in bacteria. Curr Opin Microbiol 2024; 78:102436. [PMID: 38368839 DOI: 10.1016/j.mib.2024.102436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/20/2024]
Abstract
Bacteria have evolved a variety of defence mechanisms to protect against mobile genetic elements, including restriction-modification systems and CRISPR-Cas. In recent years, dozens of previously unknown defence systems (DSs) have been discovered. Notably, diverse DSs often coexist within the same genome, and some co-occur at frequencies significantly higher than would be expected by chance, implying potential synergistic interactions. Recent studies have provided evidence of defence mechanisms that enhance or complement one another. Here, we review the interactions between DSs at the mechanistic, regulatory, ecological and evolutionary levels.
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Affiliation(s)
- Aleksei Agapov
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Kate S Baker
- Department of Genetics, University of Cambridge, CB2 3EH, UK
| | - Paritosh Bedekar
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Rama P Bhatia
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Tim R Blower
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Michael A Brockhurst
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Dover Street, Manchester M13 9PT, UK
| | - Cooper Brown
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | | | - Joanne L Fothergill
- Dept of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, UK
| | - Shirley Graham
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - James Pj Hall
- Dept of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, L69 7ZB, UK
| | - Alice Maestri
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Stuart McQuarrie
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Anna Olina
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | | | - Mario Recker
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Anna Richmond
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Steven J Shaw
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS6 7YB, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS6 7YB, UK
| | - Tiffany B Taylor
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | | | - Sam C Went
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Edze R Westra
- ESI, Centre for Ecology and Conservation, University of Exeter, UK.
| | - Malcolm F White
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Rosanna Wright
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Dover Street, Manchester M13 9PT, UK
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14
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Wang X, Leptihn S. Defense and anti-defense mechanisms of bacteria and bacteriophages. J Zhejiang Univ Sci B 2024; 25:181-196. [PMID: 38453634 PMCID: PMC10918411 DOI: 10.1631/jzus.b2300101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/24/2023] [Indexed: 03/09/2024]
Abstract
In the post-antibiotic era, the overuse of antimicrobials has led to a massive increase in antimicrobial resistance, leaving medical doctors few or no treatment options to fight infections caused by superbugs. The use of bacteriophages is a promising alternative to treat infections, supplementing or possibly even replacing antibiotics. Using phages for therapy is possible, since these bacterial viruses can kill bacteria specifically, causing no harm to the normal flora. However, bacteria have developed a multitude of sophisticated and complex ways to resist infection by phages, including abortive infection and the clustered regularly interspersed short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system. Phages also can evolve and acquire new anti-defense strategies to continue predation. An in-depth exploration of both defense and anti-defense mechanisms would contribute to optimizing phage therapy, while we would also gain novel insights into the microbial world. In this paper, we summarize recent research on bacterial phage resistance and phage anti-defense mechanisms, as well as collaborative win-win systems involving both virus and host.
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Affiliation(s)
- Xiaoqing Wang
- School of Medicine, Lishui University, Lishui 323000, China.
| | - Sebastian Leptihn
- University of Edinburgh Medical School, Biomedical Sciences, College of Medicine & Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9JZ, UK.
- HMU Health and Medical University, Am Anger 64/73- 99084 Erfurt, Germany.
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15
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Critchlow JT, Prakash A, Zhong KY, Tate AT. Mapping the functional form of the trade-off between infection resistance and reproductive fitness under dysregulated immune signaling. PLoS Pathog 2024; 20:e1012049. [PMID: 38408106 PMCID: PMC10919860 DOI: 10.1371/journal.ppat.1012049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 03/07/2024] [Accepted: 02/15/2024] [Indexed: 02/28/2024] Open
Abstract
Immune responses benefit organismal fitness by clearing parasites but also exact costs associated with immunopathology and energetic investment. Hosts manage these costs by tightly regulating the induction of immune signaling to curtail excessive responses and restore homeostasis. Despite the theoretical importance of turning off the immune response to mitigate these costs, experimentally connecting variation in the negative regulation of immune responses to organismal fitness remains a frontier in evolutionary immunology. In this study, we used a dose-response approach to manipulate the RNAi-mediated knockdown efficiency of cactus (IκBα), a central regulator of Toll pathway signal transduction in flour beetles (Tribolium castaneum). By titrating cactus activity across four distinct levels, we derived the shape of the relationship between immune response investment and traits associated with host fitness, including infection susceptibility, lifespan, fecundity, body mass, and gut homeostasis. Cactus knock-down increased the overall magnitude of inducible immune responses and delayed their resolution in a dsRNA dose-dependent manner, promoting survival and resistance following bacterial infection. However, these benefits were counterbalanced by dsRNA dose-dependent costs to lifespan, fecundity, body mass, and gut integrity. Our results allowed us to move beyond the qualitative identification of a trade-off between immune investment and fitness to actually derive its functional form. This approach paves the way to quantitatively compare the evolution and impact of distinct regulatory elements on life-history trade-offs and fitness, filling a crucial gap in our conceptual and theoretical models of immune signaling network evolution and the maintenance of natural variation in immune systems.
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Affiliation(s)
- Justin T Critchlow
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Arun Prakash
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Katherine Y Zhong
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Ann T Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Evolutionary Studies Institute, Vanderbilt University, Nashville, Tennessee, United States of America
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16
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Smith LM, Hampton HG, Yevstigneyeva MS, Mahler M, Paquet ZM, Fineran PC. CRISPR-Cas immunity is repressed by the LysR-type transcriptional regulator PigU. Nucleic Acids Res 2024; 52:755-768. [PMID: 38059344 PMCID: PMC10810281 DOI: 10.1093/nar/gkad1165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/17/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023] Open
Abstract
Bacteria protect themselves from infection by bacteriophages (phages) using different defence systems, such as CRISPR-Cas. Although CRISPR-Cas provides phage resistance, fitness costs are incurred, such as through autoimmunity. CRISPR-Cas regulation can optimise defence and minimise these costs. We recently developed a genome-wide functional genomics approach (SorTn-seq) for high-throughput discovery of regulators of bacterial gene expression. Here, we applied SorTn-seq to identify loci influencing expression of the two type III-A Serratia CRISPR arrays. Multiple genes affected CRISPR expression, including those involved in outer membrane and lipopolysaccharide synthesis. By comparing loci affecting type III CRISPR arrays and cas operon expression, we identified PigU (LrhA) as a repressor that co-ordinately controls both arrays and cas genes. By repressing type III-A CRISPR-Cas expression, PigU shuts off CRISPR-Cas interference against plasmids and phages. PigU also represses interference and CRISPR adaptation by the type I-F system, which is also present in Serratia. RNA sequencing demonstrated that PigU is a global regulator that controls secondary metabolite production and motility, in addition to CRISPR-Cas immunity. Increased PigU also resulted in elevated expression of three Serratia prophages, indicating their likely induction upon sensing PigU-induced cellular changes. In summary, PigU is a major regulator of CRISPR-Cas immunity in Serratia.
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Affiliation(s)
- Leah M Smith
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Hannah G Hampton
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Mariya S Yevstigneyeva
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Marina Mahler
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Zacharie S M Paquet
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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17
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Elliott JFK, McLeod DV, Taylor TB, Westra ER, Gandon S, Watson BNJ. Conditions for the spread of CRISPR-Cas immune systems into bacterial populations. THE ISME JOURNAL 2024; 18:wrae108. [PMID: 38896653 DOI: 10.1093/ismejo/wrae108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/29/2024] [Accepted: 06/14/2024] [Indexed: 06/21/2024]
Abstract
Bacteria contain a wide variety of innate and adaptive immune systems which provide protection to the host against invading genetic material, including bacteriophages (phages). It is becoming increasingly clear that bacterial immune systems are frequently lost and gained through horizontal gene transfer. However, how and when new immune systems can become established in a bacterial population have remained largely unstudied. We developed a joint epidemiological and evolutionary model that predicts the conditions necessary for the spread of a CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) immune system into a bacterial population lacking this system. We found that whether bacteria carrying CRISPR-Cas will spread (increase in frequency) into a bacterial population depends on the abundance of phages and the difference in the frequency of phage resistance mechanisms between bacteria carrying a CRISPR-Cas immune system and those not (denoted as ${f}_{\Delta }$). Specifically, the abundance of cells carrying CRISPR-Cas will increase if there is a higher proportion of phage resistance (either via CRISPR-Cas immunity or surface modification) in the CRISPR-Cas-possessing population than in the cells lacking CRISPR-Cas. We experimentally validated these predictions in a model using Pseudomonas aeruginosa PA14 and phage DMS3vir. Specifically, by varying the initial ratios of different strains of bacteria that carry alternative forms of phage resistance, we confirmed that the spread of cells carrying CRISPR-Cas through a population can be predicted based on phage density and the relative frequency of resistance phenotypes. Understanding which conditions promote the spread of CRISPR-Cas systems helps to predict when and where these defences can become established in bacterial populations after a horizontal gene transfer event, both in ecological and clinical contexts.
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Affiliation(s)
- Josie F K Elliott
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- ESI, Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9FE, United Kingdom
| | - David V McLeod
- Département de mathématiques et statistique, Université de Montréal, Montréal, Canada
- Institute of Ecology and Evolution, Universität Bern, Bern, Switzerland
| | - Tiffany B Taylor
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Edze R Westra
- ESI, Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9FE, United Kingdom
| | - Sylvain Gandon
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | - Bridget N J Watson
- ESI, Biosciences, University of Exeter, Cornwall Campus, Penryn TR10 9FE, United Kingdom
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18
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Watson BNJ, Capria L, Alseth EO, Pons BJ, Biswas A, Lenzi L, Buckling A, van Houte S, Westra ER, Meaden S. CRISPR-Cas in Pseudomonas aeruginosa provides transient population-level immunity against high phage exposures. THE ISME JOURNAL 2024; 18:wrad039. [PMID: 38366022 PMCID: PMC10873826 DOI: 10.1093/ismejo/wrad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/12/2023] [Accepted: 01/02/2024] [Indexed: 02/18/2024]
Abstract
The prokaryotic adaptive immune system, CRISPR-Cas (clustered regularly interspaced short palindromic repeats; CRISPR-associated), requires the acquisition of spacer sequences that target invading mobile genetic elements such as phages. Previous work has identified ecological variables that drive the evolution of CRISPR-based immunity of the model organism Pseudomonas aeruginosa PA14 against its phage DMS3vir, resulting in rapid phage extinction. However, it is unclear if and how stable such acquired immunity is within bacterial populations, and how this depends on the environment. Here, we examine the dynamics of CRISPR spacer acquisition and loss over a 30-day evolution experiment and identify conditions that tip the balance between long-term maintenance of immunity versus invasion of alternative resistance strategies that support phage persistence. Specifically, we find that both the initial phage dose and reinfection frequencies determine whether or not acquired CRISPR immunity is maintained in the long term, and whether or not phage can coexist with the bacteria. At the population genetics level, emergence and loss of CRISPR immunity are associated with high levels of spacer diversity that subsequently decline due to invasion of bacteria carrying pilus-associated mutations. Together, these results provide high resolution of the dynamics of CRISPR immunity acquisition and loss and demonstrate that the cumulative phage burden determines the effectiveness of CRISPR over ecologically relevant timeframes.
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Affiliation(s)
- Bridget N J Watson
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Loris Capria
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Ellinor O Alseth
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Benoit J Pons
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Ambarish Biswas
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9059, Otago, New Zealand
| | - Luca Lenzi
- Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, L69 7BE, United Kingdom
| | - Angus Buckling
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Stineke van Houte
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Edze R Westra
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
| | - Sean Meaden
- Biosciences, University of Exeter, Penryn, Cornwall, TR10 9FE, United Kingdom
- Department of Biology, University of York, Wentworth Way, York, North Yorkshire YO10 3DB, United Kingdom
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19
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Dion MB, Shah SA, Deng L, Thorsen J, Stokholm J, Krogfelt KA, Schjørring S, Horvath P, Allard A, Nielsen DS, Petit MA, Moineau S. Escherichia coli CRISPR arrays from early life fecal samples preferentially target prophages. THE ISME JOURNAL 2024; 18:wrae005. [PMID: 38366192 PMCID: PMC10910852 DOI: 10.1093/ismejo/wrae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 02/18/2024]
Abstract
CRISPR-Cas systems are defense mechanisms against phages and other nucleic acids that invade bacteria and archaea. In Escherichia coli, it is generally accepted that CRISPR-Cas systems are inactive in laboratory conditions due to a transcriptional repressor. In natural isolates, it has been shown that CRISPR arrays remain stable over the years and that most spacer targets (protospacers) remain unknown. Here, we re-examine CRISPR arrays in natural E. coli isolates and investigate viral and bacterial genomes for spacer targets using a bioinformatics approach coupled to a unique biological dataset. We first sequenced the CRISPR1 array of 1769 E. coli isolates from the fecal samples of 639 children obtained during their first year of life. We built a network with edges between isolates that reflect the number of shared spacers. The isolates grouped into 34 modules. A search for matching spacers in bacterial genomes showed that E. coli spacers almost exclusively target prophages. While we found instances of self-targeting spacers, those involving a prophage and a spacer within the same bacterial genome were rare. The extensive search for matching spacers also expanded the library of known E. coli protospacers to 60%. Altogether, these results favor the concept that E. coli's CRISPR-Cas is an antiprophage system and highlight the importance of reconsidering the criteria use to deem CRISPR-Cas systems active.
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Affiliation(s)
- Moïra B Dion
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC G1V 0A6, Canada
| | - Shiraz A Shah
- Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Ledreborg Alle 34, 2820 Gentofte, Denmark
| | - Ling Deng
- Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | - Jonathan Thorsen
- Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Ledreborg Alle 34, 2820 Gentofte, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Jakob Stokholm
- Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Ledreborg Alle 34, 2820 Gentofte, Denmark
- Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | - Karen A Krogfelt
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Artillerivej 5, 2300S Copenhagen, Denmark
- Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark
| | - Susanne Schjørring
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Artillerivej 5, 2300S Copenhagen, Denmark
| | - Philippe Horvath
- IFF Danisco, Health & Biosciences, Dangé-Saint-Romain 86220, France
| | - Antoine Allard
- Département de physique, de génie physique et d’optique, Université Laval, Québec, QC G1V 0A6, Canada
- Centre interdisciplinaire en modélisation mathématique, Université Laval, Québec, QC G1V 0A6, Canada
| | - Dennis S Nielsen
- Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | - Marie-Agnès Petit
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Micalis, Jouy-en-Josas 78350, France
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, QC G1V 0A6, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC G1V 0A6, Canada
- Félix d’Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec, QC G1V 0A6, Canada
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20
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Zhou SO, Arunkumar R, Irfan A, Ding SD, Leitão AB, Jiggins FM. The evolution of constitutively active humoral immune defenses in Drosophila populations under high parasite pressure. PLoS Pathog 2024; 20:e1011729. [PMID: 38206983 PMCID: PMC10807768 DOI: 10.1371/journal.ppat.1011729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/24/2024] [Accepted: 01/04/2024] [Indexed: 01/13/2024] Open
Abstract
Both constitutive and inducible immune mechanisms are employed by hosts for defense against infection. Constitutive immunity allows for a faster response, but it comes with an associated cost that is always present. This trade-off between speed and fitness costs leads to the theoretical prediction that constitutive immunity will be favored where parasite exposure is frequent. We selected populations of Drosophila melanogaster under high parasite pressure from the parasitoid wasp Leptopilina boulardi. With RNA sequencing, we found the evolution of resistance in these populations was associated with them developing constitutively active humoral immunity, mediated by the larval fat body. Furthermore, these evolved populations were also able to induce gene expression in response to infection to a greater level, which indicates an overall more activated humoral immune response to parasitization. The anti-parasitoid immune response also relies on the JAK/STAT signaling pathway being activated in muscles following infection, and this induced response was only seen in populations that had evolved under high parasite pressure. We found that the cytokine Upd3, which induces this JAK/STAT response, is being expressed by immature lamellocytes. Furthermore, these immune cells became constitutively present when populations evolved resistance, potentially explaining why they gained the ability to activate JAK/STAT signaling. Thus, under intense parasitism, populations evolved resistance by increasing both constitutive and induced immune defenses, and there is likely an interplay between these two forms of immunity.
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Affiliation(s)
- Shuyu Olivia Zhou
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Ramesh Arunkumar
- Section of population genetics, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Amina Irfan
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | | | - Alexandre B. Leitão
- Champalimaud Foundation, Champalimaud Centre of the Unknown, Lisbon, Portugal
| | - Francis M. Jiggins
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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21
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Santiago-Frangos A, Henriques WS, Wiegand T, Gauvin CC, Buyukyoruk M, Graham AB, Wilkinson RA, Triem L, Neselu K, Eng ET, Lander GC, Wiedenheft B. Structure reveals why genome folding is necessary for site-specific integration of foreign DNA into CRISPR arrays. Nat Struct Mol Biol 2023; 30:1675-1685. [PMID: 37710013 PMCID: PMC10872659 DOI: 10.1038/s41594-023-01097-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/15/2023] [Indexed: 09/16/2023]
Abstract
Bacteria and archaea acquire resistance to viruses and plasmids by integrating fragments of foreign DNA into the first repeat of a CRISPR array. However, the mechanism of site-specific integration remains poorly understood. Here, we determine a 560-kDa integration complex structure that explains how Pseudomonas aeruginosa Cas (Cas1-Cas2/3) and non-Cas proteins (for example, integration host factor) fold 150 base pairs of host DNA into a U-shaped bend and a loop that protrude from Cas1-2/3 at right angles. The U-shaped bend traps foreign DNA on one face of the Cas1-2/3 integrase, while the loop places the first CRISPR repeat in the Cas1 active site. Both Cas3 proteins rotate 100 degrees to expose DNA-binding sites on either side of the Cas2 homodimer, which each bind an inverted repeat motif in the leader. Leader sequence motifs direct Cas1-2/3-mediated integration to diverse repeat sequences that have a 5'-GT. Collectively, this work reveals new DNA-binding surfaces on Cas2 that are critical for DNA folding and site-specific delivery of foreign DNA.
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Affiliation(s)
| | - William S Henriques
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Tanner Wiegand
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Colin C Gauvin
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
- Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Murat Buyukyoruk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Ava B Graham
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Royce A Wilkinson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Lenny Triem
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Kasahun Neselu
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Edward T Eng
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Blake Wiedenheft
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
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22
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Aframian N, Eldar A. Abortive infection antiphage defense systems: separating mechanism and phenotype. Trends Microbiol 2023; 31:1003-1012. [PMID: 37268559 DOI: 10.1016/j.tim.2023.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 06/04/2023]
Abstract
Bacteria have evolved a wide array of mechanisms that allow them to eliminate phage infection. 'Abortive infection' (abi) systems are an expanding category of such mechanisms, defined as those which induce programmed cell death (or dormancy) upon infection, and thus halt phage propagation within a bacterial population. This definition entails two requirements - a phenotypic observation (cell death upon infection), and a mechanistic determination of its sources (system-induced death). The phenotypic and mechanistic aspects of abi are often implicitly assumed to be tightly linked, and studies regularly tend to establish one and deduce the other. However, recent evidence points to a complicated relationship between the mechanism of defense and the phenotype observed upon infection. We argue that rather than viewing the abi phenotype as an inherent quality of a set of defense systems, it should be more appropriately thought of as an attribute of interactions between specific phages and bacteria under given conditions. Consequently, we also point to potential pitfalls in the prevailing methods for ascertaining the abi phenotype. Overall, we propose an alternative framework for parsing interactions between attacking phages and defending bacteria.
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Affiliation(s)
- Nitzan Aframian
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Avigdor Eldar
- Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel.
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23
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Alseth EO, Custodio R, Sundius SA, Kuske RA, Brown SP, Westra ER. The impact of phage and phage resistance on microbial community dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.26.559468. [PMID: 37808693 PMCID: PMC10557685 DOI: 10.1101/2023.09.26.559468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Where there are bacteria, there will be bacteriophages. These viruses are known to be important players in shaping the wider microbial community in which they are embedded, with potential implications for human health. On the other hand, bacteria possess a range of distinct immune mechanisms that provide protection against bacteriophages, including the mutation or complete loss of the phage receptor, and CRISPR-Cas adaptive immunity. Yet little is known about how interactions between phages and these different phage resistance mechanisms affect the wider microbial community in which they are embedded. Here, we conducted a 10-day, fully factorial evolution experiment to examine how phage impact the structure and dynamics of an artificial four-species bacterial community that includes either Pseudomonas aeruginosa wild type or an isogenic mutant unable to evolve phage resistance through CRISPR-Cas. Our results show that the microbial community structure is drastically altered by the addition of phage, with Acinetobacter baumannii becoming the dominant species and P. aeruginosa being driven nearly extinct, whereas P. aeruginosa outcompetes the other species in the absence of phage. Moreover, we find that a P. aeruginosa strain with the ability to evolve CRISPR-based resistance generally does better when in the presence of A. baumannii, but that this benefit is largely lost over time as phage is driven extinct. Combined, our data highlight how phage-targeting a dominant species allows for the competitive release of the strongest competitor whilst also contributing to community diversity maintenance and potentially preventing the reinvasion of the target species, and underline the importance of mapping community composition before therapeutically applying phage.
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Affiliation(s)
- Ellinor O Alseth
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, UK
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Rafael Custodio
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, UK
| | - Sarah A Sundius
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Math, Georgia Institute of Technology, Atlanta, Georgia, USA
- Interdisciplinary Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Rachel A Kuske
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Math, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Sam P. Brown
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Edze R Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, UK
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24
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Watson BNJ, Pursey E, Gandon S, Westra ER. Transient eco-evolutionary dynamics early in a phage epidemic have strong and lasting impact on the long-term evolution of bacterial defences. PLoS Biol 2023; 21:e3002122. [PMID: 37713428 PMCID: PMC10530023 DOI: 10.1371/journal.pbio.3002122] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 09/27/2023] [Accepted: 08/07/2023] [Indexed: 09/17/2023] Open
Abstract
Organisms have evolved a range of constitutive (always active) and inducible (elicited by parasites) defence mechanisms, but we have limited understanding of what drives the evolution of these orthogonal defence strategies. Bacteria and their phages offer a tractable system to study this: Bacteria can acquire constitutive resistance by mutation of the phage receptor (surface mutation, sm) or induced resistance through their CRISPR-Cas adaptive immune system. Using a combination of theory and experiments, we demonstrate that the mechanism that establishes first has a strong advantage because it weakens selection for the alternative resistance mechanism. As a consequence, ecological factors that alter the relative frequencies at which the different resistances are acquired have a strong and lasting impact: High growth conditions promote the evolution of sm resistance by increasing the influx of receptor mutation events during the early stages of the epidemic, whereas a high infection risk during this stage of the epidemic promotes the evolution of CRISPR immunity, since it fuels the (infection-dependent) acquisition of CRISPR immunity. This work highlights the strong and lasting impact of the transient evolutionary dynamics during the early stages of an epidemic on the long-term evolution of constitutive and induced defences, which may be leveraged to manipulate phage resistance evolution in clinical and applied settings.
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Affiliation(s)
| | - Elizabeth Pursey
- ESI, Biosciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom
| | - Sylvain Gandon
- Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS-Université de Montpellier-Université Paul-Valéry Montpellier-EPHE, Montpellier, France
| | - Edze Rients Westra
- ESI, Biosciences, University of Exeter, Cornwall Campus, Penryn, United Kingdom
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25
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Critchlow JT, Prakash A, Zhong KY, Tate AT. Mapping the functional form of the trade-off between infection resistance and reproductive fitness under dysregulated immune signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552815. [PMID: 37645726 PMCID: PMC10461925 DOI: 10.1101/2023.08.10.552815] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Immune responses benefit organismal fitness by clearing parasites but also exact costs associated with immunopathology and energetic investment. Hosts manage these costs by tightly regulating the induction of immune signaling to curtail excessive responses and restore homeostasis. Despite the theoretical importance of turning off the immune response to mitigate these costs, experimentally connecting variation in the negative regulation of immune responses to organismal fitness remains a frontier in evolutionary immunology. In this study, we used a dose-response approach to manipulate the RNAi-mediated knockdown efficiency of cactus (IκBα), a central regulator of Toll pathway signal transduction in flour beetles (Tribolium castaneum). By titrating cactus activity along a continuous gradient, we derived the shape of the relationship between immune response investment and traits associated with host fitness, including infection susceptibility, lifespan, fecundity, body mass, and gut homeostasis. Cactus knock-down increased the overall magintude of inducible immune responses and delayed their resolution in a dsRNA dose-dependent manner, promoting survival and resistance following bacterial infection. However, these benefits were counterbalanced by dsRNA dose-dependent costs to lifespan, fecundity, body mass, and gut integrity. Our results allowed us to move beyond the qualitative identification of a trade-off between immune investment and fitness to actually derive its functional form. This approach paves the way to quantitatively compare the evolution and impact of distinct regulatory elements on life-history trade-offs and fitness, filling a crucial gap in our conceptual and theoretical models of immune signaling network evolution and the maintenance of natural variation in immune systems.
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Affiliation(s)
- Justin T. Critchlow
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Arun Prakash
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Katherine Y. Zhong
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Ann T. Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Evolutionary Studies Institute, Vanderbilt University, Nashville, Tennessee, United States of America
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26
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Liu ZL, Hu EZ, Niu DK. Investigating the Relationship between CRISPR-Cas Content and Growth Rate in Bacteria. Microbiol Spectr 2023; 11:e0340922. [PMID: 37022199 PMCID: PMC10269591 DOI: 10.1128/spectrum.03409-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 03/11/2023] [Indexed: 04/07/2023] Open
Abstract
CRISPR-Cas systems provide adaptive immunity for prokaryotic cells by recognizing and eliminating the recurrent genetic invaders whose sequences had been captured in a prior infection and stored in the CRISPR arrays as spacers. However, the biological/environmental factors determining the efficiency of this immune system have yet to be fully characterized. Recent studies in cultured bacteria showed that slowing the growth rate of bacterial cells could promote their acquisition of novel spacers. This study examined the relationship between the CRISPR-Cas content and the minimal doubling time across the bacteria and the archaea domains. Every completely sequenced genome could be used to predict a minimal doubling time. With a large data set of 4,142 bacterial samples, we found that the predicted minimal doubling times are positively correlated with spacer number and other parameters of the CRISPR-Cas systems, like array number, Cas gene cluster number, and Cas gene number. Different data sets gave different results. Weak results were obtained in analyzing bacterial empirical minimal doubling times and the archaea domain. Still, the conclusion of more spacers in slowly grown prokaryotes was supported. In addition, we found that the minimal doubling times are negatively correlated with the occurrence of prophages, and the spacer numbers per array are negatively associated with the number of prophages. These observations support the existence of an evolutionary trade-off between bacterial growth and adaptive defense against virulent phages. IMPORTANCE Accumulating evidence indicates that slowing the growth of cultured bacteria could stimulate their CRISPR spacer acquisition. We observed a positive correlation between CRISPR-Cas content and cell cycle duration across the bacteria domain. This observation extends the physiological conclusion to an evolutionary one. In addition, the correlation provides evidence supporting the existence of a trade-off between bacterial growth/reproduction and antiviral resistance.
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Affiliation(s)
- Zhi-Ling Liu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - En-Ze Hu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Deng-Ke Niu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
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27
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Schrom E, Kinzig A, Forrest S, Graham AL, Levin SA, Bergstrom CT, Castillo-Chavez C, Collins JP, de Boer RJ, Doupé A, Ensafi R, Feldman S, Grenfell BT, Halderman JA, Huijben S, Maley C, Moses M, Perelson AS, Perrings C, Plotkin J, Rexford J, Tiwari M. Challenges in cybersecurity: Lessons from biological defense systems. Math Biosci 2023:109024. [PMID: 37270102 DOI: 10.1016/j.mbs.2023.109024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/27/2023] [Accepted: 05/20/2023] [Indexed: 06/05/2023]
Abstract
Defending against novel, repeated, or unpredictable attacks, while avoiding attacks on the 'self', are the central problems of both mammalian immune systems and computer systems. Both systems have been studied in great detail, but with little exchange of information across the different disciplines. Here, we present a conceptual framework for structured comparisons across the fields of biological immunity and cybersecurity, by framing the context of defense, considering different (combinations of) defensive strategies, and evaluating defensive performance. Throughout this paper, we pose open questions for further exploration. We hope to spark the interdisciplinary discovery of general principles of optimal defense, which can be understood and applied in biological immunity, cybersecurity, and other defensive realms.
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Affiliation(s)
- Edward Schrom
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, United States of America
| | - Ann Kinzig
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, United States of America
| | - Stephanie Forrest
- Biodesign Center for Biocomputation, Security and Society, Arizona State University, Tempe, AZ 85287, United States of America; School of Computing and Augmented Intelligence, Arizona State University, Tempe, AZ 85287, United States of America; Santa Fe Institute, Santa Fe, NM 87501, United States of America
| | - Andrea L Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, United States of America; Santa Fe Institute, Santa Fe, NM 87501, United States of America
| | - Simon A Levin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, United States of America.
| | - Carl T Bergstrom
- Department of Biology, University of Washington, Seattle, WA 98195, United States of America
| | - Carlos Castillo-Chavez
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, United States of America
| | - James P Collins
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, United States of America
| | - Rob J de Boer
- Theoretical Biology and Bioinformatics, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Adam Doupé
- School of Computing and Augmented Intelligence, Arizona State University, Tempe, AZ 85287, United States of America; Center for Cybersecurity and Trusted Foundations, Global Security Initiative, Arizona State University, Tempe, AZ 85287, United States of America
| | - Roya Ensafi
- Department of Electrical Engineering and Computer Science, Computer Science and Engineering Division, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Stuart Feldman
- Schmidt Futures, New York, NY 10011, United States of America
| | - Bryan T Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, United States of America; Princeton School of Public and International Affairs, Princeton University, Princeton, NJ 08544, United States of America
| | - J Alex Halderman
- Department of Electrical Engineering and Computer Science, Computer Science and Engineering Division, University of Michigan, Ann Arbor, MI 48109, United States of America; Center for Computer Security and Society, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Silvie Huijben
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, United States of America
| | - Carlo Maley
- Arizona Cancer Evolution Center, Arizona State University, Tempe, AZ 85287, United States of America; Biodesign Center for Biocomputation, Security and Society, Arizona State University, Tempe, AZ 85287, United States of America
| | - Melanie Moses
- Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, United States of America; Department of Biology, University of New Mexico, Albuquerque, NM 87131, United States of America; Santa Fe Institute, Santa Fe, NM 87501, United States of America
| | - Alan S Perelson
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, United States of America; Santa Fe Institute, Santa Fe, NM 87501, United States of America
| | - Charles Perrings
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, United States of America
| | - Joshua Plotkin
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, United States of America
| | - Jennifer Rexford
- Department of Computer Science, Princeton University, Princeton, NJ 08540, United States of America
| | - Mohit Tiwari
- Department of Electrical and Computer Engineering, University of Texas, Austin, TX 78712, United States of America
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28
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Hagen EH, Blackwell AD, Lightner AD, Sullivan RJ. Homo medicus: The transition to meat eating increased pathogen pressure and the use of pharmacological plants in Homo. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 180:589-617. [PMID: 36815505 DOI: 10.1002/ajpa.24718] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 01/31/2023] [Accepted: 02/08/2023] [Indexed: 02/24/2023]
Abstract
The human lineage transitioned to a more carnivorous niche 2.6 mya and evolved a large body size and slower life history, which likely increased zoonotic pathogen pressure. Evidence for this increase includes increased zoonotic infections in modern hunter-gatherers and bushmeat hunters, exceptionally low stomach pH compared to other primates, and divergence in immune-related genes. These all point to change, and probably intensification, in the infectious disease environment of Homo compared to earlier hominins and other apes. At the same time, the brain, an organ in which immune responses are constrained, began to triple in size. We propose that the combination of increased zoonotic pathogen pressure and the challenges of defending a large brain and body from pathogens in a long-lived mammal, selected for intensification of the plant-based self-medication strategies already in place in apes and other primates. In support, there is evidence of medicinal plant use by hominins in the middle Paleolithic, and all cultures today have sophisticated, plant-based medical systems, add spices to food, and regularly consume psychoactive plant substances that are harmful to helminths and other pathogens. We propose that the computational challenges of discovering effective plant-based treatments, the consequent ability to consume more energy-rich animal foods, and the reduced reliance on energetically-costly immune responses helped select for increased cognitive abilities and unique exchange relationships in Homo. In the story of human evolution, which has long emphasized hunting skills, medical skills had an equal role to play.
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Affiliation(s)
- Edward H Hagen
- Department of Anthropology, Washington State University, Pullman, Washington, USA
| | - Aaron D Blackwell
- Department of Anthropology, Washington State University, Pullman, Washington, USA
| | - Aaron D Lightner
- Department of Anthropology, Washington State University, Pullman, Washington, USA
- Department of the Study of Religion, Aarhus University, Aarhus, Denmark
| | - Roger J Sullivan
- Department of Anthropology, California State University, Sacramento, California, USA
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29
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Forsberg KJ. Anti-CRISPR Discovery: Using Magnets to Find Needles in Haystacks. J Mol Biol 2023; 435:167952. [PMID: 36638909 PMCID: PMC10073268 DOI: 10.1016/j.jmb.2023.167952] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
CRISPR-Cas immune systems in bacteria and archaea protect against viral infection, which has spurred viruses to develop dedicated inhibitors of these systems called anti-CRISPRs (Acrs). Like most host-virus arms races, many diverse examples of these immune and counter-immune proteins are encoded by the genomes of bacteria, archaea, and their viruses. For the case of Acrs, it is almost certain that just a small minority of nature's true diversity has been described. In this review, I discuss the various approaches used to identify these Acrs and speculate on the future for Acr discovery. Because Acrs can determine infection outcomes in nature and regulate CRISPR-Cas activities in applied settings, they have a dual importance to both host-virus conflicts and emerging biotechnologies. Thus, revealing the largely hidden world of Acrs should provide important lessons in microbiology that have the potential to ripple far beyond the field.
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Affiliation(s)
- Kevin J Forsberg
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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30
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Ecology and evolution of phages encoding anti-CRISPR proteins. J Mol Biol 2023; 435:167974. [PMID: 36690071 DOI: 10.1016/j.jmb.2023.167974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/21/2023]
Abstract
CRISPR-Cas are prokaryotic defence systems that provide protection against invasion by mobile genetic elements (MGE), including bacteriophages. MGE can overcome CRISPR-Cas defences by encoding anti-CRISPR (Acr) proteins. These proteins are produced in the early stages of the infection and inhibit the CRISPR-Cas machinery to allow phage replication. While research on Acr has mainly focused on their discovery, structure and mode of action, and their applications in biotechnology, the impact of Acr on the ecology of MGE as well as on the coevolution with their bacterial hosts only begins to be unravelled. In this review, we summarise our current understanding on the distribution of anti-CRISPR genes in MGE, the ecology of phages encoding Acr, and their coevolution with bacterial defence mechanisms. We highlight the need to use more diverse and complex experimental models to better understand the impact of anti-CRISPR in MGE-host interactions.
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31
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Salgado O, Guajardo-Leiva S, Moya-Beltrán A, Barbosa C, Ridley C, Tamayo-Leiva J, Quatrini R, Mojica FJM, Díez B. Global phylogenomic novelty of the Cas1 gene from hot spring microbial communities. Front Microbiol 2022; 13:1069452. [DOI: 10.3389/fmicb.2022.1069452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
The Cas1 protein is essential for the functioning of CRISPR-Cas adaptive systems. However, despite the high prevalence of CRISPR-Cas systems in thermophilic microorganisms, few studies have investigated the occurrence and diversity of Cas1 across hot spring microbial communities. Phylogenomic analysis of 2,150 Cas1 sequences recovered from 48 metagenomes representing hot springs (42–80°C, pH 6–9) from three continents, revealed similar ecological diversity of Cas1 and 16S rRNA associated with geographic location. Furthermore, phylogenetic analysis of the Cas1 sequences exposed a broad taxonomic distribution in thermophilic bacteria, with new clades of Cas1 homologs branching at the root of the tree or at the root of known clades harboring reference Cas1 types. Additionally, a new family of casposases was identified from hot springs, which further completes the evolutionary landscape of the Cas1 superfamily. This ecological study contributes new Cas1 sequences from known and novel locations worldwide, mainly focusing on under-sampled hot spring microbial mat taxa. Results herein show that circumneutral hot springs are environments harboring high diversity and novelty related to adaptive immunity systems.
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Fitness Trade-Offs in Phage Cocktail-Resistant Salmonella enterica Serovar Enteritidis Results in Increased Antibiotic Susceptibility and Reduced Virulence. Microbiol Spectr 2022; 10:e0291422. [PMID: 36165776 PMCID: PMC9603643 DOI: 10.1128/spectrum.02914-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The rapid emergence of phage-resistant bacterial mutants is a major challenge for phage therapy. Phage cocktails have been considered one approach to mitigate this issue. However, the synergistic effect of randomly selected phages in the cocktails is ambiguous. Here, we rationally designed a phage cocktail consisting of four phages that utilize the lipopolysaccharide (LPS) O antigen, the LPS outer core, the LPS inner core, and the outer membrane proteins BtuB and TolC on the Salmonella enterica serovar Enteritidis cell surface as receptors. We demonstrated that the four-phage cocktail could significantly delay the emergence of phage-resistant bacterial mutants compared to the single phage. To investigate the fitness costs associated with phage resistance, we characterized a total of 80 bacterial mutants resistant to a single phage or the four-phage cocktail. We observed that mutants resistant to the four-phage cocktail were more sensitive to several antibiotics than the single-phage-resistant mutants. In addition, all mutants resistant to the four-phage cocktail had significantly reduced virulence compared to wild-type strains. Our mouse model of Salmonella Enteritidis infection also indicated that the four-phage cocktail exhibited an enhanced therapeutic effect. Together, our work demonstrates an efficient strategy to design phage cocktails by combining phages with different bacterial receptors, which can steer the evolution of phage-resistant strains toward clinically exploitable phenotypes. IMPORTANCE The selection pressure of phage promotes bacterial mutation, which results in a fitness cost. Such fitness trade-offs are related to the host receptor of the phage; therefore, we can utilize knowledge of bacterial receptors used by phages as a criterion for designing phage cocktails. Here, we evaluated the efficacy of a phage cocktail made up of phages that target four different receptors on Salmonella Enteritidis through in vivo and in vitro experiments. Importantly, we found that pressure from phage cocktails with different receptors can drive phage-resistant bacterial mutants to evolve in a direction that entails more severe fitness costs, resulting in reduced virulence and increased susceptibility to antibiotics. These findings suggest that phage cocktail therapy using combinations of phages targeting different important receptors (e.g., LPS or the efflux pump AcrAB-TolC) on the host surface can steer the host bacteria toward more detrimental surface mutations than single-phage therapy, resulting in more favorable therapeutic outcomes.
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Dela Ahator S, Liu Y, Wang J, Zhang LH. The virulence factor regulator and quorum sensing regulate the type I-F CRISPR-Cas mediated horizontal gene transfer in Pseudomonas aeruginosa. Front Microbiol 2022; 13:987656. [PMID: 36246261 PMCID: PMC9563714 DOI: 10.3389/fmicb.2022.987656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas aeruginosa is capable of thriving in diverse environments due to its network of regulatory components for effective response to stress factors. The survival of the bacteria is also dependent on the ability to discriminate between the acquisition of beneficial and non-beneficial genetic materials via horizontal gene transfer (HGT). Thus, bacteria have evolved the CRISPR-Cas adaptive immune system for defense against the deleterious effect of phage infection and HGT. By using the transposon mutagenesis approach, we identified the virulence factor regulator (Vfr) as a key regulator of the type I-F CRISPR-Cas system in P. aeruginosa. We showed that Vfr influences the expression of the CRISPR-Cas system through two signaling pathways in response to changes in calcium levels. Under calcium-rich conditions, Vfr indirectly regulates the CRISPR-Cas system via modulation of the AHL-QS gene expression, which could be vital for defense against phage infection at high cell density. When encountering calcium deficiency, however, Vfr can directly regulate the CRISPR-Cas system via a cAMP-dependent pathway. Furthermore, we provide evidence that mutation of vfr reduces the CRISPR-Cas spacer acquisition and interference of HGT. The results from this study add to the regulatory network of factors controlling the CRISPR-Cas system in response to abiotic factors in the environment. The findings may facilitate the design of effective and reliable phage therapies against P. aeruginosa infections, as targeting Vfr could prevent the development of the CRISPR-Cas mediated phage resistance.
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Affiliation(s)
- Stephen Dela Ahator
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China
- Research Group for Host Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Yang Liu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China
- Centro de Biotecnología y Genómica de Plantas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - Jianhe Wang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, China
- *Correspondence: Lian-Hui Zhang,
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Ahator SD, Sagar S, Zhu M, Wang J, Zhang LH. Nutrient Availability and Phage Exposure Alter the Quorum-Sensing and CRISPR-Cas-Controlled Population Dynamics of Pseudomonas aeruginosa. mSystems 2022; 7:e0009222. [PMID: 35699339 PMCID: PMC9426516 DOI: 10.1128/msystems.00092-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/10/2022] [Indexed: 11/20/2022] Open
Abstract
Quorum sensing (QS) coordinates bacterial communication and cooperation essential for virulence and dominance in polymicrobial settings. QS also regulates the CRISPR-Cas system for targeted defense against parasitic genomes from phages and horizontal gene transfer. Although the QS and CRISPR-Cas systems are vital for bacterial survival, they undergo frequent selection in response to biotic and abiotic factors. Using the opportunistic Pseudomonas aeruginosa with well-established QS and CRISPR-Cas systems, we show how the social interactions between the acyl-homoserine lactone (AHL)-QS signal-blind mutants (ΔlasRrhlR) and the CRISPR-Cas mutants are affected by phage exposure and nutrient availability. We demonstrate that media conditions and phage exposure alter the resistance and relative fitness of ΔlasRrhlR and CRISPR-Cas mutants while tipping the fitness advantage in favor of the QS signal-blind mutants under nutrient-limiting conditions. We also show that the AHL signal-blind mutants are less selected by phages under QS-inducing conditions than the CRISPR-Cas mutants, whereas the mixed population of the CRISPR-Cas and AHL signal-blind mutants reduce phage infectivity, which can improve survival during phage exposure. Our data reveal that phage exposure and nutrient availability reshape the population dynamics between the ΔlasRrhlR QS mutants and CRISPR-Cas mutants, with key indications for cooperation and conflict between the strains. IMPORTANCE The increase in antimicrobial resistance has created the need for alternative interventions such as phage therapy. However, as previously observed with antimicrobial resistance, phage therapy will not be effective if bacteria evolve resistance and persist in the presence of the phages. The QS is commonly known as an arsenal for bacteria communication, virulence, and regulation of the phage defense mechanism, the CRISPR-Cas system. The QS and CRISPR-Cas systems are widespread in bacteria. However, they are known to evolve rapidly under the influence of biotic and abiotic factors in the bacterial environment, resulting in alteration in bacterial genotypes, which enhance phage resistance and fitness. We believe that adequate knowledge of the influence of environmental factors on the bacterial community lifestyle and phage defense mechanisms driven by the QS and CRISPR-Cas system is necessary for developing effective phage therapy.
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Affiliation(s)
- Stephen Dela Ahator
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Centre for New Antibacterial Strategies (CANS) & Research Group for Host-Microbe Interactions, Faculty of Health Sciences, The Arctic University of Norway, Tromsø, Norway
| | - Sadhanna Sagar
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Minya Zhu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Jianhe Wang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
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Phage resistance-mediated trade-offs with antibiotic resistance in Salmonella Typhimurium. Microb Pathog 2022; 171:105732. [PMID: 36002113 DOI: 10.1016/j.micpath.2022.105732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/20/2022] [Accepted: 08/16/2022] [Indexed: 11/24/2022]
Abstract
This study was designed to evaluate the trade-offs between phage resistance and antibiotic resistance of Salmonella Typhimurium (STKCCM) exposed to bacteriophage PBST10 and antibiotics (ampicillin and ciprofloxacin). STKCCM was serially exposed to control (no PBST10/antibiotic added), phage alone, ampicillin alone, ampicillin with phage, ciprofloxacin alone, and ciprofloxacin with phage for 8 days at 37 °C. The treated cells were used to evaluate the antibiotic susceptibility, β-lactamase activity, relative fitness, gene expression, and phage-resistance frequency. The antibiotic susceptibility of STKCCM to ampicillin was increased in the presence of phages. The β-lactamase activity was significantly increased in the phage alone and ampicillin with phage. The combination treatments of phages and antibiotics resulted in a greater fitness cost. The efflux pump-associated tolC was suppressed in STKCCM exposed to phage alone. The highest phage-resistance frequencies were observed at phage alone, followed by ampicillin with phage and ciprofloxacin with phage. The tolC-suppressed cells showed the enhanced antibiotic susceptibility. This study provides useful information for designing effective phage-antibiotic combination treatments. The evolutionary trade-offs of phage-resistant bacteria with antibiotic resistance might be good targets for controlling antibiotic-resistant bacteria.
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Evolutionary Dynamics between Phages and Bacteria as a Possible Approach for Designing Effective Phage Therapies against Antibiotic-Resistant Bacteria. Antibiotics (Basel) 2022; 11:antibiotics11070915. [PMID: 35884169 PMCID: PMC9311878 DOI: 10.3390/antibiotics11070915] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/01/2022] [Accepted: 07/05/2022] [Indexed: 02/06/2023] Open
Abstract
With the increasing global threat of antibiotic resistance, there is an urgent need to develop new effective therapies to tackle antibiotic-resistant bacterial infections. Bacteriophage therapy is considered as a possible alternative over antibiotics to treat antibiotic-resistant bacteria. However, bacteria can evolve resistance towards bacteriophages through antiphage defense mechanisms, which is a major limitation of phage therapy. The antiphage mechanisms target the phage life cycle, including adsorption, the injection of DNA, synthesis, the assembly of phage particles, and the release of progeny virions. The non-specific bacterial defense mechanisms include adsorption inhibition, superinfection exclusion, restriction-modification, and abortive infection systems. The antiphage defense mechanism includes a clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated (Cas) system. At the same time, phages can execute a counterstrategy against antiphage defense mechanisms. However, the antibiotic susceptibility and antibiotic resistance in bacteriophage-resistant bacteria still remain unclear in terms of evolutionary trade-offs and trade-ups between phages and bacteria. Since phage resistance has been a major barrier in phage therapy, the trade-offs can be a possible approach to design effective bacteriophage-mediated intervention strategies. Specifically, the trade-offs between phage resistance and antibiotic resistance can be used as therapeutic models for promoting antibiotic susceptibility and reducing virulence traits, known as bacteriophage steering or evolutionary medicine. Therefore, this review highlights the synergistic application of bacteriophages and antibiotics in association with the pleiotropic trade-offs of bacteriophage resistance.
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Chen Q, Dharmaraj T, Cai PC, Burgener EB, Haddock NL, Spakowitz AJ, Bollyky PL. Bacteriophage and Bacterial Susceptibility, Resistance, and Tolerance to Antibiotics. Pharmaceutics 2022; 14:1425. [PMID: 35890320 PMCID: PMC9318951 DOI: 10.3390/pharmaceutics14071425] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/02/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
Bacteriophages, viruses that infect and replicate within bacteria, impact bacterial responses to antibiotics in complex ways. Recent studies using lytic bacteriophages to treat bacterial infections (phage therapy) demonstrate that phages can promote susceptibility to chemical antibiotics and that phage/antibiotic synergy is possible. However, both lytic and lysogenic bacteriophages can contribute to antimicrobial resistance. In particular, some phages mediate the horizontal transfer of antibiotic resistance genes between bacteria via transduction and other mechanisms. In addition, chronic infection filamentous phages can promote antimicrobial tolerance, the ability of bacteria to persist in the face of antibiotics. In particular, filamentous phages serve as structural elements in bacterial biofilms and prevent the penetration of antibiotics. Over time, these contributions to antibiotic tolerance favor the selection of resistance clones. Here, we review recent insights into bacteriophage contributions to antibiotic susceptibility, resistance, and tolerance. We discuss the mechanisms involved in these effects and address their impact on bacterial fitness.
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Affiliation(s)
- Qingquan Chen
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, CA 94305, USA; (T.D.); (N.L.H.); (P.L.B.)
| | - Tejas Dharmaraj
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, CA 94305, USA; (T.D.); (N.L.H.); (P.L.B.)
| | - Pamela C. Cai
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA;
| | - Elizabeth B. Burgener
- Center for Excellence in Pulmonary Biology, Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; (E.B.B.); (A.J.S.)
| | - Naomi L. Haddock
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, CA 94305, USA; (T.D.); (N.L.H.); (P.L.B.)
| | - Andy J. Spakowitz
- Center for Excellence in Pulmonary Biology, Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; (E.B.B.); (A.J.S.)
| | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center, 279 Campus Drive, Stanford, CA 94305, USA; (T.D.); (N.L.H.); (P.L.B.)
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Zaayman M, Wheatley RM. Fitness costs of CRISPR-Cas systems in bacteria. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35849532 DOI: 10.1099/mic.0.001209] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
CRISPR-Cas systems provide bacteria with both specificity and adaptability in defence against invading genetic elements. From a theoretical perspective, CRISPR-Cas systems confer many benefits. However, they are observed at an unexpectedly low prevalence across the bacterial domain. While these defence systems can be gained horizontally, fitness costs may lead to selection against their carriage. Understanding the source of CRISPR-related fitness costs will help us to understand the evolutionary dynamics of CRISPR-Cas systems and their role in shaping bacterial genome evolution. Here, we review our current understanding of the potential fitness costs associated with CRISPR-Cas systems. In addition to potentially restricting the acquisition of genetic material that could confer fitness benefits, we explore five alternative biological factors that from a theoretical perspective may influence the fitness costs associated with CRISPR-Cas system carriage: (1) the repertoire of defence mechanisms a bacterium has available to it, (2) the potential for a metabolic burden, (3) larger-scale population and environmental factors, (4) the phenomenon of self-targeting spacers, and (5) alternative non-defence roles for CRISPR-Cas.
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de Freitas Almeida GM, Hoikkala V, Ravantti J, Rantanen N, Sundberg LR. Mucin induces CRISPR-Cas defense in an opportunistic pathogen. Nat Commun 2022; 13:3653. [PMID: 35752617 PMCID: PMC9233685 DOI: 10.1038/s41467-022-31330-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 06/14/2022] [Indexed: 01/21/2023] Open
Abstract
Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a dramatic increase in CRISPR spacer acquisition, especially in low nutrient conditions where over 60% of colonies obtain at least one new spacer. Additionally, we show that the presence of a competitor bacterium further increases CRISPR spacer acquisition in F. columnare. These results suggest that ecological factors are important in determining defense strategies against phages, and that the phage-bacterium interactions on mucosal surfaces may select for the diversification of bacterial immune systems.
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Affiliation(s)
- Gabriel Magno de Freitas Almeida
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
- Faculty of Biosciences, Fisheries and Economics, Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ville Hoikkala
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
| | - Janne Ravantti
- University of Helsinki, Molecular and Integrative Biosciences Research Programme, Helsinki, Finland
| | - Noora Rantanen
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
| | - Lotta-Riina Sundberg
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland.
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40
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de Freitas Almeida GM, Hoikkala V, Ravantti J, Rantanen N, Sundberg LR. Mucin induces CRISPR-Cas defense in an opportunistic pathogen. Nat Commun 2022; 13:3653. [PMID: 35752617 DOI: 10.1101/2021.08.10.455787v1.abstract] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 06/14/2022] [Indexed: 05/27/2023] Open
Abstract
Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a dramatic increase in CRISPR spacer acquisition, especially in low nutrient conditions where over 60% of colonies obtain at least one new spacer. Additionally, we show that the presence of a competitor bacterium further increases CRISPR spacer acquisition in F. columnare. These results suggest that ecological factors are important in determining defense strategies against phages, and that the phage-bacterium interactions on mucosal surfaces may select for the diversification of bacterial immune systems.
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Affiliation(s)
- Gabriel Magno de Freitas Almeida
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
- Faculty of Biosciences, Fisheries and Economics, Norwegian College of Fishery Science, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ville Hoikkala
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
| | - Janne Ravantti
- University of Helsinki, Molecular and Integrative Biosciences Research Programme, Helsinki, Finland
| | - Noora Rantanen
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland
| | - Lotta-Riina Sundberg
- University of Jyväskylä, Department of Biological and Environmental Science and Nanoscience Center, Jyväskylä, Finland.
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41
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Chen H, Mayer A, Balasubramanian V. A scaling law in CRISPR repertoire sizes arises from the avoidance of autoimmunity. Curr Biol 2022; 32:2897-2907.e5. [PMID: 35659862 DOI: 10.1016/j.cub.2022.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/13/2022] [Accepted: 05/09/2022] [Indexed: 12/28/2022]
Abstract
Some prokaryotes possess CRISPR-Cas systems that use DNA segments called spacers, which are acquired from invading phages, to guide immune defense. Here, we propose that cross-reactive CRISPR targeting can, however, lead to "heterologous autoimmunity," whereby foreign spacers guide self-targeting in a spacer-length-dependent fashion. Balancing antiviral defense against autoimmunity predicts a scaling relation between spacer length and CRISPR repertoire size. We find evidence for this scaling through a comparative analysis of sequenced prokaryotic genomes and show that this association also holds at the level of CRISPR types. By contrast, the scaling is absent in strains with nonfunctional CRISPR loci. Finally, we demonstrate that stochastic spacer loss can explain variations around the scaling relation, even between strains of the same species. Our results suggest that heterologous autoimmunity is a selective factor shaping the evolution of CRISPR-Cas systems, analogous to the trade-offs between immune specificity, breadth, and autoimmunity that constrain the diversity of adaptive immune systems in vertebrates.
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Affiliation(s)
- Hanrong Chen
- David Rittenhouse Laboratory, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA; Laboratory of Metagenomic Technologies and Microbial Systems, Genome Institute of Singapore, Singapore 138672, Singapore.
| | - Andreas Mayer
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | - Vijay Balasubramanian
- David Rittenhouse Laboratory, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA; Theoretische Natuurkunde, Vrije Universiteit Brussel, 1050 Brussels, Belgium
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Gu L, Qin S, Sun Y, Huang J, Akbar S, Zhang L, Yang Z. Coping with antagonistic predation risks: Predator-dependent unique responses are dominant in Ceriodaphnia cornuta. Mol Ecol 2022; 31:3951-3962. [PMID: 35621395 DOI: 10.1111/mec.16550] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 11/27/2022]
Abstract
Inducible defences of prey are evolved under diverse and variable predation risks. However, during the co-evolution of prey and multiple predators, the responses of prey to antagonistic predation risks, which may put the prey into a dilemma of responding to predators, remain unclear. Based on antagonistic predation pressure from an invertebrate (Chaoborus larvae) and a vertebrate (Rhodeus ocellatus) predator, we studied the responses of multiple traits and transcriptomes of the freshwater crustacean Ceriodaphnia cornuta under multiple predation risks. Chaoborus predation risk altered the expression of genes encoding cuticle proteins and modulated the biosynthesis of steroid hormones, cutin, suberine, and wax, leading to the development of horns and increase in size at the late developmental stage. Meanwhile, fish predation risk primarily triggered genes encoding ribosomes and those involved in unsaturated fatty acid biosynthesis and cysteine and methionine metabolism, resulting in smaller individual size and earlier reproduction. Inducible responses of both transcriptome and individual traits revealed that predator-dependent unique responses were dominant and the dilemma of antagonistic responses was relatively limited. However, the unique individual traits in response to invertebrate predation could be significantly impaired by vertebrate predation risk, even though the unique responses to different predators were extremely weakly correlated and could be elicited simultaneously. These results indicate that diverse predator-dependent unique responses are favoured by Ceriodaphnia during its co-evolution with multiple predators. Nonetheless, Ceriodaphnia is not a generalist that can fully adopt all predator-dependent unique responses simultaneously under multiple predation risks.
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Affiliation(s)
- Lei Gu
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Shanshan Qin
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Yunfei Sun
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Jing Huang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Siddiq Akbar
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Lu Zhang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
| | - Zhou Yang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing, China
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43
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McKenzie RE, Keizer EM, Vink JNA, van Lopik J, Büke F, Kalkman V, Fleck C, Tans SJ, Brouns SJJ. Single cell variability of CRISPR-Cas interference and adaptation. Mol Syst Biol 2022; 18:e10680. [PMID: 35467080 PMCID: PMC10561596 DOI: 10.15252/msb.202110680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 12/26/2022] Open
Abstract
While CRISPR-Cas defence mechanisms have been studied on a population level, their temporal dynamics and variability in individual cells have remained unknown. Using a microfluidic device, time-lapse microscopy and mathematical modelling, we studied invader clearance in Escherichia coli across multiple generations. We observed that CRISPR interference is fast with a narrow distribution of clearance times. In contrast, for invaders with escaping PAM mutations we found large cell-to-cell variability, which originates from primed CRISPR adaptation. Faster growth and cell division and higher levels of Cascade increase the chance of clearance by interference, while slower growth is associated with increased chances of clearance by priming. Our findings suggest that Cascade binding to the mutated invader DNA, rather than spacer integration, is the main source of priming heterogeneity. The highly stochastic nature of primed CRISPR adaptation implies that only subpopulations of bacteria are able to respond quickly to invading threats. We conjecture that CRISPR-Cas dynamics and heterogeneity at the cellular level are crucial to understanding the strategy of bacteria in their competition with other species and phages.
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Affiliation(s)
- Rebecca E McKenzie
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Emma M Keizer
- Biometris, Department of Mathematical and Statistical MethodsWageningen UniversityWageningenThe Netherlands
| | - Jochem N A Vink
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Jasper van Lopik
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Ferhat Büke
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Vera Kalkman
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Christian Fleck
- Freiburg Center for Data Analysis and Modeling (FDM)Spatial Systems Biology GroupUniversity of FreiburgFreiburgGermany
| | - Sander J Tans
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Stan J J Brouns
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
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Lan XR, Liu ZL, Niu DK. Precipitous Increase of Bacterial CRISPR-Cas Abundance at Around 45°C. Front Microbiol 2022; 13:773114. [PMID: 35300480 DOI: 10.3389/fmicb.2022.773114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Although performing adaptive immunity, CRISPR-Cas systems are present in only 40% of bacterial genomes. We observed an abrupt increase of bacterial CRISPR-Cas abundance at around 45°C. Phylogenetic comparative analyses confirmed that the abundance correlates with growth temperature only at the temperature range around 45°C. From the literature, we noticed that the diversities of cellular predators (like protozoa, nematodes, and myxobacteria) have a steep decline at this temperature range. The grazing risk faced by bacteria reduces substantially at around 45°C and almost disappears above 60°C. We propose that viral lysis would become the dominating factor of bacterial mortality, and antivirus immunity has a higher priority at higher temperatures. In temperature ranges where the abundance of cellular predators does not change with temperature, the growth temperatures of bacteria would not significantly affect their CRISPR-Cas contents. The hypothesis predicts that bacteria should also be rich in CRISPR-Cas systems if they live in other extreme conditions inaccessible to grazing predators.
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Affiliation(s)
- Xin-Ran Lan
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Zhi-Ling Liu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Deng-Ke Niu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
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45
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Birkholz N, Jackson SA, Fagerlund RD, Fineran P. OUP accepted manuscript. Nucleic Acids Res 2022; 50:3348-3361. [PMID: 35286398 PMCID: PMC8989522 DOI: 10.1093/nar/gkac147] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 11/16/2022] Open
Abstract
Epigenetic DNA methylation plays an important role in bacteria by influencing gene expression and allowing discrimination between self-DNA and intruders such as phages and plasmids. Restriction–modification (RM) systems use a methyltransferase (MTase) to modify a specific sequence motif, thus protecting host DNA from cleavage by a cognate restriction endonuclease (REase) while leaving invading DNA vulnerable. Other REases occur solitarily and cleave methylated DNA. REases and RM systems are frequently mobile, influencing horizontal gene transfer by altering the compatibility of the host for foreign DNA uptake. However, whether mobile defence systems affect pre-existing host defences remains obscure. Here, we reveal an epigenetic conflict between an RM system (PcaRCI) and a methylation-dependent REase (PcaRCII) in the plant pathogen Pectobacterium carotovorum RC5297. The PcaRCI RM system provides potent protection against unmethylated plasmids and phages, but its methylation motif is targeted by the methylation-dependent PcaRCII. This potentially lethal co-existence is enabled through epigenetic silencing of the PcaRCII-encoding gene via promoter methylation by the PcaRCI MTase. Comparative genome analyses suggest that the PcaRCII-encoding gene was already present and was silenced upon establishment of the PcaRCI system. These findings provide a striking example for selfishness of RM systems and intracellular competition between different defences.
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Affiliation(s)
- Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Robert D Fagerlund
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- To whom correspondence should be addressed: Tel: +64 3 479 7735;
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Malone LM, Hampton HG, Morgan XC, Fineran PC. Type I CRISPR-Cas provides robust immunity but incomplete attenuation of phage-induced cellular stress. Nucleic Acids Res 2021; 50:160-174. [PMID: 34928385 PMCID: PMC8754663 DOI: 10.1093/nar/gkab1210] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/09/2021] [Accepted: 11/23/2021] [Indexed: 11/14/2022] Open
Abstract
During infection, phages manipulate bacteria to redirect metabolism towards viral proliferation. To counteract phages, some bacteria employ CRISPR-Cas systems that provide adaptive immunity. While CRISPR-Cas mechanisms have been studied extensively, their effects on both the phage and the host during phage infection remains poorly understood. Here, we analysed the infection of Serratia by a siphovirus (JS26) and the transcriptomic response with, or without type I-E or I-F CRISPR-Cas immunity. In non-immune Serratia, phage infection altered bacterial metabolism by upregulating anaerobic respiration and amino acid biosynthesis genes, while flagella production was suppressed. Furthermore, phage proliferation required a late-expressed viral Cas4 homologue, which did not influence CRISPR adaptation. While type I-E and I-F immunity provided robust defence against phage infection, phage development still impacted the bacterial host. Moreover, DNA repair and SOS response pathways were upregulated during type I immunity. We also discovered that the type I-F system is controlled by a positive autoregulatory feedback loop that is activated upon phage targeting during type I-F immunity, leading to a controlled anti-phage response. Overall, our results provide new insight into phage-host dynamics and the impact of CRISPR immunity within the infected cell.
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Affiliation(s)
- Lucia M Malone
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Hannah G Hampton
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Xochitl C Morgan
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Bacteriostatic antibiotics promote CRISPR-Cas adaptive immunity by enabling increased spacer acquisition. Cell Host Microbe 2021; 30:31-40.e5. [PMID: 34932986 DOI: 10.1016/j.chom.2021.11.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/12/2021] [Accepted: 11/24/2021] [Indexed: 01/21/2023]
Abstract
Phages impose strong selection on bacteria to evolve resistance against viral predation. Bacteria can rapidly evolve phage resistance via receptor mutation or using their CRISPR-Cas adaptive immune systems. Acquisition of CRISPR immunity relies on the insertion of a phage-derived sequence into CRISPR arrays in the bacterial genome. Using Pseudomonas aeruginosa and its phage DMS3vir as a model, we demonstrate that conditions that reduce bacterial growth rates, such as exposure to bacteriostatic antibiotics (which inhibit cell growth without killing), promote the evolution of CRISPR immunity. We demonstrate that this is due to slower phage development under these conditions, which provides more time for cells to acquire phage-derived sequences and mount an immune response. Our data reveal that the speed of phage development is a key determinant of the evolution of CRISPR immunity and suggest that use of bacteriostatic antibiotics can trigger elevated levels of CRISPR immunity in human-associated and natural environments.
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Devi V, Harjai K, Chhibber S. Self-targeting spacers in CRISPR-array: Accidental occurrence or evolutionarily conserved phenomenon. J Basic Microbiol 2021; 62:4-12. [PMID: 34904260 DOI: 10.1002/jobm.202100514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/18/2021] [Accepted: 11/27/2021] [Indexed: 11/12/2022]
Abstract
In recent years, a tremendous amount of inquisitiveness among scientists in the clustered regularly interspaced short palindrome repeats (CRISPR)-CRISPR-associated proteins (Cas) has led to many studies to delineate their exact role in prokaryotes. CRISPR-Cas is an adaptive immune system that protects prokaryotes from phages and mobile genetic elements. It incorporates small DNA fragment of the invader in the CRISPR-array and protects the host from future invasion by them. In a few instances, the CRISPR-array also incorporates self-targeting spacers, most likely by accident or leaky incorporation. A significant number of spacers are found to match with the host genes across the species; however, self-targeting spacers have not been investigated in detail in most of the organisms. The presence of self-targeting spacers in the CRISPR-array led to speculation that the CRISPR-Cas system has a lot more to offer than just being the conventional adaptive immune system. It has been implicated in gene regulation and autoimmunity more or less equally. In this review, an attempt has been made to understand self-targeting spacers in the context of gene regulation, autoimmunity, and its avoidance strategies.
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Affiliation(s)
- Veena Devi
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Kusum Harjai
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Sanjay Chhibber
- Department of Microbiology, Panjab University, Chandigarh, India
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Graham AL, Schrom EC, Metcalf CJE. The evolution of powerful yet perilous immune systems. Trends Immunol 2021; 43:117-131. [PMID: 34949534 PMCID: PMC8686020 DOI: 10.1016/j.it.2021.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 12/23/2022]
Abstract
The mammalian immune system packs serious punch against infection but can also cause harm: for example, coronavirus disease 2019 (COVID-19) made headline news of the simultaneous power and peril of human immune responses. In principle, natural selection leads to exquisite adaptation and therefore cytokine responsiveness that optimally balances the benefits of defense against its costs (e.g., immunopathology suffered and resources expended). Here, we illustrate how evolutionary biology can predict such optima and also help to explain when/why individuals exhibit apparently maladaptive immunopathological responses. Ultimately, we argue that the evolutionary legacies of multicellularity and life-history strategy, in addition to our coevolution with symbionts and our demographic history, together explain human susceptibility to overzealous, pathology-inducing cytokine responses. Evolutionary insight thereby complements molecular/cellular mechanistic insights into immunopathology.
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50
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Downie AE, Mayer A, Metcalf CJE, Graham AL. Optimal immune specificity at the intersection of host life history and parasite epidemiology. PLoS Comput Biol 2021; 17:e1009714. [PMID: 34932551 PMCID: PMC8730424 DOI: 10.1371/journal.pcbi.1009714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/05/2022] [Accepted: 12/02/2021] [Indexed: 11/30/2022] Open
Abstract
Hosts diverge widely in how, and how well, they defend themselves against infection and immunopathology. Why are hosts so heterogeneous? Both epidemiology and life history are commonly hypothesized to influence host immune strategy, but the relationship between immune strategy and each factor has commonly been investigated in isolation. Here, we show that interactions between life history and epidemiology are crucial for determining optimal immune specificity and sensitivity. We propose a demographically-structured population dynamics model, in which we explore sensitivity and specificity of immune responses when epidemiological risks vary with age. We find that variation in life history traits associated with both reproduction and longevity alters optimal immune strategies-but the magnitude and sometimes even direction of these effects depends on how epidemiological risks vary across life. An especially compelling example that explains previously-puzzling empirical observations is that depending on whether infection risk declines or rises at reproductive maturity, later reproductive maturity can select for either greater or lower immune specificity, potentially illustrating why studies of lifespan and immune variation across taxa have been inconclusive. Thus, the sign of selection on the life history-immune specificity relationship can be reversed in different epidemiological contexts. Drawing on published life history data from a variety of chordate taxa, we generate testable predictions for this facet of the optimal immune strategy. Our results shed light on the causes of the heterogeneity found in immune defenses both within and among species and the ultimate variability of the relationship between life history and immune specificity.
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Affiliation(s)
- Alexander E. Downie
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Andreas Mayer
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - C. Jessica E. Metcalf
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- School of Public and International Affairs, Princeton University, Princeton, New Jersey, United States of America
| | - Andrea L. Graham
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
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