151
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Western diet regulates immune status and the response to LPS-driven sepsis independent of diet-associated microbiome. Proc Natl Acad Sci U S A 2019; 116:3688-3694. [PMID: 30808756 DOI: 10.1073/pnas.1814273116] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sepsis is a deleterious immune response to infection that leads to organ failure and is the 11th most common cause of death worldwide. Despite plaguing humanity for thousands of years, the host factors that regulate this immunological response and subsequent sepsis severity and outcome are not fully understood. Here we describe how the Western diet (WD), a diet high in fat and sucrose and low in fiber, found rampant in industrialized countries, leads to worse disease and poorer outcomes in an LPS-driven sepsis model in WD-fed mice compared with mice fed standard fiber-rich chow (SC). We find that WD-fed mice have higher baseline inflammation (metaflammation) and signs of sepsis-associated immunoparalysis compared with SC-fed mice. WD mice also have an increased frequency of neutrophils, some with an "aged" phenotype, in the blood during sepsis compared with SC mice. Importantly, we found that the WD-dependent increase in sepsis severity and higher mortality is independent of the microbiome, suggesting that the diet may be directly regulating the innate immune system through an unknown mechanism. Strikingly, we could predict LPS-driven sepsis outcome by tracking specific WD-dependent disease factors (e.g., hypothermia and frequency of neutrophils in the blood) during disease progression and recovery. We conclude that the WD is reprogramming the basal immune status and acute response to LPS-driven sepsis and that this correlates with alternative disease paths that lead to more severe disease and poorer outcomes.
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152
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Shourian M, Qureshi ST. Resistance and Tolerance to Cryptococcal Infection: An Intricate Balance That Controls the Development of Disease. Front Immunol 2019; 10:66. [PMID: 30761136 PMCID: PMC6361814 DOI: 10.3389/fimmu.2019.00066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Cryptococcus neoformans is a ubiquitous environmental yeast and a leading cause of invasive fungal infection in humans. The most recent estimate of global disease burden includes over 200,000 cases of cryptococcal meningitis each year. Cryptococcus neoformans expresses several virulence factors that may have originally evolved to protect against environmental threats, and human infection may be an unintended consequence of these acquired defenses. Traditionally, C. neoformans has been viewed as a purely opportunistic pathogen that targets severely immune compromised hosts; however, during the past decade the spectrum of susceptible individuals has grown considerably. In addition, the closely related strain Cryptococcus gattii has recently emerged in North America and preferentially targets individuals with intact immunity. In parallel to the changing epidemiology of cryptococcosis, an increasing role for host immunity in the pathogenesis of severe disease has been elucidated. Initially, the HIV/AIDS epidemic revealed the capacity of C. neoformans to cause host damage in the absence of adaptive immunity. Subsequently, the development and clinical implementation of highly active antiretroviral treatment (HAART) led to recognition of an immune reconstitution inflammatory syndrome (IRIS) in a subset of HIV+ individuals, demonstrating the pathological role of host immunity in disease. A post-infectious inflammatory syndrome (PIIRS) characterized by abnormal T cell-macrophage activation has also been documented in HIV-negative individuals following antifungal therapy. These novel clinical conditions illustrate the highly complex host-pathogen relationship that underlies severe cryptococcal disease and the intricate balance between tolerance and resistance that is necessary for effective resolution. In this article, we will review current knowledge of the interactions between cryptococci and mammalian hosts that result in a tolerant phenotype. Future investigations in this area have potential for translation into improved therapies for affected individuals.
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Affiliation(s)
- Mitra Shourian
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Salman T Qureshi
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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153
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Bailey C, Strepparava N, Wahli T, Segner H. Exploring the immune response, tolerance and resistance in proliferative kidney disease of salmonids. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 90:165-175. [PMID: 30248359 DOI: 10.1016/j.dci.2018.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/20/2018] [Accepted: 09/20/2018] [Indexed: 05/24/2023]
Abstract
Proliferative kidney disease (PKD) of salmonids is a disease of economic and environmental concern caused by the myxozoan parasite Tetracapsuloides bryosalmonae. Finer details of the immune repertoire during T. bryosalmonae infection have been elucidated in rainbow trout (Oncorhynchus mykiss). In contrast, there remain many unanswered questions regarding the immune response of the wild fish host in Europe, the brown trout (Salmo trutta) to this parasite. The first aim of this study is to examine the brown trout immune response to T. bryosalmonae and compare it with the published information on rainbow trout as two species that have undergone a different coevolution with the parasite. According to ecoimmunology terminology, infected organisms may manage infection by reducing the damage caused by parasites (tolerance) or by limiting parasite burden (resistance). The second aim of this study is to investigate tolerance/resistance patterns of these species during PKD infection. Our results suggest subtle differences in sequential aspects of the immune response and of immune genes that correlate with parasite intensity for the brown trout, in contrast to rainbow trout, in terms of the B cell response and Th-like interplay that may be linked to PKD pathogenesis. These differences in the immune response also correlate with species-specific differences in tolerance/resistance patterns, in that brown trout had increased tolerance but rainbow trout had greater resistance to infection. The variance in tolerance/resistance investment resulted in a different evolutionary outcome for each host-parasite interaction. A greater exploration of these concepts and an association of immune mechanisms could open an additional gateway for interpreting fish host-parasite interactions.
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Affiliation(s)
- Christyn Bailey
- University of Bern, Vetsuisse Faculty, Centre for Fish and Wildlife Health, Länggassstrasse 122, CH-3012, Bern, Switzerland.
| | - Nicole Strepparava
- University of Bern, Vetsuisse Faculty, Centre for Fish and Wildlife Health, Länggassstrasse 122, CH-3012, Bern, Switzerland
| | - Thomas Wahli
- University of Bern, Vetsuisse Faculty, Centre for Fish and Wildlife Health, Länggassstrasse 122, CH-3012, Bern, Switzerland
| | - Helmut Segner
- University of Bern, Vetsuisse Faculty, Centre for Fish and Wildlife Health, Länggassstrasse 122, CH-3012, Bern, Switzerland
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154
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Saura M, Carabaño MJ, Fernández A, Cabaleiro S, Doeschl-Wilson AB, Anacleto O, Maroso F, Millán A, Hermida M, Fernández C, Martínez P, Villanueva B. Disentangling Genetic Variation for Resistance and Endurance to Scuticociliatosis in Turbot Using Pedigree and Genomic Information. Front Genet 2019; 10:539. [PMID: 31231428 PMCID: PMC6565924 DOI: 10.3389/fgene.2019.00539] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 05/17/2019] [Indexed: 12/31/2022] Open
Abstract
Selective breeding for improving host responses to infectious pathogens is a promising option for disease control. In fact, disease resilience, the ability of a host to survive or cope with infectious challenge, has become a highly desirable breeding goal. However, resilience is a complex trait composed of two different host defence mechanisms, namely resistance (the ability of a host to avoid becoming infected or diseased) and endurance (the ability of an infected host to survive the infection). While both could be targeted for genetic improvement, it is currently unknown how they contribute to survival, as reliable estimates of genetic parameters for both traits obtained simultaneously are scarce. A difficulty lies in obtaining endurance phenotypes for genetic analyses. In this study, we present the results from an innovative challenge test carried out in turbot whose design allowed disentangling the genetic basis of resistance and endurance to Philasterides dicentrarchi, a parasite causing scuticociliatosis that leads to substantial economic losses in the aquaculture industry. A noticeable characteristic of the parasite is that it causes visual signs that can be used for disentangling resistance and endurance. Our results showed the existence of genetic variation for both traits (heritability = 0.26 and 0.12 for resistance and endurance, respectively) and for the composite trait resilience (heritability = 0.15). The genetic correlation between resistance and resilience was very high (0.90) indicating that both are at a large extent the same trait, but no significant genetic correlation was found between resistance and endurance. A total of 18,125 SNPs obtained from 2b-RAD sequencing enabled genome-wide association analyses for detecting QTLs controlling the three traits. A candidate QTL region on linkage group 19 that explains 33% of the additive genetic variance was identified for resilience. The region contains relevant genes related to immune response and defence mechanisms. Although no significant associations were found for resistance, the pattern of association was the same as for resilience. For endurance, one significant association was found on linkage group 2. The accuracy of genomic breeding values was also explored for resilience, showing that it increased by 12% when compared with the accuracy of pedigree-based breeding values. To our knowledge, this is the first study in turbot disentangling the genetic basis of resistance and endurance to scuticociliatosis.
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Affiliation(s)
- María Saura
- Departamento de Mejora Genética Animal, INIA, Madrid, Spain
- *Correspondence: María Saura,
| | | | | | | | - Andrea B. Doeschl-Wilson
- Genetics and Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Roslin, United Kingdom
| | - Osvaldo Anacleto
- Genetics and Genomics, The Roslin Institute and R(D)SVS, The University of Edinburgh, Roslin, United Kingdom
| | | | | | - Miguel Hermida
- Departamento de Xenética, Universidade de Santiago de Compostela, Lugo, Spain
| | - Carlos Fernández
- Departamento de Xenética, Universidade de Santiago de Compostela, Lugo, Spain
| | - Paulino Martínez
- Departamento de Xenética, Universidade de Santiago de Compostela, Lugo, Spain
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155
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Divangahi M, Khan N, Kaufmann E. Beyond Killing Mycobacterium tuberculosis: Disease Tolerance. Front Immunol 2018; 9:2976. [PMID: 30619333 PMCID: PMC6305711 DOI: 10.3389/fimmu.2018.02976] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/04/2018] [Indexed: 12/30/2022] Open
Abstract
Host defense strategies against infectious diseases are comprised of both host resistance and disease tolerance. Resistance is the ability of the host to prevent invasion or to eliminate the pathogen, while disease tolerance is defined by limiting the collateral tissue damage caused by the pathogen and/or the immune response without exerting direct effects on pathogen growth. Our incomplete understanding of host immunity against tuberculosis (TB) is predominately rooted in our bias toward investigating host resistance. Thus, we must refocus our efforts to understand the entire spectrum of immunity against M. tuberculosis to control TB.
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Affiliation(s)
- Maziar Divangahi
- Meakins-Christie Laboratories, Departments of Medicine, Microbiology and Immunology, Pathology McGill University, McGill International TB Centre, McGill University Health Centre, Montreal, QC, Canada
| | - Nargis Khan
- Meakins-Christie Laboratories, Departments of Medicine, Microbiology and Immunology, Pathology McGill University, McGill International TB Centre, McGill University Health Centre, Montreal, QC, Canada
| | - Eva Kaufmann
- Meakins-Christie Laboratories, Departments of Medicine, Microbiology and Immunology, Pathology McGill University, McGill International TB Centre, McGill University Health Centre, Montreal, QC, Canada
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156
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Larsen AK, Nymo IH, Sørensen KK, Seppola M, Rødven R, Jiménez de Bagüés MP, Al Dahouk S, Godfroid J. Concomitant Temperature Stress and Immune Activation may Increase Mortality Despite Efficient Clearance of an Intracellular Bacterial Infection in Atlantic Cod. Front Microbiol 2018; 9:2963. [PMID: 30564213 PMCID: PMC6289035 DOI: 10.3389/fmicb.2018.02963] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/16/2018] [Indexed: 11/13/2022] Open
Abstract
The environmental temperature has profound effects on biological systems of marine aquatic organisms and plays a critical role in species distribution and abundance. Particularly during the warmer seasons, variations in habitat temperature may introduce episodes of stressful temperatures which the organisms must adapt to and compensate for to maintain physiological homeostasis. The marine environment is changing and predicted raises in water temperatures will affect numerous marine species. Translocation of pathogens follow migration of species and alternations in physical environmental parameters may have influence upon the virulence of pathogens, as well as the hosts immune responses. While pathogenicity of many true pathogens is expected to increase following climate induced temperature stress, the impact from environmental stressors on the occurrence and severity of opportunistic infections is unknown. Here we describe how thermal stress in the cold-water species Atlantic cod influenced the fish immune responses against an opportunistic intracellular bacterium. Following experimental infection with Brucella pinnipedialis at normal water temperature (6°C) and sub-optimal temperature (15°C), cod cleared the intracellular bacteria more rapidly at the highest temperature. The overall immune response was faster and of higher amplitude at 15°C, however, a significant number of cod died at this temperature despite efficient clearance of infection. An increased growth rate not affected by infection was observed at 15°C, confirming multiple energy demanding processes taking place. Serum chemistry suggested that general homeostasis was influenced by both infection and increased water temperature, highlighting the cumulative stress responses (allostatic load) generated by simultaneous stressors. Our results suggest a trade-off between resistance and tolerance to survive infection at sub-optimal temperatures and raise questions concerning the impact of increased water temperatures on the energetic costs of immune system activation in aquatic ectotherms.
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Affiliation(s)
- Anett K Larsen
- Arctic Infection Biology, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Ingebjørg H Nymo
- Arctic Infection Biology, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Karen K Sørensen
- Department of Medical Biology, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Marit Seppola
- Department of Medical Biology, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Rolf Rødven
- Department of Research and Development, UiT - The Arctic University of Norway, Tromsø, Norway
| | - María Pilar Jiménez de Bagüés
- Unidad de Tecnología en Producción y Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria, Instituto Agroalimentario de Aragón, Universidad de Zaragoza, Zaragoza, Spain
| | | | - Jacques Godfroid
- Arctic Infection Biology, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø, Norway
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157
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Fabian DK, Garschall K, Klepsatel P, Santos‐Matos G, Sucena É, Kapun M, Lemaitre B, Schlötterer C, Arking R, Flatt T. Evolution of longevity improves immunity in Drosophila. Evol Lett 2018; 2:567-579. [PMID: 30564440 PMCID: PMC6292704 DOI: 10.1002/evl3.89] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/24/2018] [Indexed: 12/20/2022] Open
Abstract
Much has been learned about the genetics of aging from studies in model organisms, but still little is known about naturally occurring alleles that contribute to variation in longevity. For example, analysis of mutants and transgenes has identified insulin signaling as a major regulator of longevity, yet whether standing variation in this pathway underlies microevolutionary changes in lifespan and correlated fitness traits remains largely unclear. Here, we have analyzed the genomes of a set of Drosophila melanogaster lines that have been maintained under direct selection for postponed reproduction and indirect selection for longevity, relative to unselected control lines, for over 35 years. We identified many candidate loci shaped by selection for longevity and late-life fertility, but - contrary to expectation - we did not find overrepresentation of canonical longevity genes. Instead, we found an enrichment of immunity genes, particularly in the Toll pathway, suggesting that evolutionary changes in immune function might underpin - in part - the evolution of late-life fertility and longevity. To test whether this genomic signature is causative, we performed functional experiments. In contrast to control flies, long-lived flies tended to downregulate the expression of antimicrobial peptides upon infection with age yet survived fungal, bacterial, and viral infections significantly better, consistent with alleviated immunosenescence. To examine whether genes of the Toll pathway directly affect longevity, we employed conditional knockdown using in vivo RNAi. In adults, RNAi against the Toll receptor extended lifespan, whereas silencing the pathway antagonist cactus--causing immune hyperactivation - dramatically shortened lifespan. Together, our results suggest that genetic changes in the age-dependent regulation of immune homeostasis might contribute to the evolution of longer life.
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Affiliation(s)
- Daniel K. Fabian
- Centre for Pathogen Evolution, Department of ZoologyUniversity of CambridgeCambridgeUnited Kingdom
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Vienna Graduate School of Population GeneticsViennaAustria
| | - Kathrin Garschall
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Peter Klepsatel
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Institute of ZoologySlovak Academy of Sciences845 06 BratislavaSlovakia
| | | | - Élio Sucena
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Departamento de Biologia AnimalFaculdade de Ciências da Universidade de LisboaLisboaPortugal
| | - Martin Kapun
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Bruno Lemaitre
- Global Health InstituteSchool of Life Sciences, EPFLLausanneSwitzerland
| | | | - Robert Arking
- Department of Biological SciencesWayne State UniversityDetroitMichigan
| | - Thomas Flatt
- Institut für PopulationsgenetikVetmeduni ViennaViennaAustria
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
- Department of BiologyUniversity of FribourgFribourgSwitzerland
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158
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Abstract
Sickness behaviors are a conserved set of stereotypic responses to inflammatory diseases. We recently demonstrated that interfering with inflammation-induced anorexia led to metabolic changes that had profound effects on survival of acute inflammatory conditions. We found that different inflammatory states needed to be coordinated with corresponding metabolic programs to actuate tissue-protective mechanisms. Survival of viral inflammation required intact glucose utilization pathways, whereas survival of bacterial inflammation required alternative fuel substrates and ketogenic programs. We thus hypothesized that organismal metabolism would be important in other classes of infectious inflammation and sought to understand its role in the prototypic parasitic disease malaria. Utilizing the cerebral malaria model, Plasmodium berghei ANKA (PbA) infection in C57BL/6J male mice, we unexpectedly found that inhibition of glycolysis using 2-deoxy glucose (2DG) conferred protection from cerebral malaria. Unlike vehicle-treated animals, 2DG-treated animals did not develop cerebral malaria and survived until ultimately succumbing to fatal anemia. We did not find any differences in parasitemia or pathogen load in affected tissues. There were no differences in the kinetics of anemia. We also did not detect differences in immune infiltration in the brain or in blood-brain barrier permeability. Rather, on pathological analyses performed on the entire brain, we found that 2DG prevented the formation of thrombi and thrombotic complications. Using thromboelastography (TEG), we found that 2DG-treated animals formed clots that were significantly less strong and stable. Together, these data suggest that glucose metabolism is involved in inflammation-induced hemostasis and provide a potential therapeutic target in treatment of cerebral malaria.
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159
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Mandl JN, Schneider C, Schneider DS, Baker ML. Going to Bat(s) for Studies of Disease Tolerance. Front Immunol 2018; 9:2112. [PMID: 30294323 PMCID: PMC6158362 DOI: 10.3389/fimmu.2018.02112] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/28/2018] [Indexed: 12/31/2022] Open
Abstract
A majority of viruses that have caused recent epidemics with high lethality rates in people, are zoonoses originating from wildlife. Among them are filoviruses (e.g., Marburg, Ebola), coronaviruses (e.g., SARS, MERS), henipaviruses (e.g., Hendra, Nipah) which share the common features that they are all RNA viruses, and that a dysregulated immune response is an important contributor to the tissue damage and hence pathogenicity that results from infection in humans. Intriguingly, these viruses also all originate from bat reservoirs. Bats have been shown to have a greater mean viral richness than predicted by their phylogenetic distance from humans, their geographic range, or their presence in urban areas, suggesting other traits must explain why bats harbor a greater number of zoonotic viruses than other mammals. Bats are highly unusual among mammals in other ways as well. Not only are they the only mammals capable of powered flight, they have extraordinarily long life spans, with little detectable increases in mortality or senescence until high ages. Their physiology likely impacted their history of pathogen exposure and necessitated adaptations that may have also affected immune signaling pathways. Do our life history traits make us susceptible to generating damaging immune responses to RNA viruses or does the physiology of bats make them particularly tolerant or resistant? Understanding what immune mechanisms enable bats to coexist with RNA viruses may provide critical fundamental insights into how to achieve greater resilience in humans.
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Affiliation(s)
- Judith N. Mandl
- Department of Physiology, McGill University, Montreal, QC, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
- McGill Research Center for Complex Traits, McGill University, Montreal, QC, Canada
| | - Caitlin Schneider
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
- McGill Research Center for Complex Traits, McGill University, Montreal, QC, Canada
| | - David S. Schneider
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Michelle L. Baker
- Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Commonwealth Scientific and Industrial Research Organisation, Geelong, VIC, Australia
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160
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Olive AJ, Sassetti CM. Tolerating the Unwelcome Guest; How the Host Withstands Persistent Mycobacterium tuberculosis. Front Immunol 2018; 9:2094. [PMID: 30258448 PMCID: PMC6143787 DOI: 10.3389/fimmu.2018.02094] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
Our understanding of the host response to infections has historically focused on “resistance” mechanisms that directly control pathogen replication. However, both pathogen effectors and antimicrobial immune pathways have the capacity to damage host tissue, and the ability to tolerate these insults can also be critical for host survival. These “tolerance” mechanisms may be equally as important as resistance to prevent disease in the context of a persistent infection, such as tuberculosis, when resistance mechanisms are ineffective and the pathogen persists in the tissue for long periods. Host tolerance encompasses a wide range of strategies, many of which involve regulation of the inflammatory response. Here we will examine general strategies used by macrophages and T cells to promote tolerance in the context of tuberculosis, and focus on pathways, such as regulation of inflammasome activation, that are emerging as common mediators of tolerance.
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Affiliation(s)
- Andrew J Olive
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States
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161
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Kell DB, Pretorius E. No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases. Biol Rev Camb Philos Soc 2018; 93:1518-1557. [PMID: 29575574 PMCID: PMC6055827 DOI: 10.1111/brv.12407] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 12/11/2022]
Abstract
Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.
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Affiliation(s)
- Douglas B. Kell
- School of ChemistryThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- The Manchester Institute of BiotechnologyThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
| | - Etheresia Pretorius
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
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162
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Grayson MH, Camarda LE, Hussain SRA, Zemple SJ, Hayward M, Lam V, Hunter DA, Santoro JL, Rohlfing M, Cheung DS, Salzman NH. Intestinal Microbiota Disruption Reduces Regulatory T Cells and Increases Respiratory Viral Infection Mortality Through Increased IFNγ Production. Front Immunol 2018; 9:1587. [PMID: 30042764 PMCID: PMC6048222 DOI: 10.3389/fimmu.2018.01587] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/26/2018] [Indexed: 12/20/2022] Open
Abstract
Alterations in gastrointestinal microbiota indirectly modulate the risk of atopic disease, but effects on respiratory viral infections are less clear. Using the murine paramyxoviral virus type 1, Sendai virus (SeV), we examined the effect of altering gastrointestinal microbiota on the pulmonary antiviral immune response. C57BL6 mice were treated with streptomycin before or during infection with SeV and resulting immune response studied. Ingestion of the non-absorbable antibiotic streptomycin led to a marked reduction in intestinal microbial diversity without a significant effect on lung microbiota. Reduction in diversity in the gastrointestinal tract was followed by greatly increased mortality to respiratory viral infection (p < 0.0001). This increase in mortality was associated with a dysregulated immune response characterized by decreased lung (p = 0.01) and intestinal (p = 0.03) regulatory T cells (Tregs), and increased lung IFNγ (p = 0.049), IL-6 (p = 0.015), and CCL2 (p = 0.037). Adoptive transfer of Treg cells or neutralization of IFNγ prevented increased mortality. Furthermore, Lin-CD4+ cells appeared to be a potential source of the increased IFNγ. Together, these results demonstrate gastrointestinal microbiota modulate immune responses at distant mucosal sites and have the ability to significantly impact mortality in response to a respiratory viral infection.
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Affiliation(s)
- Mitchell H Grayson
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States.,Division of Allergy and Immunology, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States
| | - Lauren E Camarda
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States.,Division of Pulmonary and Sleep Medicine, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Syed-Rehan A Hussain
- Division of Allergy and Immunology, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States
| | - Sarah J Zemple
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Michael Hayward
- Division of Gastroenterology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Vy Lam
- Division of Gastroenterology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Desiré A Hunter
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Jennifer L Santoro
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States.,Division of Allergy and Immunology, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States
| | - Michelle Rohlfing
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States.,Division of Allergy and Immunology, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States
| | - Dorothy S Cheung
- Division of Allergy and Clinical Immunology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Nita H Salzman
- Division of Gastroenterology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, United States
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163
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Khan I, Prakash A, Agashe D. Experimental evolution of insect immune memory versus pathogen resistance. Proc Biol Sci 2018; 284:rspb.2017.1583. [PMID: 29237849 DOI: 10.1098/rspb.2017.1583] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 11/13/2017] [Indexed: 12/13/2022] Open
Abstract
Under strong pathogen pressure, insects often evolve resistance to infection. Many insects are also protected via immune memory (immune priming), whereby sublethal exposure to a pathogen enhances survival after secondary infection. Theory predicts that immune memory should evolve when the pathogen is highly virulent, or when pathogen exposure is relatively rare. However, there are no empirical tests of these hypotheses, and the adaptive benefits of immune memory relative to direct resistance against a pathogen are poorly understood. To determine the selective pressures and ecological conditions that shape immune evolution, we imposed strong pathogen selection on flour beetle (Tribolium castaneum) populations, infecting them with Bacillus thuringiensis (Bt) for 11 generations. Populations injected first with heat-killed and then live Bt evolved high basal resistance against multiple Bt strains. By contrast, populations injected only with a high dose of live Bt evolved a less effective but strain-specific priming response. Control populations injected with heat-killed Bt did not evolve priming; and in the ancestor, priming was effective only against a low Bt dose. Intriguingly, one replicate population first evolved priming and subsequently evolved basal resistance, suggesting the potential for dynamic evolution of different immune strategies. Our work is the first report showing that pathogens can select for rapid modulation of insect priming ability, allowing hosts to evolve divergent immune strategies (generalized resistance versus specific immune memory) with potentially distinct mechanisms.
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Affiliation(s)
- Imroze Khan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK, Bellary Road, Bangalore 560065, India .,Ashoka University, Plot No. 2, Rajiv Gandhi Education City, National Capital Region, P.O. Rai, Sonepat, Haryana 131029, India
| | - Arun Prakash
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK, Bellary Road, Bangalore 560065, India
| | - Deepa Agashe
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK, Bellary Road, Bangalore 560065, India
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164
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Bauer M, Coldewey SM, Leitner M, Löffler B, Weis S, Wetzker R. Deterioration of Organ Function As a Hallmark in Sepsis: The Cellular Perspective. Front Immunol 2018; 9:1460. [PMID: 29997622 PMCID: PMC6028602 DOI: 10.3389/fimmu.2018.01460] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 06/12/2018] [Indexed: 01/12/2023] Open
Abstract
Development of organ dysfunction discriminates sepsis from uncomplicated infection. The paradigm shift implicated by the new sepsis-3 definition holds that initial impairment of any organ can pave the way for multiple organ dysfunction and death. Moreover, the role of the systemic inflammatory response, central element in previous sepsis definitions, has been questioned. Most strikingly, a so far largely underestimated defense mechanism of the host, i.e., "disease tolerance," which aims at maintaining host vitality without reducing pathogen load, has gained increasing attention. Here, we summarize evidence that a dysregulation of critical cellular signaling events, also in non-immune cells, might provide a conceptual framework for sepsis-induced dysfunction of parenchymal organs in the absence of significant cell death. We suggest that key signaling mediators, such as phosphoinositide 3-kinase, mechanistic target of rapamycin, and AMP-activated protein kinase, control the balance of damage and repair processes and thus determine the fate of affected organs and ultimately the host. Therapeutic targeting of these multifunctional signaling mediators requires cell-, tissue-, or organ-specific approaches. These novel strategies might allow stopping the domino-like damage to further organ systems and offer alternatives beyond the currently available strictly supportive therapeutic options.
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Affiliation(s)
- Michael Bauer
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Sina M Coldewey
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany.,Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Margit Leitner
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Bettina Löffler
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany.,Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Sebastian Weis
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany.,Center for Infectious Disease and Infection Control, Jena University Hospital, Jena, Germany
| | - Reinhard Wetzker
- Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany
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165
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Crane MJ, Lee KM, FitzGerald ES, Jamieson AM. Surviving Deadly Lung Infections: Innate Host Tolerance Mechanisms in the Pulmonary System. Front Immunol 2018; 9:1421. [PMID: 29988424 PMCID: PMC6024012 DOI: 10.3389/fimmu.2018.01421] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/07/2018] [Indexed: 12/16/2022] Open
Abstract
Much research on infectious diseases focuses on clearing the pathogen through the use of antimicrobial drugs, the immune response, or a combination of both. Rapid clearance of pathogens allows for a quick return to a healthy state and increased survival. Pathogen-targeted approaches to combating infection have inherent limitations, including their pathogen-specific nature, the potential for antimicrobial resistance, and poor vaccine efficacy, among others. Another way to survive an infection is to tolerate the alterations to homeostasis that occur during a disease state through a process called host tolerance or resilience, which is independent from pathogen burden. Alterations in homeostasis during infection are numerous and include tissue damage, increased inflammation, metabolic changes, temperature changes, and changes in respiration. Given its importance and sensitivity, the lung is a good system for understanding host tolerance to infectious disease. Pneumonia is the leading cause of death for children under five worldwide. One reason for this is because when the pulmonary system is altered dramatically it greatly impacts the overall health and survival of a patient. Targeting host pathways involved in maintenance of pulmonary host tolerance during infection could provide an alternative therapeutic avenue that may be broadly applicable across a variety of pathologies. In this review, we will summarize recent findings on tolerance to host lung infection. We will focus on the involvement of innate immune responses in tolerance and how an initial viral lung infection may alter tolerance mechanisms in leukocytic, epithelial, and endothelial compartments to a subsequent bacterial infection. By understanding tolerance mechanisms in the lung we can better address treatment options for deadly pulmonary infections.
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Affiliation(s)
| | | | | | - Amanda M. Jamieson
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
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166
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Burgan SC, Gervasi SS, Martin LB. Parasite Tolerance and Host Competence in Avian Host Defense to West Nile Virus. ECOHEALTH 2018; 15:360-371. [PMID: 29569179 DOI: 10.1007/s10393-018-1332-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 02/15/2018] [Accepted: 03/07/2018] [Indexed: 06/08/2023]
Abstract
Competence, or the propensity of a host to transmit parasites, is partly underlain by host strategies to cope with infection (e.g., resistance and tolerance). Resistance represents the ability of hosts to prevent or clear infections, whereas tolerance captures the ability of individuals to cope with a given parasite burden. Here, we investigated (1) whether one easy-to-measure form of tolerance described well the dynamic relationships between host health and parasite burden, and (2) whether individual resistance and tolerance to West Nile virus (WNV) were predictable from single cytokine measures. We exposed house sparrows (HOSP) to WNV and measured subsequent changes in host performance, viral burden, and cytokine expression. We then used two novel approaches (one complex, one simpler) to estimate tolerance within-individual HOSP using four separate host performance traits. We lastly investigated changes in the expression of pro-inflammatory cytokine interferon-γ (IFN-γ) and anti-inflammatory cytokine interleukin-10 (IL-10). Both approaches to estimating tolerance were equivalent among WNV-infected HOSP; thus, an easy-to-measure tolerance estimation may be successfully applied in field studies. Constitutive expression of IFN-γ and IL-10 were predictive of resistance and tolerance to WNV, implicating these cytokines as viable biomarkers of host competence to WNV.
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Affiliation(s)
- Sarah C Burgan
- Department of Integrative Biology, University of South Florida, SCA 130, 12037 USF Beard Drive, Tampa, FL, 33620, USA
| | | | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, SCA 130, 12037 USF Beard Drive, Tampa, FL, 33620, USA.
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167
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168
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Yan J, Zhang H, Xiang J, Zhao Y, Yuan X, Sun B, Lin A. The BH3-only protein BAD mediates TNFα cytotoxicity despite concurrent activation of IKK and NF-κB in septic shock. Cell Res 2018; 28:701-718. [PMID: 29795446 PMCID: PMC6028455 DOI: 10.1038/s41422-018-0041-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 03/27/2018] [Accepted: 04/18/2018] [Indexed: 12/13/2022] Open
Abstract
The inflammatory cytokine TNFα plays a crucial role in the pathology of many inflammatory and infectious diseases. However, the mechanism underlying TNFα cytotoxicity in these diseases is incompletely understood. Here we report that the pro-apoptotic BCL-2 family member BAD mediates TNFα cytotoxicity despite concurrent activation of IKK and NF-κB in vitro by inducing apoptosis in cultured cells and in vivo by eliciting tissue damage of multiple organs and contributing to mortality in septic shock. At high doses, TNFα significantly inactivates RhoA through activation of the Src-p190GAP pathway, resulting in massive actin stress fiber destabilization, followed by substantial BAD release from the cytoskeleton to the cytosol. Under this condition, activated IKK fails to phosphorylate all cytosolic BAD, allowing translocation of non-phosphorylated BAD to mitochondria to trigger apoptosis. Polymicrobial infection utilizes the same mechanism as high-dose TNFα to elicit apoptosis-associated tissue damage of multiple organs. Consequently, loss of Bad or elimination of BAD pro-apoptotic activity protects mice from tissue damage of multiple organs and reduces mortality rates. Our results support a model in which BAD mediates TNFα cytotoxicity despite concurrent activation of the IKK-NF-κB pathway in cultured mammalian cells and in septic shock.
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Affiliation(s)
- Jie Yan
- Ben May Department for Cancer Research, The University of Chicago, Chicago, IL, 60637, USA.,The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allery & Clinical Immunology, Guangzhou Medical University, Guangzhou, Guangdong, 510260, China
| | - Hao Zhang
- The State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jialing Xiang
- Department of Biology, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Yu Zhao
- Department of Biology, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Xiang Yuan
- Ben May Department for Cancer Research, The University of Chicago, Chicago, IL, 60637, USA.,The State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Beicheng Sun
- Department of Hepatobiliary Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Anning Lin
- Ben May Department for Cancer Research, The University of Chicago, Chicago, IL, 60637, USA. .,The Second Affiliated Hospital, The State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allery & Clinical Immunology, Guangzhou Medical University, Guangzhou, Guangdong, 510260, China.
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169
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Cumnock K, Gupta AS, Lissner M, Chevee V, Davis NM, Schneider DS. Host Energy Source Is Important for Disease Tolerance to Malaria. Curr Biol 2018; 28:1635-1642.e3. [PMID: 29754902 DOI: 10.1016/j.cub.2018.04.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/26/2018] [Accepted: 04/03/2018] [Indexed: 12/22/2022]
Abstract
Pathologic infections are accompanied by a collection of short-term behavioral perturbations collectively termed sickness behaviors [1, 2]. These include changes in body temperature, reduced eating and drinking, and lethargy and mimic behaviors of animals in torpor and hibernation [1, 3-6]. Sickness behaviors are important, pathogen-specific components of the host response to infection [1, 3, 7-9]. In particular, host anorexia has been shown to be beneficial or detrimental depending on the infection [7, 8]. While these studies have illuminated the effects of anorexia on infection, they consider this behavior in isolation from other behaviors and from its effects on host metabolism and energy. Here, we explored the temporal dynamics of multiple sickness behaviors and their effect on host energy and metabolism throughout infection. We used the Plasmodium chabaudi AJ murine model of malaria as it causes severe pathology from which most animals recover. We found that infected animals did become anorexic, skewing their metabolism toward fatty acid oxidation and ketosis. Metabolism of fats requires oxygen for the production of ATP. In this model, animals also suffer severe anemia, limiting their ability to carry oxygen concurrent with their switch toward fatty acid metabolism. We reasoned that the combination of anorexia and anemia would increase pressure on glycolysis as a critical energy pathway because it does not require oxygen. Treating infected mice when anorexic with the glycolytic inhibitor 2-deoxyglucose (2DG) reduced survival; treating animals with glucose improved survival. Peak parasite loads were unchanged, demonstrating changes in disease tolerance. Parasite clearance was reduced with 2DG treatment, suggesting altered resistance.
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Affiliation(s)
- Katherine Cumnock
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Avni S Gupta
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Michelle Lissner
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Victoria Chevee
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Nicole M Davis
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - David S Schneider
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
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170
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Del Giudice M, Gangestad SW. Rethinking IL-6 and CRP: Why they are more than inflammatory biomarkers, and why it matters. Brain Behav Immun 2018; 70:61-75. [PMID: 29499302 DOI: 10.1016/j.bbi.2018.02.013] [Citation(s) in RCA: 415] [Impact Index Per Article: 69.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/17/2018] [Accepted: 02/26/2018] [Indexed: 02/06/2023] Open
Abstract
Behavioral researchers have increasingly become interested in the idea that chronic, low-grade inflammation is a pathway through which social and behavioral variables exert long-term effects on health. Much research in the area employs putative inflammatory biomarkers to infer an underlying state of inflammation. Interleukin 6 (IL-6) and C-reactive protein (CRP, whose production is stimulated by IL-6) are arguably the two most commonly assayed biomarkers. Yet, in contrast with near-universal assumptions in the field, discoveries in immunology over the past two decades show that neither IL-6 nor CRP are unambiguous inflammatory markers. IL-6 operates through two distinct signaling pathways, only one of which is specifically upregulated during inflammation; both pathways have a complex range of effects and influence multiple physiological processes even in absence of inflammation. Similarly, CRP has two isoforms, one of which is produced locally in inflamed or damaged tissues. The other isoform is routinely produced in absence of inflammation and may have net anti-inflammatory effects. We propose a functional framework to account for the multiple actions of IL-6 and CRP. Specifically, we argue that both molecules participate in somatic maintenance efforts; hence elevated levels indicate that an organism is investing in protection, preservation, and/or repair of somatic tissue. Depending on the state of the organism, maintenance may be channeled into resistance against pathogens (including inflammation), pathogen tolerance and harm reduction, or tissue repair. The findings and framework we present have a range of potential implications for the interpretation of empirical findings in this area-a point we illustrate with alternative interpretations of research on socioeconomic status, stress, and depression.
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171
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Clatworthy AE, Romano KP, Hung DT. Whole-organism phenotypic screening for anti-infectives promoting host health. Nat Chem Biol 2018; 14:331-341. [PMID: 29556098 PMCID: PMC9843822 DOI: 10.1038/s41589-018-0018-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 11/20/2017] [Indexed: 01/19/2023]
Abstract
To date, antibiotics have been identified on the basis of their ability to kill bacteria or inhibit their growth rather than directly for their capacity to improve clinical outcomes of infected patients. Although historically successful, this approach has led to the development of an antibiotic armamentarium that suffers from a number of shortcomings, including the inevitable emergence of resistance and, in certain infections, suboptimal efficacy leading to long treatment durations, infection recurrence, or high mortality and morbidity rates despite apparent bacterial sterilization. Conventional antibiotics fail to address the complexities of in vivo bacterial physiology and virulence, as well as the role of the host underlying the complex, dynamic interactions that cause disease. New interventions are needed, aimed at host outcome rather than microbiological cure. Here we review the role of screening models for cellular and whole-organism infection, including worms, flies, zebrafish, and mice, to identify novel therapeutic strategies and discuss their future implications.
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Affiliation(s)
- Anne E. Clatworthy
- Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Keith P. Romano
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA, USA
| | - Deborah T. Hung
- Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Department of Genetics, Harvard Medical School, Boston, MA, USA,Correspondence and requests for materials should be addressed to D.T.H.
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172
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Brown GP, Holden D, Shine R, Phillips BL. Invasion history alters the behavioural consequences of immune system activation in cane toads. J Anim Ecol 2018; 87:716-726. [DOI: 10.1111/1365-2656.12799] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/22/2017] [Indexed: 02/02/2023]
Affiliation(s)
- Gregory P. Brown
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - Damian Holden
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - Richard Shine
- School of Life and Environmental Sciences University of Sydney Sydney NSW Australia
| | - Ben L. Phillips
- School of Biosciences University of Melbourne Parkville Vic. Australia
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173
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Troha K, Im JH, Revah J, Lazzaro BP, Buchon N. Comparative transcriptomics reveals CrebA as a novel regulator of infection tolerance in D. melanogaster. PLoS Pathog 2018; 14:e1006847. [PMID: 29394281 PMCID: PMC5812652 DOI: 10.1371/journal.ppat.1006847] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 02/14/2018] [Accepted: 01/01/2018] [Indexed: 12/15/2022] Open
Abstract
Host responses to infection encompass many processes in addition to activation of the immune system, including metabolic adaptations, stress responses, tissue repair, and other reactions. The response to bacterial infection in Drosophila melanogaster has been classically described in studies that focused on the immune response elicited by a small set of largely avirulent microbes. Thus, we have surprisingly limited knowledge of responses to infection that are outside the canonical immune response, of how the response to pathogenic infection differs from that to avirulent bacteria, or even of how generic the response to various microbes is and what regulates that core response. In this study, we addressed these questions by profiling the D. melanogaster transcriptomic response to 10 bacteria that span the spectrum of virulence. We found that each bacterium triggers a unique transcriptional response, with distinct genes making up to one third of the response elicited by highly virulent bacteria. We also identified a core set of 252 genes that are differentially expressed in response to the majority of bacteria tested. Among these, we determined that the transcription factor CrebA is a novel regulator of infection tolerance. Knock-down of CrebA significantly increased mortality from microbial infection without any concomitant change in bacterial number. Upon infection, CrebA is upregulated by both the Toll and Imd pathways in the fat body, where it is required to induce the expression of secretory pathway genes. Loss of CrebA during infection triggered endoplasmic reticulum (ER) stress and activated the unfolded protein response (UPR), which contributed to infection-induced mortality. Altogether, our study reveals essential features of the response to bacterial infection and elucidates the function of a novel regulator of infection tolerance.
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Affiliation(s)
- Katia Troha
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Joo Hyun Im
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Jonathan Revah
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Brian P. Lazzaro
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Nicolas Buchon
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, New York, United States of America
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174
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McCarville JL, Ayres JS. Disease tolerance: concept and mechanisms. Curr Opin Immunol 2018; 50:88-93. [PMID: 29253642 PMCID: PMC5884632 DOI: 10.1016/j.coi.2017.12.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/04/2017] [Accepted: 12/01/2017] [Indexed: 02/08/2023]
Abstract
Two distinct defense strategies provide a host with survival to infectious diseases: resistance and tolerance. Resistance is dependent on the ability of the host to kill pathogens. Tolerance promotes host health while having a neutral to positive impact of pathogen fitness. Immune responses are almost inevitably defined in terms of pathogen resistance. Recent evidence has shown, however, that several effects attributed to activation of innate and adaptive immune mechanisms, cannot be readily explained with the paradigm of immunity as effectors of microbial destruction. This review focuses on integrating the concept of disease tolerance into recent studies of immune system function related to the regulation and resolution of tissue damage, T cell exhaustion, and tolerance to innocuous antigen.
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Affiliation(s)
- J L McCarville
- Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - J S Ayres
- Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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175
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Schoenle LA, Schoepf I, Weinstein NM, Moore IT, Bonier F. Higher plasma corticosterone is associated with reduced costs of infection in red-winged blackbirds. Gen Comp Endocrinol 2018; 256:89-98. [PMID: 28697920 DOI: 10.1016/j.ygcen.2017.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 06/06/2017] [Accepted: 07/06/2017] [Indexed: 12/24/2022]
Abstract
Glucocorticoid hormones allow individuals to rapidly adjust their physiology and behavior to meet the challenges of a variable environment. An individual's baseline concentration of glucocorticoids can reflect shifts in life history stage and resource demands while mediating a suite of physiological and behavioral changes that include immune modulation and resource allocation. Thus, glucocorticoids could facilitate a response to parasites that is optimized for an individual's specific challenges and life history stage. We investigated the relationship between endogenous circulating glucocorticoids and measures of resistance and tolerance to Haemosporidian parasites (including those that cause avian malaria) in red-winged blackbirds (Agelaius phoeniceus). We found that higher endogenous concentrations of circulating glucocorticoids were associated with reduced costs of parasite infection, which is indicative of higher tolerance, but were unrelated to parasite burden in free ranging, breeding male birds. Post-breeding, both males and females with higher glucocorticoid concentrations had higher measures of tolerance to Haemosporidian infection. Our findings suggest a potentially adaptive role for glucocorticoids in shifting the response to parasites to align with an individual's current physiological state and the challenges they face.
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Affiliation(s)
- Laura A Schoenle
- Department of Biological Sciences, Virginia Tech, 1405 Perry St., Blacksburg, VA 24061, United States.
| | - Ivana Schoepf
- Department of Biological Sciences, Virginia Tech, 1405 Perry St., Blacksburg, VA 24061, United States; Biology Department, Queen's University, Biosciences Complex 3523, Kingston ON K7L 3N6, Canada.
| | - Nicole M Weinstein
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3900 Spruce St., Philadelphia, PA 19104, United States.
| | - Ignacio T Moore
- Department of Biological Sciences, Virginia Tech, 1405 Perry St., Blacksburg, VA 24061, United States.
| | - Frances Bonier
- Department of Biological Sciences, Virginia Tech, 1405 Perry St., Blacksburg, VA 24061, United States; Biology Department, Queen's University, Biosciences Complex 3523, Kingston ON K7L 3N6, Canada.
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176
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Kenny LC, Kell DB. Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father. Front Med (Lausanne) 2018; 4:239. [PMID: 29354635 PMCID: PMC5758600 DOI: 10.3389/fmed.2017.00239] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/12/2017] [Indexed: 12/18/2022] Open
Abstract
Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.
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Affiliation(s)
- Louise C. Kenny
- The Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
- Department of Obstetrics and Gynecology, University College Cork, Cork, Ireland
- Faculty of Health and Life Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Douglas B. Kell
- School of Chemistry, The University of Manchester, Manchester, United Kingdom
- The Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
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177
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Marchetto KM, Power AG. Coinfection Timing Drives Host Population Dynamics through Changes in Virulence. Am Nat 2017; 191:173-183. [PMID: 29351014 DOI: 10.1086/695316] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Infections of one host by multiple parasites are common, and several studies have found that the order of parasite invasion can affect both within-host competition and disease severity. However, it is unclear to what extent coinfection timing might be important to consider when modeling parasite impacts on host populations. Using a model system of two viruses infecting barley, we found that simultaneous infections of the two viruses were significantly more damaging to hosts than sequential coinfections. While priority effects were evident in within-host concentrations of sequential coinfections, priority did not influence any parameters (such as virulence or transmission rate) that affect host population dynamics. We built a susceptible-infected model to examine whether the observed difference in coinfection virulence could impact host population dynamics under a range of scenarios. We found that coinfection timing can have an important but context-dependent effect on projected host population dynamics. Studies that examine only simultaneous coinfections could inflate disease impact predictions.
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178
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Kenmoku H, Hori A, Kuraishi T, Kurata S. A novel mode of induction of the humoral innate immune response in Drosophila larvae. Dis Model Mech 2017; 10:271-281. [PMID: 28250052 PMCID: PMC5374318 DOI: 10.1242/dmm.027102] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 01/20/2017] [Indexed: 12/14/2022] Open
Abstract
Drosophila adults have been utilized as a genetically tractable model organism to decipher the molecular mechanisms of humoral innate immune responses. In an effort to promote the utility of Drosophila larvae as an additional model system, in this study, we describe a novel aspect of an induction mechanism for innate immunity in these larvae. By using a fine tungsten needle created for manipulating semi-conductor devices, larvae were subjected to septic injury. However, although Toll pathway mutants were susceptible to infection with Gram-positive bacteria as had been shown for Drosophila adults, microbe clearance was not affected in the mutants. In addition, Drosophila larvae were found to be sensitive to mechanical stimuli with respect to the activation of a sterile humoral response. In particular, pinching with forceps to a degree that might cause minor damage to larval tissues could induce the expression of the antifungal peptide gene Drosomycin; notably, this induction was partially independent of the Toll and immune deficiency pathways. We therefore propose that Drosophila larvae might serve as a useful model to analyze the infectious and non-infectious inflammation that underlies various inflammatory diseases such as ischemia, atherosclerosis and cancer.
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Affiliation(s)
- Hiroyuki Kenmoku
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Aki Hori
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.,Graduate School of Medical Sciences, Kanazawa University, Ishikawa 920-1192, Japan
| | - Takayuki Kuraishi
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan .,Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo 160-8582, Japan.,Faculty of Pharmacy, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa 920-1192, Japan.,PRESTO, Japan Science and Technology Agency, Tokyo 102-0076, Japan
| | - Shoichiro Kurata
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
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179
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Kutzer MAM, Kurtz J, Armitage SAO. Genotype and diet affect resistance, survival, and fecundity but not fecundity tolerance. J Evol Biol 2017; 31:159-171. [DOI: 10.1111/jeb.13211] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 10/06/2017] [Accepted: 11/12/2017] [Indexed: 11/29/2022]
Affiliation(s)
- M. A. M. Kutzer
- Institute for Evolution and Biodiversity; University of Münster; Münster Germany
| | - J. Kurtz
- Institute for Evolution and Biodiversity; University of Münster; Münster Germany
| | - S. A. O. Armitage
- Institute for Evolution and Biodiversity; University of Münster; Münster Germany
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180
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Hori A, Kurata S, Kuraishi T. Unexpected role of the IMD pathway in Drosophila gut defense against Staphylococcus aureus. Biochem Biophys Res Commun 2017; 495:395-400. [PMID: 29108998 DOI: 10.1016/j.bbrc.2017.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 11/01/2017] [Indexed: 12/29/2022]
Abstract
In this study, fruit fly of the genus Drosophila is utilized as a suitable model animal to investigate the molecular mechanisms of innate immunity. To combat orally transmitted pathogenic Gram-negative bacteria, the Drosophila gut is armed with the peritrophic matrix, which is a physical barrier composed of chitin and glycoproteins: the Duox system that produces reactive oxygen species (ROS), which in turn sterilize infected microbes, and the IMD pathway that regulates the expression of antimicrobial peptides (AMPs), which in turn control ROS-resistant pathogens. However, little is known about the defense mechanisms against Gram-positive bacteria in the fly gut. Here, we show that the peritrophic matrix protects Drosophila against Gram-positive bacteria S. aureus. We also define the few roles of ROS in response to the infection and show that the IMD pathway is required for the clearance of ingested microbes, possibly independently from AMP expression. These findings provide a new aspect of the gut defense system of Drosophila, and helps to elucidate the processes of gut-microbe symbiosis and pathogenesis.
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Affiliation(s)
- Aki Hori
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan; Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Shoichiro Kurata
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
| | - Takayuki Kuraishi
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan; Faculty of Pharmacy, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan; Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan; PRESTO, Japan Science and Technology Agency, Tokyo, Japan.
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181
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Abstract
Effective pathogens are successful, by definition, because they can defeat our immune response. Pingen et al. (2016) in this issue of Immunity demonstrate that some mosquito-transmitted viruses depend upon a strong host immune response triggered by the innate immune response to the bite to promote dissemination through the body.
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182
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Veiga-Fernandes H, Freitas AA. The S(c)ensory Immune System Theory. Trends Immunol 2017; 38:777-788. [DOI: 10.1016/j.it.2017.02.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/09/2017] [Accepted: 02/15/2017] [Indexed: 01/21/2023]
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183
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Interleukin-17A Aggravates Middle Ear Injury Induced by Streptococcus pneumoniae through the p38 Mitogen-Activated Protein Kinase Signaling Pathway. Infect Immun 2017; 85:IAI.00438-17. [PMID: 28739823 DOI: 10.1128/iai.00438-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/11/2017] [Indexed: 12/26/2022] Open
Abstract
Acute otitis media (AOM) is one of the most common bacterial infectious diseases in children aged 2 to 7 years worldwide. We previously demonstrated that interleukin-17A (IL-17A) promotes an acute inflammatory response characterized by the influx of neutrophils into the middle ear cavity during Streptococcus pneumoniae-induced AOM. In general, the inflammatory response is viewed as an effector that frequently causes local tissue damage. However, little is known about the pathogenic effects of IL-17A in AOM. Here, we investigated the pathogenic effects of IL-17A by using wild-type (WT) and IL-17A knockout (KO) mouse models. The results showed that the pathogenic effects of AOM, including weight loss, histopathological changes, and proinflammatory cytokine production, were more severe in WT mice than in IL-17A KO mice, suggesting that IL-17A aggravates tissue damage in AOM. Furthermore, these pathogenic effects were found to be dependent on p38 mitogen-activated protein kinase (MAPK) and could be reversed in the presence of a p38 MAPK-specific inhibitor. It was also demonstrated that IL-17A promoted the production of neutrophil myeloperoxidase (MPO) through the p38 MAPK signaling pathway, which was responsible for the middle ear tissue injury. These data support the conclusion that IL-17A contributes to middle ear injury through the p38 MAPK signaling pathway.
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184
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Nakhleh J, Christophides GK, Osta MA. The serine protease homolog CLIPA14 modulates the intensity of the immune response in the mosquito Anopheles gambiae. J Biol Chem 2017; 292:18217-18226. [PMID: 28928218 PMCID: PMC5672044 DOI: 10.1074/jbc.m117.797787] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/13/2017] [Indexed: 11/06/2022] Open
Abstract
Clip domain serine protease homologs (SPHs) are positive and negative regulators of Anopheles gambiae immune responses mediated by the complement-like protein TEP1 against Plasmodium malaria parasites and other microbial infections. We have previously reported that the SPH CLIPA2 is a negative regulator of the TEP1-mediated response by showing that CLIPA2 knockdown (kd) enhances mosquito resistance to infections with fungi, bacteria, and Plasmodium parasites. Here, we identify another SPH, CLIPA14, as a novel regulator of mosquito immunity. We found that CLIPA14 is a hemolymph protein that is rapidly cleaved following a systemic infection. CLIPA14 kd mosquitoes elicited a potent melanization response against Plasmodium berghei ookinetes and exhibited significantly increased resistance to Plasmodium infections as well as to systemic and oral bacterial infections. The activity of the enzyme phenoloxidase, which initiates melanin biosynthesis, dramatically increased in the hemolymph of CLIPA14 kd mosquitoes in response to systemic bacterial infections. Ookinete melanization and hemolymph phenoloxidase activity were further increased after cosilencing CLIPA14 and CLIPA2, suggesting that these two SPHs act in concert to control the melanization response. Interestingly, CLIPA14 RNAi phenotypes and its infection-induced cleavage were abolished in a TEP1 loss-of-function background. Our results suggest that a complex network of SPHs functions downstream of TEP1 to regulate the melanization reaction.
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Affiliation(s)
- Johnny Nakhleh
- From the Department of Biology, American University of Beirut, Beirut 1107 2020, Lebanon and
| | | | - Mike A Osta
- From the Department of Biology, American University of Beirut, Beirut 1107 2020, Lebanon and
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185
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Resistance and tolerance defenses in cancer: Lessons from infectious diseases. Semin Immunol 2017; 32:54-61. [PMID: 28865876 DOI: 10.1016/j.smim.2017.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 12/31/2022]
Abstract
Infectious disease and cancer are two maladies with multiple similarities. Both types of disease induce activation of the host immune response and induce pathologies that compromise host heath and survival. In infection biology, defense against pathogens can be broken down into two distinct components called resistance and tolerance. Resistance protects the host by killing pathogens. Tolerance protects the host by alleviating the pathology caused by the infection. The conceptual framework of resistance and tolerance, concepts explored during infectious disease, is applicable to cancer, a condition for which patient survival is dependent on tumor eradication (resistance) and the mitigation of pathologies that occur during disease (tolerance). Here, we propose that integration of the concept of disease tolerance into cancer studies will result in new therapies to complement current resistance-based treatment strategies to increase the likelihood of patient survival and to improve quality of life. Furthermore, by drawing parallels between infectious disease and cancer, we propose that host interactions with microbes could provide therapeutic insight for promoting tolerance defense and focus our discussion on cachexia, a pathology resulting in significant morbidity in cancer patients.
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186
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Nathan C. Kunkel Lecture: Fundamental immunodeficiency and its correction. J Exp Med 2017; 214:2175-2191. [PMID: 28701368 PMCID: PMC5551579 DOI: 10.1084/jem.20170637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 02/05/2023] Open
Abstract
"Fundamental immunodeficiency" is the inability of the encoded immune system to protect an otherwise healthy host from every infection that could threaten its life. In contrast to primary immunodeficiencies, fundamental immunodeficiency is not rare but nearly universal. It results not from variation in a given host gene but from the rate and extent of variation in the genes of other organisms. The remedy for fundamental immunodeficiency is "adopted immunity," not to be confused with adaptive or adoptive immunity. Adopted immunity arises from four critical societal contributions to the survival of the human species: sanitation, nutrition, vaccines, and antimicrobial agents. Immunologists have a great deal to contribute to the development of vaccines and antimicrobial agents, but they have focused chiefly on vaccines, and vaccinology is thriving. In contrast, the effect of antimicrobial agents in adopted immunity, although fundamental, is fragile and failing. Immunologists can aid the development of sorely needed antimicrobial agents, and the study of antimicrobial agents can help immunologists discover targets and mechanisms of host immunity.
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Affiliation(s)
- Carl Nathan
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY
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187
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Fisher JJ, Castrillo LA, Donzelli BGG, Hajek AE. Starvation and Imidacloprid Exposure Influence Immune Response by Anoplophora glabripennis (Coleoptera: Cerambycidae) to a Fungal Pathogen. JOURNAL OF ECONOMIC ENTOMOLOGY 2017; 110:1451-1459. [PMID: 28482047 DOI: 10.1093/jee/tox124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Indexed: 06/07/2023]
Abstract
In several insect systems, fungal entomopathogens synergize with neonicotinoid insecticides which results in accelerated host death. Using the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), an invasive woodborer inadvertently introduced into North America and Europe, we investigated potential mechanisms in the synergy between the entomopathogenic fungus Metarhizium brunneum Petch and the insecticide imidacloprid. A potential mechanism underlying this synergy could be imidacloprid's ability to prevent feeding shortly after administration. We investigated whether starvation would have an impact similar to imidacloprid exposure on the mortality of fungal-inoculated beetles. Using real-time PCR to quantify fungal load in inoculated beetles, we determined how starvation and pesticide exposure impacted beetles' ability to tolerate or resist a fungal infection. The effect of starvation and pesticide exposure on the encapsulation and melanization immune responses of the beetles was also quantified. Starvation had a similar impact on the survival of M. brunneum-inoculated beetles compared to imidacloprid exposure. The synergy, however, was not completely due to starvation, as imidacloprid reduced the beetles' melanotic encapsulation response and capsule area, while starvation did not significantly reduce these immune responses. Our results suggest that there are multiple interacting mechanisms involved in the synergy between M. brunneum and imidacloprid.
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Affiliation(s)
- Joanna J Fisher
- Department of Entomology, Cornell University, Ithaca, NY 14853-2601
| | | | - Bruno G G Donzelli
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14853-5904
| | - Ann E Hajek
- Department of Entomology, Cornell University, Ithaca, NY 14853-2601
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188
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Buscher K, Ehinger E, Gupta P, Pramod AB, Wolf D, Tweet G, Pan C, Mills CD, Lusis AJ, Ley K. Natural variation of macrophage activation as disease-relevant phenotype predictive of inflammation and cancer survival. Nat Commun 2017; 8:16041. [PMID: 28737175 PMCID: PMC5527282 DOI: 10.1038/ncomms16041] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 05/24/2017] [Indexed: 12/20/2022] Open
Abstract
Although mouse models exist for many immune-based diseases, the clinical translation remains challenging. Most basic and translational studies utilize only a single inbred mouse strain. However, basal and diseased immune states in humans show vast inter-individual variability. Here, focusing on macrophage responses to lipopolysaccharide (LPS), we use the hybrid mouse diversity panel (HMDP) of 83 inbred strains as a surrogate for human natural immune variation. Since conventional bioinformatics fail to analyse a population spectrum, we highlight how gene signatures for LPS responsiveness can be derived based on an Interleukin-12β and arginase expression ratio. Compared to published signatures, these gene markers are more robust to identify susceptibility or resilience to several macrophage-related disorders in humans, including survival prediction across many tumours. This study highlights natural activation diversity as a disease-relevant dimension in macrophage biology, and suggests the HMDP as a viable tool to increase translatability of mouse data to clinical settings.
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Affiliation(s)
- Konrad Buscher
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | - Erik Ehinger
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | - Pritha Gupta
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Akula Bala Pramod
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | - Dennis Wolf
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | - George Tweet
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | - Calvin Pan
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Charles D. Mills
- BioMedical Consultants, Marine on St. Croix, Minnesota 55047, USA
| | - Aldons J. Lusis
- Departments of Medicine, Human Genetics, and Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095, USA
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
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189
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Gupta V, Vale PF. Nonlinear disease tolerance curves reveal distinct components of host responses to viral infection. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170342. [PMID: 28791163 PMCID: PMC5541558 DOI: 10.1098/rsos.170342] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/31/2017] [Indexed: 05/07/2023]
Abstract
The ability to tolerate infection is a key component of host defence and offers potential novel therapeutic approaches for infectious diseases. To yield successful targets for therapeutic intervention, it is important that the analytical tools employed to measure disease tolerance are able to capture distinct host responses to infection. Here, we show that commonly used methods that estimate tolerance as a linear relationship should be complemented with more flexible, nonlinear estimates of this relationship which may reveal variation in distinct components such as host vigour, sensitivity to increases in pathogen loads, and the severity of the infection. To illustrate this, we measured the survival of Drosophila melanogaster carrying either a functional or non-functional regulator of the JAK-STAT immune pathway (G9a) when challenged with a range of concentrations of Drosophila C virus (DCV). While classical linear model analyses indicated that G9a affected tolerance only in females, a more powerful nonlinear logistic model showed that G9a mediates viral tolerance to different extents in both sexes. This analysis also revealed that G9a acts by changing the sensitivity to increasing pathogen burdens, but does not reduce the ultimate severity of disease. These results indicate that fitting nonlinear models to host health-pathogen burden relationships may offer better and more detailed estimates of disease tolerance.
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Affiliation(s)
- Vanika Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
| | - Pedro F. Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, EH9 3FL Edinburgh, UK
- Author for correspondence: Pedro F. Vale e-mail:
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190
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Stahlschmidt ZR, French SS, Ahn A, Webb A, Butler MW. A Simulated Heat Wave Has Diverse Effects on Immune Function and Oxidative Physiology in the Corn Snake (Pantherophis guttatus). Physiol Biochem Zool 2017; 90:434-444. [DOI: 10.1086/691315] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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191
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Bandyopadhaya A, Tsurumi A, Rahme LG. NF-κBp50 and HDAC1 Interaction Is Implicated in the Host Tolerance to Infection Mediated by the Bacterial Quorum Sensing Signal 2-Aminoacetophenone. Front Microbiol 2017; 8:1211. [PMID: 28713342 PMCID: PMC5492500 DOI: 10.3389/fmicb.2017.01211] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 06/14/2017] [Indexed: 12/11/2022] Open
Abstract
Some bacterial quorum sensing (QS) small molecules are important mediators of inter-kingdom signaling and impact host immunity. The QS regulated small volatile molecule 2-aminoacetophenone (2-AA), which has been proposed as a biomarker of Pseudomonas aeruginosa colonization in chronically infected human tissues, is critically involved in “host tolerance training” that involves a distinct molecular mechanism of host chromatin regulation through histone deacetylase (HDAC)1. 2-AA’s epigenetic reprogramming action enables host tolerance to high bacterial burden and permits long-term presence of P. aeruginosa without compromising host survival. Here, to further elucidate the molecular mechanisms of 2-AA-mediated host tolerance/resilience we investigated the connection between histone acetylation status and nuclear factor (NF)-κB signaling components that together coordinate 2-AA-mediated control of transcriptional activity. We found increased NF-κBp65 acetylation levels in 2-AA stimulated cells that are preceded by association of CBP/p300 and increased histone acetyltransferase activity. In contrast, in 2-AA-tolerized cells the protein–protein interaction between p65 and CBP/p300 is disrupted and conversely, the interaction between p50 and co-repressor HDAC1 is enhanced, leading to repression of the pro-inflammatory response. These results highlight how a bacterial QS signaling molecule can establish a link between intracellular signaling and epigenetic reprogramming of pro-inflammatory mediators that may contribute to host tolerance training. These new insights might contribute to the development of novel therapeutic interventions against bacterial infections.
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Affiliation(s)
- Arunava Bandyopadhaya
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, BostonMA, United States.,Department of Microbiology and Immunobiology, Harvard Medical School, BostonMA, United States.,Shriners Hospitals for Children Boston, BostonMA, United States
| | - Amy Tsurumi
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, BostonMA, United States.,Department of Microbiology and Immunobiology, Harvard Medical School, BostonMA, United States.,Shriners Hospitals for Children Boston, BostonMA, United States
| | - Laurence G Rahme
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, BostonMA, United States.,Department of Microbiology and Immunobiology, Harvard Medical School, BostonMA, United States.,Shriners Hospitals for Children Boston, BostonMA, United States
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192
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Debes PV, Gross R, Vasemägi A. Quantitative Genetic Variation in, and Environmental Effects on, Pathogen Resistance and Temperature-Dependent Disease Severity in a Wild Trout. Am Nat 2017; 190:244-265. [PMID: 28731797 DOI: 10.1086/692536] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Health after pathogen contact varies among individuals because of differences in pathogen load (which is limited by resistance) and disease severity in response to pathogen load (which is limited by tolerance). To understand pathogen-induced host evolution, it is critical to know not only the relative contributions of nongenetic and genetic variation to resistance and tolerance but also how they change environmentally. We quantified nongenetic and genetic variation in parasite load and the associated temperature-dependent disease among trout siblings from two rivers. We detected a genetic variance for parasite load 6.6 times as large in the colder river. By contrast, genetic variance for disease traits tended to be larger in the warmer river, where the disease was manifested more severely. The relationships between disease severity and pathogen load (tolerance) exhibited plateaus at low pathogen load and stronger steepening slopes at high pathogen load in the warmer river. Our study demonstrates the environmental influence on disease severity, nongenetic and genetic variance for health-damage-limiting host abilities, and the shape of tolerance curves. Environmental variability is predicted to govern the presence and intensity of selection, change the relative contributions of nongenetic and genetic variance, and therefore hamper evolution toward more resistant and tolerant hosts.
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193
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Weis S, Rubio I, Ludwig K, Weigel C, Jentho E. Hormesis and Defense of Infectious Disease. Int J Mol Sci 2017; 18:E1273. [PMID: 28617331 PMCID: PMC5486095 DOI: 10.3390/ijms18061273] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/16/2017] [Accepted: 05/20/2017] [Indexed: 12/22/2022] Open
Abstract
Infectious diseases are a global health burden and remain associated with high social and economic impact. Treatment of affected patients largely relies on antimicrobial agents that act by directly targeting microbial replication. Despite the utility of host specific therapies having been assessed in previous clinical trials, such as targeting the immune response via modulating the cytokine release in sepsis, results have largely been frustrating and did not lead to the introduction of new therapeutic tools. In this article, we will discuss current evidence arguing that, by applying the concept of hormesis, already approved pharmacological agents could be used therapeutically to increase survival of patients with infectious disease via improving disease tolerance, a defense mechanism that decreases the extent of infection-associated tissue damage without directly targeting pathogenic microorganisms.
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Affiliation(s)
- Sebastian Weis
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Jena, Jena 07747, Germany.
- Center for Infectious Diseases and Infection Control, University Hospital Jena, Jena 07747, Germany.
- Center for Sepsis Control and Care, University Hospital Jena, Jena 07747, Germany.
| | - Ignacio Rubio
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, Jena 07745, Germany.
| | - Kristin Ludwig
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, Jena 07745, Germany.
| | - Cynthia Weigel
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Jena, Jena 07747, Germany.
- Fritz Lipmann Institute, Leibniz Institute on Aging, Jena 07745, Germany.
| | - Elisa Jentho
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Jena, Jena 07747, Germany.
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194
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Ohmer MEB, Cramp RL, Russo CJM, White CR, Franklin CE. Skin sloughing in susceptible and resistant amphibians regulates infection with a fungal pathogen. Sci Rep 2017; 7:3529. [PMID: 28615642 PMCID: PMC5471217 DOI: 10.1038/s41598-017-03605-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 05/05/2017] [Indexed: 11/09/2022] Open
Abstract
The fungal pathogen Batrachochytrium dendrobatidis (Bd) has been implicated in amphibian population declines globally. Given that Bd infection is limited to the skin in post-metamorphic amphibians, routine skin sloughing may regulate infection. Skin sloughing has been shown to reduce the number of cultivatable microbes on amphibian skin, and Bd infection increases skin sloughing rates at high loads. However, it is unclear whether species specific differences in skin sloughing patterns could regulate Bd population growth on the skin, and influence subsequent infection dynamics. We exposed five Australian frog species to Bd, and monitored sloughing rates and infection loads over time. Sloughing reduced Bd load on the ventral skin surface, in all five species, despite wide variation in susceptibility to disease. In the least susceptible species, an increase in sloughing rate occurred at lower infection loads, and sloughing reduced Bd load up to 100%, leading to infection clearance. Conversely, the drop in Bd load with sloughing was only temporary in the more susceptible species. These findings indicate that the ability of sloughing to act as an effective immune defence is species specific, and they have implications for understanding the pattern of Bd population growth on individual hosts, as well as population-level effects.
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Affiliation(s)
- Michel E B Ohmer
- The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia. .,University of Pittsburgh, Department of Biological Sciences, Pittsburgh, PA, 15260, United States.
| | - Rebecca L Cramp
- The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia
| | - Catherine J M Russo
- The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia
| | - Craig R White
- Monash University, Centre for Geometric Biology, School of Biological Sciences, Monash, VIC 3800, Australia
| | - Craig E Franklin
- The University of Queensland, School of Biological Sciences, St. Lucia, QLD 4072, Australia
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195
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Gupta V, Vasanthakrishnan RB, Siva-Jothy J, Monteith KM, Brown SP, Vale PF. The route of infection determines Wolbachia antibacterial protection in Drosophila. Proc Biol Sci 2017; 284:20170809. [PMID: 28592678 PMCID: PMC5474083 DOI: 10.1098/rspb.2017.0809] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 05/12/2017] [Indexed: 12/03/2022] Open
Abstract
Bacterial symbionts are widespread among metazoans and provide a range of beneficial functions. Wolbachia-mediated protection against viral infection has been extensively demonstrated in Drosophila. In mosquitoes that are artificially transinfected with Drosophila melanogaster Wolbachia (wMel), protection from both viral and bacterial infections has been demonstrated. However, no evidence for Wolbachia-mediated antibacterial protection has been demonstrated in Drosophila to date. Here, we show that the route of infection is key for Wolbachia-mediated antibacterial protection. Drosophila melanogaster carrying Wolbachia showed reduced mortality during enteric-but not systemic-infection with the opportunist pathogen Pseudomonas aeruginosaWolbachia-mediated protection was more pronounced in male flies and is associated with increased early expression of the antimicrobial peptide Attacin A, and also increased expression of a reactive oxygen species detoxification gene (Gst D8). These results highlight that the route of infection is important for symbiont-mediated protection from infection, that Wolbachia can protect hosts by eliciting a combination of resistance and disease tolerance mechanisms, and that these effects are sexually dimorphic. We discuss the importance of using ecologically relevant routes of infection to gain a better understanding of symbiont-mediated protection.
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Affiliation(s)
- Vanika Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | | | - Jonathon Siva-Jothy
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Katy M Monteith
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Sam P Brown
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA
| | - Pedro F Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh EH9 3FL, UK
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196
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Romoli O, Saviane A, Bozzato A, D'Antona P, Tettamanti G, Squartini A, Cappellozza S, Sandrelli F. Differential sensitivity to infections and antimicrobial peptide-mediated immune response in four silkworm strains with different geographical origin. Sci Rep 2017; 7:1048. [PMID: 28432358 PMCID: PMC5430696 DOI: 10.1038/s41598-017-01162-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/27/2017] [Indexed: 01/19/2023] Open
Abstract
The domesticated silkworm Bombyx mori has an innate immune system, whose main effectors are the antimicrobial peptides (AMPs). Silkworm strains are commonly grouped into four geographical types (Japanese, Chinese, European and Tropical) and are generally characterised by a variable susceptibility to infections. To clarify the genetic and molecular mechanisms on which the different responses to infections are based, we exposed one silkworm strain for each geographical area to oral infections with the silkworm pathogens Enterococcus mundtii or Serratia marcescens. We detected a differential susceptibility to both bacteria, with the European strain displaying the lowest sensitivity to E. mundtii and the Indian one to S. marcescens. We found that all the strains were able to activate the AMP response against E. mundtii. However, the highest tolerance of the European strain appeared to be related to the specific composition of its AMP cocktail, containing more effective variants such as a peculiar Cecropin B6 isoform. The resistance of the Indian strain to S. marcescens seemed to be associated with its prompt capability to activate the systemic transcription of AMPs. These data suggest that B. mori strains with distinct genetic backgrounds employ different strategies to counteract bacterial infections, whose efficacy appears to be pathogen-dependent.
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Affiliation(s)
- Ottavia Romoli
- Department of Biology, University of Padova, Padova, Italy
| | - Alessio Saviane
- CREA - Honey Bee and Silkworm Research Unit, Padova Seat, Padova, Italy
| | - Andrea Bozzato
- Department of Biology, University of Padova, Padova, Italy
| | - Paola D'Antona
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Gianluca Tettamanti
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Andrea Squartini
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
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197
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Lough G, Rashidi H, Kyriazakis I, Dekkers JCM, Hess A, Hess M, Deeb N, Kause A, Lunney JK, Rowland RRR, Mulder HA, Doeschl-Wilson A. Use of multi-trait and random regression models to identify genetic variation in tolerance to porcine reproductive and respiratory syndrome virus. Genet Sel Evol 2017; 49:37. [PMID: 28424056 PMCID: PMC5396128 DOI: 10.1186/s12711-017-0312-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/29/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND A host can adopt two response strategies to infection: resistance (reduce pathogen load) and tolerance (minimize impact of infection on performance). Both strategies may be under genetic control and could thus be targeted for genetic improvement. Although there is evidence that supports a genetic basis for resistance to porcine reproductive and respiratory syndrome (PRRS), it is not known whether pigs also differ genetically in tolerance. We determined to what extent pigs that have been shown to vary genetically in resistance to PRRS also exhibit genetic variation in tolerance. Multi-trait linear mixed models and random regression sire models were fitted to PRRS Host Genetics Consortium data from 1320 weaned pigs (offspring of 54 sires) that were experimentally infected with a virulent strain of PRRS virus to obtain genetic parameter estimates for resistance and tolerance. Resistance was defined as the inverse of within-host viral load (VL) from 0 to 21 (VL21) or 0 to 42 (VL42) days post-infection and tolerance as the slope of the reaction-norm of average daily gain (ADG21, ADG42) on VL21 or VL42. RESULTS Multi-trait analysis of ADG associated with either low or high VL was not indicative of genetic variation in tolerance. Similarly, random regression models for ADG21 and ADG42 with a tolerance slope fitted for each sire did not result in a better fit to the data than a model without genetic variation in tolerance. However, the distribution of data around average VL suggested possible confounding between level and slope estimates of the regression lines. Augmenting the data with simulated growth rates of non-infected half-sibs (ADG0) helped resolve this statistical confounding and indicated that genetic variation in tolerance to PRRS may exist if genetic correlations between ADG0 and ADG21 or ADG42 are low to moderate. CONCLUSIONS Evidence for genetic variation in tolerance of pigs to PRRS was weak when based on data from infected piglets only. However, simulations indicated that genetic variance in tolerance may exist and could be detected if comparable data on uninfected relatives were available. In conclusion, of the two defense strategies, genetics of tolerance is more difficult to elucidate than genetics of resistance.
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Affiliation(s)
- Graham Lough
- The Roslin Institute & R(D)SVS, University of Edinburgh, Edinburgh, Midlothian, UK
| | - Hamed Rashidi
- Animal Breeding and Genomics Centre, Wageningen University and Research, PO Box 338, 6700 AH Wageningen, The Netherlands
| | - Ilias Kyriazakis
- School of Agriculture Food and Rural Development, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | | | - Andrew Hess
- Department of Animal Science, Iowa State University, Ames, IA 50011 USA
| | - Melanie Hess
- Department of Animal Science, Iowa State University, Ames, IA 50011 USA
| | - Nader Deeb
- Genus plc, 100 Bluegrass Commons Blvd. Suite 2200, Hendersonville, TN 37075 USA
| | - Antti Kause
- Biometrical Genetics, Natural Resources Institute Finland, 00790 Jokioinen, Finland
| | - Joan K. Lunney
- Animal Parasitic Diseases Laboratory, USDA, Beltsville, MD 20705 USA
| | | | - Han A. Mulder
- Animal Breeding and Genomics Centre, Wageningen University and Research, PO Box 338, 6700 AH Wageningen, The Netherlands
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198
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Kogut MH, Arsenault RJ. Immunometabolic Phenotype Alterations Associated with the Induction of Disease Tolerance and Persistent Asymptomatic Infection of Salmonella in the Chicken Intestine. Front Immunol 2017; 8:372. [PMID: 28421074 PMCID: PMC5378774 DOI: 10.3389/fimmu.2017.00372] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/15/2017] [Indexed: 11/15/2022] Open
Abstract
The adaptation of Salmonella enterica to the eukaryotic host is a key process that enables the bacterium to survive in a hostile environment. Salmonella have evolved an intimate relationship with its host that extends to their cellular and molecular levels. Colonization, invasion, and replication of the bacteria in an appropriate host suggest that modification of host functions is central to pathogenesis. Intuitively, this subversion of the cell must be a complex process, since hosts are not inherently programmed to provide an environment conducive to pathogens. Hosts have evolved countermeasures to pathogen invasion, establishment, and replication through two types of defenses: resistance and tolerance. Resistance functions to control pathogen invasion and reduce or eliminate the invading pathogen. Research has primarily concentrated on resistance mechanisms that are mediated by the immune system. On the other hand, tolerance is mediated by different mechanisms that limit the damage caused by a pathogen’s growth without affecting or reducing pathogen numbers or loads. The mechanisms of tolerance appear to be separated into those that protect host tissues from the virulence factors of a pathogen and those that limit or reduce the damage caused by the host immune and inflammatory responses to the pathogen. Some pathogens, such as Salmonella, have evolved the capacity to survive the initial robust immune response and persist. The persistent phase of a Salmonella infection in the avian host usually involves a complex balance of protective immunity and immunopathology. Salmonella is able to stay in the avian ceca for months without triggering clinical signs. Chronic colonization of the intestinal tract is an important aspect of persistent Salmonella infection because it results in a silent propagation of bacteria in poultry stocks due to the impossibility to isolate contaminated animals. Data from our lab promote the hypothesis that Salmonella have evolved a unique survival strategy in poultry that minimizes host defenses (disease resistance) during the initial infection and then exploits and/or induces a dramatic immunometabolic reprogramming in the cecum that alters the host defense to disease tolerance. Unfortunately, this disease tolerance results in the ongoing human food safety dilemma.
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Affiliation(s)
| | - Ryan J Arsenault
- Department of Animal and Food Sciences, University of Delaware, Newark, DE, USA
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199
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Tate AT, Andolfatto P, Demuth JP, Graham AL. The within-host dynamics of infection in trans-generationally primed flour beetles. Mol Ecol 2017; 26:3794-3807. [PMID: 28277618 DOI: 10.1111/mec.14088] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 02/17/2017] [Accepted: 02/21/2017] [Indexed: 12/19/2022]
Abstract
Many taxa exhibit plastic immune responses initiated after primary microbial exposure that provide increased protection against disease-induced mortality and the fitness costs of infection. In several arthropod species, this protection can even be passed from parents to offspring through a phenomenon called trans-generational immune priming. Here, we first demonstrate that trans-generational priming is a repeatable phenomenon in flour beetles (Tribolium castaneum) primed and infected with Bacillus thuringiensis (Bt). We then quantify the within-host dynamics of microbes and host physiological responses in infected offspring from primed and unprimed mothers by monitoring bacterial density and using mRNA-seq to profile host gene expression, respectively, over the acute infection period. We find that priming increases inducible resistance against Bt around a critical temporal juncture where host septicaemic trajectories, and consequently survival, may be determined in unprimed individuals. Our results identify a highly differentially expressed biomarker of priming, containing an EIF4-e domain, in uninfected individuals, as well as several other candidate genes. Moreover, the induction and decay dynamics of gene expression over time suggest a metabolic shift in primed individuals. The identified bacterial and gene expression dynamics are likely to influence patterns of bacterial fitness and disease transmission in natural populations.
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Affiliation(s)
- Ann T Tate
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Peter Andolfatto
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Jeffery P Demuth
- Department of Biology, University of Texas, Arlington, TX, 76010, USA
| | - Andrea L Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
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200
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Wu SR, Reddy P. Regulating Damage from Sterile Inflammation: A Tale of Two Tolerances. Trends Immunol 2017; 38:231-235. [PMID: 28268062 DOI: 10.1016/j.it.2017.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/26/2017] [Accepted: 02/10/2017] [Indexed: 02/02/2023]
Abstract
The severity of immunopathology from non-infectious inflammation is mainly understood and is managed by targeting immune cells. However, the role of target tissues in determining damage severity has been largely overlooked. Here, we discuss the concept of 'tissue tolerance' for tissue-intrinsic programs that ameliorate organ damage in the setting of sterile immunopathology.
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Affiliation(s)
- Shin-Rong Wu
- Graduate Program in Immunology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Internal Medicine, Michigan Medicine, Ann Arbor, MI, USA
| | - Pavan Reddy
- Department of Internal Medicine, Michigan Medicine, Ann Arbor, MI, USA.
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