1
|
Xiong YQ, Li Y, Goncheva MI, Elsayed AM, Zhu F, Li L, Abdelhady W, Flannagan RS, Yeaman MR, Bayer AS, Heinrichs DE. The Purine Biosynthesis Repressor, PurR, Contributes to Vancomycin Susceptibility of Methicillin-resistant Staphylococcus aureus in Experimental Endocarditis. J Infect Dis 2024; 229:1648-1657. [PMID: 38297970 PMCID: PMC11175694 DOI: 10.1093/infdis/jiad577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND Staphylococcus aureus is the most common cause of life-threatening endovascular infections, including infective endocarditis (IE). These infections, especially when caused by methicillin-resistant strains (MRSA), feature limited therapeutic options and high morbidity and mortality rates. METHODS Herein, we investigated the role of the purine biosynthesis repressor, PurR, in virulence factor expression and vancomycin (VAN) treatment outcomes in experimental IE due to MRSA. RESULTS The PurR-mediated repression of purine biosynthesis was confirmed by enhanced purF expression and production of an intermediate purine metabolite in purR mutant strain. In addition, enhanced expression of the transcriptional regulators, sigB and sarA, and their key downstream virulence genes (eg, fnbA, and hla) was demonstrated in the purR mutant in vitro and within infected cardiac vegetations. Furthermore, purR deficiency enhanced fnbA/fnbB transcription, translating to increased fibronectin adhesion versus the wild type and purR-complemented strains. Notably, the purR mutant was refractory to significant reduction in target tissues MRSA burden following VAN treatment in the IE model. CONCLUSIONS These findings suggest that the purine biosynthetic pathway intersects the coordination of virulence factor expression and in vivo persistence during VAN treatment, and may represent an avenue for novel antimicrobial development targeting MRSA.
Collapse
Affiliation(s)
- Yan Q Xiong
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Yi Li
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Mariya I Goncheva
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Ahmed M Elsayed
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Fengli Zhu
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Liang Li
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Wessam Abdelhady
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Ronald S Flannagan
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Michael R Yeaman
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Medicine, Division of Molecular Medicine, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
| | - Arnold S Bayer
- The Lundquist Institute for Biomedical Innovation, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- Department of Medicine, Division of Infectious Diseases, Harbor-University of California Los Angeles Medical Center, Torrance, California, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - David E Heinrichs
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
2
|
Parmar R, Pickering H, Ahn R, Rossetti M, Gjertson DW, Ruffin F, Chan LC, Fowler VG, Yeaman MR, Reed EF. Integrated transcriptomic analysis reveals immune signatures distinguishing persistent versus resolving outcomes in MRSA bacteremia. Front Immunol 2024; 15:1373553. [PMID: 38846955 PMCID: PMC11153731 DOI: 10.3389/fimmu.2024.1373553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 05/02/2024] [Indexed: 06/09/2024] Open
Abstract
Introduction Staphylococcus aureus bacteremia (SAB) is a life-threatening infection particularly involving methicillin-resistant S. aureus (MRSA). In contrast to resolving MRSA bacteremia (RB), persistent MRSA bacteremia (PB) blood cultures remain positive despite appropriate antibiotic treatment. Host immune responses distinguishing PB vs. RB outcomes are poorly understood. Here, integrated transcriptomic, IL-10 cytokine levels, and genomic analyses sought to identify signatures differentiating PB vs. RB outcomes. Methods Whole-blood transcriptomes of propensity-matched PB (n=28) versus RB (n=30) patients treated with vancomycin were compared in one independent training patient cohort. Gene expression (GE) modules were analyzed and prioritized relative to host IL-10 cytokine levels and DNA methyltransferase-3A (DNMT3A) genotype. Results Differential expression of T and B lymphocyte gene expression early in MRSA bacteremia discriminated RB from PB outcomes. Significant increases in effector T and B cell signaling pathways correlated with RB, lower IL-10 cytokine levels and DNMT3A heterozygous A/C genotype. Importantly, a second PB and RB patient cohort analyzed in a masked manner demonstrated high predictive accuracy of differential signatures. Discussion Collectively, the present findings indicate that human PB involves dysregulated immunity characterized by impaired T and B cell responses associated with excessive IL-10 expression in context of the DNMT3A A/A genotype. These findings reveal distinct immunologic programs in PB vs. RB outcomes, enable future studies to define mechanisms by which host and/or pathogen drive differential signatures and may accelerate prediction of PB outcomes. Such prognostic assessment of host risk could significantly enhance early anti-infective interventions to avert PB and improve patient outcomes.
Collapse
Affiliation(s)
- Rajesh Parmar
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Harry Pickering
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Richard Ahn
- Department of Microbiology, Immunology, & Molecular Genetics, University of California Los Angeles, Los Angeles, CA, United States
| | - Maura Rossetti
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - David W. Gjertson
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Felicia Ruffin
- Division of Infectious Diseases, Duke University, Durham, NC, United States
| | - Liana C. Chan
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
- Divisions of Molecular Medicine and Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, Torrance, CA, United States
- Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States
| | - Vance G. Fowler
- Division of Infectious Diseases, Duke University, Durham, NC, United States
| | - Michael R. Yeaman
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
- Divisions of Molecular Medicine and Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, Torrance, CA, United States
- Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States
| | - Elaine F. Reed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
3
|
Fu H, Pickering H, Rubbi L, Ross TM, Reed EF, Pellegrini M. Longitudinal analysis of influenza vaccination implicates regulation of RIG-I signaling by DNA methylation. Sci Rep 2024; 14:1455. [PMID: 38228690 PMCID: PMC10791625 DOI: 10.1038/s41598-024-51665-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/08/2024] [Indexed: 01/18/2024] Open
Abstract
Influenza virus infection alters the promoter DNA methylation of key immune response-related genes, including type-1 interferons and proinflammatory cytokines. However, less is known about the effect of the influenza vaccine on the epigenome. We utilized a targeted DNA methylation approach to study the longitudinal effects (day 0 pre-vaccination and day 28 post-vaccination) on influenza vaccination responses in peripheral blood mononuclear cells. We found that baseline, pre-vaccination methylation profiles are associated with pre-existing, protective serological immunity. Additionally, we identified 481 sites that were differentially methylated between baseline and day 28 post-vaccination. These were enriched for genes involved in the regulation of the RIG-I signaling pathway, an important regulator of viral responses. Our results suggest that DNA methylation changes to components of the RIG-I pathway are associated with vaccine effectiveness. Therefore, immunization strategies that target this pathway may improve serological responses to influenza vaccination.
Collapse
Affiliation(s)
- Hongxiang Fu
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Harry Pickering
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Liudmilla Rubbi
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ted M Ross
- Department of Infectious Diseases, University of Georgia, Athens, GA, USA
- Center for Vaccines and Immunology, University of Georgia, Athens, GA, USA
| | - Elaine F Reed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Matteo Pellegrini
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
4
|
Wang W, Hariharan M, Bartlett A, Barragan C, Castanon R, Rothenberg V, Song H, Nery J, Aldridge A, Altshul J, Kenworthy M, Ding W, Liu H, Tian W, Zhou J, Chen H, Wei B, Gündüz IB, Norell T, Broderick TJ, McClain MT, Satterwhite LL, Burke TW, Petzold EA, Shen X, Woods CW, Fowler VG, Ruffin F, Panuwet P, Barr DB, Beare JL, Smith AK, Spurbeck RR, Vangeti S, Ramos I, Nudelman G, Sealfon SC, Castellino F, Walley AM, Evans T, Müller F, Greenleaf WJ, Ecker JR. Human Immune Cell Epigenomic Signatures in Response to Infectious Diseases and Chemical Exposures. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.546792. [PMID: 37425926 PMCID: PMC10327221 DOI: 10.1101/2023.06.29.546792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Variations in DNA methylation patterns in human tissues have been linked to various environmental exposures and infections. Here, we identified the DNA methylation signatures associated with multiple exposures in nine major immune cell types derived from peripheral blood mononuclear cells (PBMCs) at single-cell resolution. We performed methylome sequencing on 111,180 immune cells obtained from 112 individuals who were exposed to different viruses, bacteria, or chemicals. Our analysis revealed 790,662 differentially methylated regions (DMRs) associated with these exposures, which are mostly individual CpG sites. Additionally, we integrated methylation and ATAC-seq data from same samples and found strong correlations between the two modalities. However, the epigenomic remodeling in these two modalities are complementary. Finally, we identified the minimum set of DMRs that can predict exposures. Overall, our study provides the first comprehensive dataset of single immune cell methylation profiles, along with unique methylation biomarkers for various biological and chemical exposures.
Collapse
Affiliation(s)
- Wenliang Wang
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Manoj Hariharan
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Anna Bartlett
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Cesar Barragan
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Rosa Castanon
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Vince Rothenberg
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Haili Song
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Joseph Nery
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Andrew Aldridge
- Duke University School of Medicine, Bryan Research Building, 311 Research Drive, Durham, NC 27710, USA
| | - Jordan Altshul
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Mia Kenworthy
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Wubin Ding
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Hanqing Liu
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Wei Tian
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Jingtian Zhou
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Huaming Chen
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Bei Wei
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Irem B. Gündüz
- Integrative Cellular Biology & Bioinformatics Lab, Saarland University, 66123 Saarbrücken, Germany
| | - Todd Norell
- Healthspan, Resilience, and Performance, Florida Institute for Human and Machine Cognition, 40 S Alcaniz St, Pensacola, FL 32502, USA
| | - Timothy J Broderick
- Healthspan, Resilience, and Performance, Florida Institute for Human and Machine Cognition, 40 S Alcaniz St, Pensacola, FL 32502, USA
| | - Micah T. McClain
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
- Durham Veterans Affairs Medical Center, Durham, NC 27705 USA
| | - Lisa L. Satterwhite
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Thomas W. Burke
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
| | - Elizabeth A. Petzold
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
| | - Xiling Shen
- Terasaki Institute for Biomedical Innovation, Los Angeles, CA 90024, USA
| | - Christopher W. Woods
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
- Durham Veterans Affairs Medical Center, Durham, NC 27705 USA
| | - Vance G. Fowler
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
- Duke Clinical Research Institute, Durham NC 27701 USA
| | - Felicia Ruffin
- Center for Infectious Disease Diagnostics and Innovation, Division of Infectious Diseases, Duke University Medical Center, Durham, NC 27710 USA
| | - Parinya Panuwet
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322 USA
| | - Dana B. Barr
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322 USA
| | | | - Anthony K. Smith
- Battelle Memorial Institute, 505 King Ave Columbus OH 43201, USA
| | | | - Sindhu Vangeti
- Department of Neurology, Icahn School of Medicine at Mount Sinai; New York, NY 10029, USA
| | - Irene Ramos
- Department of Neurology, Icahn School of Medicine at Mount Sinai; New York, NY 10029, USA
| | - German Nudelman
- Department of Neurology, Icahn School of Medicine at Mount Sinai; New York, NY 10029, USA
| | - Stuart C. Sealfon
- Department of Neurology, Icahn School of Medicine at Mount Sinai; New York, NY 10029, USA
| | - Flora Castellino
- U.S. Department of Health and Human Services, Administration for Strategic Preparedness and Response, Biomedical Advanced Research and Development Authority, Washington, DC, USA
| | - Anna Maria Walley
- Vaccitech plc, Unit 6-10, Zeus Building, Rutherford Avenue, Harwell OX11 0DF, United Kingdom
| | - Thomas Evans
- Vaccitech plc, Unit 6-10, Zeus Building, Rutherford Avenue, Harwell OX11 0DF, United Kingdom
| | - Fabian Müller
- Integrative Cellular Biology & Bioinformatics Lab, Saarland University, 66123 Saarbrücken, Germany
| | | | - Joseph R. Ecker
- Genomic Analysis Laboratory, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, 10010 N Torrey Pines Rd, La Jolla, CA 92037, USA
| |
Collapse
|
5
|
Sheu KM, Guru AA, Hoffmann A. Quantifying stimulus-response specificity to probe the functional state of macrophages. Cell Syst 2023; 14:180-195.e5. [PMID: 36657439 PMCID: PMC10023480 DOI: 10.1016/j.cels.2022.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/05/2022] [Accepted: 12/22/2022] [Indexed: 01/19/2023]
Abstract
Immune sentinel macrophages initiate responses to pathogens via hundreds of immune response genes. Each immune threat demands a tailored response, suggesting that the capacity for stimulus-specific gene expression is a key functional hallmark of healthy macrophages. To quantify this property, termed "stimulus-response specificity" (SRS), we developed a single-cell experimental workflow and analytical approaches based on information theory and machine learning. We found that the response specificity of macrophages is driven by combinations of specific immune genes that show low cell-to-cell heterogeneity and are targets of separate signaling pathways. The "response specificity profile," a systematic comparison of multiple stimulus-response distributions, was distinctly altered by polarizing cytokines, and it enabled an assessment of the functional state of macrophages. Indeed, the response specificity profile of peritoneal macrophages from old and obese mice showed characteristic differences, suggesting that SRS may be a basis for measuring the functional state of innate immune cells. A record of this paper's transparent peer review process is included in the supplemental information.
Collapse
Affiliation(s)
- Katherine M Sheu
- Department of Microbiology, Immunology, and Molecular Genetics, and Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, 611 Charles E. Young Dr S, Los Angeles, CA 90093, USA
| | - Aditya A Guru
- Department of Microbiology, Immunology, and Molecular Genetics, and Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, 611 Charles E. Young Dr S, Los Angeles, CA 90093, USA
| | - Alexander Hoffmann
- Department of Microbiology, Immunology, and Molecular Genetics, and Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, 611 Charles E. Young Dr S, Los Angeles, CA 90093, USA.
| |
Collapse
|
6
|
Parsons JB, Westgeest AC, Conlon BP, Fowler VG. Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Host, Pathogen, and Treatment. Antibiotics (Basel) 2023; 12:455. [PMID: 36978320 PMCID: PMC10044482 DOI: 10.3390/antibiotics12030455] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen responsible for a variety of life-threatening infections. A distinctive characteristic of this pathogen is its ability to persist in the bloodstream for several days despite seemingly appropriate antibiotics. Persistent MRSA bacteremia is common and is associated with poor clinical outcomes. The etiology of persistent MRSA bacteremia is a result of the complex interplay between the host, the pathogen, and the antibiotic used to treat the infection. In this review, we explore the factors related to each component of the host-pathogen interaction and discuss the clinical relevance of each element. Next, we discuss the treatment options and diagnostic approaches for the management of persistent MRSA bacteremia.
Collapse
Affiliation(s)
- Joshua B. Parsons
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Annette C. Westgeest
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Infectious Diseases, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Vance G. Fowler
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Duke Clinical Research Institute, Durham, NC 27710, USA
| |
Collapse
|
7
|
MRSA Isolates from Patients with Persistent Bacteremia Generate Nonstable Small Colony Variants In Vitro within Macrophages and Endothelial Cells during Prolonged Vancomycin Exposure. Infect Immun 2023; 91:e0042322. [PMID: 36602380 PMCID: PMC9872686 DOI: 10.1128/iai.00423-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Staphylococcus aureus (especially methicillin-resistant S. aureus [MRSA]) is frequently associated with persistent bacteremia (PB) during vancomycin therapy despite consistent susceptibility in vitro. Strategic comparisons of PB strains versus those from vancomycin-resolving bacteremia (RB) would yield important mechanistic insights into PB outcomes. Clinical PB versus RB isolates were assessed in vitro for intracellular replication and small colony variant (SCV) formation within macrophages and endothelial cells (ECs) in the presence or absence of exogenous vancomycin. In both macrophages and ECs, PB and RB isolates replicated within lysosome-associated membrane protein-1 (LAMP-1)-positive compartments. PB isolates formed nonstable small colony variants (nsSCVs) in vancomycin-exposed host cells at a significantly higher frequency than matched RB isolates (in granulocyte-macrophage colony-stimulating factor [GM-CSF], human macrophages PB versus RB, P < 0.0001 at 48 h; in ECs, PB versus RB, P < 0.0001 at 24 h). This phenotype could represent one potential basis for the unique ability of PB isolates to adaptively resist vancomycin therapy and cause PB in humans. Elucidating the molecular mechanism(s) by which PB strains form nsSCVs could facilitate the discovery of novel treatment strategies to mitigate PB due to MRSA.
Collapse
|
8
|
Wong Fok Lung T, Chan LC, Prince A, Yeaman MR, Archer NK, Aman MJ, Proctor RA. Staphylococcus aureus adaptive evolution: Recent insights on how immune evasion, immunometabolic subversion and host genetics impact vaccine development. Front Cell Infect Microbiol 2022; 12:1060810. [PMID: 36636720 PMCID: PMC9831658 DOI: 10.3389/fcimb.2022.1060810] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 11/16/2022] [Indexed: 12/28/2022] Open
Abstract
Despite meritorious attempts, a S. aureus vaccine that prevents infection or mitigates severity has not yet achieved efficacy endpoints in prospective, randomized clinical trials. This experience underscores the complexity of host-S. aureus interactions, which appear to be greater than many other bacterial pathogens against which successful vaccines have been developed. It is increasingly evident that S. aureus employs strategic countermeasures to evade or exploit human immune responses. From entering host cells to persist in stealthy intracellular reservoirs, to sensing the environmental milieu and leveraging bacterial or host metabolic products to reprogram host immune responses, S. aureus poses considerable challenges for the development of effective vaccines. The fact that this pathogen causes distinct types of infections and can undergo transient genetic, transcriptional or metabolic adaptations in vivo that do not occur in vitro compounds challenges in vaccine development. Notably, the metabolic versatility of both bacterial and host immune cells as they compete for available substrates within specific tissues inevitably impacts the variable repertoire of gene products that may or may not be vaccine antigens. In this respect, S. aureus has chameleon phenotypes that have alluded vaccine strategies thus far. Nonetheless, a number of recent studies have also revealed important new insights into pathogenesis vulnerabilities of S. aureus. A more detailed understanding of host protective immune defenses versus S. aureus adaptive immune evasion mechanisms may offer breakthroughs in the development of effective vaccines, but at present this goal remains a very high bar. Coupled with the recent advances in human genetics and epigenetics, newer vaccine technologies may enable such a goal. If so, future vaccines that protect against or mitigate the severity of S. aureus infections are likely to emerge at the intersection of precision and personalized medicine. For now, the development of S. aureus vaccines or alternative therapies that reduce mortality and morbidity must continue to be pursued.
Collapse
Affiliation(s)
| | - Liana C Chan
- Department of Medicine, David Geffen School of Medicine at University of California Loss Angeles (UCLA), Los Angeles, CA, United States.,Divisions of Molecular Medicine and Infectious Diseases, Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States.,Lundquist Institute for Biomedical Innovation at Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Alice Prince
- Department of Pediatrics, Columbia University, New York, NY, United States
| | - Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at University of California Loss Angeles (UCLA), Los Angeles, CA, United States.,Divisions of Molecular Medicine and Infectious Diseases, Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States.,Lundquist Institute for Biomedical Innovation at Harbor-University of California Loss Angeles (UCLA) Medical Center, Torrance, CA, United States
| | - Nathan K Archer
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - M Javad Aman
- Integrated BioTherapeutics, Rockville, MD, United States
| | - Richard A Proctor
- Department of Medicine and Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| |
Collapse
|
9
|
Qin W, Scicluna BP, van der Poll T. The Role of Host Cell DNA Methylation in the Immune Response to Bacterial Infection. Front Immunol 2021; 12:696280. [PMID: 34394088 PMCID: PMC8358789 DOI: 10.3389/fimmu.2021.696280] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
Host cells undergo complex transcriptional reprogramming upon infection. Epigenetic changes play a key role in the immune response to bacteria, among which DNA modifications that include methylation have received much attention in recent years. The extent of DNA methylation is well known to regulate gene expression. Whilst historically DNA methylation was considered to be a stable epigenetic modification, accumulating evidence indicates that DNA methylation patterns can be altered rapidly upon exposure of cells to changing environments and pathogens. Furthermore, the action of proteins regulating DNA methylation, particularly DNA methyltransferases and ten-eleven translocation methylcytosine dioxygenases, may be modulated, at least in part, by bacteria. This review discusses the principles of DNA methylation, and recent insights about the regulation of host DNA methylation during bacterial infection.
Collapse
Affiliation(s)
- Wanhai Qin
- Center of Experimental & Molecular Medicine, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Brendon P Scicluna
- Center of Experimental & Molecular Medicine, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Tom van der Poll
- Center of Experimental & Molecular Medicine, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.,Division of Infectious Diseases, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|