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Bishop LR, Starost MF, Kovacs JA. CD4, but not Cxcr6, is necessary for control of Pneumocystis murina infection. Microbes Infect 2024:105408. [PMID: 39182643 DOI: 10.1016/j.micinf.2024.105408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/30/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024]
Abstract
CD4+ T cells are critical to control of Pneumocystis infection, and Cxcr6 has been shown to be upregulated in these cells during infection, but the roles of CD4 and Cxcr6 in this setting are undefined. To explore this, mice deficient in CD4 or Cxcr6 expression were utilized in a co-housing mouse model that mimics the natural route of Pneumocystis infection. Organism load and anti-Pneumocystis antibodies were assayed over time, and immunohistochemistry, flow cytometry, and quantitative PCR were used to characterize host immune responses during infection. CD4 was found to be necessary for clearance of Pneumocystis murina, though partial control was seen in it's absence; based on ThPOK expression, double negative T cells with T helper cell characteristics may be contributing to this control. Using a Cxcr6 deficient mouse expressing gfp, control of infection in the absence of Cxcr6 was similar to that in heterozygous control mice. It is noteworthy that gfp + cells were seen in the lungs with similar frequencies between the 2 strains. Interferon-ɣ and chemokine/ligands Cxcr3, Cxcl9, and Cxcl10 increased during P. murina infection in all models. Thus, CD4, but not Cxcr6, is needed for clearance of P. murina infection.
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Affiliation(s)
- Lisa R Bishop
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, MSC 1662, Bethesda, MD 20892, USA
| | - Matthew F Starost
- Diagnostic and Research Services Branch, Division of Veterinary Resources, National Institutes of Health, Building 28A, Room 111A, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Building 10, Room 2C145, MSC 1662, Bethesda, MD 20892, USA.
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Bishop LR, Curran SJ, Kovacs JA. Mucosal-Associated Invariant T Cells Accumulate in the Lungs during Murine Pneumocystis Infection but Are Not Required for Clearance. J Fungi (Basel) 2022; 8:jof8060645. [PMID: 35736127 PMCID: PMC9224882 DOI: 10.3390/jof8060645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/01/2022] [Accepted: 06/15/2022] [Indexed: 12/02/2022] Open
Abstract
Pneumocystis is a fungal pathogen that can cause pneumonia in immunosuppressed hosts and subclinical infection in immunocompetent hosts. Mucosal-associated invariant T (MAIT) cells are unconventional lymphocytes with a semi-invariant T-cell receptor that are activated by riboflavin metabolites that are presented by the MHC-1b molecule MR1. Although Pneumocystis can presumably synthesize riboflavin metabolites based on whole-genome studies, the role of MAIT cells in controlling Pneumocystis infection is unknown. We used a co-housing mouse model of Pneumocystis infection, combined with flow cytometry and qPCR, to characterize the response of MAIT cells to infection in C57BL/6 mice, and, using MR1−/− mice, which lack MAIT cells, to examine their role in clearing the infection. MAIT cells accumulated in the lungs of C57BL/6 mice during Pneumocystis infection and remained at increased levels for many weeks after clearance of infection. In MR1−/− mice, Pneumocystis infection was cleared with kinetics similar to C57BL/6 mice. Thus, MAIT cells are not necessary for control of Pneumocystis infection, but the prolonged retention of these cells in the lungs following clearance of infection may allow a more rapid future response to other pathogens.
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Choreño-Parra JA, Jiménez-Álvarez LA, Muñoz-Torrico M, Ramírez-Martínez G, Jiménez-Zamudio LA, Salinas-Lara C, García-Latorre EA, Zúñiga J. Antigens of Mycobacterium tuberculosis Stimulate CXCR6+ Natural Killer Cells. Front Immunol 2020; 11:582414. [PMID: 33117393 PMCID: PMC7549382 DOI: 10.3389/fimmu.2020.582414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 09/07/2020] [Indexed: 12/30/2022] Open
Abstract
Natural killer (NK) cells participate in immunity against several pathogens by exerting cytotoxic and cytokine-production activities. Some NK cell subsets also mediate recall responses that resemble memory of adaptive lymphocytes against antigenic and non-antigenic stimuli. The C-X-C motif chemokine receptor 6 (CXCR6) is crucial for the development and maintenance of memory-like responses in murine NK cells. In humans, several subsets of tissue-resident and circulating NK cells with different functional properties express CXCR6. However, the role of CXCR6+ NK cells in immunity against relevant human pathogens is unknown. Here, we addressed whether murine and human CXCR6+ NK cells respond to antigens of Mycobacterium tuberculosis (Mtb). For this purpose, we evaluated the immunophenotype of hepatic and splenic CXCR6+ NK cells in mice exposed to a cell-wall (CW) extract of Mtb strain H37Rv. Also, we characterized the expression of CXCR6 in peripheral NK cells from active pulmonary tuberculosis (ATB) patients, individuals with latent TB infection (LTBI), and healthy volunteer donors (HD). Furthermore, we evaluated the responses of CXCR6+ NK cells from HD, LTBI, and ATB subjects to the in vitro exposure to CW preparations of Mtb H37Rv and Mtb HN878. Our results showed that murine hepatic CXCR6+ NK cells expand in vivo after consecutive administrations of Mtb H37Rv CW to mice. Remarkably, pooled hepatic and splenic, but not isolated splenic NK cells from treated mice, enhance their cytokine production capacity after an in vitro re-challenge with H37Rv CW. In humans, CXCR6+ NK cells were barely detected in the peripheral blood, although slightly significative increments in the percentage of CXCR6+, CXCR6+CD49a−, CXCR6+CD49a+, and CXCR6+CD69+ NK cells were observed in ATB patients as compared to HD and LTBI individuals. In contrast, the expansion of CXCR6+CD49a− and CXCR6+CD69+ NK cells in response to the in vitro stimulation with Mtb H37Rv was higher in LTBI individuals than in ATB patients. Finally, we found that Mtb HN878 CW generates IFN-γ-producing CXCR6+CD49a+ NK cells. Our results demonstrate that antigens of both laboratory-adapted and clinical Mtb strains are stimulating factors for murine and human CXCR6+ NK cells. Future studies evaluating the role of CXCR6+ NK cells during TB are warranted.
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Affiliation(s)
- José Alberto Choreño-Parra
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico.,Laboratory of Immunobiology and Genetics, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico
| | - Luis Armando Jiménez-Álvarez
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico.,Laboratory of Immunobiology and Genetics, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico
| | - Marcela Muñoz-Torrico
- Tuberculosis Clinic, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico
| | - Gustavo Ramírez-Martínez
- Laboratory of Immunobiology and Genetics, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico
| | | | - Citlaltepetl Salinas-Lara
- Department of Neuropathology, Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", Mexico City, Mexico
| | | | - Joaquín Zúñiga
- Laboratory of Immunobiology and Genetics, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City, Mexico.,Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Mexico City, Mexico
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Ashhurst AS, Flórido M, Lin LCW, Quan D, Armitage E, Stifter SA, Stambas J, Britton WJ. CXCR6-Deficiency Improves the Control of Pulmonary Mycobacterium tuberculosis and Influenza Infection Independent of T-Lymphocyte Recruitment to the Lungs. Front Immunol 2019; 10:339. [PMID: 30899256 PMCID: PMC6416161 DOI: 10.3389/fimmu.2019.00339] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/08/2019] [Indexed: 11/13/2022] Open
Abstract
T-lymphocytes are critical for protection against respiratory infections, such as Mycobacterium tuberculosis and influenza virus, with chemokine receptors playing an important role in directing these cells to the lungs. CXCR6 is expressed by activated T-lymphocytes and its ligand, CXCL16, is constitutively expressed by the bronchial epithelia, suggesting a role in T-lymphocyte recruitment and retention. However, it is unknown whether CXCR6 is required in responses to pulmonary infection, particularly on CD4+ T-lymphocytes. Analysis of CXCR6-reporter mice revealed that in naïve mice, lung leukocyte expression of CXCR6 was largely restricted to a small population of T-lymphocytes, but this population was highly upregulated after either infection. Nevertheless, pulmonary infection of CXCR6-deficient mice with M. tuberculosis or recombinant influenza A virus expressing P25 peptide (rIAV-P25), an I-Ab-restricted epitope from the immunodominant mycobacterial antigen, Ag85B, demonstrated that the receptor was redundant for recruitment of T-lymphocytes to the lungs. Interestingly, CXCR6-deficiency resulted in reduced bacterial burden in the lungs 6 weeks after M. tuberculosis infection, and reduced weight loss after rIAV-P25 infection compared to wild type controls. This was paradoxically associated with a decrease in Th1-cytokine responses in the lung parenchyma. Adoptive transfer of P25-specific CXCR6-deficient T-lymphocytes into WT mice revealed that this functional change in Th1-cytokine production was not due to a T-lymphocyte intrinsic mechanism. Moreover, there was no reduction in the number or function of CD4+ and CD8+ tissue resident memory cells in the lungs of CXCR6-deficient mice. Although CXCR6 was not required for T-lymphocyte recruitment or retention in the lungs, CXCR6 influenced the kinetics of the inflammatory response so that deficiency led to increased host control of M. tuberculosis and influenza virus.
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Affiliation(s)
- Anneliese S Ashhurst
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
| | - Manuela Flórido
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
| | - Leon C W Lin
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
| | - Diana Quan
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
| | - Ellis Armitage
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
| | - Sebastian A Stifter
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Central Clinical School Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - John Stambas
- School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Warwick J Britton
- Tuberculosis Research Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Central Clinical School Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
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Pulmonary Interleukin-17-Positive Lymphocytes Increase during Pneumocystis murina Infection but Are Not Required for Clearance of Pneumocystis. Infect Immun 2017; 85:IAI.00434-16. [PMID: 28438973 PMCID: PMC5478948 DOI: 10.1128/iai.00434-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 04/14/2017] [Indexed: 12/22/2022] Open
Abstract
Pneumocystis remains an important pathogen of immunosuppressed patients, causing a potentially life-threatening pneumonia. Despite its medical importance, the immune responses required to control infection, including the role of interleukin-17 (IL-17), which is important in controlling other fungal infections, have not been clearly defined. Using flow cytometry and intracellular cytokine staining after stimulation with phorbol myristate acetate and ionomycin, we examined gamma interferon (IFN-γ), IL-4, IL-5, and IL-17 production by lung lymphocytes in immunocompetent C57BL/6 mice over time following infection with Pneumocystismurina We also examined the clearance of Pneumocystis infection in IL-17A-deficient mice. The production of both IFN-γ and IL-17 by pulmonary lymphocytes increased during infection, with maximum production at approximately days 35 to 40, coinciding with peak Pneumocystis levels in the lungs, while minimal changes were seen in IL-4- and IL-5-positive cells. The proportion of cells producing IFN-γ was consistently higher than for cells producing IL-17, with peak levels of ∼25 to 30% of CD3+ T cells for the former compared to ∼15% for the latter. Both CD4+ T cells and γδ T cells produced IL-17. Administration of anti-IFN-γ antibody led to a decrease in IFN-γ-positive cells, and an increase in IL-5-positive cells, but did not impact clearance of Pneumocystis infection. Despite the increases in IL-17 production during infection, IL-17A-deficient mice cleared Pneumocystis infection with kinetics similar to C57BL/6 mice. Thus, while IL-17 production in the lungs is increased during Pneumocystis infection in immunocompetent mice, IL-17A is not required for control of Pneumocystis infection.
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Kutty G, Davis AS, Ferreyra GA, Qiu J, Huang DW, Sassi M, Bishop L, Handley G, Sherman B, Lempicki R, Kovacs JA. β-Glucans Are Masked but Contribute to Pulmonary Inflammation During Pneumocystis Pneumonia. J Infect Dis 2016; 214:782-91. [PMID: 27324243 PMCID: PMC4978378 DOI: 10.1093/infdis/jiw249] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/09/2016] [Indexed: 12/14/2022] Open
Abstract
β-glucans, which can activate innate immune responses, are a major component in the cell wall of the cyst form of Pneumocystis In the current study, we examined whether β-1,3-glucans are masked by surface proteins in Pneumocystis and what role β-glucans play in Pneumocystis-associated inflammation. For 3 species, including Pneumocystis jirovecii, which causes Pneumocystis pneumonia in humans, Pneumocystis carinii, and Pneumocystis murina, β-1,3-glucans were masked in most organisms, as demonstrated by increased exposure following trypsin treatment. Using quantitative polymerase chain reaction and microarray techniques, we demonstrated in a mouse model of Pneumocystis pneumonia that treatment with caspofungin, an inhibitor of β-1,3-glucan synthesis, for 21 days decreased expression of a broad panel of inflammatory markers, including interferon γ, tumor necrosis factor α, interleukin 1β, interleukin 6, and multiple chemokines/chemokine ligands. Thus, β-glucans in Pneumocystis cysts are largely masked, which likely decreases innate immune activation; this mechanism presumably was developed for interactions with immunocompetent hosts, in whom organism loads are substantially lower. In immunosuppressed hosts with a high organism burden, organism death and release of glucans appears to be an important contributor to deleterious host inflammatory responses.
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Affiliation(s)
- Geetha Kutty
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
| | - A Sally Davis
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan
| | - Gabriela A Ferreyra
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
| | - Ju Qiu
- Laboratory of Immunopathogenesis and Bioinformatics, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Maryland
| | - Da Wei Huang
- Laboratory of Immunopathogenesis and Bioinformatics, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Maryland
| | - Monica Sassi
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
| | - Lisa Bishop
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
| | - Grace Handley
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
| | - Brad Sherman
- Laboratory of Immunopathogenesis and Bioinformatics, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Maryland
| | - Richard Lempicki
- Laboratory of Immunopathogenesis and Bioinformatics, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Maryland
| | - Joseph A Kovacs
- Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda
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