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Kawka M, Płocińska R, Płociński P, Pawełczyk J, Słomka M, Gatkowska J, Dzitko K, Dziadek B, Dziadek J. The functional response of human monocyte-derived macrophages to serum amyloid A and Mycobacterium tuberculosis infection. Front Immunol 2023; 14:1238132. [PMID: 37781389 PMCID: PMC10540855 DOI: 10.3389/fimmu.2023.1238132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction In the course of tuberculosis (TB), the level of major acute phase protein, namely serum amyloid A (hSAA-1), increases up to a hundredfold in the pleural fluids of infected individuals. Tubercle bacilli infecting the human host can be opsonized by hSAA-1, which affects bacterial entry into human macrophages and their intracellular multiplication. Methods We applied global RNA sequencing to evaluate the functional response of human monocyte-derived macrophages (MDMs), isolated from healthy blood donors, under elevated hSAA-1 conditions and during infection with nonopsonized and hSAA-1-opsonized Mycobacterium tuberculosis (Mtb). In the same infection model, we also examined the functional response of mycobacteria to the intracellular environment of macrophages in the presence and absence of hSAA-1. The RNASeq analysis was validated using qPCR. The functional response of MDMs to hSAA-1 and/or tubercle bacilli was also evaluated for selected cytokines at the protein level by applying the Milliplex system. Findings Transcriptomes of MDMs cultured in the presence of hSAA-1 or infected with Mtb showed a high degree of similarity for both upregulated and downregulated genes involved mainly in processes related to cell division and immune response, respectively. Among the most induced genes, across both hSAA-1 and Mtb infection conditions, CXCL8, CCL15, CCL5, IL-1β, and receptors for IL-7 and IL-2 were identified. We also observed the same pattern of upregulated pro-inflammatory cytokines (TNFα, IL-6, IL-12, IL-18, IL-23, and IL-1) and downregulated anti-inflammatory cytokines (IL-10, TGFβ, and antimicrobial peptide cathelicidin) in the hSAA-1 treated-MDMs or the phagocytes infected with tubercle bacilli. At this early stage of infection, Mtb genes affected by the inside microenvironment of MDMs are strictly involved in iron scavenging, adaptation to hypoxia, low pH, and increasing levels of CO2. The genes for the synthesis and transport of virulence lipids, but not cholesterol/fatty acid degradation, were also upregulated. Conclusion Elevated serum hSAA-1 levels in tuberculosis enhance the response of host phagocytes to infection, including macrophages that have not yet been in contact with mycobacteria. SAA induces antigen processing and presentation processes by professional phagocytes reversing the inhibition caused by Mtb infection.
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Affiliation(s)
- Malwina Kawka
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Renata Płocińska
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | | | - Jakub Pawełczyk
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
| | - Marcin Słomka
- Biobank Lab, Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Justyna Gatkowska
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Katarzyna Dzitko
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Bożena Dziadek
- Department of Molecular Microbiology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Jarosław Dziadek
- Institute of Medical Biology, Polish Academy of Sciences, Lodz, Poland
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Karamooz E, Peterson J, Tammen A, Soma S, Kim SJ, Lewinsohn D. Calcium Signaling in MR1-Dependent Antigen Presentation of Mycobacterium tuberculosis. RESEARCH SQUARE 2023:rs.3.rs-3154465. [PMID: 37693580 PMCID: PMC10491339 DOI: 10.21203/rs.3.rs-3154465/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
MR1 is a ubiquitously expressed MHC-Ib molecule that presents microbial metabolites to MR1-restricted T cells, but there are differences in the antigen presentation pathway of an intracellular microbe compared to exogenous antigen. We have shown the importance of endosomal trafficking proteins in MR1-dependent presentation of Mycobacterium tuberculosis (Mtb). Two pore channels (TPCs) are endosomal calcium channels that regulate endosomal trafficking. Due to their location on endosomes, we hypothesized that TPCs could be required for MR1-dependent presentation of antigens derived from the intracellular microbe Mtb. We found that TPCs are critical for the presentation of Mtb by MR1; inhibition of TPCs had no effect on MR1 presentation of extracellular (exogenous) antigens, HLA-B presentation, or HLA-II presentation. Finally, we found that the calcium sensitive trafficking protein Synaptotagmin 7 was also key in the presentation of Mtb by MR1. This calcium-dependent endosomal pathway is a novel mechanism by which the immune system can sample intracellular antigens.
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Affiliation(s)
| | | | | | | | | | - David Lewinsohn
- Department of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, OR 97239, USA
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Wu S, Liang T, Jiang J, Zhu J, Chen T, Zhou C, Huang S, Yao Y, Guo H, Ye Z, Chen L, Chen W, Fan B, Qin J, Liu L, Wu S, Ma F, Zhan X, Liu C. Proteomic analysis to identification of hypoxia related markers in spinal tuberculosis: a study based on weighted gene co-expression network analysis and machine learning. BMC Med Genomics 2023; 16:142. [PMID: 37340462 DOI: 10.1186/s12920-023-01566-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 05/31/2023] [Indexed: 06/22/2023] Open
Abstract
OBJECTIVE This article aims at exploring the role of hypoxia-related genes and immune cells in spinal tuberculosis and tuberculosis involving other organs. METHODS In this study, label-free quantitative proteomics analysis was performed on the intervertebral discs (fibrous cartilaginous tissues) obtained from five spinal tuberculosis (TB) patients. Key proteins associated with hypoxia were identified using molecular complex detection (MCODE), weighted gene co-expression network analysis(WGCNA), least absolute shrinkage and selection operator (LASSO), and support vector machine recursive feature Elimination (SVM-REF) methods, and their diagnostic and predictive values were assessed. Immune cell correlation analysis was then performed using the Single Sample Gene Set Enrichment Analysis (ssGSEA) method. In addition, a pharmaco-transcriptomic analysis was also performed to identify targets for treatment. RESULTS The three genes, namely proteasome 20 S subunit beta 9 (PSMB9), signal transducer and activator of transcription 1 (STAT1), and transporter 1 (TAP1), were identified in the present study. The expression of these genes was found to be particularly high in patients with spinal TB and other extrapulmonary TB, as well as in TB and multidrug-resistant TB (p-value < 0.05). They revealed high diagnostic and predictive values and were closely related to the expression of multiple immune cells (p-value < 0.05). It was inferred that the expression of PSMB9, STAT 1, and TAP1 could be regulated by different medicinal chemicals. CONCLUSION PSMB9, STAT1, and TAP1, might play a key role in the pathogenesis of TB, including spinal TB, and the protein product of the genes can be served as diagnostic markers and potential therapeutic target for TB.
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Affiliation(s)
- Shaofeng Wu
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Tuo Liang
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jie Jiang
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jichong Zhu
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Tianyou Chen
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chenxing Zhou
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Shengsheng Huang
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yuanlin Yao
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hao Guo
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Zhen Ye
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Liyi Chen
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wuhua Chen
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Binguang Fan
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jiahui Qin
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Lu Liu
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Siling Wu
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Fengzhi Ma
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xinli Zhan
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
| | - Chong Liu
- The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
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Witt KD. Role of MHC class I pathways in Mycobacterium tuberculosis antigen presentation. Front Cell Infect Microbiol 2023; 13:1107884. [PMID: 37009503 PMCID: PMC10050577 DOI: 10.3389/fcimb.2023.1107884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 02/23/2023] [Indexed: 03/17/2023] Open
Abstract
MHC class I antigen processing is an underappreciated area of nonviral host–pathogen interactions, bridging both immunology and cell biology, where the pathogen’s natural life cycle involves little presence in the cytoplasm. The effective response to MHC-I foreign antigen presentation is not only cell death but also phenotypic changes in other cells and stimulation of the memory cells ready for the next antigen reoccurrence. This review looks at the MHC-I antigen processing pathway and potential alternative sources of the antigens, focusing on Mycobacterium tuberculosis (Mtb) as an intracellular pathogen that co-evolved with humans and developed an array of decoy strategies to survive in a hostile environment by manipulating host immunity to its own advantage. As that happens via the selective antigen presentation process, reinforcement of the effective antigen recognition on MHC-I molecules may stimulate subsets of effector cells that act earlier and more locally. Vaccines against tuberculosis (TB) could potentially eliminate this disease, yet their development has been slow, and success is limited in the context of this global disease’s spread. This review’s conclusions set out potential directions for MHC-I-focused approaches for the next generation of vaccines.
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Affiliation(s)
- Karolina D. Witt
- Pandemic Sciences Institute, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- *Correspondence: Karolina D. Witt,
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Lu T, Wang M, Liu N, Zhang S, Shi L, Bao L, Luo F, Shi L, Liu S, Yao Y. Transporter Associated with Antigen Processing 1 Gene Polymorphisms Increase the Susceptibility to Tuberculosis. Pharmgenomics Pers Med 2023; 16:325-336. [PMID: 37077653 PMCID: PMC10108862 DOI: 10.2147/pgpm.s404339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/31/2023] [Indexed: 04/21/2023] Open
Abstract
Purpose Tuberculosis (TB) is known to result from a complex interaction between the host immune response and Mycobacterium infection. The transporter associated with antigen processing (TAP) plays an important role in the processing and presentation pathways for the Mycobacterium tuberculosis (M. tb) antigen. To investigate the possible association of the TAP1 and TAP2 genes with TB. Patients and Methods A total of 449 TB patients and 435 control subjects were included in this study, and single nucleotide polymorphisms (SNPs) in the TAP gene, as well as TAP1 and TAP2 alleles, were genotyped. Results TAP gene association analysis of TB diseases showed that rs41551515-T in the TAP1 gene was significantly associated with susceptibility to TB (P=7.96E-04, OR=4.124, 95% CI: 1.683-10.102), especially pulmonary TB (PTB, P=6.84E-04, OR=4.350, 95% CI: 1.727-10.945), and the combination of rs1057141-T-rs1135216-C in the TAP1 gene significantly increased the risk of TB susceptibility (P=5.51E-05, OR=10.899, 95% CI: 2.555-46.493). Five novel TAP1 alleles were detected in Yunnan Han people, and the allele frequency of TAP1*unknown_3 (rs41555220-rs41549617-rs1057141-rs1135216-rs1057149-rs41551515: C-A-T-C-C-T) was notably increased in all TB patients, including in the PTB and EPTB subgroups, and was significantly associated with the risk of susceptibility to TB. However, no association between the TAP2 gene and TB was found in this study. Conclusion Host genetic variants of rs41551515-T and the combination rs1057141-T-rs1135216-C, as well as TAP1*unknown_3 may play a critical role in susceptibility to TB disease.
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Affiliation(s)
- Tianchang Lu
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
| | - Minyi Wang
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
- School of Life Science, Yunnan University, Kunming, 650500, People’s Republic of China
| | - Nannan Liu
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
| | - Shuqiong Zhang
- Department of Clinical Laboratory, The Third People’s Hospital of Kunming, Kunming, 650041, People’s Republic of China
| | - Lei Shi
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
| | - Ling Bao
- Department of Clinical Laboratory, The Third People’s Hospital of Kunming, Kunming, 650041, People’s Republic of China
| | - Feng Luo
- Department of Clinical Laboratory, The Third People’s Hospital of Kunming, Kunming, 650041, People’s Republic of China
| | - Li Shi
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
| | - Shuyuan Liu
- Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China
- Correspondence: Shuyuan Liu, Department of Immunogenetics, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, 650118, People’s Republic of China, Tel +86 871 68334483, Email
| | - Yufeng Yao
- Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research & Development on Severe Infectious Disease, Kunming, 650118, People’s Republic of China
- Yufeng Yao, Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research & Development on Severe Infectious Disease, Kunming, 650118, People’s Republic of China, Tel +86 871 68335632, Email
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Association between TAP gene polymorphisms and tuberculosis susceptibility in a Han Chinese population in Guangdong. Mol Genet Genomics 2022; 297:779-790. [PMID: 35325275 PMCID: PMC8943507 DOI: 10.1007/s00438-022-01885-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/08/2022] [Indexed: 12/02/2022]
Abstract
Tuberculosis (TB) is an important public health problem. Studies indicated that TAP plays a key role in the presentation and transport of antigenic peptides during anti-M.tb infection. Given the important biological role of the TAP gene involved in anti-M.tb infection, a family-based case–control study including 133 tuberculosis patients, 107 healthy household contacts, and 173 healthy controls was conducted to assess the association between TAP gene polymorphisms and TB susceptibility. The basic information of subjects and their blood samples were collected. Four SNPs including rs1135216, rs1057141, rs241447, and rs3819721 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP). Our results suggested that BMI, residence, bedroom crowding, indoor humidity, fitness activities, history of smoking, and TB exposure history were associated with the occurrence of tuberculosis (P < 0.05). A significant association was observed between the TAP1 rs1135216 CT/CC genotype and increased TB risk, and the ORs were 2.56 (95% CI 1.31–4.99) and 6.73 (95% CI 1.33–34.02), respectively. TAP2 rs3819721 GG genotype carriers also showed an increased risk of TB when compared TB patients to healthy household contacts. Haplotype analysis revealed that the haplotype CT at rs1057141 and rs1135216 (OR = 11.34, 95% CI 1.49–86.56; OR = 7.45, 95% CI 1.43–38.76), as well as TA at rs241447 and rs3819721 (OR = 2.20, 95% CI 1.07–4.56) had a significantly increased risk of TB. The genetic risk scores (GRS) analysis of the four loci indicated that the risk of tuberculosis increased with increasing GRS scores in TB vs HHC (Ptrend = 0.010) and in TB vs HC (Ptrend = 0.001). In conclusion, our findings suggested that the SNPs of rs1135216 and rs3819721 were associated with TB susceptibility among the tuberculosis-prone families in the Chinese Han population and the risk of developing tuberculosis increases with the number of risk alleles, which could help identify high-risk groups in time and take scientific preventive measures. Further cohort studies with large samples are needed to validate the role of TAP gene variants on TB susceptibility.
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Voogd L, Ruibal P, Ottenhoff TH, Joosten SA. Antigen presentation by MHC-E: a putative target for vaccination? Trends Immunol 2022; 43:355-365. [PMID: 35370095 PMCID: PMC9058203 DOI: 10.1016/j.it.2022.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 12/30/2022]
Abstract
The essentially monomorphic human antigen presentation molecule HLA-E is an interesting candidate target to enable vaccination irrespective of genetic diversity. Predictive HLA-E peptide-binding motifs have been refined to facilitate HLA-E peptide discovery. HLA-E can accommodate structurally divergent peptides of both self and microbial origin. Intracellular processing and presentation pathways for peptides by HLA-E for T cell receptor (TCR) recognition remain to be elucidated. Recent studies show that, unlike canonical peptides, inhibition of the transporter associated with antigen presentation (TAP) is essential to allow HLA-E antigen presentation in cytomegalovirus (CMV) infection and possibly also of other non-canonical peptides. We propose three alternative and TAP-independent MHC-E antigen-presentation pathways, including for Mycobacterium tuberculosis infections. These insights may help in designing potential HLA-E targeting vaccines against tumors and pathogens.
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Associations of genetic variants at TAP1 and TAP2 with pulmonary tuberculosis risk among the Chinese population. Epidemiol Infect 2021; 149:e79. [PMID: 33736739 PMCID: PMC8080186 DOI: 10.1017/s0950268821000613] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tuberculosis (TB) is a common infectious disease, and the present study aims to explore the associations of single nucleotide polymorphisms (SNPs) at rs1135216 and rs1057141 of transporter-associated antigen processing (TAP1) and rs2228396 of TAP2 with pulmonary tuberculosis (PTB) risk. A case-control study including 168 smear-positive PTB cases and 251 controls was conducted. Genotyping of the SNPs at rs1135216, rs1057141 and rs2228396 was performed, and their associations with PTB risk were analysed with SPSS software version 19.0. After conducting stratification for age, a significant association was detected for rs1057141 with increased PTB risk (OR = 0.17, 95% CI 0.04-0.79) among those aged ≥60 years. For those aged <60 years, a marginally significant association was detected between rs1135216 TC/CC and PTB risk (OR = 1.97, 95% CI 0.93-4.19). Haplotype analysis revealed that the haplotype AT at rs1135216 and rs2228396, as well as AAT at rs1057141, rs1135216 and rs2228396, was associated with increased PTB risk, and the ORs were 2.83 (95% CI 1.30-6.14) and 2.89 (95% CI 1.34-6.27), respectively. Rs1057141 is a genetic predictor of reduced PTB risk for those aged ≥60 years, while rs1135216 might be a potential genetic predictor for those aged <60 years. Haplotype AT at rs1135216 and rs2228396, as well as AAT at rs1057141, rs1135216 and rs2228396, is a genetic marker that may predict PTB risk.
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Abstract
Most studies of T lymphocytes focus on recognition of classical major histocompatibility complex (MHC) class I or II molecules presenting oligopeptides, yet there are numerous variations and exceptions of biological significance based on recognition of a wide variety of nonclassical MHC molecules. These include αβ and γδ T cells that recognize different class Ib molecules (CD1, MR-1, HLA-E, G, F, et al.) that are nearly monomorphic within a given species. Collectively, these T cells can be considered “unconventional,” in part because they recognize lipids, metabolites, and modified peptides. Unlike classical MHC-specific cells, unconventional T cells generally exhibit limited T-cell antigen receptor (TCR) repertoires and often produce innate immune cell-like rapid effector responses. Exploiting this system in new generation vaccines for human immunodeficiency virus (HIV), tuberculosis (TB), other infectious agents, and cancer was the focus of a recent workshop, “Immune Surveillance by Non-classical MHC Molecules: Improving Diversity for Antigens,” sponsored by the National Institute of Allergy and Infectious Diseases. Here, we summarize salient points presented regarding the basic immunobiology of unconventional T cells, recent advances in methodologies to measure unconventional T-cell activity in diseases, and approaches to harness their considerable clinical potential.
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Type II Secretion Substrates of Legionella pneumophila Translocate Out of the Pathogen-Occupied Vacuole via a Semipermeable Membrane. mBio 2017. [PMID: 28634242 PMCID: PMC5478897 DOI: 10.1128/mbio.00870-17] [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] [Indexed: 01/04/2023] Open
Abstract
Legionella pneumophila replicates in macrophages in a host-derived phagosome, termed the Legionella-containing vacuole (LCV). While the translocation of type IV secretion (T4S) effectors into the macrophage cytosol is well established, the location of type II secretion (T2S) substrates in the infected host cell is unknown. Here, we show that the T2S substrate ProA, a metalloprotease, translocates into the cytosol of human macrophages, where it associates with the LCV membrane (LCVM). Translocation is detected as early as 10 h postinoculation (p.i.), which is approximately the midpoint of the intracellular life cycle. However, it is detected as early as 6 h p.i. if ProA is hyperexpressed, indicating that translocation depends on the timing of ProA expression and that any other factors necessary for translocation are in place by that time point. Translocation occurs with all L. pneumophila strains tested and in amoebae, natural hosts for L. pneumophila. It was absent in murine bone marrow-derived macrophages and murine macrophage cell lines. The ChiA chitinase also associated with the cytoplasmic face of the LCVM at 6 h p.i. and in a T2S-dependent manner. Galectin-3 and galectin-8, eukaryotic proteins whose localization is influenced by damage to host membranes, appeared within the LCV of infected human but not murine macrophages beginning at 6 h p.i. Thus, we hypothesize that ProA and ChiA are first secreted into the vacuolar lumen by the activity of the T2S and subsequently traffic into the macrophage cytosol via a novel mechanism that involves a semipermeable LCVM. Infection of macrophages and amoebae plays a central role in the pathogenesis of L. pneumophila, the agent of Legionnaires’ disease. We have previously demonstrated that the T2S system of L. pneumophila greatly contributes to intracellular infection. However, the location of T2S substrates within the infected host cell is unknown. This report presents the first evidence of a L. pneumophila T2S substrate in the host cell cytosol and, therefore, the first evidence of a non-T4S effector trafficking out of the LCV. We also provide the first indication that the LCV is not completely intact but is instead semipermeable and that this occurs in human but not murine macrophages. Given this permeability, we hypothesize that other T2S substrates and LCV lumenal contents can escape into the host cell cytosol. Thus, these substrates may represent a battery of previously unidentified effectors that can interact with host factors and contribute to intracellular infection by L. pneumophila.
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Cruz FM, Colbert JD, Merino E, Kriegsman BA, Rock KL. The Biology and Underlying Mechanisms of Cross-Presentation of Exogenous Antigens on MHC-I Molecules. Annu Rev Immunol 2017; 35:149-176. [PMID: 28125356 PMCID: PMC5508990 DOI: 10.1146/annurev-immunol-041015-055254] [Citation(s) in RCA: 191] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
To monitor the health of cells, the immune system tasks antigen-presenting cells with gathering antigens from other cells and bringing them to CD8 T cells in the form of peptides bound to MHC-I molecules. Most cells would be unable to perform this function because they use their MHC-I molecules to exclusively present peptides derived from the cell's own proteins. However, the immune system evolved mechanisms for dendritic cells and some other phagocytes to sample and present antigens from the extracellular milieu on MHC-I through a process called cross-presentation. How this important task is accomplished, its role in health and disease, and its potential for exploitation are the subject of this review.
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Affiliation(s)
- Freidrich M Cruz
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655; , , , ,
| | - Jeff D Colbert
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655; , , , ,
| | - Elena Merino
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655; , , , ,
| | - Barry A Kriegsman
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655; , , , ,
| | - Kenneth L Rock
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655; , , , ,
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Hirosue S, Dubrot J. Modes of Antigen Presentation by Lymph Node Stromal Cells and Their Immunological Implications. Front Immunol 2015; 6:446. [PMID: 26441957 PMCID: PMC4561840 DOI: 10.3389/fimmu.2015.00446] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 08/17/2015] [Indexed: 12/15/2022] Open
Abstract
Antigen presentation is no longer the exclusive domain of cells of hematopoietic origin. Recent works have demonstrated that lymph node stromal cell (LNSC) populations, such as fibroblastic reticular cells, lymphatic and blood endothelial cells, not only provide a scaffold for lymphocyte interactions but also exhibit active immunomodulatory roles that are critical to mounting and resolving effective immune responses. Importantly, LNSCs possess the ability to present antigens and establish antigen-specific interactions with T cells. One example is the expression of peripheral tissue antigens, which are presented on major histocompatibility complex (MHC)-I molecules with tolerogenic consequences on T cells. Additionally, exogenous antigens, including self and tumor antigens, can be processed and presented on MHC-I complexes, which result in dysfunctional activation of antigen-specific CD8+ T cells. While MHC-I is widely expressed on cells of both hematopoietic and non-hematopoietic origins, antigen presentation via MHC-II is more precisely regulated. Nevertheless, LNSCs are capable of endogenously expressing, or alternatively, acquiring MHC-II molecules. Transfer of antigen between LNSC and dendritic cells in both directions has been recently suggested to promote tolerogenic roles of LNSCs on the CD4+ T cell compartment. Thus, antigen presentation by LNSCs is thought to be a mechanism that promotes the maintenance of peripheral tolerance as well as generates a pool of diverse antigen-experienced T cells for protective immunity. This review aims to integrate the current and emerging literature to highlight the importance of LNSCs in immune responses, and emphasize their role in antigen trafficking, retention, and presentation.
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Affiliation(s)
- Sachiko Hirosue
- Institute of Bioengineering, École Polytechnique Fédéral de Lausanne , Lausanne , Switzerland
| | - Juan Dubrot
- Department of Pathology and Immunology, Université de Genève , Geneva , Switzerland
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