scholarly journals Impaired response to Listeria in H2-M3–deficient mice reveals a nonredundant role of MHC class Ib–specific T cells in host defense

2006 ◽  
Vol 203 (2) ◽  
pp. 449-459 ◽  
Author(s):  
Honglin Xu ◽  
Taehoon Chun ◽  
Hak-Jong Choi ◽  
Bin Wang ◽  
Chyung-Ru Wang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Host Defense ◽  
Cd8 T Cells ◽  
Mhc Class Ib ◽  
Cell Responses ◽  
Mhc Class Ia ◽  
Deficient Mice ◽  
Class Ib

The major histocompatibility complex (MHC) class Ib molecule H2-M3 primes the rapid expansion of CD8+ T cells by presenting N-formylated bacterial peptides. However, the significance of H2-M3–restricted T cells in host defense against bacteria is unclear. We generated H2-M3–deficient mice to investigate the role of H2-M3 in immunity against Listeria monocytogenes (LM), a model intracellular bacterial pathogen. H2-M3–deficient mice are impaired in early bacterial clearance during primary infection, with diminished LM-specific CD8+ T cell responses and compromised innate immune functions. Although H2-M3–restricted CD8+ T cells constitute a significant proportion of the anti-listerial CD8+ T cell repertoire, the kinetics and magnitude of MHC class Ia–restricted T cell responses are not altered in H2-M3–deficient mice. The fact that MHC class Ia–restricted responses cannot compensate for the H2-M3–mediated immunity suggests a nonredundant role of H2-M3 in the protective immunity against LM. Thus, the early H2-M3–restricted response temporally bridges the gap between innate and adaptive immune responses, subsequently affecting the function of both branches of the immune system.

scholarly journals An MHC class Ib–restricted CD8 T cell response confers antiviral immunity

2008 ◽  
Vol 205 (7) ◽  
pp. 1647-1657 ◽  
Author(s):  
Phillip A. Swanson ◽  
Christopher D. Pack ◽  
Annette Hadley ◽  
Chyung-Ru Wang ◽  
Iwona Stroynowski ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Mhc Class Ib ◽  
Wild Type ◽  
Mhc Class Ia ◽  
Class Ib

Although immunity against intracellular pathogens is primarily provided by CD8 T lymphocytes that recognize pathogen-derived peptides presented by major histocompatibility complex (MHC) class Ia molecules, MHC class Ib–restricted CD8 T cells have been implicated in antiviral immunity. Using mouse polyoma virus (PyV), we found that MHC class Ia–deficient (Kb−/−Db−/−) mice efficiently control this persistently infecting mouse pathogen. CD8 T cell depletion mitigates clearance of PyV in Kb−/−Db−/− mice. We identified the ligand for PyV-specific CD8 T cells in Kb−/−Db−/− mice as a nonamer peptide from the VP2 capsid protein presented by Q9, a member of the β2 microglobulin–associated Qa-2 family. Using Q9-VP2 tetramers, we monitored delayed but progressive expansion of these antigen-specific CD8αβ T cells in Kb−/−Db−/− mice. Importantly, we demonstrate that Q9-VP2–specific CD8 T cells more effectively clear wild-type PyV than a VP2 epitopenull mutant PyV. Finally, we show that wild-type mice also generate Q9-restricted VP2 epitope–specific CD8 T cells to PyV infection. To our knowledge, this is the first evidence for a defined MHC class Ib–restricted antiviral CD8 T cell response that contributes to host defense. This study motivates efforts to uncover MHC class Ib–restricted CD8 T cell responses in other viral infections, and given the limited polymorphism of MHC class Ib molecules, it raises the possibility of developing peptide-based viral vaccines having broad coverage across MHC haplotypes.

scholarly journals Targeting Pim2 for Improving T-Cell Effector Function and Promoting Cancer Immunotherapy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1720-1720
Author(s):  
Yongxia Wu ◽  
Linlu Tian ◽  
Corey Mealer ◽  
Hee-Jin Choi ◽  
Xue-Zhong Yu
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Effector Function ◽  
Cell Responses ◽  
Deficient Mice

Abstract The Provirus Integration sites for Moloney murine leukemia virus (Pim) kinases are a highly conserved family of serine/threonine kinases. The Pim kinase family is composed of three different isoforms, Pim1, Pim2, and Pim3, which have been studied extensively in tumorigenesis and as a potential therapeutic target in various cancers. We previously reported an unexpected role of Pim2 in negatively regulates T-cell responses to alloantigen and tumor (JCI, 2015, PMID: 29781812). However, the mechanisms by which Pim2 modulates T-cell responses remain largely undefined. In the current study, using genetic Pim2-deficient mouse, we demonstrated a key role of Pim2 in regulating T-cell hemostatic and anti-tumor responses in aging, hematopoietic cell transplantation (HCT), and antigen-specific adoptive T-cell therapy (ACT). We observed that Pim2 was critical for T cells to retain quiescent in aged mice, as thymic Treg development was impaired while effector T-cell differentiation in lymphoid organs, including Tc1/Th1, Tc17/Th17 and follicular helper T cells, was increased in Pim2-deficient mice, but not in Pim1/Pim3-deficient mice. Furthermore, Pim2-deficient mice were capable to completely eradicate syngeneic breast cancer (NT2.5) growth (Figure A). During antigen specific anti-tumor response, adoptively transferred Pim2 -/- CD8 T cells showed enhanced ability for controlling established NT2.5 breast cancer and B16 melanoma (Figure B, C). Mechanistically, loss of Pim2 promoted G1 to S phase cell-cycle progression while reduced apoptosis in CD8 T cells. Pim2 -/- CD8 T cells exhibited elevated effector cytokine production while maintained higher levels of CD62L expression, leading to superior effector function, persistence and anti-tumor activity. Reduced differentiation of exhausted and suppressive subsets were observed in Pim2 -/- CD8 T cells after being adoptively transferred in tumor-bearing mice. In addition, Pim2 deficiency was associated with a higher metabolic potential, reflected by increased glycolysis and oxidative phosphorylation, which was at least partially attributed to a decreased level of autophagy in Pim2 -/- CD8 T cells. To further evaluate the clinical translation potential, we applied a Pim2-specific inhibitor (JP11646) and found that blocking Pim2 improved graft-versus-leukemia activity after autologous HCT and also enhanced CD8 T-cell mediated anti-melanoma effects after ACT in mice (Figure B, C). Furthermore, blocking Pim2 using JP11646 promoted human CD8 T-cell response during polyclonal stimulation and enhanced expansion, effector function and tumor killing ability of human melanoma antigen-specific CD8 T cells (data not shown) and CD19 CAR-T cells (Figure D). Our work demonstrated that Pim2 is a potent and distinct regulator of differentiation and maintenance of T effector cells through modulating metabolism and autophagy. Specifically target Pim2 can serve as a novel strategy for improving cancer immunotherapy. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals H2-M3–Restricted T Cells in Bacterial Infection

1999 ◽  
Vol 190 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Kristen M. Kerksiek ◽  
Dirk H. Busch ◽  
Ingrid M. Pilip ◽  
S. Elise Allen ◽  
Eric G. Pamer
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bacterial Infection ◽  
Primary Infection ◽  
T Cell Responses ◽  
T Cell Response ◽  
Mhc Class Ib ◽  
Cell Responses ◽  
Mhc Class Ia ◽  
Class Ib

Major histocompatibility complex (MHC) class Ib molecules have been implicated in CD8+ T cell–mediated defenses against intracellular bacterial infection, but the relative importance of MHC class Ib–restricted T cells in antimicrobial immunity is unknown. In this report, we use MHC tetramers to characterize T cell responses restricted by H2-M3, an MHC class Ib molecule that selectively presents N-formyl peptides. We find that sizeable H2-M3–restricted T cell responses, occurring earlier than MHC class Ia–restricted T cell responses, are mounted after primary infection with the intracellular bacterium Listeria monocytogenes. These H2-M3–restricted T cells are cytolytic and produce interferon γ. However, after a second L. monocytogenes infection, H2-M3–restricted memory T cell responses are minor in comparison to the much larger MHC class Ia–restricted responses. This first direct characterization of an MHC class Ib–restricted T cell response indicates that CD8+ T cells responding to L. monocytogenes infection can be divided into two groups: H2-M3–restricted responses, which provide rapid and quantitatively substantial effector function during primary infections but contribute relatively little to memory responses, and MHC class Ia–restricted responses, which expand later during primary infection but form memory T cells that respond rapidly and dramatically in response to subsequent infections by the same pathogen.

scholarly journals Selective dependence on IL-7 for antigen-specific CD8 T cell responses during airway influenza infection

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Abdalla Sheikh ◽  
Jennie Jackson ◽  
Hanjoo Brian Shim ◽  
Clement Yau ◽  
Jung Hee Seo ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Node ◽  
T Cell ◽  
Viral Infection ◽  
Cd8 T Cells ◽  
Mediastinal Lymph Node ◽  
Influenza Infection ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Deficient Mice

AbstractInterleukin-7 (IL-7) is a cytokine known for its importance in T cell development and survival. How IL-7 shapes CD8 T cell responses during an acute viral infection is less understood. We had previously shown that IL-7 signaling deficient mice have reduced accumulation of influenza-specific CD8 T cells following influenza infection. We sought to determine whether IL-7 affects early CD8 T cell expansion in the mediastinal lymph node and effector function in the lungs. Using IL-7Rα signaling deficient mice, we show that IL-7 is required for a normal sized mediastinal lymph node and the early clonal expansion of influenza-specific CD8 T cells therein. We show that IL-7 plays a cell-intrinsic role in the accumulation of NP366–374 and PA224–233-specific CD8 T cells in the lymph node. We also found that IL-7 shapes terminal differentiation, degranulation and cytokine production to a greater extent in PA224–233-specific than NP366–374-specific CD8 T cells. We further demonstrate that IL-7 is induced in the lung tissue by viral infection and we characterize multiple cellular sources that contribute to IL-7 production. Our findings on IL-7 and its effects on lower respiratory diseases will be important for expanding the utility of therapeutics that are currently available.

scholarly journals MHC Class Ia Empowers MHC Class Ib-restricted CD8+ T Cells with Strong Tumoricidal Capacity

2021 ◽  
Author(s):  
Yufang Shi ◽  
Qing Li ◽  
Liangyu Lin ◽  
Peishun Shou ◽  
Liu Keli ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Adoptive Transfer ◽  
Priming Effect ◽  
Mhc Class Ib ◽  
Wild Type ◽  
Mhc Haplotype ◽  
Mhc Class Ia ◽  
Class Ib

Abstract The tumoricidal effects of CD8+T cells are well acknowledged, but how MHC Ib-restricted CD8+T (Ib-CD8+T) cells contribute to anti-tumor immunity remains obscure. Here, we show that infusion of MHC Ia+ cells to Kb-/-Db-/- mice induced the expansion of Ib-CD8+T cells in tumors and potently inhibited tumor progression. Such priming of Ib-CD8+T cells by MHC-Ia is not MHC haplotype restricted and MHC Ia tetramers alone can prime Ib-CD8+T cells for activation. The MHC Ia priming promoted Tbet expression in Ib-CD8+T cells and in absence of Tbet, such priming effect diminished. Importantly, these tumoricidal Ib-CD8+T cells are positive for CX3CR1, and exhibit rapid proliferation, high expression of cytotoxic factors, and prolonged persistence at tumor sites. Adoptive transfer of CX3CR1+Ib-CD8+T cells to wild type mice resulted in potent anti-tumor effects. Our findings unravel an uncharacterized function of MHC Ia molecules in immunoregulation and raise the possibility of using Ib-CD8+T cells in tumor immunotherapy.

scholarly journals Peptide Immunization Elicits Polyomavirus-Specific MHC Class Ib-Restricted CD8 T Cells in MHC Class Ia Allogeneic Mice

2013 ◽  
Vol 26 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Amelia R. Hofstetter ◽  
Brian D. Evavold ◽  
Aron E. Lukacher
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Mhc Class Ib ◽  
Mhc Class Ia ◽  
Class Ib

scholarly journals CD4+ T-Cell Responses Are Required for Clearance of West Nile Virus from the Central Nervous System

2006 ◽  
Vol 80 (24) ◽  
pp. 12060-12069 ◽  
Author(s):  
Elizabeth M. Sitati ◽  
Michael S. Diamond
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
West Nile Virus ◽  
T Cell ◽  
Wild Type ◽  
Cell Responses ◽  
The Central Nervous System ◽  
Deficient Mice

ABSTRACT Although studies have established that innate and adaptive immune responses are important in controlling West Nile virus (WNV) infection, the function of CD4+ T lymphocytes in modulating viral pathogenesis is less well characterized. Using a mouse model, we examined the role of CD4+ T cells in coordinating protection against WNV infection. A genetic or acquired deficiency of CD4+ T cells resulted in a protracted WNV infection in the central nervous system (CNS) that culminated in uniform lethality by 50 days after infection. Mice surviving past day 10 had high-level persistent WNV infection in the CNS compared to wild-type mice, even 45 days following infection. The absence of CD4+ T-cell help did not affect the kinetics of WNV infection in the spleen and serum, suggesting a role for CD4-independent clearance mechanisms in peripheral tissues. WNV-specific immunoglobulin M (IgM) levels were similar to those of wild-type mice in CD4-deficient mice early during infection but dropped ∼20-fold at day 15 postinfection, whereas IgG levels in CD4-deficient mice were ∼100- to 1,000-fold lower than in wild-type mice throughout the course of infection. WNV-specific CD8+ T-cell activation and trafficking to the CNS were unaffected by the absence of CD4+ T cells at day 9 postinfection but were markedly compromised at day 15. Our experiments suggest that the dominant protective role of CD4+ T cells during primary WNV infection is to provide help for antibody responses and sustain WNV-specific CD8+ T-cell responses in the CNS that enable viral clearance.

scholarly journals Differential requirements for the chemokine receptor CCR7 in T cell activation during Listeria monocytogenes infection

2005 ◽  
Vol 201 (9) ◽  
pp. 1447-1457 ◽  
Author(s):  
Mischo Kursar ◽  
Uta E. Höpken ◽  
Markus Koch ◽  
Anne Köhler ◽  
Martin Lipp ◽  
...  
Keyword(s):  
T Cells ◽  
Listeria Monocytogenes ◽  
T Cell ◽  
T Cell Activation ◽  
Chemokine Receptor ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cell Responses ◽  
Listeria Monocytogenes Infection ◽  
Mhc Class Ia

Effective priming of T cell responses depends on cognate interactions between naive T cells and professional antigen-presenting cells (APCs). This contact is the result of highly coordinated migration processes, in which the chemokine receptor CCR7 and its ligands, CCL19 and CCL21, play a central role. We used the murine Listeria monocytogenes infection model to characterize the role of the CCR7/CCR7 ligand system in the generation of T cell responses during bacterial infection. We demonstrate that efficient priming of naive major histocompatibility complex (MHC) class Ia–restricted CD8+ T cells requires CCR7. In contrast, MHC class Ib–restricted CD8+ T cells and MHC class II–restricted CD4+ T cells seem to be less dependent on CCR7; memory T cell responses are independent of CCR7. Infection experiments with bone marrow chimeras or mice reconstituted with purified T cell populations indicate that CCR7 has to be expressed on CD8+ T cells and professional APCs to promote efficient MHC class Ia–restricted T cell priming. Thus, different T cell subtypes and maturation stages have discrete requirements for CCR7.

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