Role of MHC class Ib molecule, H2-M3 in host immunity against tuberculosis

Vaccine ◽  
2013 ◽  
Vol 31 (37) ◽  
pp. 3818-3825 ◽  
Author(s):  
Shabir Ahmad Mir ◽  
Sadhna Sharma
Keyword(s):  
Host Immunity ◽  
Mhc Class Ib ◽  
Class Ib

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 The role of MHC class Ib-restricted T cells during infection

2016 ◽  
Vol 68 (8) ◽  
pp. 677-691 ◽  
Author(s):  
Courtney K. Anderson ◽  
Laurent Brossay
Keyword(s):  
T Cells ◽  
Mhc Class Ib ◽  
Class Ib

scholarly journals The Selection of M3-Restricted T Cells Is Dependent on M3 Expression and Presentation of N-Formylated Peptides in the Thymus

1999 ◽  
Vol 190 (12) ◽  
pp. 1869-1878 ◽  
Author(s):  
Nancy M. Chiu ◽  
Bin Wang ◽  
Kristen M. Kerksiek ◽  
Roger Kurlander ◽  
Eric G. Pamer ◽  
...  
Keyword(s):  
T Cells ◽  
Negative Selection ◽  
Antigen Processing ◽  
Partial Agonist ◽  
Mhc Class Ib ◽  
Histocompatibility Complex ◽  
Fetal Thymic Organ Culture ◽  
Single Positive ◽  
Class Ib

The major histocompatibility complex (MHC) class Ib molecule H2-M3 binds N-formylated peptides from mitochondria and bacteria. To explore the role of M3 expression and peptide supply in positive and negative selection, we generated transgenic mice expressing an M3-restricted TCR-α/β from a CD8+ T cell hybridoma (D7) specific for a listerial peptide (LemA). Development of M3-restricted transgenic T cells is impaired in both β2-microglobulin–deficient and transporter associated with antigen processing (TAP)-deficient mice, but is not diminished by changes in the H-2 haplotype. Maturation of M3/LemA-specific CD8+ single positive cells in fetal thymic organ culture was sensitive to M3 expression levels as determined by antibody blocking and use of the castaneus mutant allele of M3. Positive selection was rescued in TAP−/− lobes by nonagonist mitochondrial and bacterial peptides, whereas LemA and a partial agonist variant caused negative selection. Thus, M3-restricted CD8+ T cells are positively and negatively selected by M3, with no contribution from the more abundant class Ia molecules. These results demonstrate that class Ib molecules can function in thymic education like class Ia molecules, despite limited ligand diversity and low levels of expression.

scholarly journals The Role of Host-Generated H2S in Microbial Pathogenesis: New Perspectives on Tuberculosis

2020 ◽  
Vol 10 ◽  
Author(s):  
Md. Aejazur Rahman ◽  
Joel N. Glasgow ◽  
Sajid Nadeem ◽  
Vineel P. Reddy ◽  
Ritesh R. Sevalkar ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Hydrogen Sulfide ◽  
Host Immunity ◽  
Microbial Pathogens ◽  
Microbial Pathogenesis ◽  
Enzymatic Production ◽  
Growth And Survival ◽  
Wide Range

For centuries, hydrogen sulfide (H2S) was considered primarily as a poisonous gas and environmental hazard. However, with the discovery of prokaryotic and eukaryotic enzymes for H2S production, breakdown, and utilization, H2S has emerged as an important signaling molecule in a wide range of physiological and pathological processes. Hence, H2S is considered a gasotransmitter along with nitric oxide (•NO) and carbon monoxide (CO). Surprisingly, despite having overlapping functions with •NO and CO, the role of host H2S in microbial pathogenesis is understudied and represents a gap in our knowledge. Given the numerous reports that followed the discovery of •NO and CO and their respective roles in microbial pathogenesis, we anticipate a rapid increase in studies that further define the importance of H2S in microbial pathogenesis, which may lead to new virulence paradigms. Therefore, this review provides an overview of sulfide chemistry, enzymatic production of H2S, and the importance of H2S in metabolism and immunity in response to microbial pathogens. We then describe our current understanding of the role of host-derived H2S in tuberculosis (TB) disease, including its influences on host immunity and bioenergetics, and on Mycobacterium tuberculosis (Mtb) growth and survival. Finally, this review discusses the utility of H2S-donor compounds, inhibitors of H2S-producing enzymes, and their potential clinical significance.

scholarly journals Tuning cancer fate: the unremitting role of host immunity

Open Biology ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 170006 ◽  
Author(s):  
B. Calì ◽  
B. Molon ◽  
A. Viola
Keyword(s):  
Immune Cells ◽  
Immune Cell ◽  
Tumour Progression ◽  
Host Immunity ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Immune Mediated ◽  
Immune Cell Subsets ◽  
Therapeutic Protocols

Host immunity plays a central and complex role in dictating tumour progression. Solid tumours are commonly infiltrated by a large number of immune cells that dynamically interact with the surrounding microenvironment. At first, innate and adaptive immune cells successfully cooperate to eradicate microcolonies of transformed cells. Concomitantly, surviving tumour clones start to proliferate and harness immune responses by specifically hijacking anti-tumour effector mechanisms and fostering the accumulation of immunosuppressive immune cell subsets at the tumour site. This pliable interplay between immune and malignant cells is a relentless process that has been concisely organized in three different phases: elimination, equilibrium and escape. In this review, we aim to depict the distinct immune cell subsets and immune-mediated responses characterizing the tumour landscape throughout the three interconnected phases. Importantly, the identification of key immune players and molecules involved in the dynamic crosstalk between tumour and immune system has been crucial for the introduction of reliable prognostic factors and effective therapeutic protocols against cancers.

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