Peptide–MHC Binding Reveals Conserved Allosteric Sites in MHC Class I- and Class II-Restricted T Cell Receptors (TCRs)

In this issue of Blood, Plesa et al demonstrate that human Foxp3+ regulatory T cells can be redirected using MHC class I–restricted T-cell receptors (TCRs), showing a surprising lack of correlation of TCR affinity and their suppressive potency.1

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Immunoglobulins, MHC and T Cell receptors genes in Cetaceans

10.1101/2020.10.24.353342 ◽

2020 ◽

Author(s):

Francisco Gambón-Deza

Keyword(s):

T Cell ◽

Mhc Class I ◽

Marine Environment ◽

T Lymphocyte ◽

T Cell Receptors ◽

Immunoglobulin M ◽

Class I ◽

Cell Receptors ◽

Vh Genes ◽

Lymphocyte Receptors

AbstractCetaceans correspond to mammals that have returned to the marine environment. Adaptive changes are very significant with the conversion of the limbs into flippers. It is studied the changes that have occurred in immunoglobulins, MHC class I and II and T cell receptors genes. Constant regions of immunoglobulins are similar to those of the rest of mammals. An exception is the IgD gene, which is composed of three CH domains but CH1 similar to CH1 of immunoglobulin M. In the IGHV locus, it exist a decrease in the number of VH genes with the absence of genes within Clan I. The number of Vλ genes is greater than that of Vκ. In the genes for T lymphocyte receptors, it exists a decrease in the number of Vα genes with loss of significant clades and subclades. In Vβ and Vγ, there is also the loss of clades. These declines of Vα, Vβ and Vγ are not present Artiodactyla, and they are specific to Cetaceans. In MHC present tree evolutive lines of class I genes. These species have DQ, DR, DO and DM genes, but they are no present DP genes.

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HLAs, TCRs, and KIRs, a Triumvirate of Human Cell-Mediated Immunity

Annual Review of Biochemistry ◽

10.1146/annurev-biochem-011520-102754 ◽

2020 ◽

Vol 89 (1) ◽

pp. 717-739 ◽

Cited By ~ 4

Author(s):

Zakia Djaoud ◽

Peter Parham

Keyword(s):

T Cells ◽

T Cell ◽

Nk Cells ◽

T Cell Receptors ◽

Hla Class I ◽

Class Ii ◽

Class I ◽

Antigenic Specificity ◽

Class I Mhc ◽

Cell Receptors

In all human cells, human leukocyte antigen (HLA) class I glycoproteins assemble with a peptide and take it to the cell surface for surveillance by lymphocytes. These include natural killer (NK) cells and γδ T cells of innate immunity and αβ T cells of adaptive immunity. In healthy cells, the presented peptides derive from human proteins, to which lymphocytes are tolerant. In pathogen-infected cells, HLA class I expression is perturbed. Reduced HLA class I expression is detected by KIR and CD94:NKG2A receptors of NK cells. Almost any change in peptide presentation can be detected by αβ CD8+ T cells. In responding to extracellular pathogens, HLA class II glycoproteins, expressed by specialized antigen-presenting cells, present peptides to αβ CD4+ T cells. In comparison to the families of major histocompatibility complex (MHC) class I, MHC class II and αβ T cell receptors, the antigenic specificity of the γδ T cell receptors is incompletely understood.

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