Major histocompatibility complex MHC class

An unknown antigen presented by the major histocompatibility complex (MHC) class II molecules causes T cells to become autoreactive (Fig. 26-1). Once activated, T cells penetrate the... 

Suppressor T cells were also shown to express a major histocompatibility complex (MHC) class II marker, I-J. However, because I-J was never cloned and its presence in the MHC never shown formally, there was considerable doubt as to the significance of I-J [reviewed in 3, 4]. 

Peptides that serve as ligands for major histocompatibility complex (MHC) class I molecules can activate vomeronasal sensory neurons. These peptides contain nine amino acid residues and activate sensory neurons from the V2 receptor... 

Finally, in this brief overview of lymphocyte defects, mention should be made of mutations affecting major histocompatibility-complex (MHC) Class II molecules. These mutations affect a multiprotein transcription factor complex that regulates the expression of MHC Class II molecules (121). Affected patients have undetectable levels of MHC Class II antigens HLA-DP, DQ, and DR on the surface of monocytes and B cells. Lack of these antigen-presenting molecules leads to impaired immune response. Affected individuals have moderate lymphopenia with a severely reduced number of CD4+ T cells and normal or increased numbers of CD8+ T cells. Since MHC molecules in the thymic epithelium play a key role in positive and negative selection of primitive T cells, selection of competent T cells is also affected in the absence of MHC Class II antigens. 

LPS can be directly mitogenic for T cells [130], but the antitumoral activity of lymphocytes depends on antigen recognition by their TCR in the context of the major histocompatibility complex (MHC) class I or n. Though LPS enhance it, T lymphocyte activity requires APC [131]. The effect of LPS on T lymphocytes has been shown to depend on monocytes independent of MHC, but to be due to the secretion of costimulatory signals and IL-12 in humans [132]. In vivo, LPS induces principally the proliferation of CD8+ T lymphocytes, but also that of CD4+ T and B lymphocytes through the activation of APC and secretion of IFN 0(7(3 in C57BL/6 mice [133],... 

McMenamin C, Holt PG The natural immune response to inhaled soluble protein antigens involves major histocompatibility complex (MHC) class I-restricted CD8+ T cell-mediated but MHC class Il-restricted CD4+ T cell-dependent immune deviation resulting in selective suppression of immunoglobulin E production. J Exp Med 1993 178 889-899. 

Sato A, Ida N, Fukuyama M, Miwa K, Kazami J, Nakamura H, Identification from a phage display library of peptides that bind to toxic shock syndrome toxin-1 and that inhibit its binding to major histocompatibility complex (MHC) class II molecules, Biochemistry, 35 10441-10447, 1996. 

Not until 1996 did Feder and colleagues identify a novel major histocompatibility complex (MHC) class I-like gene in which homozygosity for specific mutations were found in 83% of patients with hemochromatosis. 

Borrego, F., Rabat, J., Kim, D.-K., Lieto, L., Maasho, K., and Pena, J. et al. (2002). Structure and function of major histocompatibility complex (MHC) class I specific receptors expressed on human natural killer (NK) cells. Mol. Immunol. 1063, 1-24. 

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