The major histocompatibility complex

The members of the immunoglobulin superfamily that are encoded in the major histocompatibility complex (MHC) (Fig. 8) constitute a large family which, on the basis of functional criteria, can be divided into two major sets [88—91]. The first consists of antigen-presenting molecules and includes the classical transplantation antigens (class I, see below) and immune response factors (class II). The function of the second is presumably in differentiation, since these molecules (which in the mouse include the Qa and TL antigens [92]) are expressed on specific cell types molecules analogous to this second set V (CD1) are also encoded by a small family 

Antigen presentation can be viewed as an adaptation of an older cell-cell recognition function into two separate systems which identify distinct classes of MHC molecules. The first system has evolved to monitor and ensure the integrity of cell surface structures and consists of MHC molecules expressed on most cell types and mainly recognized by cytotoxic T cells (class 1 molecules). The second system has evolved to mediate cell-cell interactions in the immune response and consists of MHC molecules mostly expressed on macrophages and B cells and mainly recognized by regulatory T cells (class 11 molecules). The functional diversification between class I and class 11 molecules is reflected in substantial structural differences (see below). 

A second important difference between MHC antigen-presenting molecules and immunoglobulins is in the distribution of the repertoire of diversity within each in- 

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Eggert F., Luszyk D., Haberkorn K., Wobst B., et al. (1998/9). The major histocompatibility complex and the chemosensory signalling of individuality in humans. Genetica 104, 265-273. 

Singer A.G., Beauchamp G. and Yamazaki K. (1997). Volatile signals of the major histocompatibility complex in male mouse urine. Proc Natl Acad Sci 94, 2210-2214. 

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... 

Human leukocyte antigens (HLA) Groups of genes found on the major histocompatibility complex, which contain cell-surface antigen-presenting proteins. The body uses HLA to distinguish between self-cells and non-self-cells. 

The T-lymphocyte receptor (TCR) is involved in detection of foreign antigens, presented together with the major histocompatibility complex (MHC). Subsequendy, it regulates the clonal expansion of T cells. 

Else, KJ., Wakelin, D., Wassom, D.L. and Hauda, KM. (1990a) The influence of genes mapping within the major histocompatibility complex on resistance to Trichuris muris infections in mice. Parasitology 101, 61-67. 

Jeffreys AJ, Kauppi L, Neumann R. Intensely punctuate meiotic recombination in the class II region of the major histocompatibility complex. Nature Genet 2001 29 217-222. 

Immunoglobulins (Igs) can activate the complement system, which amplifies the immune response by enhancing chemotaxis, phagocytosis, and release of lymphokines by mononuclear cells that are then presented to T lymphocytes. The processed antigen is recognized by the major histocompatibility complex proteins on the lymphocyte surface, resulting in activation of T and B cells. 

Corzo, D., et al., "The Major Histocompatibility Complex Region Marked by HSP and HSP70-2 Variant is Associated with Clozapine-induced Agranulocytosis in Two Different Ethnic Groups," Blood, 86, 3835-3840 (1995). 

Lymphocytes, the effector cells of the acquired immune system, include morphologically indistinguishable T and B cells, the former divided into CD4+ T helper cells and CD8+ cytotoxic T cells. Since the functions of those cell subsets differ so drastically, it became important to develop tools to distinguish them from each other. Efforts to identify cell subsets according to their expression of different surface antigens have been successful, including various Cluster of Determination (CD) markers (Table 23.1). In addition, cross-reactive monoclonal antibodies, and subsequently developed species-specific polyclonal and monoclonal antibodies towards the major histocompatibility complex (MHC) have been used to label cells in circulation and in tissue sections (Table 23.1). 

Murray, B.W. and White, B.N., Sequence variation at the major histocompatibility complex DRB loci in beluga (Delphinapterus leucas) and narwhal (Monodon monoceros), Immuno genetics, 48, 242, 1998. 

Aten, J. et al., Susceptibility to the induction of either autoimmunity or immunosuppression by mercuric chloride is related to the major histocompatibility complex class II haplotype. Eur. J. Immunol., 21, 611, 1991. 

Penn, D.J. (2002) The scent of genetic compatibility sexual selection and the major histocompatibility complex. Ethology 108, 1-21. 

A major effort in contemporary olfactory research has focused upon determining the genetic basis of odours of individuality in mice with both major urinary proteins (MUPs) and the major histocompatibility complex (MHC) believed to provide a contribution to discriminable individual differences (Singer, Beauchamp and Yamazaki 1997 Hurst and Beynon 2004). Many of these studies utilized instrumental conditioning tasks in which the animals were rewarded for learning to discriminate between odours. While these experiments demonstrate what an animal... 

Paulsson, K. (2004) Evolutionary and functional perspectives of the major histocompatibility complex class I antigen-processing machinery. Cell. Mol. Life Sci. 61, 2446-2460. 

Yamazaki, K., Beauchamp, G.K., Imai, Y., Bard, J., Phelan, S.P., Thomas, L. and Boyse, E.A. (1990) Odortypes determined by the major histocompatibility complex in germfree mice. Proc. Natl. Acad. Sci. 87, 8413-8416. 

Egid, K. and Brown, J.L. (1989) The major histocompatibility complex and female mating preferences in mice. Anim. Behav. 38, 548-550. 

Landry, C., Garant, D., Duchesne, P. and Bematchez, L. (2001) Good genes as heterozygosity the major histocompatibility complex and mate choice in Atlantic salmon (Salrno salar). Proc. R. Soc. B 268, 1279-1285. 

Milinski, M. (2006) The major histocompatibility complex, sexual selection, and mate choice. Arm. Rev. Ecol. Evol. Sys. 2006, 159-186. 

Schellinck, H.M., Slotnick, B.M. and Brown, R.E. (1997) Odors of individuality originating from the major histocompatibility complex are masked by diet cues in the urine of rats. Anim. Learn. Behav. 25, 193-199. 

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