Major histocompatibility markers

Only recently has the mouse placenta been demonstrated to be a major hematopoietic organ. In the late 1970s, using major histocompatability haplotypes as markers, Melchers69 demonstrated that the placenta of day 9 to day 12 mouse embryos harbored... 

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). 

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]. 

Radka SF, Charron DJ, Brodsky FM. Class II molecules of the major histocompatibility complex considered as differentiation markers. Hum Immunol. 1986 16 390-400. 

A second class of exploitable genotypic markers that may be utilized in experimental hepatocarcinogenesis involves the use of liver cell membrane alloantigenic determinants, such as those expressed as products of the major histocompatibility complex. These determinants can exert marked control of the development of putative premalignant lesions, as indicated by the marked reduction in the number of altered liver lesions... 

As you might suspect, the farther removed the source species is from the species receiving the transplantation, the more difficulty there is in having the BU accepted. Successful crossspecies transplantation is extremely rare transplantations from individual to individual of the same species must be matched for several tissue protein markers (the major histocompatibility complex, or MHC (see Section 6.20)), and even then the recipient must usually take cyclosporin or other suppressors of the immune system in order to avoid rejection. General immune system suppression leaves the recipient susceptible to infection and cancer, but drugs such as cyclosporin A or FK506 interfere only with helper T cell activation and do not cripple nonspecific immune responses (Campbell et al, 1999). 

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