The role of immune responses and polymorphism brings about changes to parasitic responses and individuals master immune responses against pathogenic responses. In this discussion features of the major histocompatibility complex are highlighted and the mechanisms and functions of the immune system are also discussed in terms of pathogenic reactions and the role of the MHC. The importance of genetic diversity, selective pressure and polymorphism would also be discussed to suggest evolutionary changes, genetic diversity in the population and the influence of MHC on social behavior.
A description of the MHC or Major Histocompatibility Complex could suggest that MHC is a gene cluster. The MH complex consists of four million base pairs of DNA and contains 128 genes as well as 96 pseudogenes (non-functional gene remnants). The MHC is thus a multigene family, has a large cluster of genes encoding key receptor molecules that aids in the binding of foreign peptides to immune cells and this in turn leads to a successful immune response (Klein, 1986).
The vertebrate immune system has the MHC as its core and it is a multigene family encoding receptor molecules that binds and recognizes foreign peptides for immune responses and immune cells. ...
ent them to immune cells and trigger a sort of immune response and foreign proteins enter cells by infection, phagocytosis in antigen presenting cells and macrophages. Foreign proteins are comprised of small peptides and presented in MHC molecules and these proteins are transported to the cell surface and T cell population. When the peptide binds the T cells, immune responses are triggered (Klein, 1986).
The MHC is the most important genetic cluster within a mammalian immune system and the immune system is described in terms of the Major Histocompatibility Complex. The MHC is composed of cell surface glycoproteins and binds antigens from pathogens to T lymphocytes and this helps in triggering the appropriate immune response to attack of parasites in the body. Some MHC genes may produce a diversity of antigens in a population and individuals posses a unique bunch of genes and the MHC represent the immune system and immune responses quite directly so the genetic effects of population fragmentation are studied. Certain MHC genes evolve in response to selective pressure from pathogens and tend to affect the social behavior of animals as well.
Some of the issues that will be discussed here would relate to the nature of MHC, the underlying structural and functional attributes, the early history of MHC, the class I, II, and III and variations or differentiation within manifestation of MHC so that evolutionary processes and mechanisms of parasitic reactions, adaptation and selection could be explained.
The MHC has been characterized at the molecular level for many years and the population diversity of MHC molecules is quite large as for some MHC loci, over 100 different alleles have been identified (Parham and Ohta 1996). For polymorphism in MHC, the importance of mutation,