Chicken Major Histocompatibility Complex and Disease

Abstract

The chicken MHC (B complex) initially described by Briles as controlling blood antigens, is now known to be composed of at least three regions, L, F and G. Two of these, F and G, were described on the basis of recombinants found in a study of over 10,000 chickens. On the basis of biochemical, tissue distribution and functional analyses, F corresponds to the murine H-2 K/D regions. The G region is unique to the chicken since the antigenic product is expressed only on erythrocytes and their progenitors. L was identified by serological studies and corresponds to the H-2 I region; the L antigen is expressed predominantly on B lymphocytes, monocytes and 10% of T lymphocytes, and differences in the L region result in variations in immune responsiveness. A number of functional similarities exist between the chicken MHC and that of other species such as regulation of graft rejection, graft-versus-host reaction (GVHR) and mixed lymphocyte reactions (MLR), mitogenic and immune responsiveness and resistance to RNA and DNA virus infection. The chicken MHC also controls the severity of autoimmune disease, as exemplified by the spontaneous thyroiditis of Obese strain (OS) chickens. It differs from mammalian MHC's by having of lower crossing-over frequency and no apparent gene duplication.

Rapid Detection of BF Haplotypes by a Semi‐nested Polymerase Chain Reaction, which Causes Resistance/Susceptibility to Marek’s Disease in Chicken

“…The BF ⁄ BL region in the B locus is characterized by strong effects on graft rejection, mixed lymphocyte reaction and graft-versus-host reaction [2][3][4], including susceptibility or resistance to virally induced tumours [5,6]. Chickens with the MHC haplotype B 21 are highly resistant to Marek's disease (MD), whereas chickens with the MHC haplotype B 19 are highly susceptible [7][8][9][10][11].…”

Serological Screening for MHC (B)-Polymorphism in Indigenous Chickens

“…The class IV (BG) region encodes the B blood group antigens. There is a low crossing-over (1:2000) between BG and BF/BL genes in European chickens (Hala et al, 1981;Plachy et al, 1992a,b). Two of the MHC genes (BF and BG) code for glycoproteins, which are expressed on the surface of red blood cells.…”

A molecular map of the chicken major histocompatibility complex: the class II beta genes are closely linked to the class I genes and the nucleolar organizer.

“…These three loci are highly polymorphic, and numerous inbred chicken lines, including several congenic lines, have long been established (Hasek et al, 1966). An important characteristic which appeared when attempts were made to map viral disease resistance, graft rejection or immune response control to one B locus or another, was the very low recombination frequency between loci of the B complex (Hala et al, 1981). Alloantisera for either B-F or B-G antigens detected only a few recombinants between these two loci at a frequency of 0.04%.…”