A trans-acting major histocompatibility complex-linked gene whose alleles determine gain and loss changes in the antigenic structure of a classical class I molecule.
The RT1.A locus of the rat MHC encodes the H chain of the single classical class I molecule of this species. One of the alleles of this polymorphic locus, RT1.Aa, is present in several laboratory inbred, congenic, and MHC recombinant rat strains. Studies of the RT1.Aa class I molecule from a number of these strains as a target for CTL show that its antigenicity, both as an alloantigen and a restricting element, is subject to gain and loss alterations by the action of a gene mapping in the MHC to the right of RT1.A. This locus is apparently present in two allelic forms (one possibly a null allele) corresponding to the presence or absence of a dominant transacting modifier, and has been named class I modification, or cim. The antigenic change brought about by cim is scarcely detectable serologically but highly immunogenic for CTL. Biochemical investigations show that cim affects the post-translational modification of RT1.Aa.
Livingstone
A M
AM
Department of Immunology, Agricultural and Food Research Council Institute of Animal Physiology and Genetics Research, Cambridge Research Station, Babraham, United Kingdom.
Powis
S J
SJ
Diamond
A G
AG
Butcher
G W
GW
Howard
J C
JC
D000483:Alleles; D000818:Animals; D002874:Chromosome Mapping; D000939:Epitopes / Q000032:analysis; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000096:biosynthesis; D008285:Major Histocompatibility Complex; D008297:Male; D010449:Peptide Mapping; D011134:Polysaccharides / Q000032:analysis; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic
D000939:Epitopes; D015395:Histocompatibility Antigens Class I; D011134:Polysaccharides