Lymphocytes alloantigens associated with X-chromosome-linked immune response genes.

A new polymorphic alloantigen system controlled by loci on the X-chromosome has been identified by using antisera from F1 hybrid mice differing in their X-chromosome. These alloantigens are associated with the X-chromosome. These alloantigens are associated with the X-linked immune response genes controlling the immune response to the so-called "thymus independent antigens" such as type III pneumococcal polysaccharide, poly(I)-poly(C), and denatured DNA. They also show association with the histocompatibility locus present on the X-chromosome. They were mainly detected on a not yet characterized thymus-derived lymphocyte subpopulation. A certain similarity with the major histocompatibility complex of the mouse supports the possibility of additional I-like regions besides the I region of the histocompatibility-2 complex.