The independent expression of HLA and β<inf>2</inf>-microglobulin on human-mouse hybrids

Direct cytotoxicity and absorption analysis were used to detect HLA antigens on man/mouse somatic cell hybrids. Confirmation of the assignment of the Major Histocompatibility Complex to chromosome 6 was obtained. The same series of hybrids were used to study the interaction between HLA and β2m on the cell surface. Results obtained from a series of clones indicated that there was complete independence of expression of HLA and β2m. Human β2m was found to be unnecessary for the normal serological expression of HLA, suggesting that mouse β2m could possibly replace human β2m as a subunit of the HLA molecule. Evidence is presented demonstrating that this is in fact the case. Heteroantisera to human β2m and alloantiserum to HLA-A2 were used, together with complement, to selectively remove the chromosome coding for β2m and HLA from a hybrid clone. Manipulation of the karyotype in this way further confirmed the independence of HLA and β2m on somatic cell hybrids. © 1976 Plenum Publishing Corporation.