Absence of four H-2d antigenic specificites in an H-2d sarcoma.

MCG4 is a BALB/c sarcoma induced as a solid tumour with 0.2 mgs of methylcholantrene. The primary tumour was serially transplanted subcutaneously in syngeneic mice. The ascites form obtained was sued to study the expression of H-2 antigeneic specificities in a postlabelling radioassay. MCG4 did not express H-2D.4 (private specificity of H-2d haplotypes) as well as H-2.3, H-2.8 and H-2.13 (public specificities). In addition it expressed H-2.5 (a public specificity not present in H-2d cells). These results were confirmed by quantitative absorption analysis using MCG4 and positive-negative normal lymphoid cells for a particular specificity. Results are discussed with regard to the control of expression of H-2 antigens by regulatory genes.