Studies on human brain-thymus cross-reactive antigens.

Antigens shared by human brain and thymocytes and by human and mouse tissues were studied with rabbit anti-human thymocyte antiserum (RAHT). It was found that cytotoxicity of RAHT serum against mouse thymus cells was not absorbed by mouse liver or bone marrow cells. Human brain and thymus cells completely absorbed the anti-thymocyte activity from this antiserum. It was suggested that human brain had antigenic determinants identical or very similar to those found on human thymocytes. Activity of RAHT antiserum against mouse thymus cells was completely removed by an absorption of mouse brain and thymocytes. These results demonstrated that there were shared antigenic determinants between human and mouse tissues.