The distribution of histocompatibility antigens on T and B cells in the guinea pig

The distribution of histocompatibility (H) antigens on different lymphocyte populations in the guinea pig was examined with alloantisera prepared by cross immunizing strain 2 and strain 13 animals. These alloantisera killed only 30–40% of lymph node cells, and those cells that remain alive after killing by the alloantisera are markedly depleted in immunoglobulin-bearing B lymphocytes. Absorption studies of the anti-2 serum demonstrated that the alloantigen content of lymph node cells was 7–8 times that of thymocytes, while the alloantigen content of L₂C leukemia cells, a pure population of malignant B cells, was 25–30 times that of thymocytes. Furthermore, pure B lymph node cells, prepared by treating lymph node cells with an anti-T cell serum and C, were more efficient than normal lymph node cells in the absorption of the alloantisera. Finally, those lymph node cells which remain alive after treatment with the alloantisera and C failed to respond to endotoxin, a B cell mitogen, whereas these same cells responded normally to phytohemagglutinin, a T cell mitogen. These results demonstrate an increased content of H antigen on the B lymphocyte compared to the T lymphocyte. Since H antigens play a role in the cooperation between B and T cells, information as to the distribution of H antigens on these cells may have important implications for cell to cell interaction in the immune response.