| Abstract: | The differential expression of H-2 specificities recognized by antibody and by cytotoxic T lymphocytes (CTL) has been studied using a clone (FY7) of the C57BL/6 leukemia cell line FBL-3 (H-2b/H-2b). Unlike C57BL/10 spleen cells, EL-4 lymphoma cells and Y57-2C leukemia cells (all H-2b/H-2b), FY7 failed to induce the primary in vitro generation of anti-H-2b CTL by (B10.A x A)F1 (H-2a/H-2a) or B10.D2 x BALB/c)F1 (H-2d/H-2d) responder spleen cells. In addition, FY7 was not lysed by, and did not competitively inhibit anti-H-2b CTL. Quantitative absorption tests with H-2Kb and H-2Db antisera revealed that FY7 expressed these antigens in quantitatively similar amounts to EL-4. The H-2Kb product of FY7 appeared to be identical with that of C57BL/10 spleen cells both in apparent molecular weight and isoelectric point. Yet FY7 failed to inhibit anti-H-2Kb CTL competitively in a cold target inhibition assay. Possible mechanisms are discussed for the lack of T-lymphocyte recognition of the H-2Kb-gene product expressed by FY7. |
