Evidence for abnormalities in separate lymphocyte populations in NZB mice

Neonatally thymectomized, lethally irradiated NZB x DBA/2 and DBA/2 x NZB F₁ mice were reconstituted with NZB or DBA/2 bone marrow cells and NZB or DBA/2 thymocytes. Of the four resulting groups of recipient F₁ mice, those given NZB bone marrow cells developed high serum IgM levels, irrespective of the thymocyte donor strain. In contrast, recipients of NZB thymocytes were resistant to induction of tolerance to BGG, irrespective of the bone marrow donor strain. Only recipients of NZB bone marrow cells made spontaneous antierythrocyte autoantibodies; of these, the responses of NZB thymocyte recipients were greater and more consistent than those of DBA/2 thymocyte recipients. Recipients of either NZB bone marrow cells or NZB thymocytes made antibody responses to ssDNA; the highest anti-ssDNA responses occurred in recipients of both NZB bone marrow cells and NZB thymocytes. We conclude that function abnormalities in separate lymphocyte populations underlie different immune abnormalities in NZB mice.