Hyperdiploid-CD5-positive B cells in mouse.

Hyperdiploid B cells have been found in autoimmune NZB mice as they age. The hyperdiploid cells were found to be clonal both on the basis of cytogenetic analysis and studies of immunoglobulin gene rearrangements at the DNA level. Studies of the inheritance of the hyperdiploid traits in both F1 and backcrosses, as well as NZB recombinant inbred strains, revealed that the presence of hyperdiploid B cells was an inherited recessive trait linked to autoimmune hyperactivity.

Influence of host environment on growth of clonal CD5+B (Lyl+B) cells.

Autoimmune NZB mice have increased percentages of CD5+B (Lyl+B) cells in both the spleen and peritoneum. We have previously reported that as NZB mice age they develop a clonal population of hyperdiploid CD5+B cells in the spleen. These cells can readily be transplanted into unirradiated recipients.

Role of T cells in sex differences in syngeneic bone marrow transfers.

Transferred marrow cells will proliferate in normal mice not exposed to irradiation or any other type of stem cell depletion when five consecutive transfers of 40 million cells are given. Approximately 25% of the mitotic cells are of male donor origin observed cytogenetically in all of the female recipient spleens and marrow analyzed from two weeks to one and one-half years after transfusions. Male donor stem cells are accepted and form a stable component of the self-renewing stem cell pool.

Comparison of response to stem cell differentiation signals between normal and autoimmune mouse strains.

Normal DBA/2 and autoimmune NZB mice were studied with regard to signals eliciting differentiation and division of bone marrow stem cells. Irradiated (NZB X DBA/2)F1 mice were repopulated with various combinations of T-depleted bone marrow from NZB and DBA/2 mice. In response to the repopulation signal of irradiation, recipients of autoimmune NZB marrow initially demonstrated expansion of LY-5+ lymphoid and hemopoietic cells, particularly of the B cell lineage.