T and b lymphocytes in new zealand black mice, an analysis of the theta, tl and mbla markers.

The lymphocytes of thymus, blood, spleen, lymph nodes and bone marrow were studied in NZB mice between the ages of 1 and 14 months, and compared with lymphocytes of A and CBA strain mice of the same age. By standard cytotoxicity techniques, the proportion of cells possessing the θ, TL and MBLA markers was found to be similar in NZB in mice and controls. In 14-month old NZBs, whose spleen was largely replaced by reticulum cell sarcoma, and in younger recipients of the passaged tumour, there was a reduction in the percentage of θ and MBLA-positive cells in the spleen. In a few mice at 4 and 9 months, small numbers of MBLA-positive cells were present in the thymus and there was a corresponding decrease in θ-positive cells. TL-positive cells were not present outside the thymus, and θ-positive cells were not present in the bone marrow in unusual numbers. NZB peripheral lymphocytes appeared to have the same surface concentration of θ as those of A or CBA mice, as judged by anti-θ titration curves. The reticulum cell sarcoma was shown to be θ-negative and MBLA-negative, while an NZB thymoma was θ-positive, TL-positive and MBLA-negative. It was concluded that the peripheral lymphoid organs contain a large population of T lymphocytes of abnormal character.