Anti-Brain Antisera Bind Primarily to Non-T Cells in Mouse Bone Marrow 1

Abstract

Summary

Anti-brain heteroantisera are widely employed for the delineation of T lymphocytes in lymphomyeloid organs despite compelling evidence demonstrating the cross reactivity of such reagents with unrelated hemopoietic cells. The experiments described in this communication utilized absorptions of a fluoresceinated goat anti-rat brain antis-erum with thymocytes or nude bone marrow cells to determine the validity of using such an antiserum to identify T cells in the thymus, lymph nodes, spleen, and bone marrow of CBA/J mice. Thymocyte absorption of this fluorescein-ated antiserum removed virtually all of the staining of thymus, lymph node, and spleen cells by this reagent. In contrast, the percentage of labeled marrow cells was unchanged by thymocyte absorption of the anti-rat brain antiserum, although the staining could be eliminated by absorption with nude bone marrow. These results suggest that anti-brain antisera can be employed as dependable T-cell probes with suspensions of the thymus or peripheral lymphoid organs. However, the vast majority of marrow cells staining with the anti-brain antisera are not T cells. Therefore, anti-brain antisera should not be utilized to discern T lymphocytes in this tissue unless additional absorptions (with nude marrow) or special controls are performed.