Alteration of lymphoid cells in AKR mice by treatment with monoclonal antibody against Thy-1 antigen.

AKR/J mice treated with high levels of monoclonal anti-Thy-1.1 antibody and C' remained healthy without apparent side effects. Examination of the lymphatic organs of these mice demonstrated a selective depletion of T cells in lymph nodes and spleen. Following cessation of treatment of the levels of anti-Thy-1.1 antibody in the circulation fell and the peripheral lymphatic organs gradually became repopulated with T cells. Depletion occurred in lymph nodes whether or not C' was infused along with the antibody. Although the thymocytes of these mice were coated with anti-Thy-1.1 antibody they were not eliminated by the treatment. The elimination of peripheral but not thymic T cells suggests either a thymic barrier to the penetration of cofactors (possibly antibody-dependent effector cells) or that antibody acts by interfering with the normal traffic of peripheral T cells which normally "home" to the lymph nodes and spleen.