IMMUNOGLOBULINS ON THE SURFACE OF LYMPHOCYTES

Abstract
Immunofluorescent studies using live cells from antibody-forming organs and anti-immunoglobulin antibodies demonstrate two populations of small lymphocytes which are differentiated by the presence or absence of Ig on their surface membranes. Most of the lymphocytes with detectable surface Ig appear to derive from cells of the bone marrow, while most of the Ig-negative lymphocytes derive from the thymus. Thus, adult mice thymectomized, lethally irradiated, and transplanted with bone marrow cells showed a normal number of lymphocytes with surface Ig but were depleted of the Ig-negative lymphocytes. Injection of thymocytes into these mice did not result in an increase in the number of lymphocytes with surface Ig in spleen and lymph nodes. Most of the injected thymocytes could be identified by means of histocompatibility markers. Also, the spleen and lymph nodes of neonatally thymectomized mice contained lymphocytes with surface Ig but were depleted of the Ig-negative lymphocytes.