Circulating T and B lymphocytes of the mouse: I. Migratory properties

Abstract

Studies on the identity of thoracic duct lymphocytes (TDL 4 4 The following abbreviations are used: ATx, adult thymectomy; BM, bone marrow; FCS, fetal calf serum; FγG, fowl immunoglobulin G; 3HT, tritiated thymidine; 3HU, tritiated uridine; NTx, neonatal thymectomy; PALS, periarteriolar lymphocyte sheaths; TDL, thoracic duct lymphocytes; TxBM, adult thymectomized, irradiated, and marrow protected. ) from normal and T cell-depleted mice indicated that as many circulating B lymphocytes were produced by healthy T cell-depleted mice as normal mice. Proportions of T and B cells from the thoracic duct of CBA mice changed markedly during the first 4 days of drainage from 82% T cells and 16% B cells at 12 hr to approximately equal proportions of both classes after 3 days. In absolute terms, T cells were mobilized rapidly by thoracic duct drainage and B cells very slowly. Histologically, this was reflected in a rapid depletion of the T cell-dependent areas of the lymphoid organs. The B cell-dependent areas, in contrast, became depleted of lymphocytes only after drainage for a week or more. The homing properties of circulating lymphocytes were investigated using TDL from normal and T cell-depleted mice as relatively pure sources of T and B cells, respectively. Four hours after injection of 51Cr-labeled T and B cells, a large proportion of both cell classes were found in the spleen. By 24 hr, many T cells had left the spleen and appeared in the lymph nodes. Such redistribution by B cells, however, was minimal. Intravenously injected T and B cells, labeled with tritiated uridine ( 3HU), localized specifically in the T and B cell-dependent areas, respectively, of the lymphoid tissues. 3HU-labeled T cells were found to recirculate rapidly from blood to lymph. Labeled B cells, in contrast, recirculated only very slowly.