Gut-associated lymphoblasts and intestinal IgA plasma cells.

Abstract

The term “gut-associated lymphoid system” (GALS) can he applied, in the mouse and in the rat, to the lymphoid cells present in 1) the Peyers’ patches (PP) ; 2) the intestinal mucosa, where these cells consist of disseminated lymphocytes and IgA secreting plasma cells; 3) the mesenteric lymph nodes (MLN), into which the lymphatic system of the gut drains, and 4) the thoracic duct lymph (TDL), which receives the efferent MLN lymph. It has been shown in the rat that the TDL and MLN “lymphoblasts” (i.e. large dividing cells which are labeled after in vitro incubation with 3H thymidine) display, after transfer into syngeneic recipients, a strong tendency to migrate to the intestinal mucosa (1,2,3), the PP, and to some extent the MLN (2). This migration pattern is not observed with the blasts obtained from immunized peripheral lymph nodes (PLN); these blasts do not migrate to the gut and home more in the PLN than in the MLN (2). Preferential migration is characteristic of only the GALS blasts, since it is not found in transfer experiments when the total lymphoid population from TDL or MLN is labeled (2). Since these observations indicate that some of the GALS blasts have special properties, it was decided to investigate further the nature and properties of the various GALS cells in the mouse and in the rat.