title: Antigen transport II. The significance of the localization of antigen-laden cells in the spleen.
abstract: Previous studies have demonstrated that macrophage-like cells transporting antigen, e.g., human serum albumin (HSA) appear in thoracic duct lymph and blood shortly after antigen injection. The in vivo migration of these antigen-laden (Ag-L) cells from the blood stream was examined systematically by transferring Ag-L cells bearing 125I-labelled HSA into syngeneic rats. There was no evidence autoradiographically that Ag-L cells migrated into lymph nodes, but the localization in the spleen followed a defined pattern: within the first hours after transfer, a majority of radiolabelled cells were identified in the marginal zone; by 3 hr and up to 4 days later, 60-80% of labelled cells were resident in the red pulp; Ag-L cells failed to migrate into the white pulp in significant numbers. Ag-L cells which had localized to the spleen, when examined 3 and 18 hr after transfer using combined autoradiography and immunoperoxidase staining, did not express Ia determinants in situ. The ability of Ag-L cells to stimulate an adoptive secondary response was tested in splenectomized, irradiated recipients receiving HSA-specific memory cells. Removal of the spleen before transfer severely reduced the antibody response evoked by Ag-L cells transporting HSA, thus indicating the functional importance of antigen transport to the spleen. Since Ag-L cell migration was primarily into the red pulp, we have considered whether the red pulp may provide a relevant microenvironment for lymphocyte/antigen interaction.
mesh_terms: D000818:Animals; D000941:Antigens; D001692:Biological Transport; D002465:Cell Movement; D006801:Humans; D007116:Immunization, Passive; D007156:Immunologic Memory; D008214:Lymphocytes / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains; D012709:Serum Albumin / Q000276:immunology*; D013045:Species Specificity; D013154:Spleen / Q000276:immunology*; D014018:Tissue Distribution
chemical_list: D000941:Antigens; D012709:Serum Albumin