Induction of cell-mediated immunity to chemically modified antigens in guinea pigs. II. The interaction between lipid-conjugated antigens, macrophages, and T lymphocytes.
Protein antigens covalently conjugated with lipid groups (dodecanoic acid) have previously been shown to stimulate strong delayed-type hypersensitivity (DTH) without the aid of adjuvants. The present experiments show that lipid-conjugated bovine serum albumin (L-BSA) is taken up in vitro by macrophages (Mpsi) 25- to 50-fold more than unconjugated BSA or aminidated BSA, neither of which induces DTH. Macrophages that take up 125I-labeled L-BSA in vitro stimulate DTH even more efficiently, when injected into syngeneic guinea pigs, than does soluble L-BSA. Tracer studies on the fate of radiolabeled BSA and L-BSA showed that much more L-BSA than BSA was retained by draining lymph nodes. Autoradiography demonstrated that 125I-L-BSA is rapidly taken up by Mpsi in the medullary sinuses of the lymph nodes. Some of this antigen is then transported into the paracortex, a region in which T lymphocytes predominate. The capacity of lipophilic antigens to stimulate cell-mediated immune responses may be caused by their increased uptake by Mpsi, resulting in more efficient presentation to immunocompetent T lymphocytes. The anatomical site of this Mpsi-T cell interaction may be within the sinusoids or paracortex of the draining lymph nodes.
D000818:Animals; D000941:Antigens; D001202:Ascitic Fluid / Q000166:cytology; D002478:Cells, Cultured / Q000276:immunology; D005260:Female; D006168:Guinea Pigs; D007850:Lauric Acids / Q000276:immunology* / Q000494:pharmacology; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D012710:Serum Albumin, Bovine / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D007850:Lauric Acids; D012710:Serum Albumin, Bovine