Murine T cell proliferation can be specifically augmented by macrophages fed with specific antigen: alpha-2-macroglobulin conjugate.
Foreign antigens conjugated to alpha-2-Macroglobulin (alpha-2-M) were effectively taken up by murine macrophages via alpha-2-M receptors. Such effective internalization of alpha-2-M:antigen conjugate by macrophages resulted in a remarkable increase in its ability to activate murine immune T cells under the following conditions. After macrophages were incubated with alpha-2-M:antigen conjugate or unconjugated antigen, they were cultured with immune T cells and antigen-stimulated tritiated thymidine incorporation by T cells was measured. The stimulation of T cell proliferative response by macrophages fed with the conjugate was sixteen times higher than what was observed with macrophages pretreated in the same concentration of unconjugated antigen. These findings suggest a physiological function of alpha-2-M and give us a new technique of immunization.
D000818:Animals; D000941:Antigens / Q000378:metabolism*; D007941:Leukemia P388 / Q000378:metabolism; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011971:Receptors, Immunologic / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology*; D000511:alpha-Macroglobulins / Q000378:metabolism*
D000941:Antigens; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D011971:Receptors, Immunologic; D000511:alpha-Macroglobulins