Induction of anamnestic T cell proliferation by antigen‐pulsed, bone marrow‐derived macrophages

Abstract

Bone marrow‐derived macrophages (BMMϕ) were grown in a liquid culture system in the presence of L cell‐conditioned medium as a source of colony‐stimulating factor. After a 4‐h pulse with antigen, cultured irradiated BMMϕ were capable of presenting the antigen to primed T cells as assessed in a T cell proliferation assay. Proliferation was optimal when BMMϕ were used between days 5 and 8 of bone marrow cell culture. T cells of Lytl and Lyt123 phenotype had to be present at the start of the culture period to yield an optimal response. Conventional antisera and monoclonal antibodies directed against the H‐2 I region and the I‐A subregion, respectively, proved inhibitory in this system. Cultured BMMϕ from low‐responder strains failed to present antigens under immune response gene control in a form that was immunogenic to T lymphocytes. Cultured BMMϕ might thus serve as a source of antigen‐presenting cells in the study of cell‐cell interaction and immune response gene regulatory mechanisms.