Characterization and expression of H‐2I region gene products on bone marrow‐derived macrophages

Publisher Website
Google Scholar
Abstract
Antigen-presenting macrophages (M.PHI.) were derived from day 7 cultures of [mouse] bone marrow stem cells using L cell conditioned medium. The adherent bone marrow-derived macrophages (BMM.PHI.) were 100% esterase-positive, 95% positive for C [complement]3 receptors, 93% positive for Fc receptors and 95% actively phagocytic. Indirect immunofluorescence using anti-Ia monoclonal antibodies resulted in 60% Ia-positive BMM.PHI. on day 7 of stem cell culture. BMM.PHI. stimulated mixed lymphocyte reaction (MLR) proliferation across an I-A subregion difference, but not across I-J subregion differences. This contrasted with splenic M.PHI. which stimulated MLR proliferation across an I-A and I-J subregion difference. The apparent lack of I-J subregion determinants on BMMI.PHI. correlated with their ability to function as antigen-presenting cells. BMM.PHI. effectively reconstituted the trinitrophenyl-specific IgM plaque-forming cell (PFC) response of B cells, but not the primary burro red blood cell (BRBC)-specific IgM-PFC response of M.PHI.-depleted spleen cells. When BMM.PHI. were added to BRBC-primed T and B cells, they reconstituted the secondary IgG PEC response to levels obtained using splenic M.PHI.. These experiments relate the differential expression of H-2I region determinants on antigen-presenting cells with their functional capacity.