T-CELL RECOGNITION IN THE MIXED LYMPHOCYTE-RESPONSE .1. NON-T, RADIATION-RESISTANT SPLENIC ADHERENT CELLS ARE THE PREDOMINANT STIMULATORS IN THE MURINE MIXED LYMPHOCYTE-REACTION

Abstract

The ability of subpopulations of murine spleen cells to stimulate a mixed lymphocyte response (MLR) was studied. T [thymus-derived] cells (nylon-nonadherent spleen cells) and B [bone marrow-derived] cells [G-10 passed and treated with rabbit anti-mouse brain serum (RAMB) and complement (C)] were poor stimulators of an MLR. Whole spleen cells or B cells plus adherent cells (RAMB +C-treated spleen cells) produced good stimulation. A non-T, radiation-resistant splenic adherent cell (SAC) population was up to 20-50 times more efficient as a stimulator of an MLR on a per cell basis than an unseparated spleen population. These SAC expressed Ia determinants encoded by genes in I-A and I-E/C. Ia+ SAC may be the predominant stimulating cells in spleen cell populations and the preferential target for T cell recognition in cell interaction events.