T cell recognition in the mixed lymphocyte response. II. Ia-positive splenic adherent cells are required for non-I region-induced stimulation
Ahmann, G.B.; Nadler, P.I.; Birnkrant, A.; Hodes, R.J.
Journal of Immunology 127(6): 2308-2313
1981
ISSN/ISBN: 0022-1767 PMID: 6457872 Document Number: 174099
Ia-positive splenic adherent cells (SAC) were the predominant stimulators of a mixed lymphocyte response (MLR) to whole H-2 differences in which most of the proliferative response is directed against I region-encoded determinants. The ability of several purified lymphoid subpopulations to activate T cells in response to the non-H-2 linked M products or to products of the K or D regions of H-2 were examined. Adherent cell-depleted populations of T and B cells were nonstimulatory; SAC were potent stimulators for responses involving each of these genetic differences. Treatment of these SAC with anti-Ia and C abrogated their MLR-stimulating ability. Treatment of SAC with anti-Ia and C abrogated their ability to stimulate an MLR directed against K or D region-encoded determinants; this treatment had no effect on their ability to generate a cytotoxic T lymphocyte response against these same determinants. In addition to presenting allogeneic I region-encoded determinants, Ia-positive SAC appear to play a unique role in the presentation of non-I region-encoded alloantigens to proliferating T cells.