Antigen presentation by resting B cells. Effectiveness at inducing T cell proliferation is determined by costimulatory signals, not T cell receptor occupancy.
Resting B cells stimulated the proliferation of two T cell clones much less efficiently than T cell-depleted low-density APC. In contrast, low-density cells and resting B cells stimulated the clones to produce similar levels of inositol phosphates, a rapid biochemical event dependent only on occupancy of the TCR. The inefficient stimulation of T cell proliferation by resting B cell APC was dramatically improved by the addition of allogeneic low-density accessory cells incapable of being recognized by the TCR on the responding T cells. The results are most consistent with a model where low-density and resting B cell APC display similar amounts of Ag/Ia molecule complexes capable of being recognized by the TCR on the responding T cells but differ in the provision of costimulatory signals that, together with TCR occupancy, are required for IL-2 production.
Jenkins
M K
MK
Department of Microbiology, University of Minnesota Medical School, Minneapolis 55455.
Burrell
E
E
Ashwell
J D
JD
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D007295:Inositol Phosphates / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008211:Lymphocyte Cooperation / Q000187:drug effects; D008222:Lymphokines / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*
D007295:Inositol Phosphates; D007375:Interleukin-1; D015850:Interleukin-6; D008222:Lymphokines; D011948:Receptors, Antigen, T-Cell