SELECTIVE EXPANSION FOLLOWED BY PROFOUND DELETION OF MATURE V-BETA-8.3(-CELLS IN-VIVO AFTER EXPOSURE TO THE SUPERANTIGENIC LECTIN URTICA-DIOICA AGGLUTININ() T)

Urtica dioica agglutinin (UDA) is a superantigen that, in vitro, binds to specific carbohydrate structures on class II and induces a sixfold enrichment of V beta 8.3(+) BALB/c mice splenic T cells. Superantigen s have pleiotropic effects in vivo, causing the activation, proliferat ion, and deletion of specific T cells, but are heterogenous in regard to their effects on T cell tolerization. We, therefore, compared the r esponses of peripheral T cells from adult BALB/c mice with the i.v. in jection of 50 mu g UDA or the bacterial superantigen staphylococcal en terotoxin B (SEE) that also recognizes the V beta 8.3 gene product. Th e data presented indicate that activation, clonal expansion, anergy, a nd death of V beta 8.3(+) T cells occur sequentially after UDA adminis tration. Two days after UDA injection, the proportion of V beta 8.3(+) T cells in the periphery is elevated to approximately twice that of n ormal mice. This expansion occurs in both CD4(+) and CD8(+) subsets. V beta 8.3(+) T cells from UDA-primed mice are anergic to UDA restimula tion and fail to proliferate or to produce IL-2. Furthermore, the prol iferation of V beta 8.3(+) T cells is followed by their rapid disappea rance concomitant with their specific elimination by apoptosis. In 1 w k, all CD4(+) V beta 8.3(+) peripheral T cells are deleted. The declin e of V beta 8.3(+) T cells in the CD4(+) subset is more than in the CD 8(+) subset. This occurs in thymectomized and in thymus-intact animals . Two months after UDA priming, the percentage of V beta 8.3(+) T cell s is still lower than in control mice.