SYNERGY BETWEEN STIMULATOR CELLS IN THE INDUCTION OF THE ANTI‐Mls^a RESPONSE

Abstract

SUMMARY We have identified two types of clones responsive to Mls determinants. One type responded vigorously to purified B cells from mice bearing Mlsa‐stimulatory determinants. The other type, including clone Lyl‐N5, responded vigorously to unfractionated spleen cells, but failed to respond to B cells alone or to spleenadherent cells (SAC) alone from the Mlsa‐bearing mice. Synergy between two stimulator cell types, B cells and SAC, was required to induce the Mls response of clone Lyl‐N5. The failure of clone Lyl‐N5 to respond to Mlsa‐bearing B cells was reversed by the addition of SAC taken from mice bearing the Mlsb allele or the non‐stimulatory Mlsb allele. B cells were required to provide the Mlsa determinant. The Mls response of clone Ly1‐N5 is restricted by class II determinants shared by the H‐2b, H‐2d and H‐2k haplotypes, but not the H‐2q haplotype. The optimal response of the clone was obtained by using B cells bearing both Mlsa and the permissive H‐2 alloantigen. However, complementation was also observed between B cells bearing Mlsa and the non‐permissive Iaq and SAC bearing the non‐stimulatory Mlsb, but a permissive la epitope, resulting in activation of the clone. Clone Ly1‐N5 responds to Mlsa‐bearing B cells only in the presence of SAC. The SAC provide an undefined signal required for the proliferation of certain clones such as clone Ly1‐N5, which is not provided by normal B cells. In this report, we show that the AKTB‐lb B‐cell tumour line stimulates the proliferation of clone Ly1‐N5, in the absence of SAC, suggesting that the tumour line has acquired the capacity to provide this signal.

Linkage of superantigen-like stimulation of syngeneic T cells in a mouse model of follicular center B cell lymphoma to transcription of endogenous mammary tumor virus.

“…In addition, Vf16+ T hybdridomas made in other strains also respond to RCS (Tsiagbe et al, 1993). The responses of SJL T cells to RCS are inhibited by anti-I-AS (Ponzio et al, 1977a;DeKruyff et al, 1985). The putative produce of the 1.8 kb mRNA seen in RCS cells is, therefore, likely to stimulate V,B16 cells in association with I-AS.…”