Cloned T helper cells reverting to a resting state develop increasing sensitivity in their antigen‐mediated interaction with accessory cells

Abstract

A cloned murine T cell line, KIII5, specific for the polypeptide poly-L(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys [(T,G)-A--L] was compared at different stages after antigenic stimulation with respect to the conditions required for the reinduction of growth by varying concentrations of antigen presented on different types of accessory cells (AC). We show that the dose of antigen necessary for inducing half maximal proliferation in the presence of splenic AC shifts to considerably lower concentrations when the T cell blasts revert to a resting state (100 micrograms/ml on day 7 to 10 micrograms/ml on day 21-35). During the same time period the expression of interleukin 2 (IL2) receptor and the reactivity to IL2 decline. However, no direct correlation between the increasing sensitivity to antigen and the decreasing reactivity to IL2 appears to exist. With peritoneal AC "early" T cells (day 7) did not respond to (T,G)-A--L at all, but in the course of "aging" responsiveness increased and finally reached the same level as in the presence of splenic AC, although at a higher antigen dose (100 micrograms/ml on day 35-45). Furthermore, the antigen-induced proliferation of "aging" T cells became more resistant to inhibition both by anti-L3T4 and anti-T cell receptor antibodies. Two alternative interpretations of these data are possible: antigen-activated T cells, while gradually reverting to a resting state, interact more avidly with antigen-presenting cells or the triggering threshold of the T cells is decreasing.

Requirements for the growth of TH1 lymphocyte clones

“…The cloned F7.15A T cells are of (B10 x BIO.BR)F1 origin and autoreactive for Ab,Ai [17]. The Tcell clone KIIIS is of (B10 x B1O.BR)FI origin and recognizes (T,G)-A--L in the context of Ab, A; [18]. All theseTcells are CD4+ and belong to theTH1 subtype of T h cells (data not shown).…”

“…All theseTcells are CD4+ and belong to theTH1 subtype of T h cells (data not shown). They were propagated in vitro as described [9,18]. The B cell lymphoma A20 of BALB/c origin was obtained from the American Type Culture Collection (ATCC, Rockville, MD).…”

Costimulatory signalling potential of murine MHC class II‐positive T‐clone cells

“…The Aa b Ab k -restricted GAT-reactive T-cell clone KIII5 was described previously. 21 These cells represent Th1type cells based on their cytokine production profile (production of IFN-g and IL-2, no production of IL-4, IL-5 and IL-6, our unpublished results). D10.G4.1 T cells 34 In some experiments mAb, cytokines, or CTLA4-Ig fusion protein were added to the cultures.…”

“…As a representative Th1 cell clone with the characteristics of efficient IL-2R downregulation we employed the T-cell clone KIII5 with specificity for the synthetic copolymer of L-glutamic acid, Lalanine, and L-tyrosine (GAT) in combination with Aa b Ab k molecules. 21…”

Cellular immune responses in mice immunized with Anisakis simplex larval antigens

“…5). When T cells were exposed to high doses of IL-2, an increase in proliferation was observed, transforming these cells into antigen non-responding cells for several days (Kuhn et al 1988). In our experimental model, an analogous situation may have happened when the production of T-cells was maximal and the activation of these cells was minimal by day 4 p.i.…”