In vitro inhibition of the helper activity of GAT-specific T-cell lines by a syngeneic anti-idiotypic serum: Preferential effect on the IgG 1 response

Abstract

We described in this paper the characteristics of a syngeneic anti-idiotypic serum made in BALB/c against BALB/c anti-poly (Glu 60 Ala 30 Tyr 10) (GAT) antibodies. This serum recognizes idiotypic determinants present in all anti-GAT sera whatever the allotypic markers of the mice used to prepare the sera. The functional effect of this serum on two helper cell lines is also described. Cell line BDF 1/52 was obtained from GAT immunized lymph node cells (LNC). Cell line BDF 1/E 3 was selected from splenic T-cells educated in vitro on GAT-pulsed adherent cells. Both lines were propagated in presence of filler cells, antigen, and medium containing T-cell growth factor(s) from splenic cells activated with concanavalin A. Both cell lines exhibit a helper activity as measured by the plaque-forming cell (PFC) response they induce in vitro in the presence of DNP-GAT and DNP sensitized B cells. Their helper activity is specific and they require a hapten-carrier bridge to activate B cells. These lines are able to induce IgG 1, IgG 2a and IgG 2b anti-TNP PFC. Syngeneic anti-idiotypic serum B 658 inhibits specifically the function of these two lines but does not affect the helper activity of an OVA-specific T-cell line. The blocking activity of the serum can be adsorbed on a hybridoma protein with anti-GAT activity. This inhibition affects more dramatically the IgG 1 response than the IgG 2a and IgG 2b responses.