A STIMULATORY MONOCLONAL-ANTIBODY DETECTING T-CELL RECEPTOR DIVERSITY AMONG IDIOTYPE-SPECIFIC, MAJOR HISTOCOMPATIBILITY COMPLEX-RESTRICTED T-CELL CLONES

A panel of independent BALB/c T cell clones responding to a peptide of the λ2315 immunoglobulin light chain (residues 91–101), in the context of I‐Ed, has previously been described. A monoclonal antibody (mAb; GB113) to the T cell receptor (TcR) of one of the clones, 4B2A1 (Vα1, Jα19; Vβ8.2, Dβ1.1, Jβ1.2) precipitates the α/β heterodimer from 4B2A1. However, GB113 does not bind DO11‐10.2 cells bearing a similar α/β heterodimer (Vα1.1, JαTT11; Vβ8.2, Dβ1.1, Jβ1.1). GB113 does not cross‐react with the TcR of the six other clones in the panel. Furthermore, the mAb does not bind polyclonal λ2315‐specific T cell lines except 4.4% of cells of line 4 from which 4B2A1 was cloned. The mAb only binds a negligible number (0.5%) of BALB/c thymocytes and peripheral T cells. Therefore, the epitope detected by GB113 is very rarely expressed on 91‐101. λ2315‐specific TcR or on TcR of normal T cells. Soluble GB113 induces T cell activation [measured as proliferation and interleukin (IL) 2, IL 3 and interferon‐γ production]. GB113‐induced T cell activation is enhanced by soluble anti‐CD4 and anti‐Thy‐1 mAb. Copyright © 1990 Wiley‐VCH Verlag GmbH & Co. KGaA