Enhancing effect of murine anti-idiotypic serum on the proliferative response specific for poly(LTyr, LGlu)-poly(DLAla)--poly(LLys)[(T,G)-A--L]

Establishment and biological activity of a proliferative anti-idiotype-activated T cell line

Antisera were raised in rabbits against a monoclonal antibody (McAb 103) of C3H.SW origin which is specific to the synthetic polypeptide (T,G)-A-L and was shown to express the major idiotypic determinants of conventional anti-(T,G)-A-L antibodies. Antibodies were purified and were shown in a binding assay to recognize McAb 103 as well as C3H.SW anti-(T,G)-A-L antibodies. C57BL/6 mice were immunized with the purified rabbit anti-McAb 103 (Ra 103) and their lymph nodes were studied in a proliferation assay. Proliferation was observed in the presence of both Ra 103 and (T,G)-A-L, although the latter stimulated the cells to a lesser extent, suggesting the induction in vivo of (T,G)-A-L-specific clones in low frequency. A T cell line was established from these lymph node cells. The line is kept in continuous growth in the presence of IL-2 and periodic triggering with Ra 103. A significant proliferative response was obtained with Ra 103 only. This proliferation could be almost completely inhibited by either McAb 103 or by conventional anti-(T,G)-A-L antibodies of C3H.SW origin, indicating the cross reaction between the idiotypes expressed on the T cell line and the (T,G)-A-L-specific antibodies. No proliferation could be detected in the presence of either normal rabbit IgG or rabbit anti-mouse IgG. Thus, the T cell line TId 103 allows the analysis of the role of idiotype in T cell recognition and regulation.

Antiidiotype stimulation of antigen-specific antigen-independent antibody responses in vitro. I. Evidence for stimulation of helper T lymphocyte function

Antibodies specific for the idiotypes of B10 anti-(T,G)-A-L antibodies (anti-Id) induced in vivo (T,G)-A-L-primed lymphocytes to secrete anti-(T,G)-A-L antibodies in vitro in the absence of antigen. Responses to anti-Id were quantitatively and qualitatively similar to responses to antigen. Responses were specific in that: (a) only lymphocytes primed in vivo with (T,G)-A-L (but not other antigens or unprimed cells) were inducible; (b) only anti-Id (but not a variety of control antibodies) induced responses; and (c) only anti-(T,G)-A-L antibodies were secreted. Antigen-primed T lymphocytes mixed with unprimed B plus accessory cells also responded to anti-Id and the phenotype of the responding T cells was Lyt-1+, Lyt-2-. Supernatants obtained from antigen-primed T cells incubated for 3 d with anti-Id (but not when incubated with controls) provided help to unprimed B plus accessory cells in the presence of anti-Id, thus providing direct evidence for induction of T lymphocyte helper function by anti-Id. In contrast to responses to (T,G)-A-L, responses to anti-Id did not appear to be regulated by H-2-linked Ir genes. The system described is a powerful tool for delineation of the mechanisms whereby antiidiotype antibodies affect lymphocyte function.