Human anti-idiotypic T lymphocyte clones are activated by autologous anti- rabies virus antibodies presented in association with HLA-DQ molecules.

The regulatory function of antigen-specific T cells in human antibody responses to protein and carbohydrate determinants of many viral and bacterial antigens has extensively been studied in systems involving in vitro triggering of B cells by antigens or polyclonal activators. Although amply documented in experimental murine models, the existence of T helper cells with receptor specificity for idiotypic determinants of B cell immunoglobulins has not been demonstrated in a human system. We are interested in T helper cell recognition of idiotypic determinants of virus-specific antibody, secreted by human B cells in response to viral antigens, and in the role which such idiotype-specific T helper cells play, alone or in concert with virus-specific T helper cells, to regulate the antibody response. Understanding of the function of different T helper cell subsets in an anti-viral antibody response and especially of the mechanisms of idiotype recognition by T cells is important for the development, and future application in man of idiotype vaccines, the potential of which has been indicated for different pathogens in several animal species. It was realized that for the efficient characterization of each of the T helper cell subsets, the availability of cloned populations of T cells would be inevitable. Furthermore, we argued that if, as predicted by Jerne, idiotype recognizing T helper cells are involved in physiological idiotype regulation in the course of an immune response--e.g., following encounter with viru