Immunization with Leishmania-specific T cell not B cell lines or hybridomas can modulate the response of susceptible mice infected with viable parasites.

Monoclonal antibodies (mAb), T cell lines, and T or B cell hybridomas were prepared from BALB/c, CBA, or E1 mice infected with Leishmania mexicana. Various mAb were produced which inhibited the growth and motility of parasites in vitro. T cell lines (hybridomas) were screened for their ability to release interleukin 2 on specific antigen exposure. Passive transfer of mAb or T cell lines to infected adult mice caused little perturbation of parasite growth. Recipient naive mice were immunized with purified Ig or irradiated cells from these sources and were subsequently infected with viable parasites. Only preimmunization with T cell lines (hybridomas) led to exacerbation of parasite growth, although enzyme-linked immunosorbent assays could detect the production of anti-idiotype antibodies in mAb (B cell hybridoma)-immunized mice. Either nylon wool-purified T cells or serum Ig from T cell-immunized mice could be used to immunize further naive recipients for protection against parasite growth. These data have implications for the development of anti-idiotype vaccines for Leishmania antigens.