Immunotherapy of a murine B cell tumor with antibodies and F(ab')2 fragments against idiotypic determinants of its cell surface IgM.

Anti-idiotype antibodies against the IgM of the 38C-13 murine B lymphocyte cell line and F(ab')2 fragments derived from them were checked for their therapeutic effect against the killing of mice by 38C-13 cells. Both intact molecules and the F(ab')2 fragments were effective in delaying or preventing the killing of mice by 38C-13 tumors when used in large amounts and by the appropriate routes.