Defective induction of antigen‐reactive proliferating T cells in B cell‐deprived mice

Mice were injected from day of birth onward with rabbit anti‐mouse IgM antiserum or purified rabbit anti‐mouse IgM antibodies. These mice completely lacked Ig‐positive cells or serum Ig, as analyzed by specific fluoresceinated antibodies on the fluorescence‐activated cell sorter (FACS‐II), by polyclonal B cell mitogens and by specific precipitation in agar. These animals were then primed in vivo by antigen emulsified in complete Freund's adjuvant, and, subsequently, their draining lymph nodes were tested for their T cell proliferative responses in vitro, to the relevant antigen and were found to be severely impaired. However, the antigen‐presenting capacity of both spleen cells and thioglycollate‐induced peritoneal cells was found to be intact.