Production of anti‐H‐2 antibodies in thymectomized mice

Neonatally and adult thymectomized (Tx) mice of strains C57BL/10Sn and A. BY (H‐2^b) were immunized at the age of 5 – 8 weeks with lethally irradiated spleen and lymph node cells from adult B 10. A and A (H‐2^a) donors, respectively. The titer of H‐2 hemagglutinins and cytotoxins was determined at different intervals after immunization. Both untreated antibodies and antibodies reduced with 2‐mercaptoethanol (2‐Me) were tested. The non‐Tx control mice responded with production of both 2‐Me‐sensitive and 2‐Me‐resistant H‐2 antibodies. In the Tx mice, only 2‐Me‐sensitive H‐2 antibodies were detected. Thus, the anti‐H‐2 IgM response appears to be thymus‐independent and the anti‐H‐2 IgG response thymus‐dependent.