Search for I-A trans-complementation affecting the anti-thy-1 response in mice: a final report.

Twenty-nine different F1 hybrids were tested for the possible effect of the H-2 (I-A) heterozygosity purportedly mediated by I-A trans-complementation, on the magnitude of the anti-Thy-1 response. Although the hybrids tested responded well to immunization with Thy-1 disparate thymocytes from donors H-2 compatible with one of the parents they responded poorly when immunized with thymocytes from donors H-2 incompatible with both parents. Preliminary data suggest that H-2 heterozygosity may exert a small but definite effect in H-2r/H-2f hybrids.