Genetic control of the immune response to collagen. II. Antibody responses produced in fetal liver restored radiation chimeras and thymus reconstituted F1 hybrid nude mice.

The level of antibody produced in response to calf skin collagen in mice is influenced by genes which are closely linked to the I region of the H-2 major histocompatibility complex. This influence is shown to be expressed during lymphoid maturation by testing the antibody responsiveness to collagen in two types of chimeric mice. First, high responder and low responder parental strain mice were lethally irradiated and restored with fetal liver cells from (high X low responder) F1 mice. These F1 leads to parent chimeras exhibited an immune response phenotype characteristic of the irradiated parental strain animals, establishing that H-2 determinants of the host affect antigen responsiveness. Second, (high X low responder) F1 congenitally athymic (nude) mice were restored with fetal thymus transplants from either high or low responder parental strain mice. After a period of maturation these mice were shown to be competent for a T-dependent IgG response to SRBC. The responsiveness to collagen in these mice was characteristic of the parental strain thymus donors, indicating that the expression of H-2 determinants in thymic tissue during lymphoid maturation influences the antibody response phenotype expressed by mice.