Genetic control of the immune response to myoglobin. V. Antibody production in vitro is macrophage and T cell-dependent and is under control of two determinant-specific Ir genes
Kohno, Y.; Berzofsky, J.A.
Journal of Immunology 128(6): 2458-2464
1982
ISSN/ISBN: 0022-1767 PMID: 6176636 Document Number: 183963
To study the mechanism of mouse Ir gene control, an in vitro culture system was developed in which myoglobin (Mb)-specific antibody secreted in the culture supernatant can be measured. This system differs from the commonly used Mishell-Dutton type cultures in that supernatant-secreted antibody is measured rather than plaque-forming cells and in that no hapten-carrier conjugate is used. Thus, the antibodies specific for Mb, fragment (1-55) or fragment (132-153) of Mb, could all be quantitated in the same culture supernatants stimulated by whole Mb. The B cell antibody response to Mb in vitro was dependent on both T cells and macrophages. Genetic control of the in vitro response to Mb was shown to parallel the H-2-linked Ir gene control of the in vivo antibody response and the in vitro T cell proliferative response. The in vitro antibody response to Mb in the H-2d haplotype is regulated by 2 Ir genes mapping in the I-A (Ir-Mb-1) and the I-C (Ir-Mb-2) subregions of the H-2 complex. Mice of haplotype H-2d and s are high responders to Mb and mice of haplotypes H-2k and b are low responders to Mb. In the in vitro response, the mapping studies were extended beyond those previously reported in vivo. When the antigen used to stimulate in vitro is whole Mb, production of antibody specific for fragment (132-153) is controlled by I-A alone, as was found in vivo. Production of antibody specific for fragment (1-55), which could not be accurately quantitated previously, was now found to be controlled in vitro by both I-A and I-C. In a new mapping study using H-2s recombinants, not previously examined for serum antibody, only 1 gene could be detected in the H-2s haplotype, mapping in I-A, I-B or I-J. Non-H-2-linked Ir gene control, similar to that detected in vivo, also influenced the in vitro antibody response. The operation of non-H-2-linked genes in amplifying the overall response in vitro, in a manner identical to the amplification in vivo, implies that the non-H-2-linked mechanism does not require an intact organism, as might be required for a process involving clearance of antigen or antibody.