In vivo effects of antibodies to immune response gene products. II. Suppression of humoral immune responses with monoclonal anti-I-A is due to suppressor cells.

Abstract

The I region of the murine major histocompatibility complex (H-2) encodes two cell surface glycoprotein complexes (Aα:Aβ and Eα:Eβ) which exert profound control over many immunologic reactions including humoral and cellular responses to a variety of antigens, i.e., Ir gene effects, stimulation in mixed lymphocyte reaction, graft versus host disease, antigen presentation to T cells by macrophages, collaboration between T and B cells and determination of T cell help or suppression [1-13]. In the past few years, several laboratories have reported that antibodies directed against I region gene products (anti-la) are effective in modulating immune responses both in vitro and in vivo [14-32, 48-51]. The ability of anti-la antibodies to alter immune responsiveness was attributed to their interaction with macrophage la antigens, thus masking or sterically hindering la epitopes involved in antigen presentation [16,17, 33-35]. However, other reports have suggested that additional mechanisms may be involved [28, 36-...