ABSTRACT
The concept of collaboration among different populations and subpopulations of cells during an immune response is generally accepted. Immune complexes (IC) consisting of large particulate antigens coated with xenogeneic antibody might affect immunoregulatory mechanisms differently than soluble IC containing allogeneic or autochthonous antibody. Specific antibody may be assayed in nonspecific suppressor cell systems. The existence of suppressor function residing in the T lymphocytes was initially recognized because immune responses to some antigens were greater in the absence of thymic influence than in its presence. Human T cells may also be divided into two populations distinguished from each other by the presence or absence of the TH2 antigen. Human T cells and B cells may be separated by using sheep erythrocyte rosette sedimentation. B cells and macrophages adhere to the column while T cells pass through. Compared to helper T cells, suppressor T cells were reported by F. P. Siegal and M. Siegal to be exquisitely radiosensitive.
