Regulation of helper cell activity by specifically adsorbable T lymphocytes

Mice immunized with soluble proteins such as human serum albumin (HSA) or ovalbumin (OA) develop in their spleens antigen-specific T and B lymphocytes. These populations of lymphocytes can be separated from each other by different means; e.g. treatment with anti-theta-antiserum and complement removes selectively T lymphocytes, whereas passage through glass bead columns coated with mouse immunoglobulin (Ig): anti-Ig complexes creates a relatively pure population of T lymphocytes. During the course of such separation studies it was observed that the helper capacity of HSA (or OA) immune mouse spleen cells after Ig:anti-Ig column passage frequently was higher than expected from the enrichment in theta-positive cells. In addition, after adsorption onto antigen coated Bio-Gel beads this effect was even more pronounced, i.e., and increase in the relative helper capacity of about 3 or 4 times compared with an increase in the content of theta-positive cells from about 30% to 40 to 50% after adsorption. The present results will demonstrate that the increased helper capacity was a specific phenomenon which was regulated by theta-positive cells. The regulatory cells specifically adsorbed onto antigen-coated Bio-Gel beads have not been successfully eluted by EDTA or excess-free antigen so far, and they were still adsorbed after pre-incubation with anti-Ig antibodies under conditions where specific B lymphocyte adsorption was almost prevented.