Antigen binding T and B lymphocytes. I. Differences in cellular specificity and influence of metabolic activity on interaction of antigen with T and B cells.

Abstract

In the present study, conditions are described for the selective detection of specific 125 I-(T, G)-A--L binding to peripheral B and T cells. The following observations were made: 1) B cells appear to have at least 5 times more antigen receptors than do T cells. 2) When cells were allowed to react with antigen at 37°C instead of at 4°C, this had no influence on the frequency of B-ABC. In contrast, the number of T-ABC was increased 2- to 3-fold. This increase could be prevented by sodium azide, suggesting that the exposure of antigen-binding receptors on the surface of T cells depends on cellular metabolic activity. 3) Inhibition studies with chemical analogs of (T, G)-A--L revealed a different specificity of B and T cells. Whereas excess unlabeled (T, G)-A--L, (Phe, G)-A--L and (H, G)-A--L could each block 125 I-(T, G)-A--L binding to B cells, only unlabeled (T, G)-A--L could inhibit specific T-ABC. Altogether, these observations provide further evidence for profound differences between B and T cell antigen receptors.