The effect of a proline-rich polypeptide (PRP) on the humoral immune response. I. Distinct effect of PRP on the T cell properties of mouse glass-nonadherent (NAT) and glass-adherent (GAT) thymocytes in thymectomized mice.

It has been shown, using thymectomized, irradiated and reconstituted mice and a proline-rich polypeptide (PRP) that glass-nonadherent thymocytes contain a precursor of helper cell, and glass-adherent thymocytes a precursor of suppressor cells in the humoral immune response to SRBC. Precursor cells differentiate into helper or suppressor cells upon in vitro contact with PRP. Moreover, it was demonstrated that NAT and GAT fractions are related to PNA+ and PNA- thymocytes respectively.