T Lymphocyte Recognition of Alloantigen in Vitro.

Abstract

The present experiments were curried out in order to answer the question whether the precursor T cells of cytotoxic T lymphocytes (PCTL) are Fc receptor positive (FcR⁺). Fc receptor negative (FcR⁻), or both. The data show that cytotoxic T lymphocytes (CTL) can be generated in vitro from both FcR⁺ and FcR⁻ PCTL. Furthermore, we investigated if the function of FcR⁺ and FcR⁻ CTL differed in the allograft response in vitro. Qualitatively, FcR⁻ PCTL differentiate into FcR⁻ CTL only, whereas FcR⁺ PCTL differentiate into both FcR⁺ and FcR⁻ CTL. However, quantitatively, CTL generated from FcR⁺ PCTL display a higher T cell mediated cytotoxicity than CTL generated from FcR⁺ PCTL. Mixing experiments indicate that FcR⁺ T cells regulate the differentiation of FcR⁻ PCTL into CTL. These conclusions hold true for PCTL in both normal and memory responder cell populations.