Studies on Pharmacological Activation of Human Immunoglobulin G by Chemical Modification and Active Subfragments. XII. Effect of Carboxamidemethylated Fc Fragment (CM-Fc) from Human Immunoglobulin G on Mixed Lymphocyte Reaction

Abstract

The effect of carboxamidemethylated Fc fragment (CM-Fc) from human serum immunoglobulin G on mixed lymphocyte reaction (MLR) was studied. CM-Fc enhanced the MLR response when added at the start of cultivation, but suppressed the response when added 48 h after onset of cultivation. The Fc fragment had no effect. CM-Fc elevated the levels of interleukin-1 and tumor necrosis factor when added at the start of splenocyte cultivation, and somewhat did so when added 48 h after onset of cultivation. These elevations caused the induction of prostaglandin E₂ in MLR culture supernatant. The suppression of MLR by CM-Fc was abrogated by the addition of indomethacin. We considered that CM-Fc regulated the immune response being affected to the function of macrophages.