Regulation of IgG production by suppressor FcγRII+T hybridomas

摘要

AbstractIn this work, we analyzed the immunoglobulin heavy (H) and light (L) chain production by two variant B hybridomas, UN2.C3 and UN2.C17.K1 co‐cultured with cells from a FcγRII, IgG‐binding factor (IgG‐BF)‐producer T hybridoma (T2D4.C1) or with cells of a FcγRII−, IgG‐BF‐nonproducer variant (D10C5). We showed that only the FcγRII hybridoma directly inhibits the IgG secretion by UN2.C3 through a soluble mediator. This inhibition affects the H and L chain synthesis as well as the H and L chain‐encoding mRNA steady state. No apparent cytotoxic effect could be detected. In contrast, the production of ϰ chain by an H chain‐negative variant (UN2.C17.K1) was unaffected. This indicates that a complete IgG molecule is required to observe the inhibitory effect induced by T2D4.C1. The pattern of effector/target cell interactions observed in our work suggests that the soluble factor involved in the suppression of IgG production is IgG‐BF, able to transiently modify the IgG gene exp