Recombinant soluble receptors for the Fcγ portion inhibit antibody production in vitro

Abstract

The problem of the structural relationship between suppressive IgG‐binding factor and low‐affinity receptors for the Fc portion of IgG (FcγRII) has not yet been solved. In the present work we have isolated a recombinant soluble FcγRII containing only the two external domains of FcγRII, and analyzed its biochemical characteristics and biological activity. A cDNA encoding FcγRII was mutated by the creation of a stop codon at the Lys175 codon. L cells have been transfected with this cDNA inserted into an expression vector. A cell line was obtained that secretes recombinant soluble FcγRII which reacts with a monoclonal anti‐FcγRII antibody and binds to IgG1, IgG2a and IgG2b murine isotypes but n..