An enzyme-linked immunosorbent assay (ELISA) for detection of Fc alpha receptors on isotype-specific T cells.

A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) has been developed using T cell hybridomas as coating antigen, for detection of Fc receptors for IgA (Fc alpha R). T-T hybridomas were generated from fusions of Fc alpha R+ T cell clones from mouse Peyer's patches with the Fc alpha R- R1.1 T lymphoma cell line. The 2 T-T hybridomas (designated Th HA) used here express Fc alpha R as determined by a rosette method and by ELISA. Th HA cells were cultured under conditions for maximum Fc alpha R expression, were added to individual wells of 96-well EIA plates, and were fixed in situ with glutaraldehyde. Plates were incubated with purified mouse monoclonal IgA, IgM or IgG1 and were developed with beta-galactosidase-coupled goat IgG antibodies specific for mouse heavy chains. Using the ELISA, both Th HA cell lines were shown to express significant levels of Fc alpha R, lower but detectable Fc mu R, and no discernible Fc gamma 1R. Interestingly, the rosette assay only allowed detection of receptors for IgA. When splenic lymphocytes were used, good Fc mu R and less Fc alpha R expression occurred on these cells as determined by ELISA and rosetting; however, no Fc gamma 1R cells were detected by either method. Thus, the ELISA is sensitive and reproducible, and allows an objective measurement of FcR expressed on T cells.