AIM: To study TCR Vbeta binding sites of staphylococcal enterotoxin D(SED). METHODS: Six SED mutants were constructed by site-directed mutagenesis. The activity of promoting T cell proliferation by the mutants was detected by (3)H-TdR incorporation. For the mutants with decreased mitogenic activity, flow cytometry was used detect their MHC-II binding activity and TCR Vbeta specificity. RESULTS: Residue N23 played an important role in the interaction of SED with human TCR Vbeta5. Residue H26 was probably a SED binding site to human TCR Vbetas except for TCR Vbeta5, TCR Vbeta8 and TCR Vbeta12.1. CONCLUSION: Residue N23 is a key TCR Vbeta binding site of SED.
AIM: To study TCR Vbeta binding sites of staphylococcal enterotoxin D(SED). METHODS: Six SED mutants were constructed by site-directed mutagenesis. The activity of promoting T cell proliferation by the mutants was detected by (3)H-TdR incorporation. For the mutants with decreased mitogenic activity, flow cytometry was used detect their MHC-II binding activity and TCR Vbeta specificity. RESULTS: Residue N23 played an important role in the interaction of SED with human TCR Vbeta5. Residue H26 was probably a SED binding site to human TCR Vbetas except for TCR Vbeta5, TCR Vbeta8 and TCR Vbeta12.1. CONCLUSION: Residue N23 is a key TCR Vbeta binding site of SED.