FIG. 9.

Dose-response effect of anti-class II MHC and monoclonal polyclonal antibodies on HTLV-1 syncytium formation. The MonoPoly antibody and anti-class II MHC MAb H53 were tested for inhibition of HTLV-1 syncytium formation at the indicated dilutions. The antibodies were tested at these same dilutions for staining of the MT2 cells used in the syncytium assay. Intensity of antibody staining (MCF) is plotted versus the mean syncytia per HPF at the indicated antibody dilutions. H53 was used in the form of hybridoma culture supernatant. Syncytium formation in the absence of antibody was 35 ± 4 per HPF.