[Various biological characteristics of Sindbis virus]

The hemagglutinating activity of Sindbis virus on untreated or tripsinized blood red cells of some animal species was assessed. In some cases tripsinization increases the red cell sensitivity to viral hemagglutinin. Interferon (IFN) production induced by Sindbis virus on human WISH, mouse L-929 and chicken FEP cells was similar in all three cases. The effects of the temperature on virus replication were studied. Optimal growth was seem to take place at 37 degrees C. These data suggest that the viral pathogenic effect in humans in contrast to the asymptomatic infection in reservoirs is not related to differences in IFN production, but could be due to differences in host body temperature.