Inhibition of Sendai Virus by N1-Isobutylbiguanide Hydrochloride as Studied by Immunofluorescent Staining

Abstract
Summary In the presence of a non-toxic concentration of N1-isobutylbiguanide hydrochloride, HA production in L cells infected with Sendai virus was reduced to 1/16 of the control. The effect of the compound was reversible, and the presence of the compound through the entire course of infection was necessary and essential for the inhibition. The number of infectious centers was not reduced even when the cell was treated with the compound all through infection, indicating that the compound did not affect the processes of adsorption or penetration of the virus. However, the infected cells remained in the first stage of antigen development in the presence of the compound, i.e., the accumulation of antigens was limited to the juxta-nuclear region of cytoplasm and not extended to the entire cytoplasm. It is concluded that the effect of the compound is on the inhibition of the late maturation mechanism of Sendai virus synthesis.