ARBOVIRUS HEMAGGLUTININ INHIBITORS

II. INHIBITOR ACTIVITIES OF LIPID FRACTIONS FROM EGG YOLK AGAINST ARBOVIRUS

Abstract

In a previous paper, it was shown that chloroformmethanol fraction extracted from egg yolk inhibited remarkably HA activity of many arboviruses. In present paper, further purification studies have been performed and inhibitory activities of the several lipids derived from egg yolk were tested with eight strains of arboviruses. The following results were obtanied:
1) Group A arbovirus: Three strains of Getah virus (MM 2021, Sagiyama and Haruna) were highly inhibited with the fraction III containing lecithin, and were not sensitive to the fractions I (cholesterol) and IV. Specific sensitivity of Getah virus to lecithin was also confirmed by standard preparation (SIGMA L-a-lecithin). Bevaru (MM 2354) virus was sensitive to fraction IV and differed from Getah virus.
2) Group B arbovirus: Two strains of Japanese encephalitis virus (JaGAr-01 and Nakayama) were inhibited markedly with the fractions I and IV. However, Negishi virus (RSSE family, tick-borne) was not sensitive to the fraction I. As the fraction I contained mainly cholesterol, this result supported the previous view that cholesterol was the specific inhibitor to JE virus.
3) Bunyamwera group: The test was carried out with Bunyamwera original strain, and low inhibiting activity was observed against this virus with the fractions II and III.
4) Some physical influence upon HA inhibition: Although the avidity of antigens against antibodies unchanged, it was found that sensitivity of viruses to some inhibitors decreased during the storage at 4°C over one month. It was also observed that heated virus was more sensitive to inhibitors than untreated one.