CD4 down-modulation by ganglioside and phorbol ester inhibits human herpesvirus 7 infection

1 First Department of Internal Medicine, Ehime University School of Medicine, Shigenobu, Ehime 791-02 and 2 Ehime College of Health Science, Tobe, Ehime 791-21, Japan Recently, data demonstrating that CD4 is an essential component of the receptor for human herpesvirus 7 (HHV-7) as well as for human immunodeficiency virus have been accumulating. Since gangliosides and phorbol esters are known to induce selective down-modulation of cell surface CD4 expression, it might be expected that treatment with these agents would interfere with HHV-7 infection of CD4 + T cells. The present study, undertaken to verify this possibility, demonstrated that addition of monosialoganglioside-GM1 or 12- O -tetradecanoylphorbol 13-acetate effectively induced disappearance of CD4 from the cell surface and also reduced HHV-7 infectivity, as judged by the CPE on virus-infected cells and studies of indirect immunofluorescence, TCID 50 and semi-quantitative PCR of the HHV-7 genome. Taken together with previous studies, the present data strongly suggest that the CD4 molecule is a critical component of the receptor for HHV-7. * Author for correspondence. Fax +81 899 64 4766. e-mail yasukawa@m.ehime-u.ac.jp Received 27 February 1995; accepted 15 May 1995.