Microfluorometric quantitation of size, deoxyribonucleic acid and viral antigenic determinants in cells productively infected with HSV-2.

The interaction of herpes simplex virus type 2 (HSV-2) with the eukaryotic human cell line (HEp-2) was investigated by flow microfluorometric analysis. The three parameters that were quantitated include cell size, deoxyribonucleic acid content and the expression of virus-specific antigens. Productively infected cells are always smaller than uninfected ones, and they resolve into two populations with respect to viral antigenic content. Consistent with viral replication, one of these two populations, displaying a higher viral antigenic content, shows morphologic features characteristic of cell degeneration. On the other hand, the second population, with a relatively lower content of viral antigens, displays morphologic features consistent with increased cell growth. Indeed, microfluorometric measurements of the HSV-2-infected cells with respect to DNA content and expression of viral antigenic determinants resolves four cell populations. Of them, one displays the lowest level of viral antigens with the highest (equivalent to 8N) DNA content, features consistent with transformation. The results demonstrate the great potential of this technique for the detection, separation and quantitation of statistically significant cell populations not otherwise identified and for the analysis of virus-host cell interactions resulting in different pathologic outcomes.