Observations on the Fine Structure of Mature Herpes Simplex Virus and on the Composition of Its Nucleoid

Abstract

P y~s 1 To 5 (Received for publication, June 12, 1961) In recent work with adenovirus and the Rous virus, specific enzymic digestions were applied to samples of purified pelleted particles, and the resulting changes caused within the particles were then observed in thin sections with the electron microscope; in this way the site and nature of viral nucleic acid were determined (1-5). Since the accuracy of the findings was confirmed in each case by concomitant specific staining of the purified material for nucleic acids (2, 4), it was considered that the results of applying enzyme digestions and electron microscopy alone to virus particles unseparated from cells might safely be relied upon, such preparations being, of course, unsuitable for the additional checking of observations cytochemically.An approach of this kind seemed particularly appropriate in relation to herpes virus, for the mature particles can be readily recognized and their tendency to accumulate at the cell surface is well known (6-9). Furthermore, although cytochemical investigations of the nuclear inclusions arising in herpes infections have demonstrated that they contain much deoxyribonucleic acid (DNA) (10) little is known about the composition of the virus. It has sometimes been assumed that the latter also includes nucleic acid of this type (11), but even though excess DNA is in fact synthesized by cells very soon after infection with herpes virus (12), no connection has been established between this material and the constituents of the agent itself.Experiments were accordingly undertaken in which herpes-infected HeLa cells were examined in thin sections with the electron microscope so that the mature virus particles around them might be studied after treatment with various fi afives, specific nucleases, and in different embedding media, both with and without electron staining. Tests for the biological activity of the cultures examined were included in the first part of the work. The results obtained in this investigation are now reported. Materials and MethodsVirus Strain.--The HFEM strain of herpes virus has been used; it was received frozen at --70°C in infected tissue culture fluid from the 46th tIeLa cell passage (13) (through the 1 on

The familyHerpesviridae: an update

“…A typical he1~esvirion consists of (a) a core containing a linear double stranded DNA which, in some instances, forms a torus [84,163], (b) an icosadeltahedral capsid approximately 100 to 110 nm in diameter containing 12 pentameric and 150 hexameric capsomeres, the latter with a hole running down the long axis [81,231,147]; (c) an amorphous, sometimes asymmetric material which surrounds the capsid and which was designated as the tegument [188]; and (d) a membrane designated as the envelope, in which viral glycoprotein spikes are embedded and project from its surface [4,12,75,78,99,159,160,208,209,211].…”

Morphology of the Virus and of Virus-Induced Cytopathologic Changes

“…It was thought at first that EBV might perhaps be slightly smaller than other herpesviruses, but this view probably arose as a result of the particular preparative techniques \lsed; the influence of different dehydration and embedding procedures on virus size has long been recognized in thin-sectioned material (Epstein, 1962), as has the flattening effect of drying in whole mount, negatively stained preparations. Although comparative studies taking these factors into account have not been undertaken, it is not now considered that there are significant size differences between EBV and other members of the herpes group and in every other detail of morphology EBV is an absolutely typical herpesvirus.…”

Replication characteristics and core size of intranuclear herpes simplex virus (HSV-1) in genital skin lesions: Electronmicroscopy studies of a biopsy from a female patient

“…Electronmicroscopy studies of the structure of HSV have been of untyped HSV in cell cultures (Morgan et al, 1959 ;Epstein, 1962) and in smears (Smith and Coleman, 1983), HSV-1 purified nucleocapsids by immuno-electronmicroscopy to identify specific polypeptides (Vernon et al, 1981), and HSV type-1 strains, including wild type and temperature-sensitive (ts) mutants, in infected cell cultures (Dargan and Subak-Sharpe, 1983 ;Addison et al, 1984). Illustrations of intranuclear HSV-1 by Toshima et al (1967), Dargan and Subak-Sharpe (1983) and Addison et al (1984) are similar to pictures of intranuclear HSV in our work.…”

“…Epstein (1962) gave a core (nucleoid) diameter of 35 mp (nm) for HSV (untyped) in osmium methacrylate preparations. Morgan et al (1959) found that the core of virus capsids within one nucleus varied in size, shape and density; the core dimensions were in the range 20-40 mp (nm), some scattered virus having the largest core with a central region of diminished density.…”

“…There have been electron-optical investigations of HSV-1 and of its mutants in cell cultures (Epstein, 1962;Ciampor and Szanto, 1982;Dargan and Subak-Sharpe, 1983;Addison et al, 1984) and of purified nucleocapsids by immuno-electronmicroscopy (Vernon et al, 1981). There have been no electronmicroscopy studies on HSV-1 capsids and virions in biopsies of genital lesions.…”