The morphogenesis of herpes simplex virus type 1 in infected parental mouse L fibroblasts and mutant gro29 cells

Abstract

Mutants of cell lines and viruses are important biological tools. The pathway of herpesvirus particle maturation and egress are contentious issues. The mutant gro29 line of mouse L cells is defective for egress of herpes simplex virus type 1 (HSV-1) virions, and a candidate for studies of virus-cell interactions. The properties of uninfected and HSV-1-infected L fibroblasts and gro29 cells investigated by protein assay, immunoblot, titration assay, immunofluorescence light microscopy and immunogold cryosection electron microscopy are reported. The ultrastructure of both HSV-1-infected L and gro29 cells confirmed primary envelopment of virions at the nuclear membranes followed by maturing multiple de-envelopments and re-envelopments in the endoplasmic reticulum and in the Golgi complex. The gro29 cells presented changed cytoskeleton, abolished egress of virions, and were defective in the trafficking of glycoproteins, giving rise to accumulation of viral particles and glycoproteins in the endoplasmic reticulum and the Golgi complex. The results suggest that gro29 cells harbour a causal underlying defect of the cytoskeleton in addition to the HSV-1-induced cytoskeletal changes.

Varicella-Zoster Virus Infection Influences Expression and Organization of Actin and α-Tubulin but Does Not Affect Lamin A and Vimentin

“…It is known for HSV-1 that progression of the infection is signifi cantly inhibited by addition of NOC [2] or brefeldin A, which has been reported to affect both the tubulin and the vimentin networks of the treated cells and thus cause an accumulation of viral particles and glycoproteins in the perinuclear space [31] . These observations are supported by fi ndings made in mutated gro29 cells harboring an underlying defect of the cytoskeleton that were infected with HSV-1 [32] . These infected cells present abolished egress of virions and were defective in the traffi cking of glycoproteins [32] .…”

“…These observations are supported by fi ndings made in mutated gro29 cells harboring an underlying defect of the cytoskeleton that were infected with HSV-1 [32] . These infected cells present abolished egress of virions and were defective in the traffi cking of glycoproteins [32] . In our study, disruption of either one of these fi laments resulted in a decreased level of replication as indicated by plaque formation.…”

HSV trafficking and development of gene therapy vectors with applications in the nervous system

“…[7][8][9] Proteins residing in the underlying tegument are responsible for initiating gene expression from the viral genome, 10,11 shutting off host cell protein synthesis, 12,13 and assist in virion maturation and egress. [14][15][16][17][18] The virion proteins VP5, VP19c, VP23, and VP26 [19][20][21][22] form the icosadeltahedral capsid that encases the double-stranded DNA genome. The 152 kb viral genome encodes 84 genes (Figure 1b), and consists of a unique long (U L ) and a unique short (U S ) segment (Figure 1b) each flanked by repeat sequences (ab, b 0 a 0 , a 0 c 0 ca) [23][24][25][26][27] that can invert relative to one another.…”

Herpes Simplex Virus Type 2 Mucin-Like Glycoprotein mgG Promotes Virus Release from the Surface of Infected Cells

“…This arrangement is similar both to cellular sialomucins which are known to be extensively expressed on microvillus protrusions [ 51 , 52 ] and to the viral mucin-like proteins such as gp2 of equine herpesvirus 1 (EHV-1) [ 53 ] and gp150 of murine herpesvirus 4 (MHV-4) [ 54 ] that are regarded as the major virus antigens. Abundant expression at the cell plasma membrane of infected cells was also reported for gD of HSV-1 [ 55 ], an event related to possible blockage of the viral entry receptors and interference with HSV re-infection [ 56 , 57 ]. It is not known whether extensive expression of mgG on cellular protrusions coincides with the expression of the HSV attachment receptors that is, the GAG-bearing proteoglycans, however, these proteins are known to stabilize the structure of cellular microvillus protrusions (reviewed in [ 58 ]).…”