Distribution by immunofluorescence of viral products and actin-containing cytoskeletal filaments in rubella virus-infected cells

Abstract

Rubella virus (RV)-host cell interactions were examined by indirect immunofluorescence staining using antibodies to viral products and cytoskeletal components as probes. The patterns of immunofluorescence observed with human convalescent sera indicated that in infected Vero cells RV-specified proteins were distributed throughout the rough endoplasmic reticulum with some possible accumulation in the region of the Golgi complex. Viral RNA synthesis, detected with anti-double stranded RNA, appeared to be confined to small, intensely stained foci irregularly distributed in the cytoplasm. When cells were infected at a higher multiplicity, these foci appeared to aggregate into linear arrays. Infection with RV had a profound effect on the organization of actin in both Vero and BHK 21 cells, as shown by anti-actin antibodies. Actin microfilaments were observed to disintegrate progressively into amorphous aggregates of apparently monomeric actin as the infection proceeded. Because of the role actin microfilaments may play in cell mitosis it is postulated that this effect may be related to the inhibition of cell division reported to be associated with the congenital rubella syndrome.

Rubella Virus Replication and Links to Teratogenicity

“…The effects of RV infection on the cytoskeletal components of cells have been investigated by immunofluorescence studies using antibodies to actin (17). A significant alteration in the arrangement of actin filaments following RV infection was evident.…”

“…Previous work has shown two distinctive features of RV replication which may impact on normal host cell function, notably, mitochondrial abnormalities and disruption of the host cell cytoskeleton (17,82,85). More recent work has investigated the ability of RV to induce apoptosis, and a mechanism for the teratogenic effect of RV has been proposed (29,63,96,123).…”

Measles Virus-Induced Disruption of the Glial-Fibrillary-Acidic Protein Cytoskeleton in an Astrocytoma Cell Line (U-251)

“…Many viruses have been shown to cause alterations to the cytoskeleton during in vitro infection (6,10,43,47). For a review, see the work of Cudmore et al (12).…”

Neurological Aspects of Rubella Virus Infection

“…commun.]. The rubella virus has been shown to alter the cytoplasmic structural frame work, particularly actin-containing microfilaments, which could have an inhibitory effect on mitosis [ 18], One report characterized an extracellular factor released from infected cells that inhibited growth of neighboring, unin fected cells [19]. Rubella virus-infected cells have also been shown to exhibit decreased sensitivity to extracellu lar growth factors [20], Since the primary time in gesta tion when rubella virus exhibits profound teratogenicity (i.e., the first trimester) coincides with organogenesis in the developing fetus, the favored hypothesis is that altera tions induced in infected fetal progenitor cells ultimately affect organ development.…”