Biomedical subjects

N Vardaxis

Publications and source records attributed to N Vardaxis.

3 recordsLinked to original sources

PubMed2002

Respiratory syncytial virus matrix protein associates with nucleocapsids in infected cells.

Little is known about the functions of the matrix (M) protein of respiratory syncytial virus (RSV). By analogy with other negative-strand RNA viruses, the M protein should inhibit the viral polymerase prior to packaging and facilitate virion assembly. In this study, localization of the RSV M protein in infected cells and its association with the RSV nucleocapsid complex was investigated. RSV-infected cells were shown to contain characteristic cytoplasmic inclusions. Further analysis showed that these inclusions were localization sites of the M protein as well as the N, P, L and M2-1 proteins described previously. The M protein co-purified with viral ribonucleoproteins (RNPs) from RSV-infected cells. The transcriptase activity of purified RNPs was enhanced by treatment with antibodies to the M protein in a dose-dependent manner. These data suggest that the M protein is associated with RSV nucleocapsids and, like the matrix proteins of other negative-strand RNA viruses, can inhibit virus transcription.

Cell Line↗

PubMed1998

Rubella virus replication complexes are virus-modified lysosomes.

Replication complexes are membrane-bound cytoplasmic vacuoles involved in rubella virus (RV) replication. These structures can be identified by their characteristic morphology at the electron microscopy (EM) level and by their association with double-stranded (ds) RNA in immunogold labeling EM studies. Although these virus-induced structures bear some resemblance to lysosomes, their exact nature and origin are unknown. In this study, the localization of two lysosomal markers, lysosomal-associated membrane protein (Lamp-1) and acid phosphatase, relative to the replication complexes was examined by light and electron microscopy. Confocal microscopy using antibodies to dsRNA and Lamp-1 showed colocalization of these two markers in the cytoplasm of RV-infected cells. Immunogold labeling EM studies using antibodies to Lamp-1 confirmed that Lamp-1 was associated with RV replication complexes. EM histochemical studies demonstrated the presence of acid phosphatase in the vacuoles of RV replication complexes. Taken together, these studies show that RV replication complexes are virus-modified lysosomes.

Acid Phosphatase↗

PubMedDate not supplied

The 1998 Lindberg Award. Comparison of glycerol preservation with cryopreservation methods on HIV-1 inactivation.

Cryopreservation and glycerol preservation are 2 successful methods for long-term preservation of human cadaver skin. Preservation is subjected to strict criteria to minimize the risk of disease transmission. This investigation compares the effects of glycerol preservation and cryopreservation on the inactivation of HIV-1. The effects of glycerol preservation and cryopreservation on inactivation of both extracellular and intracellular HIV-1Ba-L were investigated. After exposing HIV-1Ba-L-infected material to various concentrations of glycerol or to 10% dimethyl sulfoxide followed by cryopreservation, uninfected peripheral blood mononuclear cells were added to the treated material. At different time points during the culture, supernatants were taken to quantify HIV-1Ba-L and reverse transcriptase levels to determine HIV-1Ba-L infectivity. Cell-free HIV-1Ba-L was inactivated within 30 minutes in 70% and 85% glycerol. Also, intracellular HIV-1Ba-L in infected peripheral blood mononuclear cells or infected cadaver skin was completely inactivated by glycerol treatment in vitro. Cryopreservation did not show any extracellular or intracellular HIV-1Ba-L inactivation. Glycerol preservation--but not cryopreservation--of human cadaveric donor skin can inactivate both extracellular and intracellular HIV-1.

Burns↗