Semliki Forest virus (SFV) and Sindbis virus (SIN) are enveloped alphaviruses that enter cells via low-pH-triggered fusion in the endocytic pathway and exit by budding from the plasma membrane. Previous studies with cholesterol-depleted insect cells have shown that SFV requires cholesterol in the cell membrane for both virus fusion and efficient exit of progeny virus. An SFV mutant, srf-3, show...

Semliki Forest virus vectors expressing IL-12 (SFV-IL-12) were shown to induce potent antitumor responses against s.c. MC38 colon adenocarcinomas in immunocompetent mice. However, when MC38 tumors were implanted in liver, where colon tumors usually metastasize, SFV-IL-12 efficacy was significantly reduced. We reasoned that characterization of immune responses against intrahepatic tumors in resp...

DNA hybridization experiments indicate that the genome of a tumorigenic poxvirus. Shope fibroma virus (SFV), possesses sequence homology with DNA isolated from uninfected rabbit cells. Southern blotting experiments, either with high-complexity rabbit DNA as probe and SFV restriction fragments as targets or with high-specific activity, 32P-labeled, cloned SFV sequences as probes and rabbit DNA a...

Simian virus infections of humans are an increasing public health concern. Simian foamy virus (SFV) infections have been reported in persons occupationally exposed to nonhuman primates and in a few hunters in Cameroon. To better understand this retroviral zoonosis in natural settings, we studied persons who lived in southern Cameroon, near nonhuman primate habitats. First we studied a general p...

In their vertebrate hosts, arboviruses such as Semliki Forest virus (SFV) (Togaviridae) generally counteract innate defenses and trigger cell death. In contrast, in mosquito cells, following an early phase of efficient virus production, a persistent infection with low levels of virus production is established. Whether arboviruses counteract RNA interference (RNAi), which provides an important a...

OBJECTIVE The definition of volvulus is an axial twist of a portion of the gastrointestinal tract along its mesentery. The involved bowel is obstructed partially or completely with a variable degree of arterial and venous occlusion. The colon is the most common site for volvulus. The splenic flexure is the least common site of colonic volvulus. Splenic flexure volvulus (SFV) is a very rare caus...

We have constructed a series of vectors based on simian foamy virus type 1 (SFV-1) to define the minimum cis-acting elements required for gene transfer. To characterize these vectors, we inserted the coding sequence of the bacterial lacZ gene linked to the cytomegalovirus immediate-early gene promoter. Introduction of a deletion mutation in the leader region between the 5' long terminal repeat ...

Previous reports have indicated that the entry of Semliki Forest virus (SFV) into cells depends on a membrane fusion reaction catalyzed by the viral spike glycoproteins and triggered by the low pH prevailing in the endosomal compartment. In this study the in vitro pH-dependent fusion of SFV with nuclease-filled liposomes has been used to select for a new class of virus mutants that have a pH-co...

Semliki forest virus (SFV) is internalized by clathrin-mediated endocytosis, and transported via early endosomes to late endosomes and lysosomes. The intracellular pathway taken by individual fluorescently labeled SFV particles was followed using immunofluorescence in untransfected cells, and by video-enhanced, triple-color fluorescence microscopy in live cells transfected with GFP- and RFP-tag...

OBJECTIVES Workers of X-ray departments are occupationally exposed to long-term low levels of ionizing radiation (LLIR), which may affect their humoral immunity. The aim of the study was to assess the influence of LLIR on the number and proportion of B cells (CD19+), B1 cells (CD5+CD19+) and memory B cells (CD27+CD19+) in peripheral blood of such workers. MATERIALS AND METHODS In the study gr...