Guangshan Gary Li

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It is thought that interference during human immunodeficiency virus type 1 (HIV-1) infection is established by downmodulation of the principal virus receptor, CD4. Here we present evidence to the contrary. At various times after primary infection, we superinfected T cells in vitro by exposure to a genetically distinct viral clone or to a virus carrying the(More)
INTRODUCTION Screening drugs against G protein-coupled receptors (GPCRs) - the single largest family of drug targets in the human genome - is still a major effort in pharmaceutical and biotech industries. Conventional cell-based assays generally measure a single cellular event, such as the generation of a second messenger or the relocation of a specific(More)
The spatial and temporal targeting of proteins or protein assemblies to appropriate sites is crucial to regulate the specificity and efficiency of protein-protein interactions, thus dictating the timing and intensity of cell signaling and responses. The resultant dynamic mass redistribution could be manifested by label free optical biosensor, and lead to a(More)
Two human immunodeficiency virus type 1 (HIV-1) variants derived from a single parental isolate were found to differ substantially in their ability to replicate in CD4-positive cells. Using transient chloramphenicol acetyltransferase expression assays, we show that the long terminal repeat (LTR) of the better-replicating virus has significantly higher(More)
Human immunodeficiency virus type 1 (HIV-1) replicates efficiently in nonproliferating monocytes and macrophages but not in resting primary T lymphocytes. To determine the contribution of cell division to the HIV-1 replicative cycle in T cells, we evaluated HIV-1 expression, integration of proviral DNA, and production of infectious progeny virus in C8166(More)
We have previously shown that during human immunodeficiency virus type 1 (HIV-1) infection in vitro continued reverse transcription is required for stable HIV-1 production, but entry by progeny virus is not. To determine the source of the viral RNA reverse-transcribed late in infection, we employed inhibitors of HIV-1 transmission, reverse transcription,(More)
This paper reported the use of resonant waveguide grating biosensors for studying the cytoskeleton structure in cells. This was achieved by measuring the changes in mass within the bottom portion of cells upon exposure to saponin in the absence and presence of cytoskeleton modulators. Treatment of Chinese hamster ovary cells with saponin led to a(More)
Cholesterol is an essential constituent of cell membranes and the regulation of cholesterol concentration is critical for cell functions including signaling. In this paper, we applied resonant waveguide grating (RWG) biosensor to study the cellular functions of cholesterol through real time monitoring the dynamic mass redistribution (DMR) mediated by(More)
Evaluation of the activities of antiretroviral agents and an immunoregulatory compound has been made using two models of HIV-1 infection and three measurements of virus expression. Acute infection of Jurkat cells or chronic/inducible infection in U1.1 cells was monitored at multiple time points after drug treatment. The 50% effective concentrations (EC50)(More)