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Objective To investigate the T cell cytotoxicity induced by recombinant adenovirus carrying HIV-1 vpr gene.Methods C8166 cells infected with rAd-vpr or negative control rAd-vector,were analyzed for cell cycle distribution and cell death by flow cytometry.The discrimination of living cells,apoptotic and necrotic cells were differentiated with Hoechst-PI double staining under the confocal microscopy.Changes of mitochondrial membrane potential(△ψm)were monitored by JC-1 staining method.Results Annexin V-PI and Hoechst-PI staining indicated the death effects of HIV-1 Vpr on C8166 cells.PI flow cytometric analysis showed that cell cycle arrested in G2 phase.C8166 cell△ψm collapse mediated by Vpr was detected by JC-1 fluorescent staining.Conclusion The ability of recombinant adenovirus carrying HIV-1 vpr gene to induce mitochondria dysfunction,cell cycle G2 phase arrest and cell death was confirmed in C8166 cells.
ABSTRACT
AIM:To investigate the effects of AT-2-inactivated HIV-1 particles on human CD4+T cell activation and cytokine secretion in whole blood (WB) in vitro. METHODS: HIV-1ⅢB particles were inactivated by AT-2 chemical and the concentration of p24 antigen was determined by p24 ELISA. AT-2-inactivated HIV-1ⅢB particles were added to human WB culture system in serial concentrations to stimulate the cells. PHA was used as positive control. After 24 h, all the cultural supernatants were harvested and the concentrations of Th1 (IL-2, IFN-? and TNF-?) and Th2 (IL-4, IL-6 and IL-10) cytokines released to the supernatants were detected by cytometric bead array (CBA). The percentage of CD69 expression on CD4+T cells from WB was detected by immuno-fluorescence staining plus flow cytometry. RESULTS: The concentration of p24 antigen in the AT-2-inactivated specimen was 85.5 ?g/L. 24 h later, the percentage of CD69 expression on CD4+T cells from control group was (1.62?0.63) %, whereas it was (38.82?6.00)%, (3.83?1.07)%, (5.94?0.85)% and (9.30?1.22)% in PHA group, HIV-1 (1/500) group, HIV-1 (1/50) group and HIV-1 (1/5) group, respectively. Cytokines secreted by WB in control group were mainly TNF-? and IL-6. However, all the six cytokines tested were strikingly increased in PHA group, as well as in HIV-1ⅢB groups. CONCLUSION: AT-2-inactivated HIV-1ⅢB particles activate CD4+T cells from WB, and up-regulate both Th1 and Th2 cytokine secretion in WB. Besides the effects of viral proteins, other mechanisms may be proposed that HIV-1 particles act as antigen presenting cell (APC) because many host-derived immune molecules are incorporated into HIV-1 envelop when it is released from infected cells by budding, and exert immune modulation.
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AIM: To study the effects of [8-(diethylamino) octyl-3, 4, 5 -trimethoxybenzoate] (TMB-8), an intracellular Ca2+ antagonist, on the activation, proliferation and cell-cycle distribution of the mouse T lymphocytes stimulated by concanvalin A (Con A) in vitro. METHODS: After stimulated with Con A, T cells were treated with different concentrations of TMB-8 alone and its combination with cyclosporine A (CsA). The expression of CD69, the early marker of CD3+ T cell activation, was measured by FACS. The proliferation-related index was determined by carboxyl fluorescin diacetate succinmidyl ester (CFDA-SE) flow cytometry. The cell-cycle distribution was analyzed by propidium iodide staining.RESULTS: After 6 h culture, the activation rate of CD69+ T cell in Con A group was (74.88?1.88)%. 10, 20 and 40 ?mol/L of TMB-8 inhibited the expression of CD69 (P