Effects Of SARS-CoV X4 Gene Transfection On Behaviors Of Peripheral Bood T Cells

Objective:To explore the function of the SARS-CoV X4 protein and the role in SARS pathogenesis, studies were performed on the change of T cells behaviors by transfection of SARS-CoV X4 gene.Methods:T cells were transfected with pEGFP-SARS-CoV X4 expression vector and the green fluorescence of EGFP were detected with flow cytometry and confocal microscopy; The expression level of CD69 on T cells transfected with expression vector with or without PHA stimulation were determinated by flow cytometry; Effects of SARS-CoV X4 transfection on T cell proliferation were evaluated by 3H-TdR incorporation ; The production of cytokines were investigated by Cytometric Bead Assay; Annexin V/7-AAD staining was used to assess percentage of apoptosis of T cells.Results:The expression of SARS-CoV X4-EGFP fusion protein could be detected with flow cytometry and confocal microscopy; The percentage of CD69 expression, the incorporation of 3H-TdR and the production of IL-6 and TNF-a of T cells transfected with SARS-CoV X4 were significantly higher than control group; The percentage of Annexin V single positive cells, which indicate T cells apoptosis, were no difference between two groups.Conclusion:SARS-CoV X4 gene can be expressed efficiently in T cells; The expression percentage of CD69 were higher in SARS-CoV X4 transfection group; The production of IL-6 and TNF-a increased in transfection group; the proliferation were increase in transfection group ; These results suggest that SARS-CoV X4 protein can regulate the behaviors of T cells, we propose that SARS-CoV X4 protein perhaps play an important role in SARS pathogenesis; these data provide useful information about the pathogenesis, prevention and treatment of SARS.