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Objective To investigate the effects of galectin-2, galectin-4, galectin-7, galectin-8, and galectin-9 on the apoptosis in HIV-1-infected macrophages and to provide the theoretical and application basis for elimination of HIV-1-infected cellular reservoirs. Methods Firstly, apoptosis of human monocytic cell line THP-1 cells was induced by different concentrations of galectins to determine the suitable concentration of different galetcins. Secondly, monocytes (THP-1) were stimulated to differentiate into macrophages (THP-1-Mφ) with phorbol myristate acetate (PMA), and then macrophages were prepared and infected with HIV-1. Finally, HIV-1-infected and uninfected macrophages were respectively treated with the suitable concentrations of galectin-2, galectin-4, galectin-7, galectin-8, galectin-9 and then the apoptosis in these macrophages was detected. Results The cell death rate of macrophages without treatment was 4. 39 ± 0. 74% . The cell death rates of macrophages induced by 5 μmol/L galectin-2, 5 μmol/L galectin-4, 7. 5 μmol/L galectin-7, 3 μmol/L galectin-8 and 1 μmol/L galectin-9 were 4. 78 ± 0. 41% , 7. 21 ± 1. 46% , 3. 78 ± 1. 03% , 5. 88 ± 2. 08% , 8. 10 ± 4. 13% , respectively, with no statistically significant defferences among the groups (P＞ 0. 05). The cell death rate of HIV-1-infected macrophages without treatment was 12. 69 ± 1. 16% , and that of HIV-1-infected macrophages induced by 5 μmol/L galectin-2, 5 μmol/L galectin-4, 7. 5 μmol/L galectin-7, 3 μmol/L galectin-8 and 1 μmol/L galectin-9 were 11. 69 ± 0. 90% , 17. 45 ± 1. 30% , 32. 01 ± 1. 30% , 15. 77 ± 1. 21% and 19. 27 ± 2. 13% , respectively. There were significant differences between the control group and galectin-7-treated group (P ＜ 0. 001 ). Conclusions Galectin-7-induces extensive apoptosis in HIV-1-infected macrophages but not in uninfected macrophages.
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Objective To investigate the changes of CD169 expression on the surface of peripheral blood monocytes and different subsets of monocytes in normal rhesus monkeys after SIVmac239 infection and the possible reasons.Methods Normal rhesus monkeys were infected with SIVmac239 through intravenous injection, and changes in the percentage of peripheral blood monocytes and the expression of CD169 before and after SIVmac239 infection were detected by flow cytometry. The peripheral blood CD14 +monocytes of normal rhesus monkeys sorted by flow cytometry were directly infected by SIVmac239 and stimulated by different cytokines,and changes in the expression of CD169 on the cell surface and the cytokine IFN-α were detected by flow cytometry. Results After SIVmac239 infection, the percentage of CD14 +monocytes of the normal rhesus monkeys was decreased and the expression of CD169 on their surface was increased. Meanwhile,the expression of CD169 on the surface of different subsets of peripheral blood monocytes was significantly increased,and the expression of CD169 on the CD14 +CD16 + +monocytes was increased more obviously. CD169 was not expressed on the surface of peripheral blood CD14 +monocytes of the normal rhesus monkeys after stimulated by the cytokines M-CSF, IL-4 and IL-13. However, CD169 was highly expressed after the monocytes were stimulated by the cytokine IFN-α. The expression of CD169 on the surface of CD14 +monocytes and the intracellular cytokine IFN-α was not significantly changed after the monocytes were directly infected with SIVmac239. Conclusions SIVmac239 infection can lead to the increase of CD169 expression on the surface of peripheral blood monocytes in rhesus monkeys. Its expression is not associated with the direct infection of virus,but is related to the cytokine IFN-α secreted by other cells of the monkeys in vivo.
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Objective To identify the characteristics of the subtype of PMA-induced THP-1 macrophages by flow cytometry analysis. Methods THP-1 monocytic cells differentiate into macrophages promoted by PMA, then induced into M1 and M2 by adding different cytokines, such as LPS,IL-6 and IFN-γ for THP-1-M1, IL-4,IL-13 and IL-6 for THP-1-M2. Morphology of cells were observed under a microscope and the expression of CD14, CD68, CD16, CD80, CD86, CD163, CD206, CD209, CD83, CD1a, CD11c, HLA-DR were detected by flow cytometry. Results The macrophages stimulated by PMA became adherent;THP-1-M1 and THP-1-M2 lost their spherical morphology, appeared more irregular with many obvious projections. The expression of CD83, CD1a, CD11c, HLA-DR which had the function of antigen presenting on the surface of THP-1-Mφwere very low, and most of them were negative, but those of THP-1-M1 and THP-1-M2 were very high. Conclusions The macrophages differentiated from THP-1 stimulated by PMA are weak in antigen presenting function.
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Objective To identify the characteristics of the subtype of PMA-induced THP-1 macrophages by flow cytometry analysis. Methods THP-1 monocytic cells differentiate into macrophages promoted by PMA, then induced into M1 and M2 by adding different cytokines, such as LPS,IL-6 and IFN-γ for THP-1-M1, IL-4,IL-13 and IL-6 for THP-1-M2. Morphology of cells were observed under a microscope and the expression of CD14, CD68, CD16, CD80, CD86, CD163, CD206, CD209, CD83, CD1a, CD11c, HLA-DR were detected by flow cytometry. Results The macrophages stimulated by PMA became adherent;THP-1-M1 and THP-1-M2 lost their spherical morphology, appeared more irregular with many obvious projections. The expression of CD83, CD1a, CD11c, HLA-DR which had the function of antigen presenting on the surface of THP-1-Mφwere very low, and most of them were negative, but those of THP-1-M1 and THP-1-M2 were very high. Conclusions The macrophages differentiated from THP-1 stimulated by PMA are weak in antigen presenting function.
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Sialoadhesin ( Siglec-1 or CD169 ) is a sialic acid-binding Ig-like lectin expressed selectively on macrophage subsets. In inflammatory response, Siglec-1 can modulate the secretion of MIP-1 alpha / beta, MCP-1, MIP-2 and other cytokines, and promote the occurrence of inflammatory reaction. During viral infection, Siglec-1 can promote the infection and phagocytosis of virus by mediating the binding of pathogens and macrophages. In the regulation of immunity, Siglec-1 can regulate innate immunity and adaptive immunity, by inhibiting the excessive expression of IFN-α and the activation of DC cells. This review mainly focuses on the new advances of research on Siglec-1 in pathogen infections, inflammation and immunoregulation.
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The host protein SAMHD1 has been identified as the first mammalian deoxynucleoside triphosphate triphosphohydrolase (dNTPase), which blocks the infection of HIV-1 in non-cycling immune cells.SAMHD1 protein is highly expressed in human myeloid-lineage cells and resting CD4+T lymphocytes, which restricts HIV-1 replication by hydrolyzing the cellular dNTPs, thus inhibiting reverse transcription and viral complementary DNA ( cDNA) synthesis. Recent studies have revealed that SAMHD 1 plays an important role in virus whole life by promoting HIV -1 genome recombination, degenerating viral genome RNA and restricting virus transmission between cells .In this review, these progress on SAMHD1 research are summarized and the mechanisms by which SAMHD 1 mediates retroviral restriction are analyzed .
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Objective To study the mutations of Env sequence of SIVmac239 after infection of Chinese rhesus monkeys, and compare the differences and characteristics of Gp120 sequences of enterotropic and neurotropic SIV strains. Methods Six strains of simian immunodeficiency virus were analyzed in this study: four separated from peripheral blood mononuclear cells of SIVmac239-infected monkeys and two neurotropic SIVmac251 strains.Isolated and cultured monoclonal virus was obtained by limiting dilution assay.Gp120 sequences were amplified after the RNA extraction and phylogenetic analysis was processed thereafter.So did the Gp120 amino acid sequence and N-glycosylation sites analysis of the enterotropic and neurotropic strains.Results SIVmac239 had different mutations in four rhesus monkeys.The diversity in amino acid sequences of the enterotropic and neurotropic strains concentrated in the V1 and V4 regions of Gp120.The enterotropic strains had an addition of glycosylation site in V4 but the glycosylation site changes of neurotropic strains were located in the conservative regions of C1, C2 and C3.Conclusions The addition of one glycosylation site in V4 region of GP120 and loss of one glycosylation site in C1 region are associated with enhanced enterotropism and neurotropism.The differences between the enterotropic and neurotropic strains are not dipicted in Gp120 V3 region which is closely related with the tropism of strains.
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Objective To investigate the effect of cell death by HIV-1 infection on gene 90K/Mac-2BP by RNA interference (RNAi) in U937 cell line.Methods We used human monocyte-macrophage cell line U937 as the cell model.Cells were infected by HIV-1 ( R5-tropic) 5 days, and then stained by PE-Annexin V and PerCP-7-AAD.90K/Mac-2BP in U937 cell line was knocked down , and these cells were infected by HIV-1 for 5 days.Then, cells were stained by PE-AnnexinV and PerCP-7-AAD.Apoptosis were examined upon flow cytometry .Results The percentages of Annexin V+cells without 90K/Mac-2BP knock-down were (16.27 ±0.30)% by HIV-1 infection.The percentages of them with 90K/Mac-2BP knock-down were (31.26 ±0.35)%, (25.76 ±0.30)%, (23.69 ±0.33)% respectively.The increase of cell apoptosis rate for HIV-1-infected U937 cells by 90K/Mac-2BP siRNA transfection was significantly greater than that for HIV-1-infected untreated cells (P﹤0.01).Conclusion The apoptosis of HIV-1-infected U937 cells was regulated by the expression of 90K/Mac-2BP.
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Objective To study the effect of repeated rectal exposure of low -dose simian immunodeficiency virus on the systemic cellular immunity in monkeys .Methods Eight 3-to 4-year old rhesus macaques ( Macaca mulatta) (male:female 1:1) were used in this study.The monkeys were inoculated with 10 TCID50 SIVmac239 virus through rectum twice a week for consecutive 6 weeks to establish a multiple rectal exposure model of SIVmac 239 virus infection.Then, plasma viral load, CD4+ T cell count, T cell subsets and IFN-γsecretion of the experiment monkeys were determined . Results Low-dose SIVmac239 virus induced some changes in the immune system through the rectal mucosa , but didn’t induce typical infection.Repeated rectal mucosal low-dose virus exposure can activate the cellular immune system . Conclusions This study defines the effect of repeated low -dose simian immunodeficiency virus exposure on the systemic cellular immunity, and provided basic information for HIV-1 vaccine research.