Cell-surface heparan sulfate and HIV-1 infection of differentiated THP-1 cells
Nejat Düzgüneş: 0000-0001-6159-1391
82nd General Session of the International Association for Dental Research and 33rd Annual Meeting of the American Association for Dental Research
March 10-13, 2004
Date of Presentation
Journal of Dental Research
Journal Volume Number
Objectives: Recently, it has been reported that the cell surface glycosaminoglycan, heparan sulfate (HS), mediates the attachment of HIV to adherent cells expressing low CD4, such as HeLa-CD4 cells or macrophages, prior to virus entry. The established monocytic THP-1 cell line has been used to study HIV-monocyte/macrophage interactions and the relationship between differentiation, virus production and virus latency. Treatment with phorbol myristate acetate (PMA) induces differentiation of THP-1 cells into adherent macrophage-like cells, which are susceptible to M-tropic, CCR5-dependent HIV isolates. Differentiation of THP-1 cells markedly reduces CD4 surface expression (Konopka & Düzgünes, AIDS Res. Hum. Retroviruses 2002;18:123-131). Here we examined if HS is involved in HIV binding and infectivity in differentiated THP-1 cells. Methods: PMA-treated THP-1 (THP-1/PMA) cells were incubated with either heparinase (heparin-specific) or heparitinase I (HS-specific) for 2 h at 37°C. Expression of HS on the surface of THP-1 cells was examined using a fluorescent Monoclonal Anti-HS (10E4 epitope) antibody. Infection of THP-1 cells with the M-tropic HIV-1BaL isolate and HIV binding were monitored by ELISA determination of p24 antigen in harvested culture supernatants and cell lysates, respectively. Results: PMA-treatment resulted in an upregulation of HS expression. Over 40% of THP-1/PMA cells tested highly positive for HS expression (Mean Fluorescence Intensity, MFI = 22.5) when compared to 4.0% (MFI=5.4) for THP-1 cells growing in suspension. Treatment with the HS-specific heparitinase I reduced expression of HS by over 60%. Treatment with heparinases, however, did not reduce HIV binding and did not affect HIV infection in THP-1/PMA cells. Conclusions: Our results suggest that HIV infection in THP-1/PMA cells may be independent of cell-surface HS. (This work was supported partially by the Pacific Dental Research Foundation, Grant 521.)
Cell-surface heparan sulfate and HIV-1 infection of differentiated THP-1 cells.
Paper presented at 82nd General Session of the International Association for Dental Research and 33rd Annual Meeting of the American Association for Dental Research in Honolulu, HI.