Figure 4.

Galectin-3 interacts with HIV-1 CRF07_BC envelop gp120 and binds to the virions. (A) HIV-1 CRF07_BC viruses were incubated with Jurkat-R5 cells in presence of rhGal3 at 37 °C for 1 hr. The cells were collected, lysed, and immunoprecipitated with anti-Gal3 antibodies. Co-precipitated proteins were analyzed by immunoblotting for galectin-3, CD4 and gp120 envelope proteins. N and T refer to negative control (mock) and testing groups, respectively. (B) HIV-1 CRF07_BC viruses were incubated with galectin-3, these complexes were dropped on the grid and subjected to immuno-EM analysis with staining antibodies labeled with 6 nm or 18nm gold particles. The thin and thick arrows indicate galectin-3 and gp120 protein localization, respectively. (C) The HIV-1 CRF07_BC viruses coated plates were incubated with 2.5–20 (ug/mL) rhGal3 in the presence of 10 μg B2C10 monoclonal antibody, 50 mM lactose (Lac) or 50 mM sucrose (Suc). After washing with phosphate buffer saline with tween (PBST), the wells were incubated with rabbit anti-galectin-3 polyclonal antibodies and subsequently with horseradish peroxidase (HRP)-conjugated antibodies against rabbit IgG. The results were analyzed by spectrophotometer. (D) HIV-1 CRF07_BC viruses incubated with Jurkat-R5 cells in the presence of rhGal3, lactose or sucrose. The virus bound Jurkat-R5 cells were fixed and stained with anti-gp120 Alexa-488 labeled polyclonal antibodies and analyzed using flowcytometry. 1–5 indicate different treatments. The representative data are shown (* p < 0.05; ** p < 0.01).