Secretory Leukocyte Protease Inhibitor Binds to Annexin II, a Cofactor for Macrophage HIV-1 Infection

Ma, Ge; Greenwell-Wild, Teresa; Lei, Kejian; Jin, Wenwen; Swisher, Jennifer; Hardegen, Neil; Wild, Carl T.; Wahl, Sharon M.

In indicated experiments, macrophages were pretreated for 1 h with 25 g/ml rabbit anti-annexin II (Santa Cruz Biotechnology, Inc.), 25 g/ml rabbit IgG (Jackson ImmunoResearch Laboratories), or 10 g/ml SLPI before the addition of virus. Alternatively, the HIV-1 was preincubated with 10 g/ml annexin II tetramer (US Biological) for 1 h before being added to the macrophages. After HIV-1 coculture for 2 h, virus and/or added reagents were removed by washing cells with DMEM and fresh complete medium was added. For cell-binding experiments, macrophages were treated with anti-annexin II, control antibody, or SLPI for 30 min, washed, and virus was added for 30 min at 37 Њ C. The cells were washed extensively, lysed (0.5% Triton X-100 in PBS), and p24 bound to the cells quantitated by ELISA. For infection of elutriated T cells, PHA-blasted T cells were infected with HIV-1 IIIB (Advanced Biotechnologies Inc.) for 2 h, washed, cultured for 2-8 d, and supernatants were collected every 2-3 d for p24 ELISA. In some experiments, T cells were pretreated with rabbit anti-annexin II or rabbit IgG before infection.