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.

To determine whether annexin II played a role in infection of macrophages by viral isolates other than the laboratory-adapted BaL strain, macrophages were treated with an antibody to annexin II at the time of infection with two additional laboratory-adapted M tropic isolates (ADA and JRCSF) and a primary clinical isolate (Clade B 92US712). As evident in Fig. 4 E, by blocking access to annexin II with an annexin II-specific antibody, infection by all three viral strains was dramatically inhibited, paralleling the effect seen with BaL and underscoring the contribution of annexin II to the macrophage infection process. Moreover, in CD4 Ï© T cell infection with IIIB, antibodies to annexin II were not effective in blocking the virus (Fig. 4 F) . In additional stud-ies to establish whether annexin II represented a pathway unique to HIV-1 or supported infection with other viruses, we determined in preliminary experiments that annexin II appears to play no role in infection of cells with either Ebola virus or with SARS coronavirus (not depicted). Thus, annexin II appears to selectively contribute to the pathway by which HIV-1 infects human macrophages.