A profile of cross-reactive neutralizing antibodies against various subtypes of HIV-1 strains in people with HIV-1 infection in Chongqing city

Objective To measure the levels of cross-reactive neutralizing antibodies responding to various subtypes of HIV-1 strains in people with HIV-1 infection in Chongqing and to analyze their characteristics. Methods Two hundred and thirty-six plasma samples were collected from patients with chronic HIV-1 infection in Chongqing city. The single-round-infection assay in TZM-bl cells were performed to screen the plasma samples with cross-reactive neutralizing antibodies against various subtypes of HIV-1 strains by using HIV-1 pseudovirus strains and to measure the 50% inhibitory dose (ID50). Results Eighteen out of 236 (7.63%) plasma samples were able to neutralize various B subtypes and/or C subtypes of HIV-1 pseudovirus strains, among which 15 plasma samples showed the great ability to neutralize pseudovirus strains of different subtypes. Conclusion The cross-reactive neutralizing antibodies against various subtypes of HIV-1 strains existed in plasma samples collected from people with chronic HIV-1 infection in Chongqing city. Key words: HIV-1; Broadly neutralizing antibodies