Detection of Neutralizing Antibodies in HIV-1 Patients on Antiretroviral Treatment for Over Ten Years.

BACKGROUND: Recently, many broadly applicable and potent neutralizing antibodies have been screened from HIV-1-infected patients. However, all these effective neutralizing antibodies were isolated from patients naive to anti-retroviral treatment (ART). METHODS: To better understand the induction of neutralizing antibodies in patients on ART, we screened 3 patients with an over ten-year infection history on ART from 350 patients in China for a cross-reactive neutralizing antibody response based on the use of different antigens and recombinant viruses. We studied the evolution of neutralizing activity in two patients during a one-year period with previously described recombinant viruses NL4-3 and SF162 using ELISA and neutralization assays. RESULTS: Antibodies purified from sera were able to react with recombinant virus antigens R2-gp120 and SF162-gp140 and neutralize SF162 recombinant virus but not NL4-3 recombinant virus. In addition, we observed a significant increase in the neutralizing response of immunoglobulin G (IgG) isolated from the serum sample in Patient 1 and compared it with the serum from Patient 1 six months ago. CONCLUSIONS: We thus confirm the possibility of production of neutralizing antibodies in patients infected for over ten years on ART, and it is possible over time of the improvement of HIV-1 potent neutralizing activity associated with viremia and immune reconstruction.