The presence of antibodies recognizing a peptide derived from the second conserved region of HIV-1 gp120 correlates with non-progressive HIV infection.

The C-terminus of the second conserved region of HIV-1 gp120 represents a functionally important domain, as it encompasses amino acids directly involved in the binding to the CD4 receptor and in post-receptor binding events. Previous studies have suggested that antibodies with specific affinity to a 23 amino acids-long NTM polypeptide, derived from this HIV-1 gp120 domain, may be involved in the control of HIV disease progression. In the current work, we searched for NTM-recognizing antibodies in specific cohorts of HIV-1 infected individuals, including long-term nonprogressors (LTNP) and progressors. For this purpose, we employed a previously defined bioinformatics criterion for design of an NTM peptide mimetic to select an octapeptide, NTMs (FTDNAKTI), which is more suitable for use in a solid-state enzyme-linked immunosorbent assay (ELISA). Our results show that NTMs-reactive antibodies are significantly more prevalent (p < 0.01) in LTNP as compared to progressors and healthy control subjects, indicating their association with non-progressive infection. The presence of antibodies recognizing the second conserved region of the HIV-1 gp120 derived peptide, NTMs, in LTNP sera suggest that these antibodies could be of considerable interest for development of anti-HIV immune-based therapies and vaccines.