Expression of a novel Nef epitope on the surface of HIV type 1-infected cells.

We compared antibody responses to various structural and accessory gene products of HIV-1 between long-term nonprogressors and patients who have progressed to AIDS. On the basis of our results, we performed epitope mapping of the Nef protein and identified a novel epitope. This novel epitope of the Nef protein was found to be exposed on the surface of HIV-1-infected cells. The antibody response against it correlated with CD4+ cell counts among HIV-1-infected patients (r = 0.457, p < 0.001). Although further research is necessary, we suspect that antibody response against the epitope may be protective against disease progression.