Very recently, broadly neutralizing antibodies were shown to even contribute to the control of viremia in macaques chronically infected by HIV-1 in a therapeutic setting. Furthermore, a number of broadly neutralizing monoclonal Abs targeting critical epitopes involved in HIV-1 entry have been isolated from patients with chronic HIV-1 infection. The original set of four well characterized bnmAbs has been rapidly expanded during the last few years by direct cloning from Env-specific B-cells from chronically infected patients with bnAbs in plasma. These much more potent mAbs essentially target four regions in the native trimeric Env spike, which is composed of three heterodimers of the outer envelope glycoPYR-41 protein gp120, non-covalently linked to the transmembrane protein gp41: the CD4 binding site, variable loops V1/V2 and V3 in gp120 often implicating glycan structures, and the membrane proximal external region in gp41. Characterization of the identified bnAbs often revealed unusual structural features as well as a high extent of mutations in the complementary determining regions resulting from affinity maturation for evolving Env antigens. Therefore, bnAbs need time to develop and, if present, are found in chronically infected patients after several years of infection. HIV controllers are a promising source for the identification of nAbs, as here they have time to develop and mature over years in a rather uncompromised immune system and in the absence of therapeutic selection pressure. We Diphemanil Methylsulfate previously identified LTNP and EC with neutralizing activity in plasma and dissected the humoral immune response based on phage libraries displaying short peptides or longer HIV-1 Env fragments. This allowed the identification of
ar and conformational epitopes able to induce neutralizing antibodies upon vaccination in mice. In this study we aimed at characterizing Env-specific antibodies present in the plasma of one of our LTNPs. An immune scFv phage display library was generated from LTNP MH03 with nAbs in plasma and screened with soluble gp140, which contains gp120 and the ectodomain of gp41, i.e. lacking the transmembrane and the intracellular domains of gp41.