Simon OF, Mauclere P, Fagot P, Mony-Lobe M, Mbopi-Keou FX, Loussert-Ajaka I, Bouchaud O, Descamps D, Korber B, Saragosti S, Barin F, Brun-Vezinet F; Bichat Hospital, Paris, France.
Ninety-eight patients were diagnosed as having HIV-1 group O infection. Sixteen were Cameroonian or French patients living in France and 82 were identified during an epidemiological survey in Cameroon. We isolated and partially sequenced 30 strains (C2-V3). The octameric sequence at the tip of the V3 loop was highly heterogenous, except for the GP motif. The analysis of gag and env sequences revealed few discernable phylogenetic clustering patterns. By contrast, the immunodominant domain of the gp41 (11 sequences) appeared to be highly conserved. HIV-O strains showed a wide phenotypic diversity, being naturally resistant to different non-nucleosidic RT-inhibitors. Syncytium-inducing capacity of HIV-O isolates was not related to the replicative capacity on MT2 or to the clinical stage. Clinical follow-up of the 16 HIV-O-infected patients living in France indicated that clinical and immunological characteristics are similar to those of HIV-1 group M-infected patients. In Cameroon, the frequency of group O relative to group M ranged from 1% in Far North province to 6.3% in Yaounde; there was no difference in sex, age or frequency of clinical manifestations between group M and group O infections. A differentiation strategy based on blocking EIAs using peptides mapping gp41 or V3 epitopes of group M and group O allowed a perfect serological discrimination between the two groups, in agreement with the genotyping
Results: This reliable peptides-based strategy could be useful for the further epidemiological studies.
Keywords: AEGIS, HIV-1, Immunodominant Epitopes, Peptides, Cameroon, France, Epidemiologic Studies, Human, virology, AIDS
