Antibody cross-reactivity to V3 peptides of B subtype and local BF recombinants in Argentina.

AMBROSIONI JC; BARRAL R; ACUIPIL C; ANDREANI G; ROMER Y; PANDO MA; RABINOVICH D; MARTINEZ PERALTA L

Rio de Janeiro

Conferencia; The 3rd IAS Conference on HIV Pathogenesis and Treatment.; 2005

IAS

Objectives: Studies performed on molecular epidemiology of HIV-1 in Argentina have shown the prevalence of subtype B as well as B/F recombinants in the metropolitan population. The goal of this work was to analyze cross-reactivity to V3 peptides between subtypes and recombinant forms. Materials and Methods: Plasma samples of 50 patients infected with subtype B and 37 patients infected with B/F recombinant were selected. Sequences were characterized from PBMC using genome sequencing (pol, or pol and vpu) or heteroduplex mobility assay for env. A home-made ELISA was performed using commercial anti-human IgG labelled with peroxidase (Dakopatts, Sweden). Peptides used corresponded to the 15 central aminoacids of the V3 loop of gp120 from subtype B: MN and SF2; subtype F1 and a consensus peptide from Argentinean recombinants B/F sequences. This peptide was designed taking into account sequences obtained in our laboratory from plasma samples of patients infected with B/F recombinants. For statistical analysis Wilcoxon rank sum test and chi sqare test were used. Results: The median of optical density was higher to MN peptide for samples of patients infected with both subtypes B and BF (p<0.05). When we compared the median responses to peptides MN and BF between samples of patients infected with subtype B or BF, we did not find significant differences (p>0.05). In average, there was a low reactivity to SF2 and to F1 peptides, similar to negative controls. Conclusions: We did not find differences in the reactivity to peptides B and BF in patients infected with subtypes B or BF. Both groups had higher response to MN peptide. These results could be important for studies on preventive vaccines.