RELATIVE REACTIVITY OF THE V3 LOOP PND OF HIV-1 SUBTYPE-A, SUBTYPE-B,SUBTYPE-C, SUBTYPE-D, AND SUBTYPE-F WITH SERA FROM SELECTED UGANDAN LOCALITIES

Synthetic peptides comprising the predicted principal neutralizing det erminant (PND) in new African and North American HIV-1 clones were tes ted in ELISA for reactivity with ninety six serum samples from asympto matic donors in six selected localities in Uganda. Irrespective of the geographical origin of the samples, the majority of the test sera cro ss-reacted at high intensities with the peptides derived from the nove l North American clone, BRT3.6 (Group B), the Ugandan clone, CUG045, ( Group C), and the Romanian clone) FRMA (Group Fl. The frequency of rea ctivity of the peptides from BRT3.6, CUG045, and FRMA were within the ranges of 57-100%, 50-100%, and 57-100%, respectively, for the sera co llected from these disparate localities. In contrast to these findings , the V3 peptides derived from the other Ugandan isolates showed a mor e restricted pattern of reactivity with the same serum samples: AUG06c (1-63%), DUG23c (2%), and DUG044 (38-87%). The results from ELISA inh ibition assay indicated that the V3 peptide from BRT 3.6, CUG045, and FRMA express closely related antigenic specificities quite distinct fr om those in AUG06c and DUG044. The residues comprising the PND in BRT3 .6, CUG045, and FRMA appear to be well conserved in the HIV-1 subtypes prevalent in the selected Ugandan locales.