CONTINUITY AND DISCONTINUITY IN THE ANTI-V3 IGG RESPONSE OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 1-INFECTED PERSONS IN A CROSS-SECTIONAL AND LONGITUDINAL-STUDY USING SYNTHETIC PEPTIDES

The principal neutralization domain (PND) of the V3 region of human im munodeficiency virus type 1 (HIV-1) gp120 is central to HIV pathogenes is. The IgG antibody response to PND was followed in 15 HIV-1-infected persons from southern Sweden over 2-5 years using 32 synthetic V3 pep tides. Five peptides had amino acid sequences derived from isolates fr om each of 5 patients. Sera obtained simultaneously with isolate almos t always reacted strongly with these cognate peptides; however, reacti vity was undetectable in 1 patient's serum and short lived in the sera of another, indicating inducible holes in the antibody repertoire, wh ich would facilitate dissemination of the corresponding virus strains. Reactivity to other V3 peptides correlated with sequence similarity t o the cognate peptide. Strong, stable reactivity to peptides with sequ ences similar to a south Swedish V3-consensus was accompanied by trans ient activity to less similar ones. The latter may reflect viral varia tion, B lymphocyte clonal depletion, or both. Certain IgG responses ap peared to preclude others, suggesting clonal dominance.