[Features of antigen-antibody interaction during use of linear synthetic peptides and multipeptide antigen modeling antigenic determinants of hepatitis A virus].

Aim: To study features of antigen-antibody interaction during use of linear synthetic peptides and multipeptide antigen modelling antigenic determinants of hepatitis A virus (HAV) and to evaluate perspectives for use of heterogeneous tetrameric multipeptide antigens for detection of HAV serological markers.

Materials And Methods: Linear peptides VP1 and VP3 were synthesized by fluorenylmethyloxycarbonyl (Fmoc)-polyamide solid phase method. MAP4 (VP1+VP3) was synthesized according to 9-Fmoc strategy. Interaction of these peptides with anti-HAV IgM positive sera from patients with HA was studied by noncompetitive and competitive methods of immunoenzyme assay. RESULTS. Using immunoenzyme assay, high heterogeneity of immune response in patients with HA (62 and 67% in two groups) was shown. MAP4 (VP1+VP3), unlike the combination of linear peptides VP1 and VP3, interacted with anti-HAV IgM in 41 - 45% of sera and, at the same time, did not lead to false positive results.

Conclusion: Population of HAV is not so uniform which is usually assumed. It could be reasonable to use heterogenous multipeptide antigens, including those containing VP1 (11 - 25 a.r.) and VP3 (110 - 121 a.r.), for the development of new assays for HA diagnostics.