Serological assay to detect human antibodies against monkey poxvirus

Abstract

Objective To establish a method for detection of human antibodies against monkeypox virus. Mothds The enzyme linked immunosorbent assay (ELISA) plates were coasted with two monkeypox virus peptides from B21R protein, to establish an indirect ELISA for detecting monkeypox virus IgG antibody. The healthy individuals serum samples, monkeypox virus infected patient serum samples and other virus infected patient sera samples were applied to evaluate specificity of the peptides antigen. The reaction conditions were optimized. Results Synthesized two peptides from monkeypox virus BR21R protein did not cross react obviously with healthy person serum and other virus infected serum. It was shown that the reaction condition was best with sera dilution at 1∶50 when two combined peptides were coated at 100 ng /well, and second-antibody was diluted at 1∶20 000. At this condition the cut off value of IgG antibody in serum samples for ELISA were A450 reading of 0.393. The detected results of two serum samples collected from the monkeypox patient in Sierra Leone were strongly positive, the titers of IgG antibody in two sera were both 1∶6 400. Conclusions The indirect ELISA for detection of monkeypox virus infection was established preliminarily which provided useful tools for epidemiological study and diagnosis. Key words: Monkey poxvirus; Enzyme linked immunosorbent assay; IgG antibody