Antibodies against structural and nonstructural proteins of human bocavirus in human sera

Abstract

Immunofluorescence assays (IFAs) for detection of human bocavirus (HBoV) proteins (VP1, VP2, NP-1, and NS1) were developed. The VP1 IFA was the most sensitive for detection of IgG antibody and suitable for screening. IgG antibodies in convalescent-phase sera from HBoV-positive patients were detected by VP1 and VP2 IFAs. Sensitivities of NP-1 and NS1 IFAs were low.

FIG. 1.

(A) Western blot analysis of His-VP1 (VP1), His-VP2 (VP2), His-NP-1 (NP-1), and His-NS1 (NS1) proteins of HBoV expressed by a baculovirus system, compared with negative-control protein (NC). Anti-six-histidine tag monoclonal antibody was incubated on nitrocellulose membranes. (B) Age distribution of seropositive rates for HBoV VP1 IgG (black columns), VP2 IgG (white columns), NP-1 IgG (striped columns), and NS1 IgG (gray columns). m, months; y, years. (C and D) Detection of the IgG and IgM antibodies against VP1, VP2, NP-1, and NS1 proteins of HBoV in acute-phase (A) and convalescent-phase (C) serum samples from four patients with acute HBoV infection by IFAs. White circles, black circles, white triangles, and black triangles correspond to patient numbers 1, 2, 3, and 4, respectively, in reference .