[Expression of recombinant VP2 gene in insect sf9 cells and screening of clinical specimens].

OBJECTIVE: To clone and express VP, gene from HBoV, and the expressed VP, protein was as the antigen in order to detect serum from children in Wenling area with lower respiratory tract infections. METHODS: The VP, gene was recombined with the genome of Baculovirus, which infected the insect cell. The fusion protein with HA tag was applied to confirm the specificity of expressed protein. Furthermore, the recombinant protein was observed using electron microscopy. The 176 serum from children in Wenling area with lower respiratory tract infections was screened using Western blot. RESULTS: The expressed VP2 protein was more than 60% in total proteins from insect cell, and MWt about 60 x 10(3). The virus-like particle (VLP) was observed using electron microscopy, and size about 20 nm. The 176 serum from children in wenling area with lower respiratory tract infections was screened using Western blot. The HBoV positive rate was 2.28% (4/176). CONCLUSION: The VP2 protein from human bocavirus was expressed in insect cell successfully. Through HA tag the VP2 protein was specific, and then the assay using SDS-PAGE with Western blot could detect and screen the antibody in serum from children with lower respiratory tract infections rapidly and accurately.

[Isolation and cell culture of human bocavirus (HBoV) by human bronchial epithelial cell lines].

OBJECTIVE: To investigate pave a way for studying pathogenicty of HBoV. METHODS: Isolation and cell culture of HBoV by human bronchial epithelial cell line, which was founded in our laboratory. The morphology of the virus were primarily studied with a transmission electron microscope. In addition, transcript mRNA was detected in human bronchial epithelial cells, which was passaged and infected within HBoV, using the reverse-transcription polymerase chain reaction (RT-PCR). The amplified products nucleotide sequence of HBoV were sequencing and sequence analysis. RESULTS: Cytopathic effect (CPE) was observed after the aseptic residue of filtration of 2 case sputum specimens with HBoV, which was inoculated to the human bronchial epithelial cell line. The virus particles were observed in the cytoplasm, which were hexagonal or spherical in shape and 18-26 nm in diameter,bulk was 20 nm. cDNA amplicon obtained 295 bp fragment results of electrophoresis bands as same as NS1 region of the conserved matrix gene of publish sequence of HboV. PCR products nucleotide sequence of HboV were compared with corresponding HboV GeneBank sequences. The comparison/alignment and construction of phylogenetic trees also point to an affiliation of the parvovirus to the species HBoV. CONCLUSION: Isolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicty of human bocavirus.