Immunological Identification and Characterization of Extracellular Serine Protease-Like Protein Encoded in a Putative espP2 Gene of Haemophilus parasuis
| Autor: | Ping Zhao, Pengcheng Gao, Nian-Zhang Zhang, Chu Yuefeng, Zhong-Xin Lu, Ying He |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Journal of Veterinary Medical Science. 74:983-987 |
| ISSN: | 1347-7439 0916-7250 |
| Popis: | Haemophilus parasuis is known to produce a group of virulence-associated autotransporter (AT) proteins, VtaAs; however, no other ATs have been characterized yet. On the basis of the reported sequence of a putative espP2 gene for extracellular serine protease (ESP)-like protein of H. parasuis, this putative AT gene was successfully amplified from H. parasuis serotype 5 field strain HPS0819, cloned and sequenced. The confirmed ORF sequence showed 100% identity with the reported putative espP2 gene. The recombinant ESP-like protein purified from Escherichia coli with a pET expression system was used for immunological characterization. An approximately 85 kDa antigen was detected in cultured H. parasuis by using antiserum to the purified ESP-like protein, and antibodies against the recombinant ESP-like protein were detected in a selected serum from pigs with experimental H. parasuis infection. The results indicated that H. parasuis could produce ESP-like protein in vitro and in vivo. In an immune protection study using guinea pigs, 6 out of 10 animals immunized with the recombinant ESP-like protein survived after challenge with 5 × 10(9) bacteria of strain HPS0819, whereas 7 out of 10 animals immunized with formalin-inactivated H0819 bacterin survived after challenge. The results suggest that ESP-like protein could be one of the vaccine antigen candidates for H. parasuis infection. |
| Databáze: | OpenAIRE |
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