Cloning and expression of the 4D8 gene from Hyalomma asiaticum tick

Hyalomma asiaticum tick, an important ectozoic parasite causes tickle, pain, anemia, weight loss, and paralysis in its hosts, which include humans, cattle, sheep, horses, camels, and hares. The 4D8 gene can be a potential vaccine candidate antigen for H. asiaticum. In the present study, we cloned and expressed the 4D8 gene of H. asiaticum from Xinjiang Province. Primers were designed according to the H. asiaticum tick 4D8 gene sequence available in GenBank. The gene was amplified by reverse transcription-polymerase chain reaction and the fragments were subcloned into the prokaryotic expression vector pET30a and the recombinant vector pET30a-4D8 was constructed. The expressed recombinant protein was purified and its biological activity was investigated by western blot. Results revealed that the recombinant protein was a biologically active fusion protein with a molecular weight of 20 kDa. The purified 4D8 protein would provide a strong foundation for further studies on this protein.