Expression of recombinant HBD3 protein that reduces <italic>Mycobacterial</italic> infection capacity.

Bovine tuberculosis is a disease caused by <italic>Mycobacterium bovis</italic> (<italic>M. bovis</italic>) that leads to great economic losses in cattle production. The discovery of a reasonable bioagent to reduce <italic>M. bovis</italic> infection risk and environment contamination becomes significant and urgent. Previous study reported that human β-defensin-3 (HBD3) participated in <italic>Mycobacterial</italic> immunity and was recognized as a suitable candidate reagent. However, its minimal inhibitory concentration to <italic>M. bovis</italic> is not yet reported. In this study, we first purified HBD3 protein by recombinant-DNA technology and prokaryotic expression system. Subsequently, anti-bacterial tests were used to evaluate the basic bioactivity of the protein. Results revealed that recombinant HBD3 (rHBD3) protein inhibits <italic>Staphylococcus</italic> multiplication but not the host <italic>Escherichia coli</italic>. The growth curve of <italic>M. bovis</italic> showed that rHBD3 protein controls the proliferation of <italic>M. bovis</italic> in 20 μg/ml concentration. In addition, rHBD3 protein-incubated <italic>M. bovis</italic> exhibited reduced infectivity to alveolar epithelial cells and macrophages. In conclusion, the expression of rHBD3 protein is a potential ideal bio-regent for reducing <italic>M. bovis</italic> infection. [ABSTRACT FROM AUTHOR]