RESUMEN
Objective To construct and identify the recombinant BCG (bacille Calmette-Guerin) expressing exogenous antigen, namely Dermatophagoides pteronyssinus (house dust mite), major allergen (Der p2) in form of secreting protein. Methods The gene fragments containing ?-ss signal peptide gene were amplified by polymerase chain reaction (PCR) from the Mycobacteria tuberculosis H37Rv and cloned into the Der p2-rBCG, which can express Der p2 in intracellular pattern.Then the Der p2 gene was expressed by the rBCG in form of secreting protein, and it was identified by Western blotting. Results The sequence of signal peptide gene ?-ss was verified by sequencing identification. The constructed Der p2-rBCG could shuttle from E. coli to Mycobacteria to mediat the expression of antibiotic resistance gene and it served as a vector to express the Der p2 gene as a secreted protein. Conclusions The Der p2-rBCG, which can express exogenous antigen gene in form of secreting protein, has been constructed successfully.