Evaluation of transgenicLeishmania infantumexpressingmLLO-BAX-SMACin the apoptosis of the infected macrophages in vitro and in vivo

Abstract

Background Leishmaniasis is an important infectious disease that develops because of escaping parasite from the host immune system or preventing host macrophages apoptosis. Recently, the development of transgenic methods and the manipulation of the parasite genome has provided many advantages. So, in this study, the effect of the transgenicLeishmania infantumexpressingmLLO-BAX-SMACproteins was examined in accelerating host cell apoptosis. Method The entire coding sequence of designed codon-optimized mLLO-Bax-Smacwas cloned in the pLexyNeo2 vector and integrated downstream of the 18srRNA locus ofL infantumgenome by homologous recombination. Next, the expression ofmLLO-BAX-SMACfusion protein was evaluated by the Western blotting technique and the pathogenesis of transgenic parasite was surveyed in vitro and in vivo. Results The results of PCR and Western blot confirmed proper integration and expression of mLLO-Bax-Smacsequence into the 18srRNA locus ofL infantum. Flow cytometry showed accelerating apoptosis of transgenicLeishmania-infected macrophages compared to wild-type parasite. Also, transgenic parasites were less virulent as a fewer parasitic burden was found in the spleen and liver of transgenic-infected mice compared to the control. Conclusion The data suggested that the transgenicL infantumexpressingBAX-SMACcan be used as an experimental model for developing vaccination against leishmaniasis.