expression of phlebotomus papatasi salivary protein 15 (ppsp15) in cos-7 cells

Background: cutaneous leishmaniasis (cl) is a neglected tropical infection and the most prevalent vector-borne dis-ease in iran. there is no approved human vaccine and current treatments are restricted; some drugs are expensive and have notable side effects. therefore, the need for the development of a safe and effective vaccine that can be produced at a low cost remains urgent. it has been shown that vaccinating animals with salivary gland homogenate or saliva com- ponents of sand flies protected against leishmania infection. in this study, we aimed to prepare a mammalian expres- sion vector encoding phlebotomus papatasi salivary protein 15 (ppsp15) intended to be used as a dna vaccine in our forthcoming studies.methods: in this study, we designed and constructed pcdna3. 1, a constitutive mammalian expression vector, to en- code the immunogenic protein ppsp15. the presence of the target gene was confirmed by enzymatic digestion and se- quencing. the mammalian cos-7 cells were transfected with the pcdna3.1 vector and the expression of ppsp15 pro- tein was then examined in the cell line using western blotting analysis.results: restriction enzyme digestion and sequencing revealed the correctly constructed pcdna3.1-ppsp15. after the transfection of the cos-7 cell line with pcdna3.1-ppsp15 using linear polyethylenimine, the ppsp15 protein expres- sion was confirmed by western blot analysis using anti-his antibody.conclusion: a high expression level of ppsp15 protein in cos-7 cells was achieved after the transfection of cos-7 cells, using cationic linear polyethylenimine. in subsequent research, this recombinant plasmid is supposed to be uti- lized as a candidate dna vaccine to find its immunity induction in susceptible animal models.