< i > Lactococcus lactis < /i > expressing sand fly PpSP15 salivary protein confers long-term protection against < i > Leishmania major < /i > in BALB/c mice

by Elaheh Davarpanah, Negar Seyed, Fariborz Bahrami, Sima Rafati, Reza Safaralizadeh, Tahereh Taheri Cutaneous leishmaniasisis a vector-borne disease transmitted byLeishmania infected sand flies. PpSP15 is an immunogenic salivary protein from the sand flyPhlebotomus papatasi. Immunization with PpSP15 was shown to protect againstLeishmania major infection.Lactococcus lactis is a safe non-pathogenic delivery system that can be used to express antigensin situ. Here, the codon-optimizedPpsp15-egfp gene was cloned in pNZ8121 vector downstream of the PrtP signal peptide that is responsible for expression and secretion of the protein on the cell wall. Expression of PpSP15-EGFP recombinant protein was monitored by immunofluorescence, flow cytometry and Western blot. Also, expression of protein in cell wall compartment was verified using whole cell ELISA, Western blot and TEM microscopy. BALB/c mice were immunized three times with recombinantL.lactis-PpSP15-EGFPcwa, and the immune responses were followed up, at short-term (ST, 2 weeks) and long-term (LT, 6 months) periods. BALB/c mice were challenged withL.major plusP.papatasi Salivary Gland Homogenate. Evaluation of footpad thickness and parasite burden showed a delay in the development of the disease and significantly decreased parasite numbers in PpSP15 vaccinated animals as compared to control group. In addition, immunized mice showed Th1 type immune responses. Importantly, immunization withL.lactis-PpSP15-EGFPcwa stimulated the ...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research