ABSTRACT
Background & objectives: Sand fly saliva contains proteins that modulate the host immune system and it plays an important role in both blood feeding and the outcome of Leishmania infections. The profile of the salivary proteins was examined and analyzed from an endemic focus of zoonotic cutaneous leishmaniasis by wild P. papatasi to find local and suitable antigens as potential proteins for developing Leishmania vaccine alongside the development of a new extraction technique. Methods: Specimens were caught from Bojnord, using funnel and CDC traps. Different methods of protein extraction were employed and a new technique was developed. The proteins were extracted from the salivary glands tissues with a lysis buffer. Purification was performed using RP-HPLC, with a linear gradient protocol from 0-60 % of acetonitrile. PpSP15 was characterized by SDS-PAGE. Results: The concentration of extracted protein content was 0.5 and 0.03 ?g/?l in chemical and physical methods, respectively. PpSP15 was isolated at a weight of 15kDa in 80–85 min of run time. SDS-PAGE was able to characterize PpSP15. The crude extract of the chemical method, revealed 15 separated bands, ranging from 11–100 KDa. Tajima D index was positive. Interpretation & conclusion: PpSP15 was characterized from Iranian specimens; it is a very highly hydrophobic protein of salivary glands among SP15- like proteins. The chemical method of extraction was found to be more effective than physical methods (P < 0.05). For developing a vaccine against leishmaniasis, depending on the location, choosing suitable proteins should be considered and an efficient extraction method should be used.
ABSTRACT
Background & objectives: Kala-azar is the visceral and most severe form of leishmaniasis that leads to death if untreated. The causative agents of visceral leishmaniasis (VL) are members of Leishmania (L.) donovani complex which includes L. chagasi and L. infantum. Genome sequences have raised the question whether L. chagasi and L. infantum are synonymous or different. This question has important implications for clinical and epidemiological studies, evaluation of vaccines and drugs, and disease control. LCR1 is an immunogenic molecule discovered from L. chagasi with potential as a component of a Leishmania subunit vaccine. If this protein has potentials for being used in a vaccine or diagnostic testing, there should be little variability in this molecule between L. infantum isolates from diverse geographic regions. The aim of this study was to determine whether lcr1 of an Iranian strain of L. infantum was identical to lcr1 of both L. infantum strain from a different geographic region (Spain) and that of an L. chagasi isolate from Brazil. Methods: L. infantum isolated from an Iranian kala-azar patient was studied. Lcr1 from this isolate was PCR amplified, cloned, and studied by restriction digest analysis and sequencing. Results: The sequences of lcr1 of the Iranian L. infantum were completely identical at nucleotide level to lcr1 sequences of both the Spanish L. infantum and the Brazilian L. chagasi strains. Conclusion: Complete conservation of the DNA sequence encoding for LCR1 molecule between geographically distinct Leishmania species adds credibility to the potential for LCR1 as a component of a subunit vaccine and diagnostic test for kala-azar.