title: Genetic variation in the sand fly salivary protein, SP-15, a potential vaccine candidate against Leishmania major.
abstract: SP-15 is a sandfly salivary protein that provides strong protection against cutaneous leishmaniasis, caused by Leishmania major, and has been proposed as a potential vaccine against this disease. To investigate possible antigenic variation in this protein, we examined genetic polymorphism of SP-15 in 100 Phlebotomus papatasi sandflies, from a natural population from Sudan and four laboratory colonies from Egypt, Jordan, Israel and Saudi Arabia. We found that although many variants of SP-15 may be found in nature, differences among them are minimal (mean+/-SD pairwise differences=1.69+/-0.83% for forty nucleotide sequences and 3.06+/-1.13% for thirty amino acid sequence variants). Analysis of proportions of synonymous and non-synonymous substitutions indicated that SP-15 is not under diversifying selection. Our results suggest that a vaccine based on SP-15 protein should result in a uniform immune response.
authors.affiliation: Department of Entomology, University of California at Davis, Davis, CA 95616, USA.
authors.forename: D-E A
authors.initials: DE
authors.lastname: Elnaiem
authors.forename: C
authors.initials: C
authors.lastname: Meneses
authors.forename: M
authors.initials: M
authors.lastname: Slotman
authors.forename: G C
authors.initials: GC
authors.lastname: Lanzaro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004175:Diptera / Q000235:genetics*; D014644:Genetic Variation; D007303:Insect Vectors / Q000235:genetics*; D018320:Leishmania major; D007896:Leishmaniasis / Q000235:genetics / Q000517:prevention & control*; D008877:Middle East; D008969:Molecular Sequence Data; D016052:Protozoan Vaccines / Q000235:genetics*; D012471:Salivary Proteins and Peptides / Q000235:genetics*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D016052:Protozoan Vaccines; D012471:Salivary Proteins and Peptides