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Lutzomyia longipalpis is the most important vector of AmericanVisceral Leishmaniasis (AVL) due to Leishmania chagasi in the New World. Despite its importance, AVL, a disease primarily of rural areas, has increased its prevalence and became urbanized in some large cities in Brazil and other countries in Latin America. Although the disease is treatable, other control measures include elimination of infected dogs and the use of insecticides to kill the sand flies. A better understanding of vector biology could also account as one more tool for AVL control. A wide variety of papers about L. longipalpis have been published in the recent past years. This review summarizes our current information of this particular sand fly regarding its importance, biology, morphology, pheromones genetics, saliva, gut physiology and parasite interactions.

The exploitation of insect galectins, which are associated with embryonic developments by parasites for survival in their insect hosts, is shown. PpGalec, a tandem repeat galectin expressed in the midgut of the sand fly Phlebotomus papatasi, is used by Leishmania major as a receptor for mediating specific binding to the insect midgut, an event crucial for parasite survival and accounts for species-specific vector competence.

Research has been conducted on the gene that is involved in lipophosphoglycan assembly. Results indicate that it encodes the Golgi GDP-Man transporter of the protozoan parasite Leishmania.

Leishmania donovani lipophosphoglycan (LPG) in low concentrations inhibits hemolysis induced by the Sendai virus when admitted into human erythrocyte ghost (HEG) membranes and reduces the binding of Sendai as well as the influenza virus. Though the exact molecular mechanism by which LPG inhibits viral fusion is unknown, it is possible that LPG brings about steric repulsion between the viral and HEG membranes and also modifies the bending rigidity and curvature of the HEG membrane to prevent lipid bilayer destabilization.

Comparison of the vectorial competence of Phlebotomus papatasi and P. argentipes sand flies for different Leishmania species reveals that structural polymorphisms in the surface lipophosphoglycan (LPG) of the parasite mediate the binding of promastigostes to the sand-fly midgut. Leishmania species exhibit different adhesion abilities for different vectors and the extent of binding is indicative of the parasite-sand fly combination that facilitates the transmission of diseases.

Although leishmaniasis is transmitted to humans almost exclusively by the bite of infected phlebotomine sandflies, little is known about the molecules controlling the survival and development of Leishmania parasites in [...]

Through our studies of three Drosophila enzymes involved in Heparan Sulfate Proteoglycans (HSPGs) biosynthesis: Tout-velu (EXT), Sugarless (UDP-glucose dehydrogenase), Sulfateless (N-deactylase/N-), as well as two Drosophila Glypicans (Dally and K-Glypican), we have previously documented the function of HSPGs in FGF, Wingless/Wnt and Hedgehog signaling. In addition, genetic and phenotypic evidence has suggested that the activation of Notch, by its ligands Serrate and Delta, can be modulated by the putative glycosyltransferases Fringe and Brainiac. We have recently isolated a new segment polarity gene, fringe connection (frc), from our maternal/zygotic screens. Embryos that lack both maternal and zygotic frc activity exhibit defects in Wingless, Hedgehog and FGF signaling pathways. In addition, large mutant frc clones induced in heterozygous animals exhibit a fringe-like phenotype, frc encodes a putative sugar transporter and expression constructs of the gene introduced into a Leishmania lpg2-mutant (defective in a Golgi GDP-Mannose transporter) conferred UDP-Glucuronic acid (but not UDP-Gal or GDP-Man) uptake in isolated microsomes. We propose that Frc transports putative oligosaccharide(s) needed for both the formation of the glycosaminoglycans attached to the HSPGs, as well as the glycosylation event mediated by Fringe.