Leishmania infantum: Lipophosphoglycan intraspecific variation and interaction with vertebrate and invertebrate hosts

Abstract

Interspecies variations in lipophosphoglycan (LPG) have been the focus of intense study over the years due its role in specificity during sand fly-Leishmania interaction. This cell surface glycoconjugate is highly polymorphic among species with variations in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO(4) backbone of repeat units. However, the degree of intraspecies polymorphism in LPG of Leishmania infantum (syn. Leishmania chagasi) is not known. In this study, intraspecific variation in the repeat units of LPG was evaluated in 16 strains of L. infantum from Brazil, France, Algeria and Tunisia. The structural polymorphism in the L. infantum LPG repeat units was relatively slight and consisted of three types: type I does not have side chains; type II has one β-glucose residue that branches off the disaccharide-phosphate repeat units and type III has up to three glucose residues (oligo-glucosylated). The significance of these modifications was investigated during in vivo interaction of L. infantum with Lutzomyia longipalpis, and in vitro interaction of the parasites and respective LPGs with murine macrophages. There were no consequential differences in the parasite densities in sand fly midguts infected with Leishmania strains exhibiting type I, II and III LPGs. However, higher nitric oxide production was observed in macrophages exposed to glucosylated type II LPG.

Intraspecies Variation in Trypanosoma cruzi GPI-Mucins: Biological Activities and Differential Expression of α-Galactosyl Residues

“…In L. infantum and L. major, a higher NO production was observed in the more complex LPG structures containing glucose and galactose side chains, respectively. 59,60 In T. cruzi, early studies reported intraspecies variations in the GIPLs from epimastigotes in five strains (G, G-645, Tulahuen, CL, and Y). 61 The work by Carreira and others 61 suggested that those polymorphisms could be related to differences in pathogenicity and immunomodulatory activities during T. cruzi infection.…”

Understanding the Mechanisms Controlling Leishmania amazonensis Infection In Vitro: The Role of LTB4 Derived From Human Neutrophils

“…The extract was dried by nitrogen gas evaporation, resuspended in 0.1 N acetic acid/0.1 M sodium chloride, and applied to a column of phenyl-Sepharose (2 mL). LPG was eluted using solvent E [20]. The purity of LPG was previously tested using Chinese hamster ovary cells transfected with TLR2 or TLR4 and CD25 as a reporter protein [21].…”

Leishmania virulence factors: focus on the metalloprotease GP63

“…The host cell type as well as the structure of the parasite molecules needs to be considered. In fact, interspecific and intraspecific polymorphisms of LPGs have been reported [11] and therefore may account in part for those differences.…”