Expression profile in Leishmania major exposed to Staphylococcus aureus and group A beta-hemolytic Streptococcus

Background & objectives: The interaction of Leishmania spp. with microbiota inside the midgut vector has significant output in pathogenesis. This study aimed to identify the profile of Leishmania major gene expression of LACK, gp63, and hsp70 after exposure to Staphylococcus aureus and group A beta-hemolytic Streptococci (GABHS). Methods: Leishmania major (MRHO/IR/75/ER) promastigotes were exposed with S. aureus, with GABHS, and with both GABHS and S. aureus at 25°C for 72 h. The gene expression analysis of Lmgp63, Lmhsp70, and LmLACK was assessed using SYBR Green real-time PCR by ??Ct. All experiments were repeated in triplicate. Statistical analysis was done using two-way ANOVA. A P-value less than 0.05 was considered significant. Results: Lmgp63 was expressed in the group exposed to GABHS with 1.75-fold lower than the control group (p=0.000). The LmLACK had expression in both groups exposed with GABHS and GABHS with S. aureus with 2.8 and 1.33-fold more than the control group, respectively (p=0.000). The Lmhsp70 gene expression was reported in the group exposed with GABHS with relative quantification of 5.7-fold more than the control group. Interpretation & conclusion: This study showed that the important genes encoding LACK, gp63, and hsp70 changed their expression after exposure to the S. aureus and GABHS.

Protease inhibitors as a potential agent against visceral Leishmaniasis: A review to inspire future study

Abstract Leishmaniasis is transmitted by sandfly which carries the intracellular protozoa in their midgut. Among visceral, cutaneous and mucocutaneous leishmaniasis, visceral type that is caused by Leishmania donovani is the most lethal one. Findings of leishmanial structure and species took place in 19th century and was initiated by Donovan. Leishmaniasis is still a major concern of health issues in many endemic countries in Asia, Africa, the Americas, and the Mediterranean region. Worldwide1.5-2 million new cases of cutaneous leishmaniasis and 500,000 cases of visceral leishmaniasis are reported each year. Leishmaniasis is endemic in nearly 90 countries worldwide and close to 12 million new cases of leishmaniasis are reported worldwide annually. Studies on antileishmanial drug development is of major concern as leishmaniasis are the second largest parasitic killer in the world and the available drugs are either toxic or costly. The major surface GP63 protease, also known as Zinc- metalloproteases present on the surface of leishmanial promastigotes, can be targeted for drug development. Protease inhibitors targeting such surface proteases show promising results. Different protease inhibitors have been isolated from marine actinobacteria against many infectious diseases. Metabolites produced by these actinobacteria may have greater importance for the discovery and development of new antileishmanial drugs. Hence, this review discusses the background, current situation, treatment, and protease inhibitors from marine actinobacteria for drug development against GP63 molecules.

Polyunsaturated fatty acids alter the formation of lipid droplets and eicosanoid production in Leishmania promastigotes

BACKGROUND The knowledge about eicosanoid metabolism and lipid droplet (LD) formation in the Leishmania is very limited and new approaches are needed to identify which bioactive molecules are produced of them. OBJECTIVES Herein, we compared LDs and eicosanoids biogenesis in distinct Leishmania species which are etiologic agents of different clinical forms of leishmaniasis. METHODS For this, promastigotes of Leishmania amazonensis, L. braziliensis and L. infantum were stimulated with polyunsaturated fatty acids (PUFA) and LD and eicosanoid production was evaluated. We also compared mutations in structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins, as well as the levels of these enzymes in parasite cell extracts. FINDINGS PUFAs modulate the LD formation in L. braziliensis and L. infantum. Leishmania spp with equivalent tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among Leishmania spp, however PGFS production increased during the parasite differentiation. Stimulation with arachidonic acid resulted in elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins. MAIN CONCLUSIONS Our data suggest LD formation and eicosanoid production are distinctly modulated by PUFAS dependent of Leishmania species. In addition, eicosanoid-enzyme mutations are more similar between Leishmania species with same host tropism.

Biochemical Properties of Parasite Virulence Factor: Lesson Learned from Leishmania

Leishmania, a parasitic protozoan, a single-celled organism of the genus trypanosomes that are responsible for the disease leishmaniasis. Transmission occured by sandflies of the genus Phlebotomus in the Old World, and of the genus Lutzomyia in the New World. Globally, at least 93 sandfly species are proven or probable vectors. Their primary hosts are vertebrates; Leishmania commonly infects hyraxes, canids, rodents, and humans. Leishmaniasis encompasses diverse clinical syndromes, including cutaneous, mucosal, and potentially life-threatening visceral forms. Three widely known virulence factors belongs to the genus Leishmania include the active compound named proteophosphoglycan (PPG), GP63 metalloprotease and lipophosphoglycan (LPG). these substance established on the surface of the parasite. The aim of this review article is to make an insight of the biochemical characteristics of Leishmania spp virulence factors, the armamentarium that predispose their pathogenesis, its invasion and virulence to the mammalian host.

Susceptibility of Phytomonas serpens to calpain inhibitors in vitro: interference on the proliferation, ultrastructure, cysteine peptidase expression and interaction with the invertebrate host

A pleiotropic response to the calpain inhibitor MDL28170 was detected in the tomato parasite Phytomonas serpens. Ultrastructural studies revealed that MDL28170 caused mitochondrial swelling, shortening of flagellum and disruption of trans Golgi network. This effect was correlated to the inhibition in processing of cruzipain-like molecules, which presented an increase in expression paralleled by decreased proteolytic activity. Concomitantly, a calcium-dependent cysteine peptidase was detected in the parasite extract, the activity of which was repressed by pre-incubation of parasites with MDL28170. Flow cytometry and Western blotting analyses revealed the differential expression of calpain-like proteins (CALPs) in response to the pre-incubation of parasites with the MDL28170, and confocal fluorescence microscopy confirmed their surface location. The interaction of promastigotes with explanted salivary glands of the insect Oncopeltus fasciatus was reduced when parasites were pre-treated with MDL28170, which was correlated to reduced levels of surface cruzipain-like and gp63-like molecules. Treatment of parasites with anti-Drosophila melanogaster (Dm) calpain antibody also decreased the adhesion process. Additionally, parasites recovered from the interaction process presented higher levels of surface cruzipain-like and gp63-like molecules, with similar levels of CALPs cross-reactive to anti-Dm-calpain antibody. The results confirm the importance of exploring the use of calpain inhibitors in studying parasites’ physiology.

Expression of antigens in virulent and avirulent Indian strains of Leishmania donovani.

Indo-Gen mediated surface labelling with 125I demonstrated differences in surface oriented antigens between virulent and virulent promastigote of Leishniania donovani, In case of virulent strains, surface polypeptides with molecular masses of 63, 53, 42 and 38 kDa were found to be labelled with 125I whereas in the case of aviralent stains 68, 55, 50, 46, 42 and 33 Da, components were iodinated. Further studies by immunoblot assay using different subcellular fractions of virulent and avirulent parasites demonstrated that antibody raised against gp63 cross-reacted with the 63 and 60 kDa antigen of the virulent and avirulent Leishmania donovani strains of Indian origin respectively. It indicates that these two polypeptides are antigenically similar. When virulent and avirulent cells were grown in the presence of varying concentration of tunicarnycin and immunoblot with anti gp63, it was observed that with increasing concentration of tunicamycin the 63 kDa polypeptide of the virulent cells shifted to approximately 58-57 kDa and the 60 kDa polypoptide of the aviruleni cells shifted to 57 kDa. This suggests that glycosylation may play an important role in antigenic variation between virulent and avirulent parasites.