Phenotypic Characterization of a Leishmania donovani Cyclophilin 40 Null Mutant.

Protozoan parasites of the genus Leishmania adapt to their arthropod and vertebrate hosts through the development of defined life cycle stages. Stage differentiation is triggered by environmental stress factors and has been linked to parasite chaperone activities. Using a null mutant approach we previously revealed important, nonredundant functions of the cochaperone cyclophilin 40 in L.

Geographical sequence variation in the Leishmania major virulence factor P46.

Cutaneous leishmaniasis as caused by Leishmania major is a zoonotic infection with wide epidemiological impact. The L. major P46 virulence gene was shown to boost the parasite's virulence and extends its range of experimental hosts.

The Leishmania donovani chaperone cyclophilin 40 is essential for intracellular infection independent of its stage-specific phosphorylation status.

During its life cycle, the protozoan pathogen Leishmania donovani is exposed to contrasting environments inside insect vector and vertebrate host, to which the parasite must adapt for extra- and intracellular survival. Combining null mutant analysis with phosphorylation site-specific mutagenesis and functional complementation we genetically tested the requirement of the L. donovani chaperone cyclophilin 40 (LdCyP40) for infection.

A novel marker, ARM58, confers antimony resistance to Leishmania spp.

Protozoa of the Leishmania genus cause a variety of disease forms that rank at the top of the list of neglected tropical diseases. Anti-leishmanial drugs based on pentavalent antimony have been the mainstay of therapy for over 60 years and resistance against them is increasingly encountered in the field. The biochemical basis for this is poorly understood and likely diverse.

Reduced antimony accumulation in ARM58-overexpressing Leishmania infantum.

Antimony-based drugs are still the mainstay of chemotherapy against Leishmania infections in many countries where the parasites are endemic. The efficacy of antimonials has been compromised by increasing numbers of resistant infections, the basis of which is not fully understood and likely involves multiple factors. By using a functional cloning strategy, we recently identified a novel antimony resistance marker, ARM58, from the parasite Leishmania braziliensis that protects the parasites against antimony-based antileishmanial compounds.

Identification of a Leishmania infantum gene mediating resistance to miltefosine and SbIII.

Resistance to treatment is a growing problem in efforts to control Old World leishmaniasis. Parasites resistant to new therapeutics such as miltefosine have not been reported from the field yet but based on experimental evidence, may appear soon. Therefore, we attempted to identify genetic markers that may correlate with miltefosine resistance.

Stage-specific expression of the mitochondrial co-chaperonin of Leishmania donovani, CPN10.

BACKGROUND: Leishmania spp., in the course of their parasitic life cycle, encounter two vastly different environments: the gut of sandflies and the phagosomes of mammalian macrophages. During transmission into a mammal, the parasites are exposed to increased ambient temperature as well as to different carbon sources.

A Leishmania donovani gene that confers accelerated recovery from stationary phase growth arrest.

We have isolated a gene, LdGF1, from the protozoan parasite Leishmania donovani. Overexpression of this gene confers a strong selective advantage in liquid culture after stationary phase growth arrest. We could show that recombinant L.