Journal ArticleDOI
Virulence loss and amastigote transformation failure determine host cell responses to Leishmania mexicana
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TLDR
A model for L. mexicana is reported, which is of potential value in studying host–parasite interaction and down‐regulation of Th2‐associated cytokines, but down‐regulated Rab7 and Rab9 gene expression.Abstract:
Summary
The effect of alterations in virulence and transformation by long-term in vitro culture of Leishmania mexicana promastigotes on infectivity and immune responses was investigated. Fresh parasite cultures harvested from Balb/c mice were passaged 20 times in vitro. Infectivity was decreased and was completely avirulent after 20 passages. The qPCR results showed a down-regulation of GP63, LPG2, CPC, CPB2, CPB2.8, CHT1, LACK and LDCEN3 genes after passage seven concomitant with a reduced and absence of infectivity by passages seven and 20, respectively. Parasites at passages one and 20 are referred to as virulent and avirulent, respectively. The growth of avirulent and virulent parasite was affected by conditioned media derived from macrophages or monocytes infected with parasites for 2 h. Giemsa staining showed the failure of avirulent but not virulent parasites to transform to the amastigote stage in infected host cells with both virulent and avirulent modulating the expression of CCL-22, Tgad51, Cox2, IL-1, IL-10, TGF-β, TNF-α, Rab7, Rab9 and A2 genes; virulent but not avirulent L. mexicana significantly up-regulated Th2-associated cytokines, but down-regulated Rab7 and Rab9 gene expression. In conclusion, a model for L. mexicana is reported, which is of potential value in studying host–parasite interaction.read more
Citations
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Journal ArticleDOI
Leishmania, the phagosome, and host responses: The journey of a parasite.
Olivier Séguin,Albert Descoteaux +1 more
TL;DR: The nature of those interactions, how they affect the host immune system, and how they affects parasite survival are discussed from the very beginning of the life cycle in the vector to its dissemination within the mammalian host.
Journal ArticleDOI
New insights into experimental visceral leishmaniasis: Real-time in vivo imaging of Leishmania donovani virulence.
Guilherme D. Melo,Sophie Goyard,Hervé Lecoeur,Eline Rouault,Pascale Pescher,Laurence Fiette,Alexandre Boissonnas,Paola Minoprio,Thierry Lang +8 more
TL;DR: New perspectives are opened up on the study of visceral leishmaniasis, especially in the fields of therapeutics and vaccinology, since the model described herein renders now possible long-lasting follow up studies, with easy and accurate day-by-day verifications of the infection status along with a reduced number of laboratory animals.
Journal ArticleDOI
Induction of apoptosis and differentiation by atractylenolide-1 isolated from Atractylodes macrocephala in human leukemia cells.
TL;DR: Interestingly, it is found that ATL-I induced not only apoptosis but also differentiation, as upregulation of CD14 and CD68 surface markers and increase of phagocytosis ability were discovered in ATL-i-treated K562 CML and U937 AML cells.
Journal ArticleDOI
Comparative Fitness of a Parent Leishmania donovani Clinical Isolate and Its Experimentally Derived Paromomycin-Resistant Strain.
Sarah Hendrickx,Annelies Leemans,Annelies Mondelaers,Suman Rijal,Basudha Khanal,Jean-Claude Dujardin,Peter Delputte,Paul Cos,Louis Maes +8 more
TL;DR: The study results suggest that the epidemiological implications of acquired paromomycin-resistance may remain minimal other than the loss of one of the last remaining drugs effective against visceral leishmaniasis.
Journal ArticleDOI
High-Content Assay for Measuring Intracellular Growth of Leishmania in Human Macrophages
Michael J Dagley,Eleanor C Saunders,Kaylene J. Simpson,Kaylene J. Simpson,Malcolm J. McConville +4 more
TL;DR: A new high-content imaging method for quantifying the intracellular growth of Leishmania mexicana parasites in THP-1 macrophages that does not require the generation of transgenic fluorescent or bioluminescent parasite lines and can be readily adapted for screening different Leishmanial species, strains, or mutant lines in a wide range of phagocytic host cell types.
References
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Mycobacterium tuberculosis glycosylated phosphatidylinositol causes phagosome maturation arrest
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Macrophages define the invasive microenvironment in breast cancer
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