Project description:Leishmania (Viannia) braziliensis is the main etiological agent of cutaneous and mucocutaneous leishmaniasis in Latin America. Reports have described non-ulcerated atypical tegumentary leishmaniasis cases caused by L. braziliensis in several regions of the world, including in patients from the Xacriabá Indigenous reserve, in São João das Missões/Minas Gerais - Brazil. Parasites isolated from these atypical clinical lesions have previously been found to be resistant to antimony-based therapeutics. In the present study, proteins displaying differential abundance in 2 strains of L. braziliensis isolated from patients with atypical lesions compared with 4 strains isolated from patients with typical lesions were identified using a quantitative proteomics approach based on tandem mass tag labeling (TMT) and mass spectrometry. A total of 532 (p value <0.05) differentially abundant proteins were identified (298 up-regulated and 234 down-regulated) in strains from atypical lesions compared to strains from typical lesions. We observed a variety of proteins with differential abundance among the studied strains. Prominent positively regulated in atypical strains included proteins which may confer a greater survival inside the macrophage, proteins related to resistance to antimony and higher peroxidase activity. Also were identified proteins suggest as new drug and vaccines target. Our data contribute to characterization of these intriguing L. braziliensis strains, and sheds new light on ACL cases has been associated with therapeutic failures.
Project description:The host immune response plays a critical role not only in protection from human leishmaniasis, but also in promoting disease severity. Although candidate gene approaches in mouse models of leishmaniasis have been extremely informative, a global understanding of the immune pathways active in lesions from human patients is lacking. To address this issue, genome-wide transcriptional profiling of Leishmania braziliensis-infected cutaneous lesions and normal skin controls was carried out. A signature of the L. braziliensis skin lesion was defined that includes over 2,000 differentially regulated genes. Pathway-level analysis of this transcriptional response revealed key biological pathways, as well as specific genes, associated with cutaneous pathology, generating a testable 'metapathway' model of immune-driven lesion pathology, and providing new insights for treatment of human leishmaniasis. Thirty-five skin biopsies were analyzed, including 10 normal skin biopsies (2 from North America and 8 from non-endemic area in Brazil), and 25 skin lesion biopsies (8 early cutaneous lesions, 17 late cutaneous lesions) obtained from Leishmania brazilensis-infected patients presenting at the Corte de Pedra Health Post in Corte de Pedra, Bahia, Brazil.
Project description:The host immune response plays a critical role not only in protection from human leishmaniasis, but also in promoting disease severity. Although candidate gene approaches in mouse models of leishmaniasis have been extremely informative, a global understanding of the immune pathways active in lesions from human patients is lacking. To address this issue, genome-wide transcriptional profiling of Leishmania braziliensis-infected cutaneous lesions and normal skin controls was carried out. A signature of the L. braziliensis skin lesion was defined that includes over 2,000 differentially regulated genes. Pathway-level analysis of this transcriptional response revealed key biological pathways, as well as specific genes, associated with cutaneous pathology, generating a testable 'metapathway' model of immune-driven lesion pathology, and providing new insights for treatment of human leishmaniasis.
Project description:This study was carried out to evaluate the changes that occur in the skin after the development of cutaneous leishmaniasis, aiming at a comprehensive understanding of immune pathways and biological functions activated in lesions caused by L. braziliensis.
