Banca de DEFESA: PAULO RICARDO PORFÍRIO DO NASCIMENTO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : PAULO RICARDO PORFÍRIO DO NASCIMENTO
DATA : 13/12/2016
HORA: 14:00
LOCAL: Sala Carl Peter von Dietrich - Depto. de Bioquímica - CB/UFRN
TÍTULO:

Transcriptional profile and histopathological alterations in canine visceral leishmaniasis.

PALAVRAS-CHAVES:

Canine Visceral Leishmaniasis, Histopathology, Transcriptome.

PÁGINAS: 116
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Background Dog is the main domestic reservoir of Leishmania infantum and shows a wide spectrum of clinical manifestations, varying from mild weight loss to severe hepatosplenomegaly and body spread lesions, classical signs of canine visceral leishmaniasis (CVL). The goal of this study was to evaluate the gene expression profile of spleen and peripheral blood cells from Leishmania-infected dogs and investigate microstructural alterations in spleen, liver, gut and skin in order to determine possible molecular pathways and histopathological process underlying the mechanisms related to disease progression and resistance. Methodology: 21 animals were recruited to this study at Zoonotic Control Center in Natal-RN and a sub group was selected for transcriptomic studies. Spleen fragments were obtained from 5 mongrel dogs, one of them showing negative serology for SLA, two animals were classified as asymptomatic and other two as symptomatic. In addition, spleen, liver, gut and blood parasitism were estimated by qPCR. Total RNA was extracted and cDNA libraries were constructed and sequenced in an Illumina platform. The reads obtained were filtered and aligned against Canis familiaris genome using Bowtie. Differential gene expression was analyzed using the Cufflinks workflow, functional annotation and molecular features for each gene was obtained from Gene Ontology and KEGG database using STRINGdb. A fragment of liver, gut, skin and another spleen fragment were collected, processed and stained by HE and immunofluorescence for histopathological analysis. Results: We observed a marked difference in gene expression profile of spleen and peripheral blood samples from symptomatic dogs compared to asymptomatic ones. Approximately, 756 genes were upregulated in the spleens of symptomatics animals, as CTLA4, CCL2 and IL27, furthermore, about 1,190 genes were downregulated in the same group of animals, as BMP6, C1QB and C1QC. After an enrichment analysis for molecular pathways associated to visceral leishmaniasis pathogenesis, we found that NK cells activation, toll-like and NOD-like receptors pathways is highly expressed in the spleen of symptomatic ones, while GPI-anchors synthesis and immuneprotesome activation related genes is downregulated in these dogs. Additionally, we observed that in symptomatic animals, the cytoarchitecture of spleen is altered, where white and red pulp delimitations is partially lost. We still observed an intense inflammatory infiltrate in the liver, gut and skin of these animals. Confirmig the RNA-Seq findings, we observed by immunofluorescence CTLA4, CCR7 and NLRP3 is the spleen of symptomatic dogs. Conclusions: Taken together, these results suggests that misregulation of mechanisms classically described as acting in innate immunity is involved in CVL pathogenesis and an efficient antigen presentation maybe decisive for resistance to clinical signs development and tissue integrity during L. infantum infection in dogs.

MEMBROS DA BANCA:
Externo à Instituição - CLAUDIA IDA BRODSKYN - IGM
Interno - 1149356 - ELIZEU ANTUNES DOS SANTOS
Externo à Instituição - MATHEUS AUGUSTO DE BITTENCOURT PASQUALI - UFCG
Externo ao Programa - 1939184 - SANDRO JOSE DE SOUZA
Presidente - 350647 - SELMA MARIA BEZERRA JERONIMO