Banca de DEFESA: KASSIA REGINA DA SILVA CARNEIRO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KASSIA REGINA DA SILVA CARNEIRO
DATE: 02/10/2024
TIME: 14:00
LOCAL: Google Meet
TITLE:

Anti-inflammatory and anti-infective action of Canavalia brasiliensis lectin in experimental models of listeriosis

KEY WORDS:

ConBr, Listeria monocytogenes, listeriosis, therapeutic adjuvants, immunomodulatory action.

PAGES: 130
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Doenças Infecciosas de Animais
SUMMARY:

Listeria monocytogenes is the causative agent of listeriosis, a foodborne disease that affects humans and animals. Considering the development of immunotherapeutic formulations for the control of microbial infections, previous studies point to several biological actions of the plant lectin ConBr, such as: immunomodulatory, antimicrobial, healing actions, neuroprotective action, in vivo activation of T lymphocytes and induction of cell apoptosis. In this study, the objective was to clarify the immunomodulatory potential of the lectin from Canavalia brasiliensis in the treatment of experimental infections caused by Listeria monocytogenes. Previously, cytotoxicity assays with different dosages of ConBr (100 to 0.78 µg/mL) were carried out with primary cultures of macrophages obtained from the peritoneal cavity of the animals, with cell viability determined through evaluation of cellular metabolic activity, with the After using resazurin, intracellular bacterial quantification was carried out inside the macrophages. In the experimental design, Swiss mice (N=20) were inoculated in a suspension of L. monocytogenes () orally and, after 24h, treated intraperitoneally, with non-toxic doses of the lectin ConBr 10mg/kg and 1mg/kg associated or not with antibiotics. After 24 hours of treatment, the animals were euthanized to collect biological material, such as: blood, peritoneal fluid, spleen and liver, for analysis of Colony Forming Units, RNA extraction and total and differential leukocyte counts. In another experiment, another 40 animals were treated and monitored for 7 days to analyze the survival rate. The results of in vitro analyzes showed that ConBr increased the cell viability of macrophages infected by Listeria monocytogenes, in addition to corroborating the greater elimination of bacteria inside the macrophages, despite not having a direct antimicrobial effect against L. monocytogenes. In in vivo tests, the administration of ConBr significantly reduced the recruitment of leukocytes to the peritoneal cavity and the number of leukocytes circulating in the blood. A significant difference was also observed in the quantification of CFU/mL liver, spleen, peritoneal fluid and blood when compared between the groups infected with ConBr 1mg/kg and ConBr 10mg/kg and the untreated/infected group. Analysis of the animals survival rate revealed that 50% of the animal’s survived treatment with doses of ConBr 10mg/kg and 1mg/kg, on the other hand, all animals in the infected/untreated group (PBS group) died. Therefore, the results obtained point to a promising perspective regarding the potential of using ConBr as an anti-inflammatory and control of systemic infections caused by Listeria monocytogenes.

COMMITTEE MEMBERS:
Interno - JOAQUIM EVENCIO NETO
Presidente - JOSE VITOR MOREIRA LIMA FILHO
Externo à Instituição - MÁRCIO VIANA RAMOS - UFC
Externa à Instituição - ROSSANA DE AGUIAR CORDEIRO - UFC
Externa à Instituição - VÂNIA MARIA MACIEL MELO - UFC