Banca de DEFESA: PATRICIA KAUANNA FONSECA DAMASCENO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : PATRICIA KAUANNA FONSECA DAMASCENO
DATE: 27/05/2022
TIME: 14:00
LOCAL: IGM Sala Virtual 3
TITLE:

Immunomodulatory potential of genetically modified mesenchymal stem cells for overexpression of IL-15, flagellin, and CCL21 in antitumor responses in vitro and in vivo

KEY WORDS:

Mesenchymal stem cells, CCL21, Flagellin, IL-15, cancer, gene editing

PAGES: 121
BIG AREA: Ciências Biológicas
AREA: Genética
SUMMARY:

Cancer is a public health problem worldwide, being responsible for millions of deaths every year. Although the advancement of medicine and oncological therapies has allowed a greater disease-free survival to patients, the treatment of cancer patients is still limited. The most promising treatment currently is immunotherapy, which consists of enhancing the immune system to recognize and eliminate malignant cells. In parallel, the tumor tropism property of mesenchymal stem cells (MSC) has been evidenced by the potential to carry molecules of interest to the tumor microenvironment. Thus, the overexpression of factors that stimulate the immune system in MSC may be an effective mechanism in tumor regression. This project aims to evaluate the potential inducing antitumor responses of MSC strains genetically modified to overexpress CCL21, IL-15 and flagellin, which are agents with immune-stimulating potential. For this, three cell lines were produced (CTM-CCL21, CTM-IL15 and CTM-Flag), using a second-generation lentiviral system to carry out the genetic modification. The lines generated were characterized as to the maintenance of the mesenchymal phenotype through cell differentiation assays in the chondrogenic, osteogenic and adipogenic lines, in addition to immunophenotyping by flow cytometry for the markers Sca1, CD45, CD44, CD90, CD29 and CD11b. The immunogenic properties of each strain generated were evaluated in vitro through specific assays, according to the biological activity of each inserted factor. For the CTM-IL15 strain, the lymphoproliferation assay was performed; for CTM-Flag, the macrophage activation assay; and, for CTM-CCL21, the leukocyte chemoattraction assay. Furthermore, the properties inducing antitumor responses in vivo were evaluated through an experimental model of subcutaneous melanoma (B16F10 cell lineage) in C57Bl/6 mice. The generated strains were characterized, and demonstrated to maintain the mesenchymal profile and differentiation ability even after gene editing. The in vitro assays demonstrated the immunostimulatory potential of the three strains, through a greater proliferation of lymphocytes by MSC-IL15, greater attraction of dendritic cells by MSC-CCL21 and greater activation of macrophages by MSC-Flag, in the presence of supernatants of the modified cells when compared to supernatant from control MSCs or DMEM medium. In the in vivo model, the intravenous administration of cells from the 3 strains promoted a significantly greater inhibition of tumor growth compared to the control MSC strain. In conclusion, genetically modified MSC strains were successfully generated and have immunogenic activities that can be exploited in anticancer therapy.

BANKING MEMBERS:
Presidente - 012.993.637-50 - MILENA BOTELHO PEREIRA SOARES - UFRJ
Interno - 287831 - MITERMAYER GALVAO DOS REIS
Interna - 011.952.725-10 - NATALIA MACHADO TAVARES - UFBA
Externa à Instituição - SHEILLA ANDRADE DE OLIVEIRA - Fiocruz - PE
Externo ao Programa - 1221606 - VITOR ANTONIO FORTUNA