Submitted by PPG Pediatria e Sa?de da Crian?a (pediatria-pg@pucrs.br) on 2018-08-30T19:28:55Z No. of bitstreams: 1 Disserta??o Final Gabriela Fabiano de Souza.pdf: 1295606 bytes, checksum: 81a673082dab9c871a133af1f8517135 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-09-03T12:11:04Z (GMT) No. of bitstreams: 1 Disserta??o Final Gabriela Fabiano de Souza.pdf: 1295606 bytes, checksum: 81a673082dab9c871a133af1f8517135 (MD5) / Made available in DSpace on 2018-09-03T12:19:46Z (GMT). No. of bitstreams: 1 Disserta??o Final Gabriela Fabiano de Souza.pdf: 1295606 bytes, checksum: 81a673082dab9c871a133af1f8517135 (MD5) Previous issue date: 2018-03-19 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Respiratory syncytial virus (RSV) is the major cause of infection in children up to five years of age. Reinfection is very common among patients, causing symptoms such as cold or allergy. However, in children, immunosuppressed patients and elderly infection is exacerbated leading to hospitalization and in some case, even death. The number of hospitalizations each year is alarming, even more so because up to now there is still no vaccine for RSV. Tissue damage in the lung caused by RSV leads to an immune response, where infected cells signal activation of signaling pathways, production of reactive oxygen species (ROS), and massive production of inflammatory mediators. Among this production is the macrophage migration inhibitory factor (MIF), which is a pro-inflammatory cytokine, which has been shown to play an important role in the immune response. Knowing this importance, we evaluated MIF expression macrophages from BALB/c mice. The cells were infected with different concentrations of RSV and analyzed by western blot, real-time PCR and Cytometric Bead Array (CBA). After confirmation of MIF expression by the infection, different inhibitors of signaling pathways and ROS were used to evaluate its importance for the expression of MIF. From the results obtained, we showed the dependence of ROS, 5-lipoxygenase (5-LOX), COX, PI3K and partially of P38 MAPK, for MIF expression, besides the need for viral activity. MIF was shown to be important for the release of cytokines such as TNF?, MCP-1 and IL-10. Based on this information MIF may play an important role in the exacerbation of infection, so it was extremely important to explore mechanisms involved in the expression of MIF in relation to RSV. / O V?rus sincicial respirat?rio (VSR) ? a maior causa de infec??o em crian?as at? os cinco anos de idade. A reinfec??o ? muito comum entre os pacientes, causando sintomas como de uma gripe ou alergia, no entanto, em crian?as, pacientes imunossuprimidos e idosos a infec??o ? muito mais exacerbada, o que acaba levando a necessidade de interna??o, podendo levar o paciente a ?bito. O n?mero de interna??es a cada ano ? alarmante, ainda mais que at? os dias atuais ainda n?o se tem uma vacina para o VSR. O dano tecidual no pulm?o, causado por VSR leva a uma resposta imune, onde c?lulas infectadas sinalizam para que ocorra a ativa??o de vias de sinaliza??o, produ??o de esp?cies reativas de oxig?nio (EROs) e tamb?m uma produ??o massiva de mediadores inflamat?rios. Dentre essa produ??o, est? o fator inibidor de migra??o de macr?fagos (MIF), que ? uma citocina pr?-inflamat?ria, que tem demonstrado um importante papel na resposta imune. Sabendo dessa import?ncia, avaliamos a express?o de MIF em macr?fagos de camundongos BALB/c. As c?lulas foram infectadas com diferentes concentra??es de VSR e analisadas por western blot, PCR em tempo real e Cytometric Bead Array (CBA). Ap?s a confirma??o da express?o de MIF pela infec??o, foram utilizados diferentes inibidores de vias de sinaliza??o e de EROs, para que fosse poss?vel avaliar sua import?ncia para a express?o de MIF. A partir dos resultados obtidos mostramos a depend?ncia de EROS, 5-lipoxigenase (5-LOX), COX, PI3K e parcialmente de P38 MAPK, para a express?o de MIF, al?m da necessidade de atividade viral. MIF se mostrou importante para a libera??o de citocinas como TNF ?, MCP-1 e IL-10. Baseado nessas informa??es MIF pode desempenhar um papel importante na exacerba??o da infec??o, sendo assim, foi de extrema import?ncia explorar mecanismos envolvidos na express?o de MIF em rela??o ao VSR.