Evaluation of the influence of the osteopontin protein in modulating the cellular inflammatory response after in vitro infection by Chikungunya virus and its therapeutic potential

• Grant number: 24/05524-2
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2024
• End date: May 31, 2026
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Benedito Antônio Lopes da Fonseca
• Grantee: Danillo Lucas Alves Espósito
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 19/26119-0 - Emerging and re-emerging viruses: biology, pathogenesis and prospection, AP.TEM

Abstract

We have demonstrated in a previous study that the SPP1 gene was positively modulated in vitro after infection with MAYV, which is a virus different from other arthritogenic viruses from the same family, as it induces a more attenuated inflammatory response. This may result from differential modulation of SPP1. The SPP1 gene encodes osteopontin, a protein that has several functions, such as bone remodeling, angiogenesis, tumor migration, in addition to being related to the repair of inflammatory processes. In contrast, osteopontin appears to regulate the T cell response, with inhibition of the anti-inflammatory cytokine IL-10 and increase in the pro-inflammatory Th1 response. Mice deficient in osteopontin have increased IL-10 and decreased IL-12 and interferon gamma. The high expression of osteopontin after CHIKV infection may contribute to inflammatory processes, with modulation of the Th cell response. The objective of this project is to evaluate the influence of osteopontin on the modulation of the inflammatory response induced by CHIKV, with the hypothesis that its expression leads to a compromised balance between the inflammatory and anti-inflammatory response, which can accentuate the symptoms presented by patients. To study the influence of osteopontin on the inflammatory response to CHIKV, gene expression silencing and subsequent analysis of the expression of pro- and anti-inflammatory cytokines will be used in the face of virus infection. Initially, cells of the human monocytic lineage (U937) will be used to delete the coding region of the SPP1 gene using the CRISPR-Cas9 technique, with guide RNA specific for this gene. In addition, RNAi silencing will be performed in U937 and PBMC for the transcript that encodes the osteopontin protein. In infected cells, the expression profile of cytokines will be evaluated by Luminex, in addition to gene expression by RT-qPCR, of pro-inflammatory and regulatory cytokines.