Role of IRF5 in Oropouche vírus pathogenesis and neurovirulence

• Grant number: 22/04420-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: December 10, 2022
• End date: December 09, 2023
• Field of knowledge: Biological Sciences - Microbiology
• Principal Investigator: José Luiz Proença Módena
• Grantee: Pierina Lorencini Parise
• Supervisor: Patricia Veronica Aguilar
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of Texas Medical Branch at Galveston (UTMB), United States
• Associated to the scholarship: 17/26908-0 - The role of IRF-5 in Oropouche virus pathogenesis and neurovirulence, BP.DD

Abstract

Oropouche orthobunyavirus (OROV) is an emerging arbovirus that causes an exanthematous fever disease associated with neurological complications in some infected patients in the Amazon region from South American countries. Golden hamsters, newborns, and IRF5-/- infected animals are vulnerable and usually die from meningoencephalitis. Thus, since it has been shown that OROV can cross the blood-brain barrier (BBB) to cause Central Nervous Sistem (CNS) infection, this study aims to characterize the role of IRF5 in protecting endothelial cells from OROV infection. For this, CDH5cre IRF5f/f animals, which do not express IRF5 in endothelial cells, were subcutaneously infected with OROV. These animals were vulnerable to infection, developed neurological signs, presented high viral load in the CNS, accumulation of perivascular cells, and microglia activation in the brain. Also, this deletion seems to favor neuroinvasion from infected circulating immune cells, since the transference of isolated infected splenocytes from WT to CDH5cre IRF5f/f animals was able to promote neurological signs and high viral titers in these animals' CNS. In addition, we demonstrated that OROV is able to replicate more efficiently in human endothelial cells (HBMEC) than in murine endothelial cells (BEND3), probably as a consequence of a more effective innate immune response in murine cells. Also, an increase in the expression of some endothelial adhesion factors was observed in both infected cells. Finally, OROV infection in endothelial cells using a transwell system did not reveal signs of disruption, alteration on tight junction proteins expression, or viral load when the IRF5 gene was suppressed by RNAi. These results suggested that the presence of IRF5 in endothelial cells is essential for restricting OROV neuropathogenesis. We believe that this mechanism is dependent on a trojan horse transport where infected peripheral leukocytes carry the virus into the CNS. Despite the advances in the project, the exact mechanism by which IRF5 controls the OROV neuroinvasion in humans still needs to be elucidated. Them the next steps will be to develop a model of human vascularized brain organoid that will be grown on a perfusable microfluidic device wich simulates the blood-brain barrier into the brain. In this model, we will deplete IRF5 in the endothelial cells to analyze how the virus crosses this barrier, either by direct cell infection, tight junctions breakdown, or being carried by infected leukocytes. We will also evaluate the neurological involvement in CDH5Cre IRF5f/f mice infected with a currently circulating OROV strain, in order to observe if this mechanism is conserved in other lineages. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERNANDEZ, DIANA; YUN, RUIMEI; ZHOU, JIEHUA; PARISE, PIERINA L.; MOSSO-GONZALEZ, CLEMENTE; VILLASANTE-TEZANOS, ALEJANDRO; WEAVER, SCOTT C.; PANDO-ROBLES, VICTORIA; V. AGUILAR, PATRICIA. Differential Susceptibility of Aedes aegypti and Aedes albopictus Mosquitoes to Infection by Mayaro Virus Strains. American Journal of Tropical Medicine and Hygiene, v. 109, n. 1, p. 8-pg., 2023-07-01. (22/04420-3)