Metabolic reprogramming and viral persistence importance in immune cells to the development of chronic Chikungunya Arthritis

Abstract

In Brazil, the emerging infections caused by Arboviruses such as Dengue and Yellow fever (DENV and YIF) are historical and have been causing serious sequels along years. More recently, the health problems caused by Zika (ZIKV), and Chikungunya (CHIKV) viruses have been reported. Although CHIKV infection may be asymptomatic, it usually leads to the development of Chikungunya Fever, a disease characterized by the onset of fever, rashes and arthralgia. While many of the symptoms disappear within one week, arthralgia may persist in almost 50% of patients for up to a few years. The molecular mechanisms of chronicity development of this disease are very complex and remain unknow. This project aims to study the immunological and metabolomic pathways and factors associated with chronic Arthritis in patients previously exposed to CHIKV. Thus, contributing to understand the natural course of Chikungunya from infection to chronicity. To answer our hypothesis, we will obtain ex vivo samples from naturally CHIKV-infected patients from a cohort of the National Clinical Research Network in CHIKV (CNPq 421724/2017), also we will perform in vitro studies, for the evaluation of immunologic/metabolic processes associated with the initiation of immune response and viral persistence. For this, we will characterize the levels of cytokines, serum levels of metabolic regulators (adipokines, insulin, GLP-1, ghrelin), mRNA expression of key transcription factors involved in metabolic regulation (HIF-1alpha, SREBPs, PKM2, AHR, ChREBP, LXRs, among others) and metabolic pathways (PFKFB3, LDH, GLUT1, SDH, OPA1, DRP1, among others). We will also evaluate the glycolytic and mitochondrial metabolism by Seahorse Analyzer during acute infection, convalescence, and chronic phases. In addition, we will use PBMCs of CHIKV-infected patients to determine the profile of productively and persistently infected cells, the diversity of monocytes and dendritic cells and T-cells phenotypes, including T cell exhaustion and memory phenotype and CD8 and CD4 T cell profile (Th1, Th2, Th17 and regulatory T cell). Lastly, we will determine the viral load in different phases of CHIKV infection. Of interest is to understand whether CHIKV alters the metabolism of immune cells and impairs subsequent initiation of adaptive immune response. Moreover, we aim to understand if viral persistence plays a role in the chronicity establishment and metabolism alteration. This study will contribute to a better understanding of the molecular mechanisms that contribute to the clinical evolution of chronic Chikungunya and, consequently, the development of therapies and diagnosis. (AU)