Proteome modulation triggers potent antiviral response in Japanese Encephalitis Virus infected human macrophages

Japanese encephalitis virus (JEV) is a mosquito-borne neurotropic virus that claims thousands of children's lives globally every year, causing neuropsychiatric sequelae. While neuronal cell pathogenesis is a terminal consequence of JEV infection, the virus hijacks macrophages during initial replication and propagation, making macrophages critical cells of host immune defense that dictate the outcomes of infection. Though a plethora of studies have been reported using various neuronal and immune cells, a global response of human macrophages to JEV infection is yet to be explored. In this study, we assessed the kinetics of global proteome dysregulation employing an in vitro JEV infection model using human monocyte-derived macrophages (THP-1). A comparative assessment of the proteome of the infected THP-1 cells revealed differential regulation of 428 proteins at 24 h post-infection (hpi), which was later increased to 443 by 48 h post-infection. Global gene ontology analysis of the differentially expressed proteins highlighted several critical pathways related to immune and metabolic processes that are known to play either proviral or antiviral effects during infection. Notably, several antiviral proteins, including STAT2, OAS1, MX1, MX2, RIG-I, ISG15, and ISG20, were significantly upregulated at both time points post-infection. In contrast, a considerable downregulation of BCL-2, an anti-apoptotic protein at 48hpi indicates the activation of cell death pathways. Further, gene set enrichment analysis identified the type I interferon signaling pathway as one of the top upregulated pathways following JEV infection in human macrophages. Altogether, this study demonstrates human macrophage responses to JEV infection at the proteome level for the first time, highlighting several critical and novel antiviral proteins and pathways that not only advance our understanding of anti-JEV immunity but also aid in developing strategies to control this acute global public health menace.