MicroRNAs (miRNAs) are single-stranded small RNA molecules that regulate various cellular processes. miRNA 155 (miR-155) regulates various aspects of innate and adaptive immune responses and plays a key role in various viral infections and the resulting neuroinflammation. The present study evaluated the involvement of miR-155 in modulating Japanese encephalitis virus (JEV)-induced neuroinflammation. We observed that miR-155 expression was upregulated during JEV infection of mouse primary microglia, the BV-2 microglia cell line, and in both mouse and human brains. In vitro and in vivo knockdown of miR-155 minimized JEV-induced inflammatory responses. In the present study, we confirmed targeting of the Src homology 2-containing inositol phosphatase 1 (SHIP1) 3= untranslated region (UTR) by miR-155 in the context of JEV infection. Inhibition of SHIP1 by miR-155 resulted in higher beta interferon (IFN-␤) and proinflammatory cytokine production through activation of TANKbinding kinase 1 (TBK-1). Based on these observations, we conclude that miR-155 modulates the neuroinflammatory response during JEV infection via negative regulation of SHIP1 expression. Thus, modulation of miR-155 could be a novel strategy to regulate JEV-induced neuroinflammation. IMPORTANCE Japanese encephalitis virus (JEV), a member of the family Flaviviridae that causes Japanese encephalitis (JE), is the most common mosquito-borne encephalitis virus in the Japanese encephalitis virus (JEV), a member of the family Flaviviridae, is a single-stranded, positive-sense RNA virus that causes Japanese encephalitis (JE) (1, 2). JE is endemic in most Southeast Asian countries (3, 4). The availability of an effective vaccine and an active immunization program have resulted in a reduced number of JE cases in a few countries (5). The early clinical features of JE include fever, headache, and vomiting. Two weeks after JEV infection, patients develop neurological symptoms, like seizure, tremor, photophobia, and movement disorder (6). These clinical features are not exclusive to JEV infection, and hence, laboratory diagnosis is needed to differentiate it from other neurological disorders. Detection of anti-JEV IgM antibodies in the cerebrospinal fluid (CSF) and serum is frequently used to diagnose JE (7). The fatality rate of JEV infection is ϳ25%. A majority of survivors (ϳ50%) have neuropsychiatric sequelae; only ϳ25% recover completely (8). Hence, JEV poses major health concerns and economic burdens in the Asia-Pacific region. During the last decade, we and others have made significant progress in the understanding molecular mechanisms involved in JEV infection.MicroRNAs (miRNAs) are small, noncoding RNAs ϳ19 to 22 nucleotides in length that regulate various cellular processes by binding to the 3= untranslated region (UTR) of target proteins, resulting in either degradation of RNA or translational suppression (9, 10). Our knowledge of the role of miRNAs in various diseases is expanding rapidly. Various reports support the role of miRNAs in neuroviral...

Japanese encephalitis virus (JEV), a single-stranded RNA (ssRNA) virus, is the leading cause of encephalitis in Asia. Microglial activation is one of the key events in JEV-induced neuroinflammation. Although the various microRNAs (miRNAs) has been shown to regulate microglia activation during pathological conditions including neuroviral infections, till date, the involvement of miRNAs in JEV infection has not been evaluated. Hence, we sought to evaluate the possible role of miRNAs in mediating JEV-induced microglia activation. Initial screening revealed significant up-regulation of miR-29b in JEV-infected mouse microglial cell line (BV-2) and primary microglial cells. Furthermore, using bioinformatics tools, we identified tumor necrosis factor alpha-induced protein 3, a negative regulator of nuclear factor-kappa B signaling as a potential target of miR-29b. Interestingly, in vitro knockdown of miR-29b resulted in significant overexpression of tumor necrosis factor alpha-induced protein 3, and subsequent decrease in nuclear translocation of pNFjB. JEV infection in BV-2 cell line elevated inducible nitric oxide synthase, cyclooxygenase-2, and pro-inflammatory cytokine expression levels, which diminished after miR-29b knockdown. Collectively, our study demonstrates involvement of miR-29b in regulating JEV-induced microglial activation.

COVID-19 is an infectious disease caused by SARS-CoV-2, which enters host cells via the cell surface proteins ACE2 and TMPRSS2. Using normal and malignant models and tissues from the aerodigestive and respiratory tracts, we investigated the expression and regulation of ACE2 and TMPRSS2. We find that ACE2 expression is restricted to a select population of highly epithelial cells and is repressed by ZEB1, in concert with ZEB1's established role in promoting epithelial to mesenchymal transition (EMT). Notably, infection of lung cancer cells with SARS-CoV-2 induces metabolic and transcriptional changes consistent with EMT, including upregulation of ZEB1 and AXL, thereby downregulating ACE2 postinfection. This suggests a novel model of SARS-CoV-2 pathogenesis in which infected cells shift toward an increasingly mesenchymal state and lose ACE2 expression, along with its acute respiratory distress syndrome-protective effect, in a ZEB1-dependent manner. AXL-inhibition and ZEB1-reduction, as with bemcentinib, offers a potential strategy to reverse this effect.

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Harnessing the immune-system to eradicate cancer is becoming a reality in recent years. Engineered immune cells, such as chimeric antigen receptor (CAR) T cells, are facing the danger of an overt life-threatening immune response due to the ON-target OFF-tumor cytotoxicity and Cytokine Release Syndrome. We therefore developed synthetic promoters for regulation of gene expression under the control of inflammation and Hypoxia-induced signals that are associated with the tumor microenvironment (TME). We termed this methodology as chimeric-antigen-receptor-tumor-induced-vector (CARTIV). For proof of concept, we studied synthetic promoters based on promoter-responsive elements (PREs) of IFNγ, TNFα and hypoxia; triple PRE-based CARTIV promoter manifested a synergistic activity in cell-lines and potent activation in human primary T-cells. CARTIV platform can improve safety of CAR T-cells or other engineered immune-cells, providing TME-focused activity and opening a therapeutic window for many tumor-associated antigens that are also expressed by non-tumor healthy tissues.

COVID-19 is an infectious disease caused by SARS-CoV-2, which enters host cells via the cell surface proteins ACE2 and TMPRSS2. Using a variety of normal and malignant models and tissues from the aerodigestive and respiratory tracts, we investigated the expression and regulation of ACE2 and TMPRSS2 . We find that ACE2 expression is restricted to a select population of epithelial cells. Notably, infection with SARS-CoV-2 in cancer cell lines, bronchial organoids, and patient nasal epithelium, induces metabolic and transcriptional changes consistent with epithelial to mesenchymal transition (EMT), including upregulation of ZEB1 and AXL , resulting in an increased EMT score. Additionally, a transcriptional loss of genes associated with tight junction function occurs with SARS-CoV-2 infection. The SARS-CoV-2 receptor, ACE2, is repressed by EMT via TGFbeta, ZEB1 overexpression and onset of EGFR TKI inhibitor resistance. This suggests a novel model of SARS-CoV-2 pathogenesis in which infected cells shift toward an increasingly mesenchymal state, associated with a loss of tight junction components with acute respiratory distress syndrome-protective effects. AXL-inhibition and ZEB1-reduction, as with bemcentinib, offers a potential strategy to reverse this effect. These observations highlight the utility of aerodigestive and, especially, lung cancer model systems in exploring the pathogenesis of SARS-CoV-2 and other respiratory viruses, and offer important insights into the potential mechanisms underlying the morbidity and mortality of COVID-19 in healthy patients and cancer patients alike.

Despite of remarkable progress made in the head and neck cancer (HNC) therapy, the survival rate of this metastatic disease remain low. Tailoring the appropriate therapy to patients is a major challenge and highlights the unmet need to have a good preclinical model that will predict clinical response. Hence, we developed an accurate and time efficient drug screening method of tumor ex vivo analysis (TEVA) system, which can predict patient-specific drug responses. In this study, we generated six patient derived xenografts (PDXs) which were utilized for TEVA. Briefly, PDXs were cut into 2 × 2 × 2 mm3 explants and treated with clinically relevant drugs for 24 h. Tumor cell proliferation and death were evaluated by immunohistochemistry and TEVA score was calculated. Ex vivo and in vivo drug efficacy studies were performed on four PDXs and three drugs side-by-side to explore correlation between TEVA and PDX treatment in vivo. Efficacy of drug combinations was also ventured. Optimization of the culture timings dictated 24 h to be the time frame to detect drug responses and drug penetrates 2 × 2 × 2 mm3 explants as signaling pathways were significantly altered. Tumor responses to drugs in TEVA, significantly corresponds with the drug efficacy in mice. Overall, this low cost, robust, relatively simple and efficient 3D tissue-based method, employing material from one PDX, can bypass the necessity of drug validation in immune-incompetent PDX-bearing mice. Our data provides a potential rationale for utilizing TEVA to predict tumor response to targeted and chemo therapies when multiple targets are proposed.