The Galveston National Laboratory (GNL) in Galveston, Texas, United States, is a high security National Biocontainment Laboratory housing several Biosafety level 4 research laboratories. The lab is run by the University of Texas Medical Branch (UTMB) for exotic disease diagnosis and research. The GNL is one of the 15 biosecurity level 4 facilities in the United States and the largest one in the world located on an academic campus.
Microglial cells exhibit crucial metabolic adaptations to maintain neural homeostasis. However, their dysregulated activation during infections can lead to neurotoxicity and contribute to the development of neuroinflammatory disorders. Understanding the physiological and metabolic changes of microglia during immune activation is crucial for identifying protective targets against neuroinflammation. This study investigates how the Zika virus (ZIKV) alters microglia metabolism during inflammation, highlighting cellular adaptations that sustain oxidative metabolism linked to cell survival during cellular activation and viral replication. After identifying an enriched abundance of proteins related to oxidative phosphorylation and cellular component organization in the global proteomics of mouse brains following ZIKV exposure, we investigated the relevance of these pathways during in vitro infection of human microglia. ZIKV infection led to cytoskeleton remodeling via β-tubulin reallocation, which characterized an ameboid-like phenotype. Despite the indication of a shift toward increased glycolytic activity due to decreased intracellular glucose, which suggests its consumption, and the accumulation of tricarboxylic acid cycle (TCA) intermediates, ZIKV-infected microglia exhibit enhanced respiratory capacity and an abundance of smaller-sized mitochondria in the perinuclear region. The accumulation of citrate, succinate, and malate, while maintaining mitochondrial function, suggests an important metabolic adaptation that supports biosynthetic pathways and sustains cell viability under stress. Decreased intracellular glutamate abundance supports mitochondrial oxidative metabolism. Pre-treatment with the anti-inflammatory docosahexaenoic acid (DHA) mitigates ZIKV-induced metabolic alterations by reducing pro-inflammatory markers, downregulating viral entry receptors, and lowering microglial activation and viral load. This study reveals that while ZIKV induces cell death in neuronal-like cells, the mitochondrial adaptation observed in microglial infection could be a key to maintaining cell survival throughout neuroinflammation. Our findings elucidate a novel cellular adaptation during ZIKV infection involving β-tubulin reorganization and metabolic dynamics, reflecting microglial flexibility and resistance during neuroinflammation, and demonstrating the therapeutic potential of DHA in mitigating ZIKV-induced pathology.
The first-ever recent Marburg virus (MARV) outbreak in Tanzania and recent emergences in Rwanda, Ghana and Equatorial Guinea underscore the importance of therapeutic or vaccine development against the virus, for which none are approved. mRNA vaccines were proven successful in a pandemic-response to severe acute respiratory syndrome coronavirus-2, making it an appealing platform to target pathogenic emerging viruses. Here, we develop 1-methyl-pseudouridine-modified mRNA vaccines formulated in lipid nanoparticles (LNP) targeting the glycoproteins (GP) of MARV and the closely-related Ravn virus (RAVV). Vaccination of female guinea pigs elicits robust binding and neutralizing antibodies and confers complete protection against homologous and heterologous virus replication, disease and death. Characterization of antibody responses identifies disparities in the binding and functional profiles between the two viruses and regions in GP that are broadly reactive. The glycan cap is highlighted as an immunoreactive site for orthomarburgviruses, inducing antibody responses that are virus dependent. Profiling the antibody responses against the two viruses provides insight into how antigenic differences may affect the response towards conserved GP regions, which would otherwise be predicted to be cross-reactive, and has implications for the future design of broadly protective vaccines. The results support the use of mRNA-LNPs against pathogens of high consequence.
Chapare virus (CHAPV) is an emerging arenavirus first discovered in Bolivia. Clinical cases have a high case-fatality rate and a concerning capacity for person-to-person spread. Animal models of Chapare hemorrhagic fever are needed to study pathogenesis and development of medical counter measures. Here, we present a narrowly focused study describing lethal infection of strain 13 guinea pigs with CHAPV. Animals challenged with CHAPV had progressive weight loss, lymphocytopenia, neutropenia, thrombocytopenia, hepatitis, vascular leakage, and gastrointestinal hemorrhage, resulting in uniform lethality between 7 and 16 days following challenge. This work lays the foundation for development of a small animal model of CHAPV infection. Animal models of the emerging mammarenavirus, Chapare virus (CHAPV), are needed to study pathogenesis and development of medical counter measures. Here, we present a narrowly focused study describing lethal infection of strain 13 guinea pigs with CHAPV.
A cocktail of human monoclonal antibodies 1C3 and 1C11 previously protected macaques from a lethal exposure to either Ebola virus (EBOV) or Sudan virus (SUDV). 1C3 is of particular interest because its paratope strongly binds with unique stoichiometry to the glycoprotein head of several orthoebolaviruses, resulting in neutralization of EBOV and SUDV. Therefore, we evaluated the protective activity of 1C3 as a standalone therapeutic in macaques exposed to either EBOV or SUDV. Two doses of 1C3 monotherapy, administered 4 and 7 days post-exposure, did not protect SUDV-exposed macaques and partially protected EBOV-exposed macaques. Notably, in a macaque that succumbed to EBOV infection, we identified two mutually exclusive escape mutations that emerged immediately after the first dose and resulted in two amino acid changes at the 1C3 binding site. We also detected a subconsensus treatment-emergent mutation likely affecting the 1C3 binding site in all three deceased SUDV-exposed macaques. Our findings highlight combination treatment with 1C11 as critical for protection, particularly against SUDV, and in vivo activity of unpartnered 1C3 as susceptible to rapid EBOV and SUDV escape under therapeutic pressure. IMPORTANCE:A cocktail of human monoclonal antibodies 1C3 and 1C11 previously protected macaques exposed to a lethal dose of either Ebola virus (EBOV) or Sudan virus (SUDV). Since the unique binding characteristics of 1C3 are of particular interest, we evaluated its protective activity as monotherapy in macaques exposed to either EBOV or SUDV. Two doses of 1C3 alone did not protect SUDV-exposed macaques and only partially protected EBOV-exposed macaques. Importantly, failure to protect was associated with the rapid emergence of previously in vitro-identified escape mutations at the 1C3 binding site, highlighting the importance of its use in combination with 1C11 for protection against fatal disease outcome and avoiding rapid EBOV and SUDV escape. Findings have broader implications for the wise use of combination-based monoclonal antibody therapeutics to improve outcomes and prevent resistance in filovirid diseases.
