Development and preclinical evaluation of virus-like particle vaccine against COVID-19 infection.

BACKGROUND: Vaccines that incorporate multiple SARS-CoV-2 antigens can further broaden the breadth of virus-specific cellular and humoral immunity. This study describes the development and immunogenicity of SARS-CoV-2 VLP vaccine that incorporates the four structural proteins of SARS-CoV-2. METHODS: VLPs were generated in transiently transfected HEK293 cells, purified by multimodal chromatography, and characterized by tunable-resistive pulse sensing, AFM, SEM, and TEM. Immunoblotting studies verified the protein identities of VLPs. Cellular and humoral immune responses of immunized animals demonstrated the immune potency of the formulated VLP vaccine. RESULTS: Transiently transfected HEK293 cells reproducibly generated vesicular VLPs that were similar in size to and expressing all four structural proteins of SARS-CoV-2. Alum adsorbed, K3-CpG ODN-adjuvanted VLPs elicited high titer anti-S, anti-RBD, anti-N IgG, triggered multifunctional Th1-biased T-cell responses, reduced virus load, and prevented lung pathology upon live virus challenge in vaccinated animals. CONCLUSION: These data suggest that VLPs expressing all four structural protein antigens of SARS-CoV-2 are immunogenic and can protect animals from developing COVID-19 infection following vaccination.

Stepwise Reversal of Immune Dysregulation Due to STAT1 Gain-of-Function Mutation Following Ruxolitinib Bridge Therapy and Transplantation.

PURPOSE: Patients with heterozygous gain-of-function (GOF) mutations in STAT1 frequently exhibit chronic mucocutaneous candidiasis (CMC), immunodeficiency and autoimmune manifestations. Several treatment options including targeted therapies and hematopoietic stem cell transplantation (HSCT) are available for STAT1 GOF patients but modalities and outcomes are not well established. Herein, we aimed to unravel the effect of ruxolitinib as a bridge therapy in a patient with sporadic STAT1 T385M mutation to manage infections and other disease manifestations. METHODS: Peripheral blood mononuclear cells were isolated from the patient prior to, during ruxolitinib treatment and 6 months after HSCT. IFN-ß-induced STAT1 phosphorylation/dephosphorylation levels and PMA/ionomycin-stimulated intracellular IL-17A/IFN-γ production in CD4+ T cells were evaluated. Differentially expressed genes between healthy controls and the patient prior to, during ruxolitinib treatment and post-transplantation were investigated using Nanostring nCounter Profiling Panel. RESULTS: Ruxolitinib provided favorable responses by controlling candidiasis and autoimmune hemolytic anemia in the patient. Dysregulation in STAT1 phosphorylation kinetics improved with ruxolitinib treatment and was completely normalized after transplantation. TH17 deficiency persisted after ruxolitinib treatment, but normalized following HSCT. Consistent with the impairment in JAK/STAT signaling, multiple immune related pathways were found to be dysregulated in the patient. At baseline, genes related to type I IFN-related pathways, antigen processing, T-cell and B-cell functions were upregulated, while NK-cell function and cytotoxicity related genes were downregulated. Dysregulated gene expression was partially improved with ruxolitinib treatment and normalized after transplantation. CONCLUSION: Our findings suggest that improved disease management and immune dysregulatory profile can be achieved with ruxolitinib treatment before transplantation and this would be beneficial to reduce the risk of adverse outcome of HSCT.