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A self-transcribing and replicating RNA (STARR)-based vaccine (LUNAR-COV19) has been developed to prevent SARS-CoV-2 infection. The vaccine encodes an alphavirus-based replicon and the SARS-CoV-2 full-length spike glycoprotein. Translation of the replicon produces a replicase complex that amplifies and prolongs SARS-CoV-2 spike glycoprotein expression. A single prime vaccination in mice led to robust antibody responses, with neutralizing antibody titers increasing up to day 60. Activation of cell-mediated immunity produced a strong viral antigen-specific CD8+ T lymphocyte response. Assaying for intracellular cytokine staining for interferon (IFN)γ and interleukin-4 (IL-4)-positive CD4+ T helper (Th) lymphocytes as well as anti-spike glycoprotein immunoglobulin G (IgG)2a/IgG1 ratios supported a strong Th1-dominant immune response. Finally, single LUNAR-COV19 vaccination at both 2 μg and 10 μg doses completely protected human ACE2 transgenic mice from both mortality and even measurable infection following wild-type SARS-CoV-2 challenge. Our findings collectively suggest the potential of LUNAR-COV19 as a single-dose vaccine.

Airborne diseases are the leading cause of infectious disease-related deaths in the world. In particular, the influenza virus activates a network of immune cells that leads to clearance or an overzealous response that can be fatal. Tight regulation of the cytokines that enable proper activation and function of immune cells is necessary to clear infections efficiently while minimizing damage to the host. Interleukin-7 (IL-7) is a cytokine known for its importance in T cell development and survival. How IL-7 shapes CD8 T cell responses during an acute viral infection is less understood. We had previously shown that IL-7 signaling deficient mice have reduced accumulation of influenza-specific CD8 T cells following infection. We sought to determine whether IL-7 affects early CD8 T cell expansion in the mediastinal lymph node and effector function in the lungs. Using IL-7Rα signaling deficient mice, we show that IL-7 is required for a normal sized mediastinal lymph node and the early clonal expansion of antigen-specific CD8 T cells therein. Bone marrow chimeric models and adoptive transfer of transgenic TCR CD8 T cells reveal a cell-intrinsic role for IL-7 in the accumulation of NP366–374 and PA224–233-specific CD8 T cells. We also found that IL-7 dictates terminal differentiation, degranulation and cytokine production in PA224–233-specific but not NP366–374-specific CD8 T cells. We further demonstrate that IL-7 is induced in the lung tissue by viral infection and we characterize multiple cellular sources that contribute to IL-7 production. Drugs that manipulate IL-7 signaling are currently under clinical trial for multiple conditions. Our findings on IL-7 and its effects on lower respiratory diseases will be important for expanding the utility of these therapeutics.Author SummaryInterleukin-7 plays an important role in development of immune cells such as lymphocytes. In recent years, its role in the immune system has been expanded beyond the development of immune cells to include revitalizing of lymphocytes during tumor and chronic viral response. We show here that IL-7 is required for accumulation and function of specialized lymphocytes in the lungs during an acute influenza infection.

Zika virus (ZIKV) is an Aedes mosquito-borne flavivirus that causes debilitating congenital and developmental disorders. No licensed ZIKV vaccine or treatment exist, due largely to an incomplete understanding of ZIKV pathogenesis. In this study, we used a panel of ZIKV strains, including a pair that differ by just a single amino acid substitution (phenylalanine to leucine substitution, M-F37L) in the membrane (M) protein, and coupled these with unbiased whole genome gene expression studies to demarcate the border between attenuated and pathogenic infection. We identified infection-induced metabolic dysregulation as a minimal set of host alterations that differentiated attenuated from pathogenic ZIKV strains. Glycolytic rewiring reduced availability of tricarboxylic acid (TCA) cycle substrates, resulting in impaired oxidative phosphorylation and mitochondrial dysfunction that triggered inflammation and apoptosis in pathogenic but not attenuated ZIKV strains. Exogenous supplementation of pyruvate and glutamine that feed directly into the TCA cycle, reduced inflammatory and apoptotic responses induced by wild-type ZIKV infection. Critically, pyruvate supplementation to ZIKV-infected dams prevented gross fetal developmental abnormalities and rescued fetal growth. Our findings thus pinpoint dysregulated metabolism as an underpinning of ZIKV pathogenicity and that pyruvate supplementation to expectant women could be explored as a prophylaxis for congenital Zika syndrome.

BACKGROUND: The emergence of Zika virus (ZIKV) as an important cause of congenital and childhood developmental disorders presents another challenge to global health. Efforts to develop a Zika vaccine have begun although vaccine development against flaviviruses, of which ZIKV belongs to, has proven to be time-consuming and challenging. Defining the vaccine attributes that elicit adaptive immune response necessary for preventing ZIKV infection could provide an evidence-based guide to Zika vaccine development.METHODS: We used a previously described attenuated ZIKV DN-2 strain in a type-I interferon receptor deficient mouse model and tested the hypothesis that duration of vaccine burden rather than peak level of infection, is a determinant of immunogenicity. We quantified both humoral and cellular responses against ZIKV using plaque reduction neutralisation test and flow cytometry with ELISPOT assays, respectively. Vaccinated mice were challenged with wild-type ZIKV (H/PF/2013 strain) to determine the level of protection against infection.FINDINGS: We found that the overall vaccine burden is directly correlated with neutralising antibody titres. Reduced duration of vaccine burden lowered neutralising antibody titres that resulted in subclinical infection, despite unchanged peak vaccine viraemia levels. We also found that sterilising immunity is dependant on both neutralising antibody and CD8+T cell responses; depletion of CD8+T cells in vaccinated animals led to wild-type ZIKV infection, especially in the male reproductive tract.INTERPRETATION: Our findings indicate that duration of attenuated virus vaccine burden is a determinant of humoral and cellular immunity and also suggest that vaccines that elicit both arms of the adaptive immune response are needed to fully prevent ZIKV transmission.FUNDING: This study was supported by the National Medical Research Council through the Clinician-Scientist Award (Senior Investigator) to E.E.O. Salary support for S.W. was from a Competitive Research Programme grant awarded by the National Research Foundation of Singapore.

A self-transcribing and replicating RNA (STARR™) based vaccine (LUNAR®-COV19) has been developed to prevent SARS-CoV-2 infection. The vaccine encodes an alphavirus-based replicon and the SARS-CoV-2 full length spike glycoprotein. Translation of the replicon produces a replicase complex that amplifies and prolong SARS-CoV-2 spike glycoprotein expression. A single prime vaccination in mice led to robust antibody responses, with neutralizing antibody titers increasing up to day 60. Activation of cell mediated immunity produced a strong viral antigen specific CD8+ T lymphocyte response. Assaying for intracellular cytokine staining for IFN-γ and IL-4 positive CD4+ T helper lymphocytes as well as anti-spike glycoprotein IgG2a/IgG1 ratios supported a strong Th1 dominant immune response. Finally, single LUNAR-COV19 vaccination at both 2 μg and 10 μg doses completely protected human ACE2 transgenic mice from both mortality and even measurable infection following wild-type SARS-CoV-2 challenge. Our findings collectively suggest the potential of Lunar-COV19 as a single dose vaccine.

// Miriam S. Butler 1, *, # , Mani Roshan-Moniri 1, *, # , Michael Hsing 1, *, # , Desmond Lau 2, *, # , Ari Kim 1 , Paul Yen 1 , Marta Mroczek 1 , Mannan Nouri 1 , Scott Lien 1 , Peter Axerio-Cilies 1 , Kush Dalal 1 , Clement Yau 1 , Fariba Ghaidi 1 , Yubin Guo 1 , Takeshi Yamazaki 1 , Sam Lawn 1 , Martin E. Gleave 1 , Cheryl Y. Gregory-Evans 3 , Lawrence P. McIntosh 2, * , Michael E. Cox 1, * , Paul S. Rennie 1, * and Artem Cherkasov 1, * 1 Vancouver Prostate Centre and the Department of Urologic Sciences, University of British Columbia, Vancouver, BC V6H 3Z6, Canada 2 Department of Biochemistry and Molecular Biology, Department of Chemistry, Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada 3 Department of Ophthalmology and Visual Sciences, Eye Care Centre, University of British Columbia, Vancouver, BC V5Z 3N9, Canada * These authors contributed equally to this work # Co-first authors Correspondence to: Michael E. Cox, email: mcox@prostatecentre.com Artem Cherkasov, email: acherkasov@prostatecentre.com Keywords: prostate cancer, ERG, rational drug design, small molecule inhibitor, TMPRSS2-ERG Received: July 29, 2016 Accepted: April 04, 2017 Published: April 15, 2017 ABSTRACT Genomic alterations involving translocations of the ETS-related gene ERG occur in approximately half of prostate cancer cases. These alterations result in aberrant, androgen-regulated production of ERG protein variants that directly contribute to disease development and progression. This study describes the discovery and characterization of a new class of small molecule ERG antagonists identified through rational in silico methods. These antagonists are designed to sterically block DNA binding by the ETS domain of ERG and thereby disrupt transcriptional activity. We confirmed the direct binding of a lead compound, VPC-18005, with the ERG-ETS domain using biophysical approaches. We then demonstrated VPC-18005 reduced migration and invasion rates of ERG expressing prostate cancer cells, and reduced metastasis in a zebrafish xenograft model. These results demonstrate proof-of-principal that small molecule targeting of the ERG-ETS domain can suppress transcriptional activity and reverse transformed characteristics of prostate cancers aberrantly expressing ERG. Clinical advancement of the developed small molecule inhibitors may provide new therapeutic agents for use as alternatives to, or in combination with, current therapies for men with ERG-expressing metastatic castration-resistant prostate cancer.

Genomic alterations involving translocations of the ETS-related gene ERG occur in approximately half of prostate cancer cases. These alterations result in aberrant, androgen-regulated production of ERG protein variants that directly contribute to disease development and progression. This study describes the discovery and characterization of a new class of small molecule ERG antagonists identified through rational in silico methods. These antagonists are designed to sterically block DNA binding by the ETS domain of ERG and thereby disrupt transcriptional activity. We confirmed the direct binding of a lead compound, VPC-18005, with the ERG-ETS domain using biophysical approaches. We then demonstrated VPC-18005 reduced migration and invasion rates of ERG expressing prostate cancer cells, and reduced metastasis in a zebrafish xenograft model. These results demonstrate proof-of-principal that small molecule targeting of the ERG ETS domain can suppress transcriptional activity and reverse transformed characteristics of prostate cancers aberrantly expressing ERG. Clinical advancement of the developed small molecule inhibitors may provide new therapeutic agents for use as alternatives to, or in combination with, current therapies for men with ERG-expressing metastatic castration-resistant prostate cancer. Citation Format: Miriam S. Butler, Mani Roshan-Moniri, Michael Hsing, Desmond Lau, Ari Kim, Paul Yen, Marta Mroczek, Mannan Nouri, Scott Lien, Peter Axerio-Cilies, Kush Dalal, Clement Yau, Fariba Ghaidi, Yubin Guo, Takeshi Yamazaki, Sam Lawn, Martin Gleave, Cheryl Y. Gregory-Evans, Lawrence P. McIntosh, Paul S. Rennie, Artem Cherkasov, Michael E. Cox. Discovery and characterization of small molecules targeting the DNA-binding ETS domain of ERG in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 130. doi:10.1158/1538-7445.AM2017-130