mrt67307 and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

The production of class-switched high-affinity autoantibodies derived from organized germinal centers (GCs) is a hallmark of many autoimmune inflammatory diseases, including rheumatoid arthritis (RA). TANK-binding kinase 1 (TBK-1) is a serine/threonine kinase involved in the maturation of GC follicular helper T (Tfh) cells downstream of inducible costimulator signaling. We undertook this study to assess the therapeutic potential of TBK-1 inhibition using the small-molecule inhibitor WEHI-112 in antibody-dependent models of inflammatory arthritis.. Using the models of collagen-induced arthritis (CIA), antigen-induced arthritis (AIA), and K/BxN serum-transfer-induced arthritis (STIA), we determined the effectiveness of WEHI-112 at inhibiting clinical and histologic features of arthritis in C57BL/6 and DBA/1 mice. We used immunohistochemistry to characterize GC populations during CIA development, and we used enzyme-linked immunosorbent assays to determine levels of Ig autoantibodies in WEHI-112-treated mice compared to vehicle-treated mice.. WEHI-112, a tool compound that is semiselective for TBK-1 but that also has activity against IKKε and JAK2, abolished TBK-1-dependent activation of interferon (IFN) regulatory factor 3 and inhibited type I IFN responses in vitro. In vivo, treatment with WEHI-112 selectively abrogated clinical and histologic features of established, antibody-dependent CIA, but had minimal effects on an antibody-independent model of AIA or on K/BxN STIA. In keeping with these findings, WEHI-112 reduced arthritogenic type II collagen-specific IgG1 and IgG2b antibody production. Furthermore, WEHI-112 altered the GC Tfh cell phenotype and GC B cell function in CIA.. We report that TBK-1 inhibition using WEHI-112 abrogated antibody-dependent CIA. As WEHI-112 failed to inhibit non-antibody-driven joint inflammation, we conclude that the major effect of this compound was most likely the targeting of TBK-1-mediated mechanisms in the GC reaction. This approach may have therapeutic potential in RA and in other GC-associated autoantibody-driven inflammatory diseases.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Autoantibodies; Azetidines; Collagen Type II; Cyclobutanes; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Freund's Adjuvant; Germinal Center; Immunohistochemistry; Immunologic Factors; In Vitro Techniques; Interferon Regulatory Factor-3; Interferon Type I; Janus Kinase Inhibitors; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Morpholines; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Purines; Pyrazoles; Serum Albumin, Bovine; Sulfonamides; T-Lymphocytes, Helper-Inducer