Selective CK1α degraders exert antiproliferative activity against a broad range of human cancer cell lines.

Molecular-glue degraders are small molecules that induce a specific interaction between an E3 ligase and a target protein, resulting in the target proteolysis. The discovery of molecular glue degraders currently relies mostly on screening approaches. Here, we describe screening of a library of cereblon (CRBN) ligands against a panel of patient-derived cancer cell lines, leading to the discovery of SJ7095, a potent degrader of CK1α, IKZF1 and IKZF3 proteins. Through a structure-informed exploration of structure activity relationship (SAR) around this small molecule we develop SJ3149, a selective and potent degrader of CK1α protein in vitro and in vivo. The structure of SJ3149 co-crystalized in complex with CK1α + CRBN + DDB1 provides a rationale for the improved degradation properties of this compound. In a panel of 115 cancer cell lines SJ3149 displays a broad antiproliferative activity profile, which shows statistically significant correlation with MDM2 inhibitor Nutlin-3a. These findings suggest potential utility of selective CK1α degraders for treatment of hematological cancers and solid tumors.

Interferon lambda protects the female reproductive tract against Zika virus infection.

Although Zika virus (ZIKV) can be transmitted sexually and cause congenital birth defects, immune control mechanisms in the female reproductive tract (FRT) are not well characterized. Here we show that treatment of primary human vaginal and cervical epithelial cells with interferon (IFN)-α/ß or IFN-λ induces host defense transcriptional signatures and inhibits ZIKV infection. We also assess the effects of IFNs on intravaginal infection of the FRT using ovariectomized mice treated with reproductive hormones. We find that mice receiving estradiol are protected against intravaginal ZIKV infection, independently of IFN-α/ß or IFN-λ signaling. In contrast, mice lacking IFN-λ signaling sustain greater FRT infection when progesterone is administered. Exogenous IFN-λ treatment confers an antiviral effect when mice receive both estradiol and progesterone, but not progesterone alone. Our results identify a hormonal stage-dependent role for IFN-λ in controlling ZIKV infection in the FRT and suggest a path for minimizing sexual transmission of ZIKV in women.

In Vivo Imaging with Bioluminescent Enterovirus 71 Allows for Real-Time Visualization of Tissue Tropism and Viral Spread.

Hand, foot, and mouth disease (HFMD) is a reemerging illness caused by a variety of enteroviruses. The main causative agents are enterovirus 71 (EV71), coxsackievirus A16 (CVA16), and, most recently, coxsackievirus A6 (CVA6). Enterovirus infections can vary from asymptomatic infections to those with a mild fever and blisters on infected individuals' hands, feet, and throats to infections with severe neurological complications. Viral persistence for weeks postinfection (wpi) has also been documented by the demonstration of virus in children's stools. However, little is known about disease progression, viral spread, and tissue tropism of these viruses. These types of studies are limited because many recently developed mouse models mimic the severe neurological complications that occur in a small percentage of enterovirus infections. In the present study, we documented real-time EV71 infection in two different mouse strains by the use of in vivo imaging. Infection of BALB/c mice with a bioluminescent mouse-adapted EV71 construct (mEV71-NLuc) resulted in a lack of clinical signs of disease but in relatively high viral replication, as visualized by luminescence, for 2 wpi. In contrast, mEV71-NLuc infection of AG129 mice (alpha/beta and gamma interferon receptor deficient) showed rapid spread and long-term persistence of the virus in the brain. Interestingly, AG129 mice that survived infection maintained luminescence in the brain for up to 8 wpi. The results we present here will allow future studies on EV71 antiviral drug susceptibility, vaccine efficacy, transmissibility, and pathogenesis. IMPORTANCE We report here that a stable full-length enterovirus 71 (EV71) reporter construct was used to visualize real-time viral spread in AG129 and BALB/c mice. To our knowledge, this is the first report of in vivo imaging of infection with any member of the Picornaviridae family. The nanoluciferase (NLuc) gene, one of the smallest luciferase genes currently available, was shown to be stable in the EV71 genome for eight passages on rhabdomyosarcoma cells. Real-time visualization of EV71 infection in mice identified areas of tropism that would have been missed by traditional methods, including full characterization of EV71 replication in BALB/c mice. Additionally, the bioluminescent construct allowed for increased speed and sensitivity of cell culture assays and will allow future studies involving various degrees of enterovirus infection in mice, not just severe infections. Our data suggest that interferon plays an important role in controlling EV71 infection in the central nervous system of mice.

A Single Mutation in the VP1 of Enterovirus 71 Is Responsible for Increased Virulence and Neurotropism in Adult Interferon-Deficient Mice.

UNLABELLED: Hand, foot, and mouth disease (HFMD) has spread throughout the Asia-Pacific region, affecting millions of young children, who develop symptoms ranging from painful blisters around their mouths and hands to neurological complications. Many members of the genus Enterovirus (family Picornaviridae) cause HFMD. Enterovirus 71 (EV71) is one of the primary causative agents and has been linked to severe disease. Vaccine efficacy and pathogenesis studies for EV71 have been limited because there is a lack of suitable animal models. Previously, we generated a mouse-adapted EV71 (mEV71) capable of infecting 12-week-old interferon receptor-deficient AG129 mice and used the model to evaluate the efficacy of candidate HFMD vaccines. Here, we present data investigating the genetic correlates of EV71 adaptation and characterize the virus's tissue tropism in mice. Using reverse genetics, a VP1 mutation (K244E) was shown to be necessary for mEV71 virulence in adult mice. Another VP1 mutation (H37R) was required for mEV71 recovery on rhabdomyosarcoma (RD) cells. Viral loads determined by real-time reverse transcription (RT)-PCR confirmed the presence of mEV71 in the sera and multiple organs of mice. Histological analysis revealed signs of meningitis and encephalitis, characteristic of severe human disease. The further description of this model has provided insight into EV71 pathogenesis and demonstrates the importance of the VP1 region in facilitating mEV71 adaptation. IMPORTANCE: EV71 is a reemerging pathogen, and little is known about the genetic determinants involved in its pathogenesis. The absence of animal models has contributed to this lack of knowledge. The data presented here improve upon the existing animal models by characterizing a mouse-adapted strain of EV71. We determined that a VP1 mutation (K244E) was needed for EV71 virulence in adult AG129 mice. While this mutation was found previously for EV71 adaptation in 5-day-old BALB/c mice, neurotropic disease did not develop. Using interferon-deficient mice, we raised the age of susceptibility beyond 6 weeks and provided clear evidence that our model mimics severe human infections. The model can be exploited to identify determinants of EV71 virulence and to reveal molecular mechanisms that control the virus-host interaction, especially those associated with neurotropic disease. Furthermore, these data provide useful information regarding the importance of VP1, specifically position 244, in host adaptation and tissue dissemination.