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Oncoviruses are viruses that can cause tumors. Seven viruses are currently recognized as oncogenic in humans: Epstein Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV, also known as HHV8), human papillomaviruses (HPVs), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-lymphotropic virus-1 (HTLV-1), and Merkel cell polyomavirus (MCPyV). The clinical phenotypes resulting from infection with these oncoviruses range from asymptomatic infection to invasive cancers. Patients with inborn errors of immunity (IEI) are prone to the development of infectious diseases caused by a narrow or broad spectrum of pathogens, including oncoviruses in some cases. Studies of patients with IEI have deepened our understanding of the non-redundant mechanisms underlying the control of EBV, HHV8 and HPV infections. The human genetic factors conferring predisposition to oncogenic HBV, HCV, HTLV-1 and MCPyV manifestations remain elusive. We briefly review here what is currently known about the IEI conferring predisposition to severe infection with oncoviruses.

To repurpose therapeutics for fibrolamellar carcinoma (FLC), we developed and validated patient-derived xenografts (PDX) from surgical resections. Most agents used clinically and inhibitors of oncogenes overexpressed in FLC showed little efficacy on PDX. A high-throughput functional drug screen found primary and metastatic FLC were vulnerable to clinically available inhibitors of TOPO1 and HDAC and to napabucasin. Napabucasin's efficacy was mediated through reactive oxygen species and inhibition of translation initiation, and specific inhibition of eIF4A was effective. The sensitivity of each PDX line inversely correlated with expression of the antiapoptotic protein Bcl-xL, and inhibition of Bcl-xL synergized with other drugs. Screening directly on cells dissociated from patient resections validated these results. This demonstrates that a direct functional screen on patient tumors provides therapeutically informative data within a clinically useful time frame. Identifying these novel therapeutic targets and combination therapies is an urgent need, as effective therapeutics for FLC are currently unavailable. SIGNIFICANCE: Therapeutics informed by genomics have not yielded effective therapies for FLC. A functional screen identified TOPO1, HDAC inhibitors, and napabucasin as efficacious and synergistic with inhibition of Bcl-xL. Validation on cells dissociated directly from patient tumors demonstrates the ability for functional precision medicine in a solid tumor.

Our prior studies demonstrated that the rat hippocampal opioid system can undergo sex-specific adaptations to external stimuli that can influence opioid-associated learning processes. This opioid system extensively overlaps with the cannabinoid system. Moreover, acute administration of Delta(9)Tetrahydrocannabinoid (THC), the primary psychoactive constituent of cannabis, can alter cognitive behaviors that involve the hippocampus. Here, we use light and electron microscopic immunocytochemical methods to examine the effects of acute THC (5 mg/kg, i.p., 1 h) on mossy fiber Leu-Enkephalin (LEnk) levels and the distribution and phosphorylation levels of delta and mu opioid receptors (DORs and MORs, respectively) in CA3 pyramidal cells and parvalbumin dentate hilar interneurons of adult female and male Sprague-Dawley rats. In females with elevated estrogen states (proestrus/estrus stage), acute THC altered the opioid system so that it resembled that seen in vehicle-injected females with low estrogen states (diestrus) and males: (1) mossy fiber LEnk levels in CA2/3a decreased; (2) phosphorylated-DOR levels in CA2/3a pyramidal cells increased; and (3) phosphorylated-MOR levels increased in most CA3b laminae. In males, acute THC resulted in the internalization of MORs in parvalbumin-containing interneuron dendrites which would decrease disinhibition of granule cells. In both sexes, acute THC redistributed DORs to the near plasma membrane of CA3 pyramidal cell dendrites, however, the dendritic region varied with sex. Additionally, acute THC also resulted in a sex-specific redistribution of DORs within CA3 pyramidal cell dendrites which could differentially promote synaptic plasticity and/or opioid-associated learning processes in both females and males.

The molecular basis of platelet-fibrin interactions remains poorly understood despite the predominance of fibrin in thrombi. We have studied the interaction of platelets with polymerizing fibrin by adding thrombin to washed platelets in the presence of the peptide RGDW, which inhibits the initial platelet aggregation mediated by fibrinogen binding to aIIbb3 but leaves intact a delayed increase in light transmission (delayed wave; DW) as platelets interact with the polymerizing fibrin. The DW was absent in platelets from a patient with Glanzmann thrombasthenia, indicating a requirement for aIIbb3. The DW required aIIbb3 activation and it was inhibited by the aIIbb3 antagonists eptifibatide and the monoclonal antibody (mAb) 7E3, but only at much higher concentrations than needed to inhibit platelet aggregation initiated by a thrombin receptor activating peptide (T6). Surface plasmon resonance and scanning electron microscopy studies both supported fibrin having greater avidity for aIIb b3 than fibrinogen rather than greater affinity, consistent with fibrin's multivalency. mAb 10E5, a potent inhibitor of T6-induced platelet aggregation, did not inhibit the DW, suggesting that fibrin differs from fibrinogen in its mechanism of binding. Inhibition of factor XIII-mediated fibrin cross-linking by .95% reduced the DW by only 32%. Clot retraction showed a pattern of inhibition similar to that of the DW. We conclude that activated aIIbb3 is the primary mediator of platelet-fibrin interactions leading to clot retraction, and that the interaction is avidity driven, does not require fibrin cross-linking, and is mediated by a mechanism that differs subtly from that of the interaction of aIIbb3 with fibrinogen.

SARS-CoV-2 infections display tremendous interindividual variability, ranging from asymptomatic infections to life-threatening disease. Inborn errors of, and autoantibodies directed against, type I interferons (IFNs) account for about 20% of critical COVID-19 cases among SARS-CoV-2-infected individuals. By contrast, the genetic and immunological determinants of resistance to infection per se remain unknown. Following the discovery that autosomal recessive deficiency in the DARC chemokine receptor confers resistance to Plasmodium vivax, autosomal recessive deficiencies of chemokine receptor 5 (CCR5) and the enzyme FUT2 were shown to underlie resistance to HIV-1 and noroviruses, respectively. Along the same lines, we propose a strategy for identifying, recruiting, and genetically analyzing individuals who are naturally resistant to SARS-CoV-2 infection.

CRISPR-Cas systems provide immunity to bacteria by programing Cas nucleases with RNA guides that recognize and cleave infecting viral genomes. Bacteria and their viruses each encode recombination systems that could repair the cleaved viral DNA. However, it is unknown whether and how these systems can affect CRISPR immunity. Bacteriophage lambda uses the Red system (gam-exo-bet) to promote recombination between related phages. Here, we show that lambda Red also mediates evasion of CRISPR-Cas targeting. Gam inhibits the host E. coli RecBCD recombination system, allowing recombination and repair of the cleaved DNA by phage Exo-Beta, which promotes the generation of mutations within the CRISPR target sequence. Red recombination is strikingly more efficient than the host's RecBCD-RecA in the production of large numbers of phages that escape CRISPR targeting. These results reveal a role for Red-like systems in the protection of bacteriophages against sequence-specific nucleases, which may facilitate their spread across viral genomes.

Fanconi anemia, the most frequent genetic cause of bone marrow failure, is characterized by an extreme predilection toward multiple malignancies, including a greater than 500-fold incidence of head and neck squamous cell carcinoma (HNSCC) relative to the general population. Fanconi anemia-associated HNSCC and esophageal SCC (FA-HNSCC) often present at advanced stages with poor survival. Surgical resection remains the primary treatment for FA-HNSCC, and there is often great reluctance to administer systemic agents and/or radiotherapy to these patients given their susceptibility to DNA damage. The paucity of FA-HNSCC case reports limits evidence-based management, and such cases have not been analyzed collectively in detail. We present a systematic review of FA-HNSCC treatments reported from 1966 to 2020, defining a cohort of 119 patients with FA-HNSCC including 16 esophageal SCCs (131 total primary tumors), who were treated with surgery, radiotherapy, systemic therapy (including cytotoxic agents, EGFR inhibitors, or immune checkpoint inhibitors), or a combination of modalities. We summarize the clinical responses and regimen-associated toxicities by treatment modality. The collective evidence suggests that when possible, surgical resection with curative intent should remain the primary treatment modality for FA-HNSCC. Radiation can be administered with acceptable toxicity in the majority of cases, including patients who have undergone stem cell transplantation. Although there is little justification for cytotoxic chemotherapy, EGFR inhibitors and tyrosine kinase inhibitors may be both safe and effective. Immunotherapy may also be considered. Most oncologists have little personal experience with FA-HNSCC. This review is intended as a comprehensive resource for clinicians.

This year's Lasker Award recognizes Dieter Oesterhelt, Peter Hegemann, and Karl Deisseroth for their discovery of microbial opsins as light-activated ion conductors and the development of optogenetics using these proteins to regulate neural activity in awake, behaving animals. Optogenetics has revolutionized neuroscience and transformed our understanding of brain function.

Neurons in nucleus gigantocellularis (NGC) have been shown by many lines of evidence to be important for regulating generalized CNS arousal. Our previous study on mouse pups suggested that the development of NGC neurons' capability to fire action potential (AP) trains may both lead to the development of behavioral arousal and may itself depend on an increase in delayed rectifier currents. Here with whole-cell patch clamp we studied delayed rectifier currents in two stages. First, primary cultured neurons isolated from E12.5 embryonic hindbrain (HB), a dissection which contains all of NGC, were used to take advantage of studying neurons in vitro over using neurons in situ or in brain slices. HB neurons were tested with Guangxitoxin-1E and Resveratrol, two inhibitors of Kv2 channels which mediate the main bulk of delayed rectifier currents. Both inhibitors depressed delayed rectifier currents, but differentially: Resveratrol, but not Guangxitoxin-1E, reduced or abolished action potentials in AP trains. Since Resveratrol affects the Kv2.2 subtype, the development of the delayed rectifier mediated through Kv2.2 channels may lead to the development of HB neurons' capability to generate AP trains. Stage Two in this work found that electrophysiological properties of the primary HB neurons recorded are essentially the same as those of NGC neurons. Thus, from the two stages combined, we propose that currents mediated through Kv2.2 are crucial for generating AP trains which, in turn, lead to the development of mouse pup behavioral arousal.