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Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the last 60+ years has responded to reduce this disease burden with vaccines and antivirals. Despite this long history, the COVID-19 pandemic has brought unprecedented attention to the field of virology. Some of this attention is focused on concern about the safe conduct of research with human pathogens. A small but vocal group of individuals has seized upon these concerns - conflating legitimate questions about safely conducting virus-related research with uncertainties over the origins of SARS-CoV-2. The result has fueled public confusion and, in many instances, ill-informed condemnation of virology. With this article, we seek to promote a return to rational discourse. We explain the use of gain-of-function approaches in science, discuss the possible origins of SARS-CoV-2 and outline current regulatory structures that provide oversight for virological research in the United States. By offering our expertise, we - a broad group of working virologists - seek to aid policy makers in navigating these controversial issues. Balanced, evidence-based discourse is essential to addressing public concern while maintaining and expanding much-needed research in virology.

Background: An in-silico screen identified mebendazole with potential antiviral activity that could be a repurposed drug against SARS-CoV-2. Mebendazole is a well-tolerated and cheap antihelminthic agent that is readily available worldwide and thus could be a therapeutic tool in the fight against COVID-19., Methods: This is an observational retrospective study of PCR-confirmed COVID-19 patients who received mebendazole with the intention-to-treat. The study included an inpatient cohort (157 inpatients) and an outpatient cohort (185 outpatients). Of the 157 inpatients and 185 outpatients, 68 (43.3%) and 94 (50.8%) received mebendazole, respectively. Patients who presented within the same timeframe but did not receive mebendazole were used as controls. Patients received standard-of-care treatment including remdesivir, dexamethasone, and anticoagulants as deemed necessary by the treating physician. The following clinical outcomes were evaluated: for the inpatient cohort, length of stay (LOS) at the hospital, need for ventilation (combined invasive and noninvasive), and mortality; for the outpatient cohort, time to symptom resolution, need for hospitalization, and mortality., Results: For the inpatient cohort, the median age did not differ between the treatment and control groups; 62 (56, 67) vs. 62 (56, 68), P , and there was a comparable proportion of males in both groups; 43 (63%) vs. 55 (62%), P =0.85. The hospital LOS was 3.5 days shorter in the treatment group compared to the control group ( P < 0.001). There were fewer patients who required invasive or noninvasive ventilation in the treatment group, 2 (2.9%) vs. 7 (7.9%), and the mortality rate is lower in the treatment group, 3 (4.4%) vs. 8 (9.0%), though the differences did not reach statistical significance. For the outpatient cohort, the median age was lower in the treatment group compared with the control group; 40 (34, 48) vs. 48 (41, 54), P < 0.001. There was a comparable proportion of males between both groups; 50 (53%) vs. 52 (57%), P =0.59. Patients in the treatment group were 3.3 days closer to symptom resolution ( P < 0.001). There were numerically fewer patients requiring hospitalization in the treatment group compared with the control group, 3 (3.2%) vs. 6 (6.6%), though this did not reach statistical significance ( P =0.33)., Conclusion: In this retrospective observational study, the use of mebendazole in COVID-19 patients was associated with shorter hospitalizations in the inpatient cohort and shorter durations of symptom resolution in the outpatient cohort. The findings from this small observational study are hypothesis-generating and preclude drawing conclusions about clinical efficacy. Further studies are needed to examine the role of mebendazole in the treatment of COVID-19 patients., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 Mostafa W. Galal et al.)

Genetic variation in a sensor of double-stranded RNA can exacerbate COVID-19.

Pathogenesis of COVID-19 is associated with a hyperinflammatory response; however, the precise mechanism of SARS-CoV-2-induced inflammation is poorly understood. Here we investigated direct inflammatory functions of major structural proteins of SARS-CoV-2. We observed that spike (S) protein potently induces inflammatory cytokines and chemokines including IL-6, IL-1ß, TNFa, CXCL1, CXCL2, and CCL2, but not IFNs in human and mouse macrophages. No such inflammatory response was observed in response to membrane (M), envelope (E), and neucleocapsid (N) proteins. When stimulated with extracellular S protein, human lung epithelial cells A549 also produce inflammatory cytokines and chemokines. Interestingly, epithelial cells expressing S protein intracellularly are non-inflammatory, but elicit an inflammatory response in macrophages when co-cultured. Biochemical studies revealed that S protein triggers inflammation via activation of the NF-κB pathway in a MyD88-dependent manner. Further, such an activation of the NF-κB pathway is abrogated in Tlr2-deficient macrophages. Consistently, administration of S protein induces IL-6, TNF-a, and IL-1 ß in wild-type, but not Tlr2-deficient mice. Together these data reveal a mechanism for the cytokine storm during SARS-CoV-2 infection and suggest that TLR2 could be a potential therapeutic target for COVID-19.

Interferons (IFNs) exert their anti-viral effects by inducing the expression of hundreds of IFN-stimulated genes (ISGs). The activity of known ISGs is insufficient to account for the antiretroviral effects of IFN, suggesting that ISGs with antiretroviral activity are yet to be described. We constructed an arrayed library of ISGs from rhesus macaques and tested the ability of hundreds of individual macaque and human ISGs to inhibit early and late replication steps for 11 members of the retroviridae from various host species. These screens uncovered numerous ISGs with antiretroviral activity at both the early and late stages of virus replication. Detailed analyses of two antiretroviral ISGs indicate that indoleamine 2,3-dioxygenase 1 (IDO1) can inhibit retroviral replication by metabolite depletion while tripartite motif-56 (TRIM56) accentuates ISG induction by IFNα and inhibits the expression of late HIV-1 genes. Overall, these studies reveal numerous host proteins that mediate the antiretroviral activity of IFNs., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Vaccinia virus (VACV) K1L and C7L function equivalently in many mammalian cells to support VACV replication and antagonize antiviral activities induced by type I interferons (IFNs). While K1L is limited to orthopoxviruses, genes that are homologous to C7L are found in diverse mammalian poxviruses. In this study, we showed that the C7L homologues from sheeppox virus and swinepox virus could rescue the replication defect of a VACV mutant deleted of both K1L and C7L (vK1L(-)C7L(-)). Interestingly, the sheeppox virus C7L homologue could rescue the replication of vK1L(-)C7L(-) in human HeLa cells but not in murine 3T3 and LA-4 cells, in contrast to all other C7L homologues. Replacing amino acids 134 and 135 of the sheeppox virus C7L homologue, however, made it functional in the two murine cell lines, suggesting that these two residues are critical for antagonizing a putative host restriction factor which has some subtle sequence variation in human and murine cells. Furthermore, the C7L family of host range genes from diverse mammalian poxviruses were all capable of antagonizing type I IFN-induced antiviral activities against VACV. Screening of a library of more than 350 IFN-stimulated genes (ISGs) identified interferon-regulated factor 1 (IRF1) as an inhibitor of vK1L(-)C7L(-) but not wild-type VACV. Expression of either K1L or C7L, however, rendered vK1L(-)C7L(-) resistant to IRF1-induced antiviral activities. Altogether, our data show that K1L and C7L antagonize IRF1-induced antiviral activities and that the host modulation function of C7L is evolutionally conserved in all poxviruses that can readily replicate in tissue-cultured mammalian cells.

Adenoviruses invading the organism via normal digestive or respiratory routes require the Coxsackie-adenovirus receptor (CAR) to infect the epithelial barrier cells. Because CAR is a component of tight junctions and the basolateral membrane and is normally excluded from the apical membrane, most epithelia are resistant to adenoviruses. However, we discovered that a specialized epithelium, the retinal pigment epithelium (RPE), anomalously expressed CAR at the apical surface and was highly susceptible to adenovirus infection. These properties of RPE cells correlated with the absence of the epithelial-specific clathrin adaptor AP1B. Furthermore, knockdown of this basolateral sorting adaptor in adenovirus-resistant MDCK cells promoted apical localization of CAR and increased dramatically Adenovirus infectivity. Targeting assays showed that AP1B is required for accurate basolateral recycling of CAR after internalization. AP1B knock down MDCK cells missorted CAR from recycling endosomes to the apical surface. In summary, we have characterized the cellular machinery responsible for normal sorting of an adenovirus receptor and illustrated how tissue-specific variations in such machinery result in drastic changes in tissue-susceptibility to adenoviruses.

The adenovirus major late transcription unit (MLTU) encodes the main structural capsid proteins. Expression from the MLTU is accomplished through alternative mRNA processing and use of a terminal exon coding strategy. The capsid proteins hexon, penton, and fiber contribute to efficient infection by adenovirus, and each contributes in some manner to the antiviral immune response against adenovirus infection. The ability to manipulate these genes affords one the opportunity to "detarget" adenovirus, to retarget adenovirus, and to alter immune recognition. In this chapter, we are presenting a terminal exon-replacement strategy that can be used to genetically manipulate capsid proteins expressed from the MLTU. An emphasis will be placed on manipulations of fiber as an intact terminal exon.

PGE(2) levels are altered in human epidermis after in vivo wounding; however, mechanisms modulating PGE(2) production in activated keratinocytes are unclear. In previous studies, we showed that PGE(2) is a growth-promoting autacoid in human primary keratinocyte cultures, and its production is modulated by plating density, suggesting that regulated PGE(2) synthesis is an important component of wound healing. Here, we examine the role of phospholipase A(2) (PLA(2)) and cyclooxygenase (COX) enzymes in modulation of PGE(2) production. We report that the increased PGE(2) production that occurs in keratinocytes grown in nonconfluent conditions is also observed after in vitro wounding, indicating that similar mechanisms are involved. This increase was associated with coordinate upregulation of both COX-2 and secretory PLA(2) (sPLA(2)) proteins. Increased sPLA(2) activity was also observed. By RT-PCR, we identified the presence of type IIA and type V sPLA(2), along with the M-type sPLA(2) receptor. Thus the coordinate expression of sPLA(2) and COX-2 may be responsible for the increased prostaglandin synthesis in activated keratinocytes during wound repair.