Rapid Generation of Reverse Genetics Systems for Coronavirus Research and High-Throughput Antiviral Screening Using Gibson DNA Assembly.

Coronaviruses (CoVs) pose a significant threat to human health, as demonstrated by the COVID-19 pandemic. The large size of the CoV genome (around 30 kb) represents a major obstacle to the development of reverse genetics systems, which are invaluable for basic research and antiviral drug screening. In this study, we established a rapid and convenient method for generating reverse genetic systems for various CoVs using a bacterial artificial chromosome (BAC) vector and Gibson DNA assembly.

Development of pyrimidone derivatives as nonpeptidic and noncovalent 3-chymotrypsin-like protease (3CL) inhibitors with anti-coronavirus activities.

3CL is crucial to the life cycle of SARS-CoV-2 and exhibits high sequence similarity with other coronaviruses, while being absent in human proteases. This makes it an ideal target for developing broad-spectrum antiviral drugs. Ensitrelvir (S-217622) is the only launched non-covalent, non-peptidomimetic 3CL inhibitor, offering certain advantages in terms of dosage and metabolism.

Discovery of orally bioavailable SARS-CoV-2 papain-like protease inhibitor as a potential treatment for COVID-19.

The RNA-dependent RNA polymerase (RdRp), 3C-like protease (3CL), and papain-like protease (PL) are pivotal components in the viral life cycle of SARS-CoV-2, presenting as promising therapeutic targets. Currently, all FDA-approved antiviral drugs against SARS-CoV-2 are RdRp or 3CL inhibitors. However, the mutations causing drug resistance have been observed in RdRp and 3CL from SARS-CoV-2, which makes it necessary to develop antivirals with novel mechanisms.

Identification of adenosine analogues as nsp14 N7‑methyltransferase inhibitors for treating coronaviruses infection.

Coronaviruses are RNA viruses that have coevolved with humans and animals over time, exhibiting high mutation rates and mortality rates upon epidemic outbreaks. The nonstructural protein (nsp14) is crucial for various coronaviruses processes, including genome replication, protein translation, virus particle assembly, and evasion of host immunity via RNA methylation modification. In this study, a series of adenosine analogs were designed, synthesized, and evaluated for their inhibitory activities.

REV-ERBα negatively regulates NLRP6 transcription and reduces the severity of infection in mice.

Non-typhoidal infection is among the most frequent foodborne diseases threatening human health worldwide. The host circadian clock orchestrates daily rhythms to adapt to environmental changes, including coordinating immune function in response to potential infections. However, the molecular mechanisms underlying the interplay between the circadian clock and the immune system in modulating infection processes are incompletely understood.

NLRP6 induces RIP1 kinase-dependent necroptosis via TAK1-mediated p38/MK2 phosphorylation in . infection.

Programmed cell death (PCD) is tightly orchestrated by molecularly defined executors and signaling pathways. NLRP6, a member of cytoplasmic pattern recognition receptors, has a multifaceted role in host resistance to bacterial infection. However, whether and how NLRP6 may contribute to regulate host PCD during Gram-negative bacterial infection remain to be illuminated.

pH-sensitive dual-preventive siRNA-based nanomicrobicide reactivates autophagy and inhibits HIV infection in vaginal CD4+ cells.

Women are more susceptible to HIV transmission through unprotected heterosexual intercourse due to biological and social vulnerabilities. Intravaginal delivery of siRNAs targeting viral genes, host genes, or in combination has shown promising outcomes against HSV, HPV and HIV. Therefore, in this study, we designed, developed and evaluated a pH-sensitive RNAi-based combination nanomicrobide for the prevention/reduction of vaginal transmission of HIV.

SARS-CoV-2 ORF3a sensitizes cells to ferroptosis via Keap1-NRF2 axis.

Viral infection-induced cell death has long been considered as a double-edged sword in the inhibition or exacerbation of viral infections. Patients with severe Coronavirus Disease 2019 (COVID-19) are characterized by multiple organ dysfunction syndrome and cytokine storm, which may result from SARS-CoV-2-induced cell death. Previous studies have observed enhanced ROS level and signs of ferroptosis in SARS-CoV-2 infected cells or specimens of patients with COVID-19, but the exact mechanism is not clear yet.

Synthesis of deuterated S-217622 (Ensitrelvir) with antiviral activity against coronaviruses including SARS-CoV-2.

S-217622 (Ensitrelvir) is a reversible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3-chymotrypsin-like protease (3CL) inhibitor which obtained emergency regulatory approval in Japan for the treatment of SARS-CoV-2 infection on Nov 22, 2022. Herein, analogs of S-271622 with deuterium-for-hydrogen replacement were synthesized for comparison of the antiviral activities and pharmacokinetic (PK) profiles. Compared to the parent compound, C11-d2-S-217622 compound YY-278 retained in vitro activity against 3CL and SARS-CoV-2.

A soluble DR5-Fc chimeric protein attenuates inflammatory responses induced by coronavirus MHV-A59 and SARS-CoV-2.

Mortality in coronavirus disease 2019 (COVID-19) patients has been linked to the presence of a "cytokine storm" induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which involves elevated levels of circulating cytokines and immune-cell hyperactivation. Targeting cytokines during the management of COVID-19 patients has the potential to improve survival rates and reduce mortality. Although cytokine blockers and immune-host modulators are currently being tested in severely ill COVID-19 patients to cope with the overwhelming systemic inflammation, there is not too many successful cases, thus finding new cytokine blockers to attenuate the cytokine storm syndrome is meaningful.

Evidence of Infection of Human Embryonic Stem Cells by SARS-CoV-2.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was initially described to target the respiratory system and now has been reported to infect a variety of cell types, including cardiomyocytes, neurons, hepatocytes, and gut enterocytes. However, it remains unclear whether the virus can directly infect human embryonic stem cells (hESCs) or early embryos. Herein, we sought to investigate this question in a cell-culture system of hESCs.

The adenosine analog prodrug ATV006 is orally bioavailable and has preclinical efficacy against parental SARS-CoV-2 and variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus driving the ongoing coronavirus disease 2019 (COVID-19) pandemic, continues to rapidly evolve. Because of the limited efficacy of vaccination in prevention of SARS-CoV-2 transmission and continuous emergence of variants of concern (VOCs), orally bioavailable and broadly efficacious antiviral drugs are urgently needed. Previously, we showed that the parent nucleoside of remdesivir, GS-441524, has potent anti-SARS-CoV-2 activity.

Comparison of model-specific histopathology in mouse models of COVID-19.

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the causative agent of the current coronavirus disease 2019 pandemic. Development of animal models that parallel the clinical and pathologic features of disease are highly essential to understanding the pathogenesis of SARS-CoV-2 infection and the development of therapeutics and prophylactics. Several mouse models that express the human angiotensin converting enzyme 2 (hACE2) have been created, including transgenic and knock-in strains, and viral vector-mediated delivery of hACE2.

Fused deposition modeling three-dimensional printing of flexible polyurethane intravaginal rings with controlled tunable release profiles for multiple active drugs.

We designed and engineered novel intravaginal ring (IVR) medical devices via fused deposition modeling (FDM) three-dimensional (3D) printing for controlled delivery of hydroxychloroquine, IgG, gp120 fragment (encompassing the CD4 binding site), and coumarin 6 PLGA-PEG nanoparticles (C6NP). The hydrophilic polyurethanes were utilized to 3D-print reservoir-type IVRs containing a tunable release controlling membrane (RCM) with varying thickness and adaptable micro porous structures (by altering the printing patterns and interior fill densities) for controlled sustained drug delivery over 14 days. FDM 3D printing of IVRs were optimized and implemented using a lab-developed Cartesian 3D printer.

Salmonella pSLT-encoded effector SpvB promotes RIPK3-dependent necroptosis in intestinal epithelial cells.

Salmonella is one of the most important worldwide zoonotic pathogens. After invading a host orally, the bacteria break through the intestinal epithelial barrier for further invasion. Intestinal epithelial cells (IECs) play a crucial role in maintaining the integrity of the intestinal epithelial barrier.

A detrimental role of NLRP6 in host iron metabolism during Salmonella infection.

Maintaining host iron homeostasis is an essential component of nutritional immunity responsible for sequestrating iron from pathogens and controlling infection. Nucleotide-oligomerization domain-like receptors (NLRs) contribute to cytoplasmic sensing and antimicrobial response orchestration. However, it remains unknown whether and how NLRs may regulate host iron metabolism, an important component of nutritional immunity.

Effector SpvB Inhibits NF-κB Activity KEAP1-Mediated Downregulation of IKKβ.

Bacterial pathogens have a broad arsenal of genes that are tightly regulated and coordinated to facilitate adaptation to alter host inflammatory response and prolong intracellular bacterial survival. serovar Typhimurium utilizes a type III secretion system (T3SS) to deliver effector molecules into host cells and regulate signal transduction pathways such as NF-κB, thereby resulting in salmonellosis. SpvB, a pSLT-encoded cytotoxic protein secreted by pathogenicity island-2 T3SS, is associated with enhanced survival and intracellular replication.

effector SpvB aggravates dysregulation of systemic iron metabolism via modulating the hepcidin-ferroportin axis.

Iron withholding, an essential component of nutritional immunity, plays a fundamental role in host resistance to infection. Our previous study showed that SpvB, an important pSLT-encoded cytotoxic effector, facilitated pathogenesis within macrophages via perturbing cellular iron metabolism. However, the underlying mechanisms of SpvB in -relevant disorders of systemic iron metabolism have not yet been identified.

Effector SpvB Disrupts Intestinal Epithelial Barrier Integrity for Bacterial Translocation.

are common enteric bacterial pathogens that infect both humans and animals. Intestinal epithelial barrier, formed by a single layer of epithelial cells and apical junctional complex (AJC), plays a crucial role in host defense against enteric pathogens to prevent bacterial translocation. However, the underlying mechanisms of intestinal epithelial barrier dysfunction caused by are poorly understood.

Anti-αβ monoclonal antibody-conjugated nanoparticles block integrin αβ on intravaginal T cells in rhesus macaques.

Intravenous administration of anti-αβ monoclonal antibody in macaques decreases simian immunodeficiency virus (SIV) vaginal infection and reduces gut SIV loads. Because of potential side effects of systemic administration, a prophylactic strategy based on mucosal administration of anti-αβ antibody may be safer and more effective. With this in mind, we developed a novel intravaginal formulation consisting of anti-αβ monoclonal antibody-conjugated nanoparticles (NPs) loaded in a 1% hydroxyethylcellulose (HEC) gel (NP-αβ gel).

effector SpvB interferes with intracellular iron homeostasis regulation of transcription factor NRF2.

Iron is a necessary nutrient for humans and nearly all bacterial species. During infection, macrophages limit the availability of iron to intracellular pathogens in one of the central components of nutritional immunity. However, also have mechanisms to interfere with the antimicrobial effect of host iron withdrawal and meet their own nutrient requirements by scavenging iron from the host.

Autophagy induction and PDGFR-β knockdown by siRNA-encapsulated nanoparticles reduce chlamydia trachomatis infection.

C. trachomatis is the most common sexually transmitted bacterial infection in the world. Although the infection can be easily controlled by the use of antibiotics, several reports of clinical isolates that are resistant to antibiotics have prompted us to search for alternative strategies to manage this disease.

Implant delivering hydroxychloroquine attenuates vaginal T lymphocyte activation and inflammation.

Evidence suggests that women who are naturally resistant to HIV infection exhibit low baseline immune activation at the female genital tract (FGT). This "immune quiescent" state is associated with lower expression of T-cell activation markers, reduced levels of gene transcription and pro-inflammatory cytokine or chemokine production involved in HIV infection while maintaining an intact immune response against pathogens. Therefore, if this unique immune quiescent state can be pharmacologically induced locally, it will provide an excellent women-oriented strategy against HIV infection To our knowledge, this is the first research article evaluating in vivo, an innovative trackable implant that can provide controlled delivery of hydroxychloroquine (HCQ) to successfully attenuate vaginal T lymphocyte activation and inflammation in a rabbit model as a potential strategy to induce an "immune quiescent" state within the FGT for the prevention of HIV infection.