Interferon-dependent signaling is critical for viral clearance in airway neutrophils

Potential protective role of interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) in COVID-19

The COVID-19 pandemic has prompted a quest to understand why certain individuals remain uninfected or asymptomatic despite repetitive exposure to SARS-CoV-2. Here, we focused on six exposed females residing with their symptomatic and reinfected SARS-CoV-2 PCR-positive COVID-19 partners. Peripheral blood mononuclear cell samples from couples were analysed for poly (I:C)-induced mRNA expression of type I/III interferons and interferon-stimulated genes (ISGs). Remarkably, we found a significant upregulation of the ISG interferon-inducible protein with tetrapeptide repeats 3 (IFIT3) gene exclusively in exposed uninfected or asymptomatic females, suggesting a potential role in protective immunity against symptomatic COVID-19.

Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils' functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis.

IFIT3 mediates TBK1 phosphorylation to promote activation of pDCs and exacerbate systemic sclerosis in mice

OBJECTIVE

To assess the impact of the IFIT3/TBK1 signalling pathway in activating plasmacytoid dendritic cells (pDCs) and its role in the development of SSc.

METHODS

Utilized single-cell RNA sequencing (scRNA-seq) and high-throughput transcriptome RNA sequencing to reveal the differential abundance of pDCs and the role of the key gene IFIT3 in SSc. Conducted in vitro cell experiments to evaluate the effect of IFIT3/TBK1 signalling pathway intervention on pDC activation cytokine release and fibroblast function. Constructed an IFIT3-/- mouse model using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing to assess the potential benefits of intervening in the IFIT3/TBK1 signalling pathway on skin and lung fibrosis in the SSc mouse model.

RESULTS

The IFIT3/TBK1 signalling pathway plays a crucial role in activating pDCs, with IFIT3 acting as an upstream regulator of TBK1. Intervention in the IFIT3/TBK1 signalling pathway can inhibit pDC activation cytokine release and impact fibroblast function. The IFIT3-/- mouse model shows potential benefits of targeting the IFIT3/TBK1 signalling pathway in reducing skin and lung fibrosis in the SSc mouse model.

CONCLUSION

This study provides new insights into potential therapeutic targets for SSc, highlighting the critical role of the IFIT3/TBK1 signalling pathway in SSc development.

HIGHLIGHTS

This study elucidates the pivotal role of plasmacytoid dendritic cells (pDCs) in systemic sclerosis (SSc). This study identified the key regulatory gene involved in systemic sclerosis (SSc) as IFIT3. This study has found that IFIT3 functions as an upstream regulatory factor, activating TBK1. This study provides Evidence of the regulatory effects of the IFIT3/TBK1 pathway on plasmacytoid dendritic cells (pDCs). This study validated the therapeutic potential using the IFIT3-/- mouse model.

Innate Immunity in Protection and Pathogenesis During Coronavirus Infections and COVID-19

The COVID-19 pandemic was caused by the recently emerged β-coronavirus SARS-CoV-2. SARS-CoV-2 has had a catastrophic impact, resulting in nearly 7 million fatalities worldwide to date. The innate immune system is the first line of defense against infections, including the detection and response to SARS-CoV-2. Here, we discuss the innate immune mechanisms that sense coronaviruses, with a focus on SARS-CoV-2 infection and how these protective responses can become detrimental in severe cases of COVID-19, contributing to cytokine storm, inflammation, long-COVID, and other complications. We also highlight the complex cross talk among cytokines and the cellular components of the innate immune system, which can aid in viral clearance but also contribute to inflammatory cell death, cytokine storm, and organ damage in severe COVID-19 pathogenesis. Furthermore, we discuss how SARS-CoV-2 evades key protective innate immune mechanisms to enhance its virulence and pathogenicity, as well as how innate immunity can be therapeutically targeted as part of the vaccination and treatment strategy. Overall, we highlight how a comprehensive understanding of innate immune mechanisms has been crucial in the fight against SARS-CoV-2 infections and the development of novel host-directed immunotherapeutic strategies for various diseases.

Silicone implant surface microtopography modulates inflammation and tissue repair in capsular fibrosis

Excessive fibrous capsule formation around silicone mammary implants (SMI) involves immune reactions to silicone. Capsular fibrosis, a common SMI complication linked to host responses, worsens with specific implant topographies. Our study with 10 patients investigated intra- and inter-individually, reduced surface roughness effects on disease progression, wound responses, chronic inflammation, and capsular composition. The results illuminate the significant impact of surface roughness on acute inflammatory responses, fibrinogen accumulation, and the subsequent fibrotic cascade. The reduction of surface roughness to an average roughness of 4 μm emerges as a promising approach for mitigating detrimental immune reactions, promoting healthy wound healing, and curbing excessive fibrosis. The identified proteins adhering to rougher surfaces shed light on potential mediators of pro-inflammatory and pro-fibrotic processes, further emphasizing the need for meticulous consideration of surface design. The composition of the implant capsule and the discovery of intracapsular HSP60 expression highlight the intricate web of stress responses and immune activation that can impact long-term tissue outcomes.

Disparate viral pandemics from COVID19 to monkeypox and beyond: a simple, effective and universal therapeutic approach hiding in plain sight

The field of antiviral therapeutics is fixated on COVID19 and rightly so as the fatalities at the height of the pandemic in the United States were almost 1,000,000 in a twelve month period spanning parts of 2020/2021. A coronavirus called SARS-CoV2 is the causative virus. Development of a vaccine through molecular biology approaches with mRNA as the inducer of virus spike protein has played a major role in driving down mortality and morbidity. Antivirals have been of marginal value in established infections at the level of hospitalization. Thus, the current focus is on early symptomatic infection of about the first five days. The Pfizer drug paxlovid which is composed of nirmatrelvir, a peptidomimetic protease inhibitor of SARS-CoV2 Mpro enzyme, and ritonavir to retard degradation of nirmatrelvir, is the current FDA recommended treatment of early COVID19. There is no evidence of broad antiviral activity of paxlovid against other diverse viruses such as the influenza virus, poxviruses, as well as a host of respiratory viruses. Although type I interferons (IFNs) are effective against SARS-CoV2 in cell cultures and in early COVID19 infections, they have not been broadly recommended as therapeutics for COVID19. We have developed stable peptidomimetics of both types I and II IFNs based on our noncanonical model of IFN signaling involving the C-terminus of the IFNs. We have also identified two members of intracellular checkpoint inhibitors called suppressors of cytokine signaling (SOCS), SOCS1 and SOCS3 (SOCS1/3), and shown that they are virus induced intrinsic virulence proteins with activity against IFN signaling enzymes JAK2 and TYK2. We developed a peptidomimetic antagonist, based on JAK2 activation loop, against SOCS1/3 and showed that it synergizes with the IFN mimetics for potent broad spectrum antiviral activity without the toxicity of intact IFN molecules. IFN mimetics and the SOCS1/3 antagonist should have an advantage over currently used antivirals in terms of safety and potency against a broad spectrum of viruses.