Macrophage phagocytosis of SARS-CoV-2-infected cells mediates potent plasmacytoid dendritic cell activation.

Early and strong interferon type I (IFN-I) responses are usually associated with mild COVID-19 disease, whereas persistent or unregulated proinflammatory cytokine responses are associated with severe disease outcomes. Previous work suggested that monocyte-derived macrophages (MDMs) are resistant and unresponsive to SARS-CoV-2 infection. Here, we demonstrate that upon phagocytosis of SARS-CoV-2-infected cells, MDMs are activated and secrete IL-6 and TNF. Importantly, activated MDMs in turn mediate strong activation of plasmacytoid dendritic cells (pDCs), leading to the secretion of high levels of IFN-α and TNF. Furthermore, pDC activation promoted IL-6 production by MDMs. This kind of pDC activation was dependent on direct integrin-mediated cell‒cell contacts and involved stimulation of the TLR7 and STING signaling pathways. Overall, the present study describes a novel and potent pathway of pDC activation that is linked to the macrophage-mediated clearance of infected cells. These findings suggest that a high infection rate by SARS-CoV-2 may lead to exaggerated cytokine responses, which may contribute to tissue damage and severe disease.

Epigenomic landscape exhibits interferon signaling suppression in the patient of myocarditis after BNT162b2 vaccination.

After the outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, a novel mRNA vaccine (BNT162b2) was developed at an unprecedented speed. Although most countries have achieved widespread immunity from vaccines and infections, yet people, even who have recovered from SARS-CoV-2 infection, are recommended to receive vaccination due to their effectiveness in lowering the risk of recurrent infection. However, the BNT162b2 vaccine has been reported to increase the risk of myocarditis. To our knowledge, for the first time in this study, we tracked changes in the chromatin dynamics of peripheral blood mononuclear cells (PBMCs) in the patient who underwent myocarditis after BNT162b2 vaccination. A longitudinal study of chromatin accessibility using concurrent analysis of single-cell assays for transposase-accessible chromatin with sequencing and single-cell RNA sequencing showed downregulation of interferon signaling and upregulated RUNX2/3 activity in PBMCs. Considering BNT162b2 vaccination increases the level of interferon-α/γ in serum, our data highlight the immune responses different from the conventional responses to the vaccination, which is possibly the key to understanding the side effects of BNT162b2 vaccination.

Autoantibodies against type I interferons in COVID-19 infection: A systematic review and meta-analysis.

OBJECTIVES: In this study, we aimed to study the rate of autoantibodies against type I interferons (IFNs) in patients with COVID-19 and analyze its dependence on severity of infection and some other variables. METHODS: A systemic review with the search terms: "COVID-19" or "SARS-CoV-2" and "autoantibodies" or "autoantibody" and "IFN" or "interferon" for the period 20 December 2019 to 15 August 2022 was carried out using PubMed, Embase, Cochrane, and Web of Science. R 4.2.1 software was used for meta-analysis of the published results. Pooled risk ratios and 95% confidence intervals (CIs) were calculated. RESULTS: We identified eight studies involving 7729 patients, of whom 5097 (66%) had severe COVID-19 and 2632 (34%) had mild or moderate symptoms. The positive rate of anti-type-I-IFN-autoantibodies in the total dataset was 5% (95% CI, 3-8%), but reached 10% (95% CI, 7-14%) in those with severe infection. The most common subtypes were anti-IFN-α (89%) and anti-IFN-ω (77%). The overall prevalence in male patients was 5% (95% CI, 4-6%), and in female patients 2% (95% CI, 1-3%). CONCLUSION: Severe COVID-19 is associated with high rates of autoantibodies against type-I-IFN and more so in male than female patients.

CD4+ T cell calibration of antigen-presenting cells optimizes antiviral CD8+ T cell immunity.

Antiviral CD8+ T cell immunity depends on the integration of various contextual cues, but how antigen-presenting cells (APCs) consolidate these signals for decoding by T cells remains unclear. Here, we describe gradual interferon-α/interferon-ß (IFNα/ß)-induced transcriptional adaptations that endow APCs with the capacity to rapidly activate the transcriptional regulators p65, IRF1 and FOS after CD4+ T cell-mediated CD40 stimulation. While these responses operate through broadly used signaling components, they induce a unique set of co-stimulatory molecules and soluble mediators that cannot be elicited by IFNα/ß or CD40 alone. These responses are critical for the acquisition of antiviral CD8+ T cell effector function, and their activity in APCs from individuals infected with severe acute respiratory syndrome coronavirus 2 correlates with milder disease. These observations uncover a sequential integration process whereby APCs rely on CD4+ T cells to select the innate circuits that guide antiviral CD8+ T cell responses.

Cellular Immune Responses to SARS-CoV-2 in Exposed Seronegative Individuals.

Some SARS-CoV-2-exposed individuals develop immunity without overt infection. We identified 11 individuals who were negative by nucleic acid testing during prolonged close contact and with no serological diagnosis of infection. As this could reflect natural immunity, cross-reactive immunity from previous coronavirus exposure, abortive infection due to de novo immune responses, or other factors, our objective was to characterize immunity against SARS-CoV-2 in these individuals. Blood was processed into plasma and peripheral blood mononuclear cells (PBMC) and screened for IgG, IgA, and IgM antibodies (Ab) against SARS-CoV-2 and common ß-coronaviruses OC43 and HKU1. Receptor blocking activity and interferon-alpha (IFN-α) in plasma were also measured. Circulating T cells against SARS-CoV-2 were enumerated and CD4+ and CD8+ T cell responses discriminated after in vitro stimulation. Exposed uninfected individuals were seronegative against SARS-CoV-2 spike (S) and selectively reactive against OC43 nucleocapsid protein (N), suggesting common ß-coronavirus exposure induced Ab cross-reactive against SARS-CoV-2 N. There was no evidence of protection from circulating angiotensin-converting enzyme (ACE2) or IFN-α. Six individuals had T cell responses against SARS-CoV-2, with four involving CD4+ and CD8+ T cells. We found no evidence of protection from SARS-CoV-2 through innate immunity or immunity induced by common ß-coronaviruses. Cellular immune responses against SARS-CoV-2 were associated with time since exposure, suggesting that rapid cellular responses may contain SARS-CoV-2 infection below the thresholds required for a humoral response.

Therapeutic Effectiveness of Interferon-α2b against COVID-19 with Community-Acquired Pneumonia: The Ukrainian Experience.

Despite several targeted antiviral drugs against SARS-CoV-2 currently being available, the application of type I interferons (IFNs) still deserves attention as an alternative antiviral strategy. This study aimed to assess the therapeutic effectiveness of IFN-α in hospitalized patients with COVID-19-associated pneumonia. The prospective cohort study included 130 adult patients with coronavirus disease (COVID-19). A dose of 80,000 IU of IFN-α2b was administered daily intranasally for 10 days. Adding IFN-α2b to standard therapy reduces the length of the hospital stay by 3 days (p < 0.001). The level of CT-diagnosed lung injuries was reduced from 35% to 15% (p = 0.011) and CT injuries decreased from 50% to 15% (p = 0.017) by discharge. In the group of patients receiving IFN-α2b, the SpO2 index before and after treatment increased from 94 (92-96, Q1-Q3) to 96 (96-98, Q1-Q3) (p < 0.001), while the percentage of patients with normal saturation increased (from 33.9% to 74.6%, p < 0.05), but the level of SpO2 decreased in the low (from 52.5% to 16.9%) and very low (from 13.6% to 8.5%) categories. The addition of IFN-α2b to standard therapy has a positive effect on the course of severe COVID-19.

Plasmacytoid dendritic cells stimulated with Lactococcus lactis strain Plasma produce soluble factors to suppress SARS-CoV-2 replication.

Innate immune responses are important in the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. We have previously found a lactic acid bacteria species, Lactococcus lactis strain Plasma (LC-Plasma), which possesses specific feature to activate plasmacytoid dendritic cells (pDCs) and thus may affect innate immune responses. Here, we investigated the impact of pDC activation by LC-Plasma on SARS-CoV-2 replication in vitro. Addition of the culture supernatant of pDCs stimulated with LC-Plasma resulted in suppression of SARS-CoV-2 replication in Vero and Calu-3 cells. We confirmed interferon-α (IFN-α) secretion in the supernatant of pDCs stimulated with LC-Plasma and induction of IFN-stimulated genes in cells treated with the pDC supernatant. Anti-IFN-α antibody impaired the suppression of SARS-CoV-2 replication by the supernatant of LC-Plasma-stimulated pDCs, suggesting that IFN-α plays an important role in the SARS-CoV-2 suppression. Our results indicate the potential of LC-Plasma to induce inhibitory responses against SARS-CoV-2 replication through pDC stimulation with IFN-α secretion.

Transcriptomic and antiviral analyses of PoIFN-Delta5 against porcine enteric viruses in porcine intestinal epithelial cells.

The interferon-delta family was first reported in domestic pigs and belongs to the type I interferon (IFN-I) family. The enteric viruses could cause diarrhea in newborn piglets with high morbidity and mortality. We researched the function of the porcine IFN-delta (PoIFN-δ) family in the porcine intestinal epithelial cells (IPEC-J2) cells infected with porcine epidemic diarrhea virus (PEDV). Our study found that all PoIFN-δs shared a typical IFN-I signature and could be divided into five branches in the phylogenic tree. Different strains of PEDV could induce typical IFN transitorily, and the virulent strain AH2012/12 had the strongest induction of porcine IFN-δ and IFN-alpha (PoIFN-α) in the early stage of infection. In addition, it was found that PoIFN-δ5/6/9/11 and PoIFN-δ1/2 were highly expressed in the intestine. PoIFN-δ5 had a better antiviral effect on PEDV compared to PoIFN-δ1 due to its higher induction of ISGs. PoIFN-δ1 and PoIFN-δ5 also activated JAK-STAT and IRS signaling. For other enteric viruses, transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), and porcine rotavirus (PoRV), PoIFN-δ1 and PoIFN-δ5 both showed an excellent antiviral effect. Transcriptome analyses uncovered the differences in host responses to PoIFN-α and PoIFN-δ5 and revealed thousands of differentially expressed genes were mainly enriched in the inflammatory response, antigen processing and presentation, and other immune-related pathways. PoIFN-δ5 would be a potential antiviral drug, especially against porcine enteric viruses. These studies were the first to report the antiviral function against porcine enteric viruses and broaden the new acquaintances of this type of interferon though not novelly discovered.

Clinical efficacy and safety of interferon (Type I and Type III) therapy in patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials.

Interferon (IFN) has been highlighted in several randomized controlled trials as an attractive therapeutic candidate based plausible mode of action, suppressed response in severe COVID-19, and inhibition of SARS-CoV-2 replication. This study investigated the efficacy and safety of IFN in patients with COVID-19 according to clinical severity. Randomized controlled trials evaluating the efficacy and safety of IFN (systemic or inhaled IFN-α, -ß, and -λ) treatment in adult patients with COVID-19 were identified by systematically searching electronic databases until January 2023. Risk of bias were assessed using the Cochrane risk of bias tool, meta-analysis, and certainty of evidence grading were followed for the systematic review. We included 11 trials comprising 6,124 patients. Compared with exclusive standard care or placebo, IFN therapy did not provide significant clinical benefits for mortality at day 28 (pooled risk ratio [RR] = 0.86, 95% confidence interval [CI]: 0.62-1.18, 9 studies, low-certainty evidence) and progression to mechanical ventilation (pooled RR = 1.08, 95% CI: 0.81-1.43, 6 studies, low-certainty evidence) in patients with COVID-19. IFN therapy resulted in significantly increased hospital discharge on day 14 relative to the control arm (pooled RR = 1.29, 95% CI: 1.04-1.59). These results were inconsistent compared to other comparable outcomes such as recovery at day 14 and time to clinical improvement. The IFN-treated arm was as safe as the control arm, regardless of clinical severity (pooled RR = 0.87, 95% CI: 0.64-1.19, 9 studies, low-certainty evidence). In conclusion, IFN therapy was safe but did not demonstrate favorable outcomes for major clinical indices in patients with COVID-19, particularly those with higher than moderate severity. IFN therapy was not associated with worsening outcomes in patients with severe COVID-19. Future clinical trials should evaluate the clinical efficacy of IFN therapy in patients with mild COVID-19 or at an earlier stage. Trial registration: The protocol for this review was prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42022301413.

Type I and III interferons are good markers to monitor COVID-19 pathophysiology.

The COVID-19 pandemic has caused millions of deaths and has resulted in disastrous societal and economic impacts worldwide. During SARS-CoV-2 infection, abnormal levels of pro-inflammatory cytokines have been observed and were associated to the severity of the disease. Type I (-α/ß) and Type III (IFN-λ) interferons are family members of cytokines that play an important role in fighting viral replication during the early phases of infection. The location and timing of the IFNs production have been shown to be decisive for the COVID-19 outcome. Despite the effectiveness of COVID-19 vaccines and with the emergence of new SARS-CoV-2 variants, a better understanding of the involvement of IFNs as players in antiviral immunity in the COVID-19 pathophysiology is necessary to implement additional potent prophylactic and/or therapeutic approaches. In this study, we investigated the role of type I and III IFN in COVID-19 pathophysiology. We first analyzed the IFN-α, IFN-ß and IFN- λ mRNA expression in nasopharyngeal swabs and blood samples from Moroccan patients infected with SARS-CoV-2 and secondly correlated these IFNs expressions with COVID-19 clinical and biological parameters. Our results showed that in the upper airways of patients with mild, non-severe, or severe COVID-19 manifestations, the IFN- α, - ß and - λ are expressed in the same manner as in controls. However, in blood samples their expression was downregulated in all groups. Univariate linear models with interferons as predictors to evaluate clinical-biological parameters highlighted that the main clinical-biological relations were found when testing: FiO2, Lymphocyte values and virus load. Furthermore, the multivariate models confirmed that quantifications of interferons during COVID-19 are good biological markers for tracking COVID-19 pathophysiology.

COVID-19 mRNA vaccine protects against SARS-CoV-2 Omicron BA.1 infection in diet-induced obese mice through boosting host innate antiviral responses.

BACKGROUND: Obesity is a worldwide epidemic and is considered a risk factor of severe manifestation of Coronavirus Disease 2019 (COVID-19). The pathogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and host responses to infection, re-infection, and vaccination in individuals with obesity remain incompletely understood. METHODS: Using the diet-induced obese (DIO) mouse model, we studied SARS-CoV-2 Alpha- and Omicron BA.1-induced disease manifestations and host immune responses to infection, re-infection, and COVID-19 mRNA vaccination. FINDINGS: Unlike in lean mice, Omicron BA.1 and Alpha replicated to comparable levels in the lungs of DIO mice and resulted in similar degree of tissue damages. Importantly, both T cell and B cell mediated adaptive immune responses to SARS-CoV-2 infection or COVID-19 mRNA vaccination are impaired in DIO mice, leading to higher propensity of re-infection and lower vaccine efficacy. However, despite the absence of neutralizing antibody, vaccinated DIO mice are protected from lung damage upon Omicron challenge, accompanied with significantly more IFN-α and IFN-ß production in the lung tissue. Lung RNAseq and subsequent experiments indicated that COVID-19 mRNA vaccination in DIO mice boosted antiviral innate immune response, including the expression of IFN-α, when compared to the nonvaccinated controls. INTERPRETATION: Our findings suggested that COVID-19 mRNA vaccination enhances host innate antiviral responses in obesity which protect the DIO mice to a certain degree when adaptive immunity is suboptimal. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Effect of cigarette smoke on mucosal vaccine response with activation of plasmacytoid dendritic cells: The outcomes of in vivo and in vitro experiments.

Mucosal vaccines offer several advantages over transdermal vaccines, including the ability to acquire systemic and mucosal immunities. Smoking is a huge public health threat and major risk factor for various diseases that exacerbate or prolong respiratory symptoms and conditions. However, its impact on the efficacy of mucosal vaccines remains partially explored. Thus, this study investigates the effects of smoking on mucosal vaccine reactivity by assessing the induction of Th1 immunity, a vital response in infection defense. Cigarette smoke condensate was prepared as a substitute for mainstream smoke. We intranasally administered diphtheria toxoid as an antigen and natural CpG oligonucleotide G9.1, which enhances the Th1-type antibody (Ab) response in a plasmacytoid dendritic cells (pDCs) dependent manner, as an adjuvant to mice to assess the effect of cigarette smoke condensate on Ab responses. The mechanism of its effect was evaluated using human peripheral blood mononuclear cells and their pDC-rich fraction cultured with or without G9.1. In mice, cigarette smoke condensate tended to decrease diphtheria toxoid-specific Ab response, with a higher reduction in Th1-type IgG2 Ab response than in Th2-type IgG1 Ab response. In human peripheral blood mononuclear cells, cigarette smoke condensate significantly reduced the induction of IFN-α production by G9.1. Moreover, G9.1-induced increases in the CD83 expression in pDCs and the CD80 expression in DCs were suppressed via treatment with cigarette smoke condensate. Among the mechanisms suggested were decreased expression of toll-like receptor 9 mRNA, decreased expression of mRNA for IFN regulatory factor 7, and increased CpG methylation of its promoter region. The analysis of Tbet and GATA3 expressions revealed that cigarette smoke condensate exhibits Th1-directed immunostimulatory activity at a steady state but becomes more Th2-directed under G9.1 stimulation. In conclusion, smoking could reduce mucosal vaccine responses by decreasing pDC activation and, consequently, Th1-dominant immunity.

Assessment of Proinflammatory Cytokines Among Patients with Middle East Respiratory Syndrome Coronavirus Infection.

Middle East respiratory syndrome coronavirus (MERS-CoV) is associated with significant morbidity and mortality. This study was performed to assess the proinflammatory cytokines profile among MERS-CoV patients. A total of 46 MERS-CoV-infected patients (27 symptomatic and 19 asymptomatic) were assessed and compared with 52 normal healthy controls for plasma levels of interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, IL-17, IL-7, IL-6, interferon (IFN)-α, and IL-15 using a customized luminex kit. Whereas asymptomatic MERS-CoV patients and controls were no different; the mean plasma levels among MERS-CoV symptomatic patients were significantly higher than the normal controls: IL-1ß (16.89 ± 1.23 vs. 12.80 ± 0.59 pg/mL; p < 0.001), TNF-α (14.04 ± 0.93 vs. 10.35 ± 0.29 pg/mL; p < 0.0001), IL-17 (14.3 ± 0.89 vs. 11.47 ± 0.61 pg/mL; p < 0.001), IL-7 (21.56 ± 1.00 vs. 16.31 ± 0.30 pg/mL; p < 0.0001), IL-6 (156.5 ± 37.90 vs. 18.60 ± 1.59 pg/mL; p < 0.0001), and IFN-α (68.73 ± 13.06 vs. 23.57 ± 1.05 pg/mL; p < 0.0001). The mean plasma levels of IL-7 (24.81 ± 1.63 vs. 19.79 ± 0.94 pg/mL; p < 0.01), IL-6 (312.7 ± 94.67 vs. 101.2 ± 25.67 pg/mL; p < 0.01), and IFN-α (89.00 ± 18.97 vs. 51.05 ± 8.68 pg/mL; p < 0.05) were significantly elevated among MERS-CoV symptomatic patients with fatal outcome compared with MERS-CoV symptomatic patients who survived. Only IL-7 was found to have a higher risk ratio of mortality (4.76, 95% confidence interval: 1.5-14.94; p < 0.01). No differences were observed in IL-15 levels among the groups. Significantly elevated proinflammatory cytokines among symptomatic MERS-CoV-infected patients may contribute to manifestations of cytokine storm frequently observed among critically ill MERS-CoV patients and IL-7 may serve as a marker for disease activity.

Can the Prognosis of COVID-19 Disease Be Determined by Fecal Markers and Cytokines?

The coronavirus disease 2019 (COVID-19) pandemic has affected the entire world, and has a variety of clinical presentations. The aim of this study is to determine the relationships of fecal cytokines and markers with the symptoms and prognosis of children with COVID-19 infection, and to identify noninvasive markers during follow-up. In a cohort of 40 COVID-19-positive children and 40 healthy controls, fecal cytokines and markers were examined in stool samples. A binary logistic model was used to assess the potential of cytokines as risk factors for hospitalization. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported. A P-value <0.05 was accepted as statistically significant. Levels of fecal lysozyme, myeloperoxidase, hemoglobin, and interleukin-5 (IL-5) (P < 0.05) were significantly higher among the patients than controls. In a logistic regression analysis, fecal IL-2 (OR = 3.83; 95% CI: 1.44-15.92), IL-4 (OR = 2.96; 95% CI: 1.09-12.93), IL-5 (OR = 4.56; 95% CI: 1.18-27.88), IL-10 (OR = 2.71 95% CI: 1.19-7.94), interferon-gamma (IFN-γ) (OR = 4.03; 95% CI: 1.44-15.73), IFN-α (OR = 3.02; 95% CI: 1.08-11.65), calcium-binding protein B S100 (S100 B) (OR = 4.78; 95% CI: 1.31-27.82), neutrophil elastase (NE) 2 (OR = 4.07; 95% CI: 1.17-19.69), and matrix metalloproteinase 1 (MMP-1) (OR = 3.67; 95% CI: 1.1-18.82) levels were significantly higher in hospitalized patients with COVID-19 infection than outpatients. We demonstrated that various fecal cytokines and markers were increased in patients who had COVID-19. Fecal IL-2, IL-4, IL-5, IL-10, IFN-γ, IFN-α, S100 B, NE, and MMP-1 levels were significantly elevated in hospitalized patients. We suggest that the fecal and serum levels of cytokines could be used to predict the prognosis of COVID-19 disease, although more studies are needed to confirm this.

Is IFN expression by NK cells a hallmark of severe COVID-19?

Natural Killer cells (NK) are crucial in host defense against viruses. There are many unanswered questions about the immune system in COVID-19, especially the mechanisms that contribute to the development of mild or severe forms of the disease. Although NK cells may have an essential role in the pathogenesis of COVID-19, the mechanisms involved in this process are not yet fully elucidated. Here, we demonstrate that CD3-CD56+ NK cells frequency in the volunteers who recovered from mild COVID-19 (Mild CoV) presented a significant increase compared to the healthy control (HC) and individuals recovering from severe COVID-19 (Severe CoV) groups. Furthermore, distinct IFN profiles in recovered COVID-19 patients with mild or severe clinical forms of the disease were observed in the total NK cells (CD3-CD56+). In the first group, NK cells express increased levels of IFN-α compared to the severe CoV, while higher production of IFN-γ in severe CoV was found. Moreover, NK cells in mild CoV express more cytolytic granules depicted by granzyme B and perforin. Compared to HC, PBMCs from mild CoV presented higher Ki-67 and TIM-3 production after Pool CoV-2 and Pool Spike CoV-2 peptides stimulus. In addition, non-stimulated PBMCs in the mild CoV group had higher NK TIM-3+ frequency than severe CoV. In the mild CoV group, Pool Spike CoV-2 and Pool CoV-2 peptides stimuli elicited higher granzyme B and perforin coexpression and IFN-α production by PBMCs. However, in severe CoV, Pool Spike CoV-2 reduced the coexpression of granzyme B, perforin, and CD107a suggesting a decrease in the cytotoxic activity of NK cells. Therefore, our study shows that NK cells may have a crucial role in COVID-19 with the involvement of IFN-α and cytotoxic properties that aid in developing qualified immune responses. Furthermore, the data suggest that higher amounts of IFN-γ may be linked to the severity of this disease.

Polymorphism in interferon alpha/beta receptor contributes to glucocorticoid response and outcome of ARDS and COVID-19.

BACKGROUND: The use of glucocorticoids has given contradictory results for treating acute respiratory distress syndrome (ARDS). The use of intravenous Interferon beta (IFN ß) for the treatment of ARDS was recently tested in a phase III ARDS trial (INTEREST), in which more than half of the patients simultaneously received glucocorticoids. Trial results showed deleterious effects of glucocorticoids when administered together with IFN ß, and therefore, we aimed at finding the reason behind this. METHODS: We first sequenced the genes encoding the IFN α/ß receptor of the patients, who participated in the INTEREST study (ClinicalTrials.gov Identifier:  NCT02622724 , November 24, 2015) in which the patients were randomized to receive an intravenous injection of IFN ß-1a (144 patients) or placebo (152 patients). Genetic background was analyzed against clinical outcome, concomitant medication, and pro-inflammatory cytokine levels. Thereafter, we tested the influence of the genetic background on IFN α/ß receptor expression in lung organ cultures and whether, it has any effect on transcription factors STAT1 and STAT2 involved in IFN signaling. RESULTS: We found a novel disease association of a SNP rs9984273, which is situated in the interferon α/ß receptor subunit 2 (IFNAR2) gene in an area corresponding to a binding motif of the glucocorticoid receptor (GR). The minor allele of SNP rs9984273 associates with higher IFNAR expression, more rapid decrease of IFN γ and interleukin-6 (IL-6) levels and better outcome in IFN ß treated patients with ARDS, while the major allele associates with a poor outcome especially under concomitant IFN ß and glucocorticoid treatment. Moreover, the minor allele of rs9984273 associates with a less severe form of coronavirus diseases (COVID-19) according to the COVID-19 Host Genetics Initiative database. CONCLUSIONS: The distribution of this SNP within clinical study arms may explain the contradictory results of multiple ARDS studies and outcomes in COVID-19 concerning type I IFN signaling and glucocorticoids.

Elevated IFNA1 and suppressed IL12p40 associated with persistent hyperinflammation in COVID-19 pneumonia.

Introduction: Despite of massive endeavors to characterize inflammation in COVID-19 patients, the core network of inflammatory mediators responsible for severe pneumonia stillremain remains elusive. Methods: Here, we performed quantitative and kinetic analysis of 191 inflammatory factors in 955 plasma samples from 80 normal controls (sample n = 80) and 347 confirmed COVID-19 pneumonia patients (sample n = 875), including 8 deceased patients. Results: Differential expression analysis showed that 76% of plasmaproteins (145 factors) were upregulated in severe COVID-19 patients comparedwith moderate patients, confirming overt inflammatory responses in severe COVID-19 pneumonia patients. Global correlation analysis of the plasma factorsrevealed two core inflammatory modules, core I and II, comprising mainly myeloid cell and lymphoid cell compartments, respectively, with enhanced impact in a severity-dependent manner. We observed elevated IFNA1 and suppressed IL12p40, presenting a robust inverse correlation in severe patients, which was strongly associated with persistent hyperinflammation in 8.3% of moderate pneumonia patients and 59.4% of severe patients. Discussion: Aberrant persistence of pulmonary and systemic inflammation might be associated with long COVID-19 sequelae. Our comprehensive analysis of inflammatory mediators in plasmarevealed the complexity of pneumonic inflammation in COVID-19 patients anddefined critical modules responsible for severe pneumonic progression.

Efficacy of interferon alpha for the treatment of hospitalized patients with COVID-19: A meta-analysis.

Introduction: IFN-α intervention may block SARS-CoV-2 replication and normalize the deregulated innate immunity of COVID-19. Aim: This meta-analysis aimed to investigate the efficacy of interferon IFN-α-containing regimens when treating patients with moderate-to-severe COVID-19. Material and methods: PubMed, SCOPUS, and ClinicalTrials.gov were searched from inception to 15 January 2022. A systematic literature search was conducted by applying relevant terms for 'COVID-19' and 'interferon-α'. The primary outcome enclosed the all-cause hospital mortality. The secondary outcomes constituted the length of hospital stay; hospital discharge; nucleic acid negative conversion. Results: Eleven studies are enclosed in the meta-analysis. No significant difference in the all-cause mortality rate was found between the study and control groups (OR 0.2; 95% CI 0.05-1.2; I2 = 96%). The implementation of interferon did not influence such outcomes as the length of hospital stay (OR 0.9; 95% CІ, 0.3-2.6; I2 = 91%), nucleic acid negative conversion (OR 0.8; 95% CI, 0.04-17.2; I2 = 94%). Nevertheless, IFN-α treatment resulted in a higher number of patients discharged from the hospital (OR 26.6; 95% CІ, 2.7-254.3; I2 = 95%). Conclusions: Thus, IFN-α does not benefit the survival of hospitalized COVID-19 patients but may increase the number of patients discharged from the hospital. Systematic review registration: www.crd.york.ac.uk/prospero, identifier (CRD42022374589).

Human IRF1 governs macrophagic IFN-γ immunity to mycobacteria.

Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/ß-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/ß immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/ß. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/ß-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/ß-dependent antiviral immunity.

Lidocaine inhibits influenza a virus replication by up-regulating IFNα4 via TBK1-IRF7 and JNK-AP1 signaling pathways.

Influenza A viruses (IAV), significant respiratory pathogenic agents, cause seasonal epidemics and global pandemics in intra- and interannual cycles. Despite effective therapies targeting viral proteins, the continuous generation of drug-resistant IAV strains is challenging. Therefore, exploring novel host-specific antiviral treatment strategies is urgently needed. Here, we found that lidocaine, widely used for local anesthesia and sedation, significantly inhibited H1N1(PR8) replication in macrophages. Interestingly, its antiviral effect did not depend on the inhibition of voltage-gated sodium channels (VGSC), the main target of lidocaine for anesthesia. Lidocaine significantly upregulated early IFN-I, interferon α4 (IFNα4) mRNA, and protein levels, but not those of early IFNß in mouse RAW 264.7 cell line and human THP-1 derived macrophages. Knocking out IFNα4 by CRISPR-Cas9 partly reversed lidocaine's inhibition of PR8 replication in macrophages. Mechanistically, lidocaine upregulated IFNα4 by activating TANK-binding kinase 1 (TBK1)-IRF7 and JNK-AP1 signaling pathways. These findings indicate that lidocaine has an incredible antiviral potential by enhancing IFN-I signaling in macrophages. In conclusion, our results indicate the potential auxiliary role of lidocaine for anti-influenza A virus therapy and even for anti-SARS-CoV-2 virus therapy, especially in the absence of a specific medicine.