Serum IFN-γ-induced protein 10 (IP-10) as a biomarker for severity of acute respiratory infection in healthy adults

Biomarkers of mortality in adults and adolescents with advanced HIV in sub-Saharan Africa

One-third of people with HIV in sub-Saharan Africa start antiretroviral therapy (ART) with advanced disease. We investigated associations between immune biomarkers and mortality in participants with advanced HIV randomised to cotrimoxazole or enhanced antimicrobial prophylaxis in the Reduction of Early Mortality in HIV-Infected Adults and Children Starting Antiretroviral Therapy (REALITY) trial (ISRCTN43622374). Biomarkers were assayed using ELISA and Luminex. Associations between baseline values and all-cause 24-week mortality were analysed using Cox models, and for cause-specific mortality used Fine & Gray models, including prophylaxis randomisation, viral load, CD4, WHO stage, age, BMI, and site as covariates; and weighted according to inverse probability of selection into the substudy. Higher baseline CRP, IFN-γ, IL-6 and IP-10 were associated with higher all-cause mortality; and higher IL-23, IL-2 and RANTES with lower all-cause mortality. Associations varied by cause of death: tuberculosis-associated mortality was most strongly associated with higher CRP and sST2, and cryptococcosis-associated mortality with higher IL-4 and lower IL-8. Changes in I-FABP (p = 0.002), faecal alpha-1 antitrypsin (p = 0.01) and faecal myeloperoxidase (p = 0.005) between baseline and 4 weeks post-ART were greater in those receiving enhanced versus cotrimoxazole prophylaxis. Our findings highlight how the immune milieu shapes outcomes following ART initiation, and how adjunctive antimicrobials can modulate the gut environment in advanced HIV.

The glycosaminoglycan-binding chemokine fragment CXCL9(74-103) reduces inflammation and tissue damage in mouse models of coronavirus infection

Introduction

Pulmonary diseases represent a significant burden to patients and the healthcare system and are one of the leading causes of mortality worldwide. Particularly, the COVID-19 pandemic has had a profound global impact, affecting public health, economies, and daily life. While the peak of the crisis has subsided, the global number of reported COVID-19 cases remains significantly high, according to medical agencies around the world. Furthermore, despite the success of vaccines in reducing the number of deaths caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there remains a gap in the treatment of the disease, especially in addressing uncontrolled inflammation. The massive recruitment of leukocytes to lung tissue and alveoli is a hallmark factor in COVID-19, being essential for effectively responding to the pulmonary insult but also linked to inflammation and lung damage. In this context, mice models are a crucial tool, offering valuable insights into both the pathogenesis of the disease and potential therapeutic approaches.

Methods

Here, we investigated the anti-inflammatory effect of the glycosaminoglycan (GAG)-binding chemokine fragment CXCL9(74-103), a molecule that potentially decreases neutrophil transmigration by competing with chemokines for GAG-binding sites, in two models of pneumonia caused by coronavirus infection.

Results

In a murine model of betacoronavirus MHV-3 infection, the treatment with CXCL9(74-103) decreased the accumulation of total leukocytes, mainly neutrophils, to the alveolar space and improved several parameters of lung dysfunction 3 days after infection. Additionally, this treatment also reduced the lung damage. In the SARS-CoV-2 model in K18-hACE2-mice, CXCL9(74-103) significantly improved the clinical manifestations of the disease, reducing pulmonary damage and decreasing viral titers in the lungs.

Discussion

These findings indicate that CXCL9(74-103) resulted in highly favorable outcomes in controlling pneumonia caused by coronavirus, as it effectively diminishes the clinical consequences of the infections and reduces both local and systemic inflammation.

Studying the correlation of inflammatory cytokines to COVID-19 disease

Extreme response of the immune system develops cytokine storm which might be crucial in the pathology of COVID-19. The research aims to evaluate the serum level of IL-6, TNF-α, and IP-10 in severe, mild, and pre-vaccinated one-dose COVID-19 patients and investigate their clinical value and effect in the disease development among different groups of patients. A total of 72 samples were collected 18 as healthy control and 54 from confirmed COVID-19 patients including 18 mild, 18 severe, and 18 pre-vaccinated (one dose). It was confirmed that the severe group of COVID-19 patients had the highest circulating IL-6, TNF- α, and IP-10. IL-6 level in mild and pre-vaccinated (one dose) was significantly lower than in severe. In conclusion, IL-6, TNF-α, and IP-10 are associated with the pathogenicity of COVID-19, furthermore, vaccination could help to control severity of the disease.

The gut virome is associated with stress-induced changes in behaviour and immune responses in mice

The microbiota-gut-brain axis has been shown to play an important role in the stress response, but previous work has focused primarily on the role of the bacteriome. The gut virome constitutes a major portion of the microbiome, with bacteriophages having the potential to remodel bacteriome structure and activity. Here we use a mouse model of chronic social stress, and employ 16S rRNA and whole metagenomic sequencing on faecal pellets to determine how the virome is modulated by and contributes to the effects of stress. We found that chronic stress led to behavioural, immune and bacteriome alterations in mice that were associated with changes in the bacteriophage class Caudoviricetes and unassigned viral taxa. To determine whether these changes were causally related to stress-associated behavioural or physiological outcomes, we conducted a faecal virome transplant from mice before stress and autochthonously transferred it to mice undergoing chronic social stress. The transfer of the faecal virome protected against stress-associated behaviour sequelae and restored stress-induced changes in select circulating immune cell populations, cytokine release, bacteriome alterations and gene expression in the amygdala. These data provide evidence that the virome plays a role in the modulation of the microbiota-gut-brain axis during stress, indicating that these viral populations should be considered when designing future microbiome-directed therapies.

FLUAV RAM-IGIP: A modified live influenza virus vaccine that enhances humoral and mucosal responses against influenza

Current influenza A vaccines fall short, leaving both humans and animals vulnerable. To address this issue, we have developed attenuated modified live virus (MLV) vaccines against influenza using genome rearrangement techniques targeting the internal gene segments of FLUAV. The rearranged M2 (RAM) strategy involves cloning the M2 ORF downstream of the PB1 ORF in segment 2 and incorporating multiple early stop codons within the M2 ORF in segment 7. Additionally, the IgA-inducing protein (IGIP) coding region was inserted into the HA segment to further attenuate the virus and enhance protective mucosal responses. RAM-IGIP viruses exhibit similar growth rates to wild type (WT) viruses in vitro and remain stable during multiple passages in cells and embryonated eggs. The safety, immunogenicity, and protective efficacy of the RAM-IGIP MLV vaccine against the prototypical 2009 pandemic H1N1 strain A/California/04/2009 (H1N1) (Ca/04) were evaluated in Balb/c mice and compared to a prototypic cold-adapted live attenuated virus vaccine. The results demonstrate that the RAM-IGIP virus exhibits attenuated virulence in vivo. Mice vaccinated with RAM-IGIP and subsequently challenged with an aggressive lethal dose of the Ca/04 strain exhibited complete protection. Analysis of the humoral immune response revealed that the inclusion of IGIP enhanced the production of neutralizing antibodies and augmented the antibody-dependent cellular cytotoxicity response. Similarly, the RAM-IGIP potentiated the mucosal immune response against various FLUAV subtypes. Moreover, increased antibodies against NP and NA responses were observed. These findings support the development of MLVs utilizing genome rearrangement strategies in conjunction with the incorporation of immunomodulators.

IMPORTANCE

Current influenza vaccines offer suboptimal protection, leaving both humans and animals vulnerable. Our novel attenuated MLV vaccine, built by rearranging FLUAV genome segments and incorporating the IgA-inducing protein, shows promising results. This RAM-IGIP vaccine exhibits safe attenuation, robust immune responses, and complete protection against lethal viral challenge in mice. Its ability to stimulate broad-spectrum humoral and mucosal immunity against diverse FLUAV subtypes makes it a highly promising candidate for improved influenza vaccines.

Point-of-care biomarker assay for rapid multiplexed detection of CRP and IP-10

Rapid and accurate measurements of immune protein markers are essential for diagnosis and treatment in all clinical settings. The recent pandemic has revealed a stark need for developing new tools and assays that could be rapidly used in diverse settings and provide useful information to clinicians. Here, we describe the development and test application of a novel one-step CRP/IP-10 duplex assay for the LightDeck platform capable of delivering reproducible and accurate measurements in under eight minutes. We used the optimized assay to measure CRP and IP-10 levels in human blood and serum samples from healthy, SARS-CoV-2 (COVID-19) positive, and influenza-like illness (ILI) presenting patients. Our results agreed with previously published analyte levels and enabled us to make statistically significant comparisons relevant to multiple clinical parameters. Our duplex assay is a simple and powerful tool for aiding prognostic decision-making in diverse settings.

Immune biomarkers associated with COVID-19 disease severity in an urban, hospitalized population

Objectives

We sought to identify immune biomarkers associated with severe Coronavirus disease 2019 (COVID-19) in patients admitted to a large urban hospital during the early phase of the SARS-CoV-2 pandemic.

Design

The study population consisted of SARS-CoV-2 positive subjects admitted for COVID-19 (n = 58) or controls (n = 14) at the Los Angeles County University of Southern California Medical Center between April 2020 through December 2020. Immunologic markers including chemokine/cytokines (IL-6, IL-8, IL-10, IP-10, MCP-1, TNF-α) and serologic markers against SARS-CoV-2 antigens (including spike subunits S1 and S2, receptor binding domain, and nucleocapsid) were assessed in serum collected on the day of admission using bead-based multiplex immunoassay panels.

Results

We observed that body mass index (BMI) and SARS-CoV-2 antibodies were significantly elevated in patients with the highest COVID-19 disease severity. IP-10 was significantly elevated in COVID-19 patients and was associated with increased SARS-CoV-2 antibodies. Interactions among all available variables on COVID-19 disease severity were explored using a linear support vector machine model which supported the importance of BMI and SARS-CoV-2 antibodies.

Conclusions

Our results confirm the known adverse association of BMI on COVID-19 severity and suggest that IP-10 and SARS-CoV-2 antibodies could be useful to identify patients most likely to experience the most severe forms of the disease.

Individual participant data systematic review and meta-analysis of randomised controlled trials assessing adult mindfulness-based programmes for mental health promotion in non-clinical settings

Introduction

Mindfulness-based programmes (MBPs) are widely used to prevent mental ill-health that is becoming the leading global cause of morbidity. Evidence suggests beneficial average effects but wide variability. We aimed to confirm the effect of MBPs on psychological distress, and to understand whether and how baseline distress, gender, age, education, and dispositional mindfulness modify the effect of MBPs on distress among adults in non-clinical settings.

Methods

We conducted a pre-registered systematic review and individual participant data (IPD) meta-analysis (PROSPERO CRD42020200117). Thirteen databases were searched in December 2020 for randomised controlled trials satisfying a quality threshold and comparing in-person, expert-defined MBPs in non-clinical settings with passive control groups. Two researchers independently selected, extracted, and appraised trials using the revised Cochrane Risk-of-Bias Tool (RoB2). Anonymised IPD of eligible trials were sought from collaborating authors. The primary outcome was psychological distress (unpleasant mental or emotional experiences including anxiety and depression) at 1 to 6 months after programme completion. Data were checked and imputed if missing. Pairwise, random-effects, two-stage IPD meta-analyses were conducted. Effect modification analyses followed a within-studies approach. Public and professional stakeholders were involved in the planning, conduct and dissemination of this study.

Results

Fifteen trials were eligible, 13 trialists shared IPD (2,371 participants representing 8 countries, median age 34 years-old, 71% women, moderately distressed on average, 20% missing outcome data). In comparison with passive control groups, MBPs reduced average distress between one- and six-months post-intervention with a small to moderate effect size (standardised mean difference (SMD) -0.32; 95% confidence interval (CI) -0.41 to -0.24; p-value < 0.001; 95% prediction interval (PI) -0.41 to -0.24 (no heterogeneity)). Results were robust to sensitivity analyses, and similar for the other psychological distress time point ranges. Confidence in the primary outcome result is high. We found no clear indication that this effect is modified by baseline psychological distress, gender, age, education level, or dispositional mindfulness.

Conclusions

Group-based teacher-led MBPs generally reduce psychological distress among community adults who volunteer to receive this type of intervention. More research is needed to identify sources of variability in outcomes at an individual level.

The pro-inflammatory response to influenza A virus infection is fueled by endothelial cells

Morbidity and mortality from influenza are associated with high levels of systemic inflammation. Endothelial cells play a key role in systemic inflammatory responses during severe influenza A virus (IAV) infections, despite being rarely infected in humans. How endothelial cells contribute to systemic inflammatory responses is unclear. Here, we developed a transwell system in which airway organoid-derived differentiated human lung epithelial cells were co-cultured with primary human lung microvascular endothelial cells (LMECs). We compared the susceptibility of LMECs to pandemic H1N1 virus and recent seasonal H1N1 and H3N2 viruses and assessed the associated pro-inflammatory responses. Despite the detection of IAV nucleoprotein in LMEC mono-cultures, there was no evidence for productive infection. In epithelial-endothelial co-cultures, abundant IAV infection of epithelial cells resulted in the breakdown of the epithelial barrier, but infection of LMECs was rarely detected. We observed a significantly higher secretion of pro-inflammatory cytokines in LMECs when co-cultured with IAV-infected epithelial cells than LMEC mono-cultures exposed to IAV. Taken together, our data show that LMECs are abortively infected by IAV but can fuel the inflammatory response.

Curtailing virus-induced inflammation in respiratory infections: emerging strategies for therapeutic interventions

Acute respiratory viral infections (ARVI) are the most common illnesses worldwide. In some instances, mild cases of ARVI progress to hyperinflammatory responses, which are damaging to pulmonary tissue and requiring intensive care. Here we summarize available information on preclinical and clinical effects of XC221GI (1-[2-(1-methyl imidazole-4-yl)-ethyl]perhydroazin-2,6-dione), an oral drug with a favorable safety profile that has been tested in animal models of influenza, respiratory syncytial virus, highly pathogenic coronavirus strains and other acute viral upper respiratory infections. XC221GI is capable of controlling IFN-gamma-driven inflammation as it is evident from the suppression of the production of soluble cytokines and chemokines, including IL-6, IL-8, CXCL10, CXCL9 and CXCL11 as well as a decrease in migration of neutrophils into the pulmonary tissue. An excellent safety profile of XC221GI, which is not metabolized by the liver, and its significant anti-inflammatory effects indicate utility of this compound in abating conversion of ambulatory cases of respiratory infections into the cases with aggravated presentation that require hospitalization. This drug is especially useful when rapid molecular assays determining viral species are impractical, or when direct antiviral drugs are not available. Moreover, XC221GI may be combined with direct antiviral drugs to enhance their therapeutic effects.

Pathogenesis of Anemia in Canine Babesiosis: Possible Contribution of Pro-Inflammatory Cytokines and Chemokines-A Review

Canine babesiosis is a tick-borne protozoan disease caused by intraerythrocytic parasites of the genus Babesia. The infection may lead to anemia in infected dogs. However, anemia is not directly caused by the pathogen. The parasite's developmental stages only have a marginal role in contributing to a decreased red blood cell (RBC) count. The main cause of anemia in affected dogs is the immune response to the infection. This response includes antibody production, erythrophagocytosis, oxidative damage of RBCs, complement activation, and antibody-dependent cellular cytotoxicity. Moreover, both infected and uninfected erythrocytes are retained in the spleen and sequestered in micro-vessels. All these actions are driven by pro-inflammatory cytokines and chemokines, especially IFN-γ, TNF-α, IL-6, and IL-8. Additionally, imbalance between the actions of pro- and anti-inflammatory cytokines plays a role in patho-mechanisms leading to anemia in canine babesiosis. This article is a review of the studies on the pathogenesis of anemia in canine babesiosis and related diseases, such as bovine or murine babesiosis and human or murine malaria, and the role of pro-inflammatory cytokines and chemokines in the mechanisms leading to anemia in infected dogs.

Dynamic Changes in Circulatory Cytokines and Chemokines Levels in Mild to Severe COVID-19 Patients

Immune dysregulation is a key feature of the coronavirus disease-2019 (COVID-19). However, disparities in responses across ethnic groups are underappreciated. This study aimed to determine the relationship between chemokines and cytokines and the severity of COVID-19. Multiplex magnetic bead-based Luminex-100 was used to assess chemokine and cytokine levels in COVID-19 patients at admission (day-1) and after 4 days. The mean age of the patients recruited was 54.3 years, with 19 (63.3%) males. COVID-19 patients had significantly lower lymphocyte, monocyte, hemoglobin and eosinophil levels than controls (p < 0.05). COVID-19 patients showed significantly higher neutrophil levels than controls (p < 0.05). The baseline levels of IL-2, IL-6, IL-8, IL-10, and IFN-α/γ significantly increased in COVID-19 patients (p < 0.05). Chemokine levels (IP-10, MCP-1, MIG, and CCL-5) were significantly in COVID-19 patients. IL-8, IP-10, and MIG levels were significantly higher in the patients with severe COVID-19 (p < 0.05). Individuals with mild COVID-19 showed significantly higher levels of INF-α, IL-2, IL-6, and IL-8, whereas IL-10 levels were significantly lower (p < 0.05). TNF-levels decreased significantly in individuals with severe COVID-19, whereas IL-6, IL-8, and MIG levels increased (p < 0.05). After 4 days, INFα-, IL-2, IL-6, IL-8, IP-10, and MIG levels were significantly higher in patients with mild disease, whereas IL-6, MIG, and TNF-αlevels were significantly higher in patients with severe disease (p < 0.05). Thus, we conclude that COVID-19 is characterized by INF-α/γ, IL-6, IL-10, IP-10, MCP-1, MIG, and CCL5 dysregulation. IL-8, MIG, and IP-10 levels distinguish between moderate and severe COVID-19. Changes in INF-α, IL-2, IL-6, IL-8, IP-10, and MIG levels can be used to monitor disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01108-x.

Patterns of cytokine and chemokine expression in peripheral blood of patients with COVID-19 associated with disease severity

OBJECTIVES

Cytokine dysregulation has been proposed as one of the main culprits for severe COVID-19 and poor prognosis. We examined the parallel presence of lymphopoietic, proinflammatory, Th1, Th2, regulatory cytokines, and chemokines in the serum of 47 patients with mild, moderate, and severe COVID-19 and evaluated the association between cytokine concentrations and disease severity.

METHODS

A multiplex quantitative cytokine analysis ProcartaPlex™ immunoassay was applied, using the Luminex^TM 200X detection system (Invitrogen).

RESULTS

The concentrations of twelve cytokines: IL-18, IFN-gamma, TNF-alpha; IL-21; IL-1alpha, IL-1beta, IL-6, IL-22; IL-10, IL-1RA; IL-7 and IFN-alpha were consistently elevated in the studied serum samples. All examined chemokines-Eotaxin, GRO-alpha, IL-8, IP-10, MCP-1, MIP-1alpha, MIP-1beta, SDF-1alpha, and RANTES, were detectable in all studied groups, confirming their importance in mediating the adaptive immune response regardless of disease severity. The serum concentrations of six mediators: IL-1beta, IL-6, IL-18, IL-10, IL-8, and IP-10, showed statistically significant differences among the groups with different disease severity. IL-6, IL-1beta, and IL-10 were more significantly elevated in severe cases while milder symptoms were associated with lower levels of IL-8 and IP-10.

CONCLUSION

Overall, the studied chemokines demonstrated an associated production in acute COVID-19 infection. A strong correlation was observed between the Th1 mediators IL-18 and IL-10 and the proinflammatory IL-6 in the severe COVID-19 group. Our results indicated that severe COVID-19 was characterized by a dysregulated cytokine pattern whereby the Th1 immune response is outweighed by the immunoregulatory response, while inhibitory signals cannot balance the hyperinflammatory response.

Role of CCL2/CCR2 axis in the pathogenesis of COVID-19 and possible Treatments: All options on the Table

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is cause of the novel coronavirus disease (COVID-19). In the last two years, SARS-CoV-2 has infected millions of people worldwide with different waves, resulting in the death of many individuals. The evidence disclosed that the host immune responses to SARS-CoV-2 play a pivotal role in COVID-19 pathogenesis and clinical manifestations. In addition to inducing antiviral immune responses, SARS-CoV-2 can also cause dysregulated inflammatory responses characterized by the noticeable release of proinflammatory mediators in COVID-19 patients. Among these proinflammatory mediators, chemokines are considered a subset of cytokines that participate in the chemotaxis process to recruit immune and non-immune cells to the site of inflammation and infection. Researchers have demonstrated that monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor (CCR2) are involved in the recruitment of monocytes and infiltration of these cells into the lungs of patients suffering from COVID-19. Moreover, elevated levels of CCL2 have been reported in the bronchoalveolar lavage fluid (BALF) obtained from patients with severe COVID-19, initiating cytokine storm and promoting CD163⁺ myeloid cells infiltration in the airways and further alveolar damage. Therefore, CCL2/CCR axis plays a key role in the immunopathogenesis of COVID-19 and targeted therapy of involved molecules in this axis can be a potential therapeutic approach for these patients. This review discusses the biology of the CCL2/CCR2 axis as well as the role of this axis in COVID-19 immunopathogenesis, along with therapeutic options aimed at inhibiting CCL2/CCR2 and modulating dysregulated inflammatory responses in patients with severe SARS-CoV-2 infection.

CXCL10 Chemokine: A Critical Player in RNA and DNA Viral Infections

Chemokines constitute a group of small, secreted proteins that regulate leukocyte migration and contribute to their activation. Chemokines are crucial inflammatory mediators that play a key role in managing viral infections, during which the profile of chemokine expression helps shape the immune response and regulate viral clearance, improving clinical outcome. In particular, the chemokine ligand CXCL10 and its receptor CXCR3 were explored in a plethora of RNA and DNA viral infections. In this review, we highlight the expression profile and role of the CXCL10/CXCR3 axis in the host defense against a variety of RNA and DNA viral infections. We also discuss the interactions among viruses and host cells that trigger CXCL10 expression, as well as the signaling cascades induced in CXCR3 positive cells.

Human innate lymphoid cell activation by adenoviruses is modified by host defense proteins and neutralizing antibodies

Innate lymphoid cells (ILCs), the complements of diverse CD4 T helper cells, help maintain tissue homeostasis by providing a link between innate and adaptive immune responses. While pioneering studies over the last decade have advanced our understanding how ILCs influence adaptive immune responses to pathogens, far less is known about whether the adaptive immune response feeds back into an ILC response. In this study, we isolated ILCs from blood of healthy donors, fine-tuned culture conditions, and then directly challenged them with human adenoviruses (HAdVs), with HAdVs and host defense proteins (HDPs) or neutralizing antibodies (NAbs), to mimic interactions in a host with pre-existing immunity. Additionally, we developed an ex vivo approach to identify how bystander ILCs respond to the uptake of HAdVs ± neutralizing antibodies by monocyte-derived dendritic cells. We show that ILCs take up HAdVs, which induces phenotypic maturation and cytokine secretion. Moreover, NAbs and HDPs complexes modified the cytokine profile generated by ILCs, consistent with a feedback loop for host antiviral responses and potential to impact adenovirus-based vaccine efficacy.

Preclinical immunogenicity assessment of a cell-based inactivated whole-virion H5N1 influenza vaccine

In influenza vaccine development, Madin–Darby canine kidney (MDCK) cells provide multiple advantages, including large-scale production and egg independence. Several cell-based influenza vaccines have been approved worldwide. We cultured H5N1 virus in a serum-free MDCK cell suspension. The harvested virus was manufactured into vaccines after inactivation and purification. The vaccine effectiveness was assessed in the Wuhan Institute of Biological Products BSL2 facility. The pre- and postvaccination mouse serum titers were determined using the microneutralization and hemagglutination inhibition tests. The immunological responses induced by vaccine were investigated using immunological cell classification, cytokine expression quantification, and immunoglobulin G (IgG) subtype classification. The protective effect of the vaccine in mice was evaluated using challenge test. Antibodies against H5N1 in rats lasted up to 8 months after the first dose. Compared with those of the placebo group, the serum titer of vaccinated mice increased significantly, Th1 and Th2 cells were activated, and CD8+ T cells were activated in two dose groups. Furthermore, the challenge test showed that vaccination reduced the clinical symptoms and virus titer in the lungs of mice after challenge, indicating a superior immunological response. Notably, early after vaccination, considerably increased interferon-inducible protein-10 (IP-10) levels were found, indicating improved vaccine-induced innate immunity. However, IP-10 is an adverse event marker, which is a cause for concern. Overall, in the case of an outbreak, the whole-virion H5N1 vaccine should provide protection.

The Variable Nature of Vitamin C—Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

Urine biomarkers of pulmonary tuberculosis

INTRODUCTION

Sputum-based tuberculosis diagnosis does not address the needs of certain categories of patients. Active development of a noninvasive urine-based diagnosis could provide an alternative approach. We reviewed publications covering more than 30 urine biomarkers proposed as significant for TB diagnosis. Analytical approaches were heterogeneous in design and methods; few studies on diagnostic outcome prediction described a formal specificity and sensitivity analysis.

AREAS COVERED

This review describes studies of non-sputum diagnostic approaches of pulmonary TB based on urine using specific TB biomarkers. The search was performed until December 2021, using terms [Tuberculosis] + [urine] + [biomarkers] in PubMed and Cochrane databases. Publications concerning LAM urine diagnostics were excluded as they have been described elsewhere.

EXPERT OPINION

Microbiological culture of sputum is considered to be the 'gold standard' diagnostic for pulmonary TB but the methodology is slow due to the slow growth of the TB bacteria. Urine provides a large volume of sample. Investigators have evaluated urine for either TB pathogen biomarkers or host biomarkers with some success as the review demonstrates. Detection sensitivity remains a significant problem. In future, combination of host and pathogen biomarkers could increase the sensitivity and specificity of TB diagnosis.

<em>In vitro</em> and <em>in vivo</em> pharmacodynamic activity of the new compound XC221GI in models of the viral inflammation of the respiratory tract

The viruses most commonly affecting the human respiratory tract include rhinoviruses, respiratory syncytial virus (RSV), influenza viruses, and coronaviruses (CoVs). The virus infection of the epithelial cells of the respiratory tract triggers an inflammation accompanied by the release of pro-inflammatory cytokines and chemokines including IL6, IL8(CXCL8), IL1β, and tumor necrosis factor α (TNFα). A subsequent acute inflammatory response in the lungs is accompanied by an increase in the production of cytokines and chemokines − CXCR3 receptor ligands – that are key players of acute inflammatory response that induce an influx of neutrophils and T cells into the lungs.

We studied the pharmacodynamic activity of the new compound XC221GI to suppress the IL6 and IL8 of an experimental RSV infection in vitro in human lung carcinoma cells A549 and in vivo in the lungs of cotton rats. We also studied the effect of XC221GI on the production of the chemokines CXCL10, CXCL9, and CXCL11 in mouse bronchoalveolar lavage as well as on the influx of neutrophils into the mouse lungs after the intranasal administration of interferon γ (IFNγ).

The obtained results demonstrate the anti-inflammatory activity of XC221GI, which suppresses the production of excessive levels of the key inflammatory markers IL6, IL8, CXCL10, CXCL9, and CXCL11 as well as the influx of neutrophils into the lungs thereby reducing lung pathology. These data confirm the effectiveness of XC221GI as a means of preventive anti-inflammatory therapy during a viral infection of the respiratory tract.

Interleukin-6-Production Is Responsible for Induction of Hepatic Synthesis of Several Chemokines as Acute-Phase Mediators in Two Animal Models: Possible Significance for Interpretation of Laboratory Changes in Severely Ill Patients

Simple Summary

The release of acute-phase proteins and cytokine storms are considered critical parameters for the progression of COVID-19 disease. The increase in the serum levels of cytokines such as IL6 and IL8 observed in patients primarily infected with the SARS-CoV-2 virus has been used to determine the severity of clinical conditions resulting from infection and for prognostic purposes. Animal models have been used to understand the mechanisms of the changes in homeostasis observed under pathological conditions. In the present study, we therefore report the changes in serum levels and hepatic gene expression of cytokines and chemokines in two different animal models of acute-phase responses. The acute-phase response is a transient emergency response aimed at preserving life and bringing about the changes necessary to reduce and repair tissue damage after the removal of damaging noxious agents. Our data suggest that the liver may be responsible for the increase in the serum levels of cytokines and chemokines as part of the body’s defense response to tissue damage. It is therefore doubtful that inhibiting this response at any stage after infection could improve the prognosis of patients. These results may help to interpret the laboratory changes observed in critically ill patients, as may be the case following SARS-CoV-2 infection.

Abstract

A mild to moderate increase in acute-phase proteins (APPs) and a decrease in serum albumin levels are detected in hospitalized COVID-19 patients. A similar trend is also observed for acute-phase cytokines (APC), mainly IL6, besides chemokines (e.g., CXCL8 and CCL2). However, the source of the chemokines in these patients at different stages of disease remains to be elucidated. We investigated hepatic gene expression of CXC- and CC-chemokines in a model of a localized extrahepatic aseptic abscess and in a model of septicemia produced by the intramuscular injection of turpentine oil (TO) into each hindlimb or lipopolysaccharide (LPS) intraperitoneally (i.p.) in rats and mice (wild-type (WT) and IL6-KO). Together with a striking increase in the serum IL6 level, strong serum CXCL2 and CXCL8 concentrations were detected. Correspondingly, rapid (2 h) upregulation of CXCL1, CXCL2, CXCL5, and CXCL8 was observed in rat liver after intramuscular TO injection. The induction of the gene expression of CXCL1 and CXCL8 was the fastest and strongest. The hepatic CXC-chemokines behaved like positive APPs that depend on IL6 production by activated macrophages recruited to extrahepatic damaged tissue. Chemokine upregulation was greatly reduced in IL6-KO mice. However, IL6 was dispensable in the LPS–APR model, as massive induction of hepatic chemokines studied was measured in IL6-KO mice.

Immune signature of acute pharyngitis in a Streptococcus pyogenes human challenge trial

Streptococcus pyogenes causes at least 750 million infections and more than 500,000 deaths each year. No vaccine is currently available for S. pyogenes and the use of human challenge models offer unique and exciting opportunities to interrogate the immune response to infectious diseases. Here, we use high-dimensional flow cytometric analysis and multiplex cytokine and chemokine assays to study serial blood and saliva samples collected during the early immune response in human participants following challenge with S. pyogenes. We find an immune signature of experimental human pharyngitis characterised by: 1) elevation of serum IL-1Ra, IL-6, IFN-γ, IP-10 and IL-18; 2) increases in peripheral blood innate dendritic cell and monocyte populations; 3) reduced circulation of B cells and CD4+ T cell subsets (Th1, Th17, Treg, TFH) during the acute phase; and 4) activation of unconventional T cell subsets, γδTCR + Vδ2+ T cells and MAIT cells. These findings demonstrate that S. pyogenes infection generates a robust early immune response, which may be important for host protection. Together, these data will help advance research to establish correlates of immune protection and focus the evaluation of vaccines.

BCG vaccination and the risk of COVID 19: A possible correlation

Bacillus Calmette-Guérin (BCG) vaccine is currently used to prevent tuberculosis infection. The vaccine was found to enhance resistance to certain types of infection including positive sense RNA viruses. The current COVID-19 pandemic is caused by positive sense RNA, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A higher mortality rate of COVID-19 patients was reported in countries where BCG vaccination is not routinely administered, when compared to the vaccinated ones. We hypothesized that BCG vaccine may control SARS-CoV2 infection via modulating the monocyte immune response. We analyzed GSE104149 dataset to investigate whether human monocytes of BCG-vaccinated individuals acquire resistance to SARS-CoV-2 infection. Differentially expressed genes obtained from the dataset were used to determine enriched pathways, biological processes, and molecular functions for monocytes post BCG vaccination. Our data show that BCG vaccine promotes a more effective immune response of monocytes against SARS-CoV2, but probably not sufficient to prevent the infection.

Nature of the Interplay Between Periodontal Diseases and COVID-19

The coronavirus disease 2019 (COVID-19) is mostly a mild condition, however, in some patients, it could progress into a severe and even fatal disease. Recent studies have shown that COVID-19 infection and severity could be associated with the presence of periodontitis, one of the most prevalent chronic diseases. This association could be explained by the fact that periodontitis and COVID-19 share some common risk factors that included chronic diseases, such as diabetes and hypertension as well as conditions such as age, sex, and genetic variants. Another possible explanation could be the systemic inflammation and the aspiration of periodontopathogens seen in patients with periodontitis, which could have a synergism with the virus or compromise the reaction of the body against COVID-19. This narrative review explores the nature of these associations, the evidence behind them, and their implications.

Changes in serum interferon-γ-inducible protein-10 levels and liver stiffness among chronic hepatitis C Egyptian patients in response to directly acting antiviral agents

BACKGROUND

Interferon-γ inducible protein-10 (IP-10) is chemokine biomarker of liver inflammation, elevated in patients with chronic hepatitis C infection.

AIMS

Investigating if changes in serum IP-10 levels in response to directly acting antiviral agents (DAAs) treatment for chronic HCV patients are paralleled by changes in liver stiffness measurements (LSM), and assessing role of using serum IP-10 as a noninvasive accurate method to predict changes in hepatic necro-inflammation and fibrosis.

MATERIAL AND METHODS

A prospective observational study included 92 Egyptian chronic HCV patients, who received treatment with sofosbuvir with daclatasvir regimen. Patients were classified into two groups; group I (53 patients) with non to mild significant liver fibrosis (F0-F1), and group II (39 patients) with significant to advanced liver fibrosis (F2-F4). Fibroscan and serum IP-10 were assessed pretreatment and 3 months after end of treatment.

RESULTS

All patients achieved SVR. Both IP-10 and LSM showed significant decline after treatment in both groups. No significant correlation was found between changes in LSM and IP-10. IP-10 detected liver cirrhosis at cut off level of 17.8 pg/ml, with 75% sensitivity and 73.86% specificity, with area under the curve = 0.66, however, IP-10 had no statistical significance in detecting advanced fibrosis.

CONCLUSION

IP-10 might be of significance as a noninvasive predictor of liver cirrhosis. IP-10 significant decline post-DAAs treatment in chronic HCV genotype IV infected patients reflects significant improvement in fibrosis stage and hepatic necro-inflammation in response to treatment. No significant correlation was detected in the changes of both IP-10 and LSM.

Sex-Related Differences in Innate and Adaptive Immune Responses to SARS-CoV-2

Coronavirus disease 2019 (COVID-19) exhibits a sex bias with males showing signs of more severe disease and hospitalizations compared with females. The mechanisms are not clear but differential immune responses, particularly the initial innate immune response, between sexes may be playing a role. The early innate immune responses to SARS-CoV-2 have not been studied because of the gap in timing between the patient becoming infected, showing symptoms, and getting the treatment. The primary objective of the present study was to compare the response of dendritic cells (DCs) and monocytes from males and females to SARS-CoV-2, 24 h after infection. To investigate this, peripheral blood mononuclear cells (PBMCs) from healthy young individuals were stimulated in vitro with the virus. Our results indicate that PBMCs from females upregulated the expression of HLA-DR and CD86 on pDCs and mDCs after stimulation with the virus, while the activation of these cells was not significant in males. Monocytes from females also displayed increased activation than males. In addition, females secreted significantly higher levels of IFN-α and IL-29 compared with males at 24 h. However, the situation was reversed at 1 week post stimulation and males displayed high levels of IFN-α production compared with females. Further investigations revealed that the secretion of CXCL-10, a chemokine associated with lung complications, was higher in males than females at 24 h. The PBMCs from females also displayed increased induction of CTLs. Altogether, our results suggest that decreased activation of pDCs, mDCs, and monocytes and the delayed and prolonged IFN-α secretion along with increased CXCL-10 secretion may be responsible for the increased morbidity and mortality of males to COVID-19.

A Stronger Innate Immune Response During Hyperacute Human Immunodeficiency Virus Type 1 (HIV-1) Infection Is Associated With Acute Retroviral Syndrome

BACKGROUND

Acute retroviral syndrome (ARS) is associated with human immunodeficiency virus type 1 (HIV-1) subtype and disease progression, but the underlying immunopathological pathways are poorly understood. We aimed to elucidate associations between innate immune responses during hyperacute HIV-1 infection (hAHI) and ARS.

METHODS

Plasma samples obtained from volunteers (≥18.0 years) before and during hAHI, defined as HIV-1 antibody negative and RNA or p24 antigen positive, from Kenya, Rwanda, Uganda, Zambia, and Sweden were analyzed. Forty soluble innate immune markers were measured using multiplexed assays. Immune responses were differentiated into volunteers with stronger and comparatively weaker responses using principal component analysis. Presence or absence of ARS was defined based on 11 symptoms using latent class analysis. Logistic regression was used to determine associations between immune responses and ARS.

RESULTS

Of 55 volunteers, 31 (56%) had ARS. Volunteers with stronger immune responses (n = 36 [65%]) had increased odds of ARS which was independent of HIV-1 subtype, age, and risk group (adjusted odds ratio, 7.1 [95% confidence interval {CI}: 1.7-28.8], P = .003). Interferon gamma-induced protein (IP)-10 was 14-fold higher during hAHI, elevated in 7 of the 11 symptoms and independently associated with ARS. IP-10 threshold >466.0 pg/mL differentiated stronger immune responses with a sensitivity of 84.2% (95% CI: 60.4-96.6) and specificity of 100.0% (95% CI]: 90.3-100.0).

CONCLUSIONS

A stronger innate immune response during hAHI was associated with ARS. Plasma IP-10 may be a candidate biomarker of stronger innate immunity. Our findings provide further insights on innate immune responses in regulating ARS and may inform the design of vaccine candidates harnessing innate immunity.

Pro-inflammatory microenvironment and systemic accumulation of CXCR3+ cell exacerbate lung pathology of old rhesus macaques infected with SARS-CoV-2

Understanding the pathological features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in an animal model is crucial for the treatment of coronavirus disease 2019 (COVID-19). Here, we compared immunopathological changes in young and old rhesus macaques (RMs) before and after SARS-CoV-2 infection at the tissue level. Quantitative analysis of multiplex immunofluorescence staining images of formalin-fixed paraffin-embedded (FFPE) sections showed that SARS-CoV-2 infection specifically induced elevated levels of apoptosis, autophagy, and nuclear factor kappa-B (NF-κB) activation of angiotensin-converting enzyme 2 (ACE2)+ cells, and increased interferon α (IFN-α)- and interleukin 6 (IL-6)-secreting cells and C-X-C motif chemokine receptor 3 (CXCR3)+ cells in lung tissue of old RMs. This pathological pattern, which may be related to the age-related pro-inflammatory microenvironment in both lungs and spleens, was significantly correlated with the systemic accumulation of CXCR3+ cells in lungs, spleens, and peripheral blood. Furthermore, the ratio of CXCR3+ to T-box protein expression in T cell (T-bet)+ (CXCR3+/T-bet+ ratio) in CD8+ cells may be used as a predictor of severe COVID-19. These findings uncovered the impact of aging on the immunopathology of early SARS-CoV-2 infection and demonstrated the potential application of CXCR3+ cells in predicting severe COVID-19.

Cytokine Signature Associated With Disease Severity in COVID-19

Coronavirus disease 2019 (COVID-19) broke out and then became a global epidemic at the end of 2019. With the increasing number of deaths, early identification of disease severity and interpretation of pathogenesis are very important. Aiming to identify biomarkers for disease severity and progression of COVID-19, 75 COVID-19 patients, 34 healthy controls and 23 patients with pandemic influenza A(H1N1) were recruited in this study. Using liquid chip technology, 48 cytokines and chemokines were examined, among which 33 were significantly elevated in COVID-19 patients compared with healthy controls. HGF and IL-1β were strongly associated with APACHE II score in the first week after disease onset. IP-10, HGF and IL-10 were correlated positively with virus titers. Cytokines were significantly correlated with creatinine, troponin I, international normalized ratio and procalcitonin within two weeks after disease onset. Univariate analyses were carried out, and 6 cytokines including G-CSF, HGF, IL-10, IL-18, M-CSF and SCGF-β were found to be associated with the severity of COVID-19. 11 kinds of cytokines could predict the severity of COVID-19, among which IP-10 and M-CSF were excellent predictors for disease severity. In conclusion, the levels of cytokines in COVID-19 were significantly correlated with the severity of the disease in the early stage, and serum cytokines could be used as warning indicators of the severity and progression of COVID-19. Early stratification of disease and intervention to reduce hypercytokinaemia may improve the prognosis of COVID-19 patients.

Antiviral effect of fufang yinhua jiedu (FFYH) granules against influenza A virus through regulating the inflammatory responses by TLR7/MyD88 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fufang-Yinhua-Jiedu Granules (FFYH) optimized from a Yin-Qiao-San, as traditional Chinese medicine (TCM), was used to treat influenza and upper respiratory tract infection and was recommended for the prevention and treatment of SARS in 2003 and current COVID-19 in Anhui Province in 2020.

AIM OF STUDY

In the clinical studies, FFYH was very effective for the treatment of influenza, but the mechanism of action against influenza A virus remains unclear. In the present study, we investigated the antiviral effect of FFYH against influenza A virus in vitro and vivo. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was investigated for the first time.

MATERIALS AND METHODS

CPE inhibition assay and HA assay were used to evaluate the in vitro antiviral effects of FFYH against influenza A virus H1N1, H3N2, H5N1, H7N9 and H9N2. Mice were used to evaluate the antiviral effect of FFYH in vivo with ribavirin and lianhuaqingwen as positive controls. RT-PCR was used to quantify the mRNA transcription of TNF-α, IL-6, IFN-γ, IP10, and IL-1β mRNA. ELISA was used to examine the expression of inflammatory factors such as TNF-α, IL-6, IFN-γ, IP10, and IL-1β in sera. The blood parameters were analyzed with auto hematology analyzer. Moreover, the potential mechanism of FFYH against influenza A virus in vivo was also investigated.

RESULTS

FFYH showed a broad-spectrum of antiviral activity against H1N1, H3N2, H5N1, H7N9, and H9N2 influenza A viruses. Furthermore, FFYH dose-dependently increased the survival rate, significantly prolonged the median survival time of mice, and markedly reduced lung injury caused by influenza A virus. Also, FFYH significantly improve the sick signs, food taken, weight loss, blood parameters, lung index, and lung pathological changes. Moreover, FFYH could markedly inhibit the inflammatory cytokine expression of TNF-α, IL-6, IFN-γ, IP10, IL-10, and IL-1β mRNA or protein via inhibition of the TLR7/MyD88/NF-κB signaling pathway in vivo.

CONCLUSION

FFYH not only showed a broad-spectrum of anti-influenza virus activity in vitro, but also exhibited a significant protective effect against lethal influenza virus infection in vivo. Furthermore, our results indicated that the in vivo antiviral effect of FFYH against influenza virus may be attributed to suppressing the expression of inflammatory cytokines via regulating the TLR7/MyD88/NF-κB signaling pathway. These findings provide evidence for the clinical treatment of influenza A virus infection with FFYH.

Exploratory analysis to identify the best antigen and the best immune biomarkers to study SARS-CoV-2 infection

BACKGROUND

Recent studies proposed the whole-blood based IFN-γ-release assay to study the antigen-specific SARS-CoV-2 response. Since the early prediction of disease progression could help to assess the optimal treatment strategies, an integrated knowledge of T-cell and antibody response lays the foundation to develop biomarkers monitoring the COVID-19. Whole-blood-platform tests based on the immune response detection to SARS-CoV2 peptides is a new approach to discriminate COVID-19-patients from uninfected-individuals and to evaluate the immunogenicity of vaccine candidates, monitoring the immune response in vaccine trial and supporting the serological diagnostics results. Here, we aimed to identify in the whole-blood-platform the best immunogenic viral antigen and the best immune biomarker to identify COVID-19-patients.

METHODS

Whole-blood was overnight-stimulated with SARS-CoV-2 peptide pools of nucleoprotein-(NP) Membrane-, ORF3a- and Spike-protein. We evaluated: IL-1β, IL-1Ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12p70, IL-13, IL- 15, IL-17A, eotaxin, FGF, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF, RANTES, TNF-α, VEGF. By a sparse partial least squares discriminant analysis we identified the most important soluble factors discriminating COVID-19- from NO-COVID-19-individuals.

RESULTS

We identified a COVID-19 signature based on six immune factors: IFN-γ, IP-10 and IL-2 induced by Spike; RANTES and IP-10 induced by NP and IL-2 induced by ORF3a. We demonstrated that the test based on IP-10 induced by Spike had the highest AUC (0.85, p  <  0.0001) and that the clinical characteristics of the COVID-19-patients did not affect IP-10 production. Finally, we validated the use of IP-10 as biomarker for SARS-CoV2 infection in two additional COVID-19-patients cohorts.

CONCLUSIONS

We set-up a whole-blood assay identifying the best antigen to induce a T-cell response and the best biomarkers for SARS-CoV-2 infection evaluating patients with acute COVID-19 and recovered patients. We focused on IP-10, already described as a potential biomarker for other infectious disease such as tuberculosis and HCV. An additional application of this test is the evaluation of immune response in SARS-CoV-2 vaccine trials: the IP-10 detection may define the immunogenicity of a Spike-based vaccine, whereas the immune response to the virus may be evaluated detecting other soluble factors induced by other viral-antigens.

High sensitivity and specificity of a 5-analyte protein and microRNA biosignature for identification of active tuberculosis

Objectives

Non‐sputum‐based tests to accurately identify active tuberculosis (TB) disease and monitor response to therapy are urgently needed. This study examined the biomarker capacity of a panel of plasma proteins alone, and in conjunction with a previously identified miRNA signature, to identify active TB disease.

Methods

The expression of nine proteins (IP‐10, MCP‐1, sTNFR1, RANTES, VEGF, IL‐6, IL‐10, TNF and Eotaxin) was measured in the plasma of 100 control subjects and 100 TB patients, at diagnosis (treatment naïve) and over the course of treatment (1‐, 2‐ and 6‐month intervals). The diagnostic performance of the nine proteins alone, and with the miRNA, was assessed.

Results

Six proteins were significantly up‐regulated in the plasma of TB patients at diagnosis compared to controls. Receiver operator characteristic curve analysis demonstrated that IP‐10 with an AUC = 0.874, sensitivity of 75% and specificity of 87% was the best single biomarker candidate to distinguish TB patients from controls. IP‐10 and IL‐6 levels fell significantly within one month of commencing treatment and may have potential as indicators of a positive response to therapy. The combined protein and miRNA panel gave an AUC of 1.00. A smaller panel of only five analytes (IP‐10, miR‐29a, miR‐146a, miR‐99b and miR‐221) showed an AUC = 0.995, sensitivity of 96% and specificity of 97%.

Conclusions

A novel combination of miRNA and proteins significantly improves the sensitivity and specificity as a biosignature over single biomarker candidates and may be useful for the development of a non‐sputum test to aid the diagnosis of active TB disease.

Broad Impact of Exchange Protein Directly Activated by cAMP 2 (EPAC2) on Respiratory Viral Infections

The recently discovered exchange protein directly activated by cAMP (EPAC), compared with protein kinase A (PKA), is a fairly new family of cAMP effectors. Soon after the discovery, EPAC has shown its significance in many diseases including its emerging role in infectious diseases. In a recent study, we demonstrated that EPAC, but not PKA, is a promising therapeutic target to regulate respiratory syncytial virus (RSV) replication and its associated inflammation. In mammals, there are two isoforms of EPAC-EPAC1 and EPAC2. Unlike other viruses, including Middle East respiratory syndrome coronavirus (MERS-CoV) and Ebola virus, which use EPAC1 to regulate viral replication, RSV uses EPAC2 to control its replication and associated cytokine/chemokine responses. To determine whether EPAC2 protein has a broad impact on other respiratory viral infections, we used an EPAC2-specific inhibitor, MAY0132, to examine the functions of EPAC2 in human metapneumovirus (HMPV) and adenovirus (AdV) infections. HMPV is a negative-sense single-stranded RNA virus belonging to the family Pneumoviridae, which also includes RSV, while AdV is a double-stranded DNA virus. Treatment with an EPAC1-specific inhibitor was also included to investigate the impact of EPAC1 on these two viruses. We found that the replication of HMPV, AdV, and RSV and the viral-induced immune mediators are significantly impaired by MAY0132, while an EPAC1-specific inhibitor, CE3F4, does not impact or slightly impacts, demonstrating that EPAC2 could serve as a novel common therapeutic target to control these viruses, all of which do not have effective treatment and prevention strategies.

Cytokine and chemokine profiles in episodes of persistent high-risk febrile neutropenia in children with cancer

BACKGROUND

In children with cancer and persistent high-risk febrile neutropenia (HRFN), cytokines/chemokines profiles can guide the differentiation of febrile neutropenia (FN) due to infections and episodes of unknown origin (FN-UO).

METHODS

A prospective, multicenter study in Santiago, Chile included patients ≤ 18 years with cancer and HRFN. Clinical and microbiological studies were performed according to validated protocols. Serum levels of 38 cytokines/chemokines were determined on day 4 of persistent HRFN. We performed comparisons between i) HRFN episodes with a detected etiological agent (FN-DEA) and FN-UO, and ii) bacterial versus viral infections. ROC curves were used to assess the discriminatory power of the analytes.

RESULTS

110 HRFN episodes were enrolled (median age 8 years, 53% female). Eighty-four patients were FN-DEA: 44 bacterial, 32 viral, and 8 fungal infections. Twenty-six cases were categorized as FN-UO. Both groups presented similar clinical and laboratory characteristics. Nineteen out of 38 analytes had higher concentrations in the FN-DEA versus FN-UO group. G-CSF, IL-6, and Flt-3L showed the highest discriminatory power to detect infection (AUC 0.763, 0.741, 0.701). Serum levels of G-CSF differentiated bacterial infections and IP-10 viral agents. A combination of G-CSF, IL-6, Flt-3L, and IP-10 showed an AUC of 0.839, 75% sensitivity, and 81% specificity.

CONCLUSION

A specific immune response is present on day four of persistent HRFN in children with cancer. We propose a combined measure of serum concentrations of G-CSF, IL-6, IP-10, and Flt-3L, in order to predict the presence of an infectious agent as compared to an episode of FN with unknown origin.

Ex vivo peripheral blood mononuclear cell response to R848 in children after supplementation with the probiotic Lactobacillus acidophilus NCFM/Bifidobacterium lactis Bi-07

Several studies have demonstrated a decrease in upper respiratory infection (URI) frequency and severity in subjects taking probiotic supplements. We hypothesised beneficial effects of probiotics on viral URI in children are due to modulation of inflammatory innate immune responses. We tested this hypothesis, providing children with a probiotic combination of Lactobacillus acidophilus/Bidfidobacterium animalis ssp. lactis Bi-07 (NCFM/Bi-07) and measuring levels of cytokines in response to stimulation of peripheral blood mononuclear cells (PBMCs) to toll-like receptor (TLR) 7/8 agonist resiquimod (R848). In this open label study, 21 (2 dropouts) children received probiotic containing 5×10⁹ cfu each of NCFM/(Bi-07) daily for 30 days. Whole blood was taken from each subject at study entry and 30 days for culture of PBMCs. PBMCs stimulated with resiquimod (R848) or unstimulated were incubated and a panel of immune markers was measured. There was a significant decrease in the net (stimulated-null) level of myeloid progenitor inhibitory factor 1 (MPIF-1) (mean decrease 0.1 ng/ml, 95% confidence interval 0.01-0.24, P=0.032) following probiotic supplementation. The change in immune marker levels after supplementation, when analysed together with respect to expected inflammatory/anti-inflammatory effects, was increased for interleukin (IL)-10 and decreased for MPIF-1, IL-8, interferon gamma induced protein 10, macrophage inflammatory protein 3 alpha (MIP-3α) and E-selectin (P=0.01). Adverse events were mild. In conclusion, supplementation with this probiotic combination was safe and resulted in significant modulation of PBMC limited immune response to TLR7/8 agonist R848 and in levels of MPIF-1 and MIP-3α. The anti-inflammatory effect may be one mechanism by which probiotics modulate the immune system however further study is needed.

Chemokines and chemokine receptors during COVID-19 infection

Chemokines are crucial inflammatory mediators needed during an immune response to clear pathogens. However, their excessive release is the main cause of hyperinflammation. In the recent COVID-19 outbreak, chemokines may be the direct cause of acute respiratory disease syndrome, a major complication leading to death in about 40% of severe cases. Several clinical investigations revealed that chemokines are directly involved in the different stages of SARS-CoV-2 infection. Here, we review the role of chemokines and their receptors in COVID-19 pathogenesis to better understand the disease immunopathology which may aid in developing possible therapeutic targets for the infection.

A Missing Link: Engagements of Dendritic Cells in the Pathogenesis of SARS-CoV-2 Infections

Dendritic cells (DC) connect the innate and adaptive arms of the immune system and carry out numerous roles that are significant in the context of viral disease. Their functions include the control of inflammatory responses, the promotion of tolerance, cross-presentation, immune cell recruitment and the production of antiviral cytokines. Based primarily on the available literature that characterizes the behaviour of many DC subsets during Severe acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19), we speculated possible mechanisms through which DC could contribute to COVID-19 immune responses, such as dissemination of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to lymph nodes, mounting dysfunctional inteferon responses and T cell immunity in patients. We highlighted gaps of knowledge in our understanding of DC in COVID-19 pathogenesis and discussed current pre-clinical development of therapies for COVID-19.

Interferon-γ-induced protein 10 (IP-10) and serum amyloid A (SAA) are excellent biomarkers for the prediction of COVID-19 progression and severity

Aims

Early diagnosis and appropriate treatment are essential in reducing the morbidity and mortality of COVID-19-infected patients. The current study aimed to measure the levels of serum IP-10 and SAA in positive COVID-19 Egyptian patients to explore their clinical values and significance in discrimination between moderate and severe COVID-19 infection and predicting the severity and prognosis of COVID-19 disease.

Main methods

A total of 150 COVID-19 patients and 50 controls were enrolled into our study. Beside the routine lab work of positive COVID-19 patients; IP-10 and SAA were measured using ELISA kit.

Key findings

Our results revealed that the levels of D-dimer (2.64 ± 3.34), ferritin (494.11 ± 260.96), SAA (171.89 ± 51.96), IP-10 (405.0 ± 85.27), WBCs count (14.38 ± 6.06) and neutrophils count (79.26 ± 5.57) were highly significantly increased in severe to critically severe patients when compared with mild to moderate patients; while lymphocytes count (14.21 ± 5.13) was highly significantly decreased when compared to moderate patients. ROC curve analysis results showed that AUC from high to low was IP-10 ˃ SAA ˃ Ferritin ˃ D-dimer ˃ CRP.

Significance

From these results we can conclude that both IP-10 and SAA could be excellent biomarkers in discrimination between moderate and severe COVID-19 infection and predicting the severity and prognosis of COVID-19 disease.

Prognostic Accuracy of Soluble Triggering Receptor Expressed on Myeloid Cells (sTREM-1)-based Algorithms in Febrile Adults Presenting to Tanzanian Outpatient Clinics

BACKGROUND

The inability to identify individuals with acute fever at risk of death is a barrier to effective triage and management of severe infections, especially in low-resource settings. Since endothelial and immune activation contribute to the pathogenesis of various distinct life-threatening infections, we hypothesized that measuring mediators of these pathways at clinical presentation would identify febrile adults at risk of death.

METHODS

Plasma concentrations of markers of endothelial (angiopoetin-1/2, soluble fms-like tyrosine kinase-1, soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1) and immune (soluble triggering receptor expressed on myeloid cells [sTREM-1], interleukin-6, interleukin-8, chitinase-3-like protein-1, soluble tumor necrosis factor receptor-1, procalcitonin [PCT], C-reactive protein [CRP]) activation pathways were determined in consecutive adults with acute fever (≥38°C) at presentation to outpatient clinics in Dar es Salaam, Tanzania. We evaluated the accuracy of these mediators in predicting all-cause mortality and examined whether markers could improve the prognostic accuracy of clinical scoring systems, including the quick sequential organ failure assessment (qSOFA) and Glasgow coma scale (GCS).

RESULTS

Of 507 febrile adults, 32 died (6.3%) within 28 days of presentation. We found that sTREM-1 was the best prognostic marker for 28-day mortality (area under the receiver operating characteristic [AUROC] 0.87, 95% confidence interval [CI] 0.81-0.92) and was significantly better than CRP (P < .0001) and PCT (P = .0001). The prognostic accuracy of qSOFA and the GCS were significantly enhanced when sTREM-1 was added (0.80 [95% CI 0.76-0.83] to 0.91 [95% CI 0.88-0.94; P < .05] and 0.72 [95% CI 0.63-0.80] to 0.94 [95% CI 0.91-0.97; P < .05], respectively).

CONCLUSIONS

Measuring sTREM-1 at clinical presentation can identify febrile individuals at risk of all-cause febrile mortality. Adding severity markers such as sTREM-1 to simple clinical scores could improve the recognition and triage of patients with life-threatening infections in resource-limited settings.

Mindfulness-based programmes for mental health promotion in adults in nonclinical settings: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

There is an urgent need for mental health promotion in nonclinical settings. Mindfulness-based programmes (MBPs) are being widely implemented to reduce stress, but a comprehensive evidence synthesis is lacking. We reviewed trials to assess whether MBPs promote mental health relative to no intervention or comparator interventions.

METHODS AND FINDINGS

Following a detailed preregistered protocol (PROSPERO CRD42018105213) developed with public and professional stakeholders, 13 databases were searched to August 2020 for randomised controlled trials (RCTs) examining in-person, expert-defined MBPs in nonclinical settings. Two researchers independently selected, extracted, and appraised trials using the Cochrane Risk-of-Bias Tool 2.0. Primary outcomes were psychometrically validated anxiety, depression, psychological distress, and mental well-being questionnaires at 1 to 6 months after programme completion. Multiple testing was performed using p < 0.0125 (Bonferroni) for statistical significance. Secondary outcomes, meta-regression and sensitivity analyses were prespecified. Pairwise random-effects multivariate meta-analyses and prediction intervals (PIs) were calculated. A total of 11,605 participants in 136 trials were included (29 countries, 77% women, age range 18 to 73 years). Compared with no intervention, in most but not all scenarios MBPs improved average anxiety (8 trials; standardised mean difference (SMD) = -0.56; 95% confidence interval (CI) -0.80 to -0.33; p-value < 0.001; 95% PI -1.19 to 0.06), depression (14 trials; SMD = -0.53; 95% CI -0.72 to -0.34; p-value < 0.001; 95% PI -1.14 to 0.07), distress (27 trials; SMD = -0.45; 95% CI -0.58 to -0.31; p-value < 0.001; 95% PI -1.04 to 0.14), and well-being (9 trials; SMD = 0.33; 95% CI 0.11 to 0.54; p-value = 0.003; 95% PI -0.29 to 0.94). Compared with nonspecific active control conditions, in most but not all scenarios MBPs improved average depression (6 trials; SMD = -0.46; 95% CI -0.81 to -0.10; p-value = 0.012, 95% PI -1.57 to 0.66), with no statistically significant evidence for improving anxiety or distress and no reliable data on well-being. Compared with specific active control conditions, there is no statistically significant evidence of MBPs' superiority. Only effects on distress remained when higher-risk trials were excluded. USA-based trials reported smaller effects. MBPs targeted at higher-risk populations had larger effects than universal MBPs. The main limitation of this review is that confidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is moderate to very low, mainly due to inconsistency and high risk of bias in many trials.

CONCLUSIONS

Compared with taking no action, MBPs of the included studies promote mental health in nonclinical settings, but given the heterogeneity between studies, the findings do not support generalisation of MBP effects across every setting. MBPs may have specific effects on some common mental health symptoms. Other preventative interventions may be equally effective. Implementation of MBPs in nonclinical settings should be partnered with thorough research to confirm findings and learn which settings are most likely to benefit.

Tryptanthrin suppresses double-stranded RNA-induced CXCL10 expression via inhibiting the phosphorylation of STAT1 in human umbilical vein endothelial cells

Tryptanthrin is a bioactive component of indigo plants such as Polygonum tinctrorium and known to have an anti-inflammatory activity. The aim of this study was to investigate the effects of tryptanthrin on Toll-like receptor 3 (TLR3)-mediated cytokine and chemokine expression in human umbilical vein endothelial cells (HUVEC). Herein, we found that tryptanthrin suppressed the expression of CXCL10 in HUVEC upon stimulation with a TLR3 ligand polyinosinic-polycytidylic acid (poly IC). Tryptanthrin did not inhibit poly IC-induced activation of interferon regulatory factor 3 (IRF3) or the mRNA expression of interferon (IFN)-β, while it significantly suppressed the expression of RIG-I, MDA5, and classical IFN-stimulated genes (ISGs). Tryptanthrin attenuated the phosphorylation and nuclear translocation of STAT1 in HUVEC stimulated with not only poly IC but also recombinant IFN-β. These results suggested that tryptanthrin inhibited poly IC-induced expression of CXCL10 and ISGs via suppressing the activation of STAT1 in HUVEC. Our findings indicate that tryptanthrin may be useful for regulating TLR3-mediated vascular inflammation.

Severe COVID-19: what have we learned with the immunopathogenesis?

The COVID-19 outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global major concern. In this review, we addressed a theoretical model on immunopathogenesis associated with severe COVID-19, based on the current literature of SARS-CoV-2 and other epidemic pathogenic coronaviruses, such as SARS and MERS. Several studies have suggested that immune dysregulation and hyperinflammatory response induced by SARS-CoV-2 are more involved in disease severity than the virus itself.Immune dysregulation due to COVID-19 is characterized by delayed and impaired interferon response, lymphocyte exhaustion and cytokine storm that ultimately lead to diffuse lung tissue damage and posterior thrombotic phenomena.Considering there is a lack of clinical evidence provided by randomized clinical trials, the knowledge about SARS-CoV-2 disease pathogenesis and immune response is a cornerstone to develop rationale-based clinical therapeutic strategies. In this narrative review, the authors aimed to describe the immunopathogenesis of severe forms of COVID-19.

Longitudinal COVID-19 profiling associates IL-1RA and IL-10 with disease severity and RANTES with mild disease

BACKGROUND

Identifying immune correlates of COVID-19 disease severity is an urgent need for clinical management, vaccine evaluation, and drug development. Here, we present a temporal analysis of key immune mediators, cytokines, and chemokines in blood of hospitalized COVID-19 patients from serial sampling and follow-up over 4 weeks.

METHODS

A total of 71 patients with laboratory-confirmed COVID-19 admitted to Beijing You'an Hospital in China with either mild (53 patients) or severe (18 patients) disease were enrolled with 18 healthy volunteers. We measured 34 immune mediators, cytokines, and chemokines in peripheral blood every 4-7 days over 1 month per patient using a bioplex multiplex immunoassay.

RESULTS

We found that the chemokine RANTES (CCL5) was significantly elevated, from an early stage of the infection, in patients with mild but not severe disease. We also found that early production of inhibitory mediators including IL-10 and IL-1RA were significantly associated with disease severity, and a combination of CCL5, IL-1 receptor antagonist (IL-1RA), and IL-10 at week 1 may predict patient outcomes. The majority of cytokines that are known to be associated with the cytokine storm in virus infections such as IL-6 and IFN-γ were only significantly elevated in the late stage of severe COVID-19 illness. TNF-α and GM-CSF showed no significant differences between severe and mild cases.

CONCLUSION

Together, our data suggest that early intervention to increase expression of CCL5 may prevent patients from developing severe illness. Our data also suggest that measurement of levels of CCL5, as well as IL-1RA and IL-10 in blood individually and in combination, might be useful prognostic biomarkers to guide treatment strategies.

The cytokine storm in COVID-19: An overview of the involvement of the chemokine/chemokine-receptor system

In 2019-2020 a new coronavirus named SARS-CoV-2 was identified as the causative agent of a several acute respiratory infection named COVID-19, which is causing a worldwide pandemic. There are still many unresolved questions regarding the pathogenesis of this disease and especially the reasons underlying the extremely different clinical course, ranging from asymptomatic forms to severe manifestations, including the Acute Respiratory Distress Syndrome (ARDS). SARS-CoV-2 showed phylogenetic similarities to both SARS-CoV and MERS-CoV viruses, and some of the clinical features are shared between COVID-19 and previously identified beta-coronavirus infections. Available evidence indicate that the so called "cytokine storm" an uncontrolled over-production of soluble markers of inflammation which, in turn, sustain an aberrant systemic inflammatory response, is a major responsible for the occurrence of ARDS. Chemokines are low molecular weight proteins with powerful chemoattractant activity which play a role in the immune cell recruitment during inflammation. This review will be aimed at providing an overview of the current knowledge on the involvement of the chemokine/chemokine-receptor system in the cytokine storm related to SARS-CoV-2 infection. Basic and clinical evidences obtained from previous SARS and MERS epidemics and available data from COVID-19 will be taken into account.

ISG56 is involved in CXCL10 expression induced by TLR3 signaling in BEAS-2B bronchial epithelial cells

Purpose and aim of the study: Bronchial epithelial cells play an important role in immune response against viral infections. Toll-like receptor 3 (TLR3) is a pathogen recognition receptor that recognizes viral double-stranded RNA (dsRNA). Activation of TLR3 induces the expression of interferon (IFN)-β, and newly synthesized IFN-β exhibits anti-viral activity by upregulating the expression of IFN-stimulated genes (ISGs). ISG56 encodes a multifunctional protein with tetratricopeptide motifs and is involved in anti-viral reactions through various mechanisms. Expression of chemokines such as CXCL10, which induces leukocyte chemotaxis, is essential for defense against airway microbes. However, regulation of chemokine expression by ISG56 in bronchial epithelial cells has not been fully investigated. The aim of this study was to examine the expression of ISG56 and its role in CXCL10 production in BEAS-2B bronchial epithelial cells treated with dsRNA.Materials and methods: BEAS-2B bronchial epithelial cells were treated with polyinosinic-polycytidylic acid (poly IC), a synthetic TLR3 ligand. The mRNA and protein expression levels of ISG 56 were analyzed by quantitative reverse transcription polymerase chain reaction and western blotting. The effect of knocking down TLR3, IFN-β, and ISG56 was examined using RNA interference. The protein expression of CXCL10 in culture medium was measured using an enzyme-linked immunosorbent assay.Results: Poly IC induced ISG56 expression in a concentration- and time- dependent manner. RNA interference showed that ISG56 induction was inhibited by knockdown of TLR3 or IFN-β and that ISG 56 knockdown decreased CXCL10 expression.Conclusions: ISG56 was induced by poly IC through TLR3/IFN-β axis, and ISG56 may positively regulated CXCL10 expression in BEAS-2B cells. ISG56 may modulate anti-viral innate immunity, at least in part, by regulating the expression of CXCL10 in bronchial epithelial cells.

Evaluation of cytokine levels using QuantiFERON-TB Gold Plus in patients with active tuberculosis

OBJECTIVES

A recently released new QuantiFERON (QFT) product, QFT TB Gold plus (QFT-plus), is optimized for both CD4 and CD8 responses and reported to have higher sensitivity compared to the former QFT-3 G. Previously, using supernatants of QFT-3 G, we and others have demonstrated that cytokines other than IFN-γ may be useful in diagnosing tuberculosis. The present study aimed to identify cytokines that are useful for accurately diagnosing active tuberculosis by using QFT-plus and compared the data to those with QFT-3 G.

METHODS

Eighty-three active tuberculosis patients and 70 healthy control subjects who were examined by QFT at Tokyo National Hospital from June 2017 to July 2018 were enrolled. QFT-3 G and QFT-plus were performed according to the manufacturer's instructions. At the same time, blood cell culture supernatants were collected and assayed for their cytokine levels using R&D Systems Luminex Assay and MAGPIX System. The levels of cytokines were compared between different antigen-containing tubes (3 G Ag, TB1 and TB2 tubes), as well as between the patients and the control subjects. ROC curves were drawn, and the AUCs were calculated.

RESULTS

Five cytokines, i.e., IL-2, IL-6, IL-8, IP-10 and MIP-1β, produced by human blood cells in three independent tubes containing different tuberculosis antigens were higher in the 3 G Ag tube compared to both the TB1 and TB2 tubes. Further, when the TB1 and TB2 tubes were compared, TB2 showed greater production of only PDGF-BB, and less production of IL-6 and TNF-α. For diagnosing active tuberculosis, the levels of IP-10 were superior to the level of IFN-γ based on showing a larger AUC for ROC curves in our present study setting. Finally, the levels of IFN-γ, IL-1RA, IL-2, IP-10, MCP-1 and MIP-1β were distinctly different between the active tuberculosis patients and healthy controls.

CONCLUSIONS

In summary, there was no cytokine that was higher in the tubes of QFT-plus compared to the tube of QFT-3 G, suggesting inferiority of QFT-plus antigens to 3 G Ag in terms of elicitation of cytokine production. Our results also suggest the usefulness of cytokines that showed a significant difference between the active tuberculosis patients and the healthy controls-namely, IFN-γ, IL-1RA, IL-2, IP-10, MCP-1 and MIP-1β-for diagnosing tuberculosis, but the roles of these cytokines in the pathogenesis of tuberculosis need to be elucidated (UMIN000035253).

Nasal epithelial cells to assess in vitro immune responses to respiratory virus infection in pregnant women with asthma

Respiratory virus-induced asthma exacerbations occur frequently during pregnancy and are associated with adverse outcomes for mother and child. Primary nasal epithelial cells (pNECs) provide a useful method to study immune responses in pregnancy. pNECs were obtained by nasal brushings from pregnant and non-pregnant women with and without asthma. pNECS were infected in vitro with major group Rhinovirus 43 (RV43) and seasonal influenza (H3N2). Following infection, pNECs showed measurable quantities of interferon (IFN)-λ, IL-1β, IL-8, IP-10 and MIP1-α. pNECs provide a safe and effective method for studying respiratory epithelial cell responses during pregnancy.

HNL (Human Neutrophil Lipocalin) and a multimarker approach to the distinction between bacterial and viral infections

OBJECTIVES

The distinction between bacterial and viral causes of acute infections is a major clinical challenge. In this report we investigate the diagnostic performance in this regard of nine candidate biomarkers together with HNL (Human Neutrophil Lipocalin).

METHODS

Blood was obtained from patients with symptoms of infectious (n = 581). HNL was measured in whole blood (B-HNL) after pre-activation with the neutrophil activator fMLP or in plasma (P-HNL). Azurocidin also known as heparin-binding protein (HBP), Calprotectin, PMN-CD64, CRP (C-reactive protein), IP-10 (Interferon γ-induced Protein 10 kDa), PCT (Procalcitonin), TK1 (Thymidine kinase 1), TRAIL (TNF-related apoptosis-inducing ligand) were measured in plasma/serum. Area under the ROC (receiver operating characteristics) curve (AuROC) was used for the evaluation of the clinical performance of the biomarkers.

RESULTS

Side-by-side comparisons of the ten biomarkers showed large difference in the AuROC with B-HNL being the superior biomarker (0.91, 95% CI 0.86-0.95) and with the other nine biomarkers varying from AuROC of 0.63-0.79. The combination of B-HNL with IP-10 and/or TRAIL increased the diagnostic performance further to AuROCs of 0.94-0.97. The AuROCs of the combination of CRP with IP-10 and/or TRAIL were significantly lower than combinations with B-HNL 0.87 (95% CI 0.83-0.91).

CONCLUSION

The diagnostic performance of whole blood activated HNL was superior in the distinction between bacterial or viral infections. The addition of IP-10 and/or TRAIL to the diagnostic algorithm increased the performance of B-HNL further. The rapid analysis of HNL, reflecting bacterial infections, together with biomarkers reflecting viral infections may be the ideal combination of diagnostic biomarkers of acute infections.

Celiac Disease in Children, Particularly with Accompanying Type 1 Diabetes, Is Characterized by Substantial Changes in the Blood Cytokine Balance, Which May Reflect Inflammatory Processes in the Small Intestinal Mucosa

Cytokines play a pivotal role in the maintenance of intestinal homeostasis inducing pro- or anti-inflammatory response and mucosal barrier function in celiac disease (CD) and type 1 diabetes (T1D). We aimed to compare the levels of pro- and anti-inflammatory cytokines in CD patients without and with coexisting T1D, as well as to evaluate its association with the presence of enteroviruses (EV), regulatory T cells (Tregs), and dendritic cells (DCs) in small bowel mucosa. Altogether, 72 patients (median age 10.1 years) who had undergone small bowel biopsy were studied. The study group consisted of 24 patients with CD (median age 6.5 years), 9 patients with CD and concomitant T1D (median age 7.0 years), two patients with T1D (median age 8.5 years), and 37 patients (median age 14.0 years) with functional gastrointestinal disorders (FGD) and a normal small bowel mucosa as controls. The levels of 33 cytokines in serum were measured by multiple analysis using the Milliplex® MAP Magnetic Bead assay. The densities of FOXP3+ Tregs, CD11c+ DC, indoleamine 2,3-dioxygenase+ (IDO+) DC, langerin+ (CD207+) DCs, and EV were evaluated by immunohistochemistry as described in our previous studies. Circulating anti-EV IgA and IgG were evaluated using ELISA. The most important finding of the study is the significant increase of the serum levels of IL-5, IL-8, IL-13, IL-15, IL-17F, IL-22, IL-27, IP-10, MIP-1β, sIL-2Rα, sTNFRII, and TNFα in CD patients compared to controls and its correlation with the degree of small bowel mucosa damage graded according to the Marsh classification. The leptin level was higher in females in all study groups. The levels of IL-2, IL-6, IL-12 (P70), IL-15, IP-10, and IFNγ correlated significantly with the density of FOXP3+ Tregs in lamina propria of the small bowel mucosa, which supports the evidence about the signaling role of these cytokines in the peripheral maintenance of FOXP3+ Tregs. At the same time, a significant negative correlation occurred between the level of IL-4 and density of FOXP3+ Tregs in controls. Another important finding of our study was the correlation of IL-17F, IP-10, sTNFRII, MCP-1, and GM-CSF with the density of EV-positive cells in the lamina propria of the small bowel mucosa. Correlation of MIP-1 (CCL-4) with CD103+ DC and langerin+ DC densities may point to their significance in the recruitment of immune cells into the lamina propria and in driving the inflammatory response in CD patients. Our results suggest the predominance of Th1 and Th17 immune responses over EV VP1 protein in CD and T1D patients. The significant elevation of Th2 cytokines, like IL-5 and IL-13, but not IL-4, in CD patients and its correlation with the degree of small bowel mucosa damage could reflect the role of these cytokines in gut defense and inflammation.

A possible link between recurrent upper respiratory tract infections and lower cytokine production in patients with Q fever fatigue syndrome

Besides fatigue, many Q fever fatigue syndrome (QFS) patients also complain of frequently recurring upper respiratory tract infections with severe symptoms. We investigated whether immunologic dysregulation contributes to these complaints. Cytokine and chemokine production was measured after stimulating monocytes of QFS patients and age‐ and sex‐matched healthy controls with LPS and several viral ligands. The H3K4me3 mark of open chromatin was measured at the promoter regions of cytokines and chemokines that differed significantly from healthy controls. Monocytes of QFS patients produced significantly less TNF‐α (p = 0.032), IL‐1β (0.004, 0.024, and 0.008), IL‐6 (0.043), RANTES (0.033), IP‐10 (0.049), MCP‐1 (0.022), IL‐ 13 (0.029), and IL‐10 (0.026) than healthy controls when stimulated with various ligands. H3K4me3 expression was significantly lower in QFS patients than in healthy controls on the promoter regions of IL‐1β (p = 0.004), MCP‐1 (<0.001 and <0.001), IP‐10 (<0.001), IL‐10 (0.041), and IL‐13 (<0.001, <0.001, and 0.001). QFS patients showed diminished cytokine responses to various stimuli compared to age‐ and sex‐matched healthy controls, likely due to epigenetic remodeling and long‐term memory as a result from the acute Q fever infection. This might explain the upper respiratory tract ailments in QFS.