Cytokine levels during symptomatic viral upper respiratory tract infection

The Picornaviridae Family: Knowledge Gaps, Animal Models, Countermeasures, and Prototype Pathogens

Picornaviruses are nonenveloped particles with a single-stranded RNA genome of positive polarity. This virus family includes poliovirus, hepatitis A virus, rhinoviruses, and Coxsackieviruses. Picornaviruses are common human pathogens, and infection can result in a spectrum of serious illnesses, including acute flaccid myelitis, severe respiratory complications, and hand-foot-mouth disease. Despite research on poliovirus establishing many fundamental principles of RNA virus biology and the first transgenic animal model of disease for infection by a human virus, picornaviruses are understudied. Existing knowledge gaps include, identification of molecules required for virus entry, understanding cellular and humoral immune responses elicited during virus infection, and establishment of immune-competent animal models of virus pathogenesis. Such knowledge is necessary for development of pan-picornavirus countermeasures. Defining enterovirus A71 and D68, human rhinovirus C, and echoviruses 29 as prototype pathogens of this virus family may provide insight into picornavirus biology needed to establish public health strategies necessary for pandemic preparedness.

The Role of Innate Immunity and Bioactive Lipid Mediators in COVID-19 and Influenza

In this review, we discuss spatiotemporal kinetics and inflammatory signatures of innate immune cells specifically found in response to SARS-CoV-2 compared to influenza virus infection. Importantly, we cover the current understanding on the mechanisms by which SARS-CoV-2 may fail to engage a coordinated type I response and instead may lead to exaggerated inflammation and death. This knowledge is central for the understanding of available data on specialized pro-resolving lipid mediators in severe SARS-CoV-2 infection pointing toward inhibited E-series resolvin synthesis in severe cases. By investigating a publicly available RNA-seq database of bronchoalveolar lavage cells from patients affected by COVID-19, we moreover offer insights into the regulation of key enzymes involved in lipid mediator synthesis, critically complementing the current knowledge about the mediator lipidome in severely affected patients. This review finally discusses different potential approaches to sustain the synthesis of 3-PUFA-derived pro-resolving lipid mediators, including resolvins and lipoxins, which may critically aid in the prevention of acute lung injury and death from COVID-19.

Cognitive reappraisal and nasal cytokine production following experimental rhinovirus infection

Following exposure to the common cold (i.e., rhinovirus), locally produced nasal cytokines (rather than the infection itself) drive the progression of one's symptoms (Hendley et al., 1973; Cohen et al., 1999). Stress-induced local inflammation exacerbates local cytokine production (e.g., marital hostility; Kiecolt-Glaser et al., 2005). An individual's ability to effectively manage their emotions is a critical component of positive health and well-being. Here, we evaluated whether one's self-reported frequency of cognitive reappraisal, an adaptive emotion regulation strategy, predicts nasal cytokine production following experimental rhinovirus exposure. Emotion regulation strategies were assessed at baseline prior to experimental infection. After the baseline assessment, each participant was exposed to a strain of rhinovirus (RV-39) and followed for 5 days in quarantine. Nasal interleukin (IL)-1β, IL-6, and IL-8 and subjective symptoms were assessed at baseline and on each of the 5 days of quarantine. A multilevel analysis of the data for 159 participants with documented infection demonstrated that less frequent use of cognitive reappraisal predicted heightened production of the nasal cytokine composite. Those who self-reported using cognitive reappraisal strategies less frequently displayed elevated nasal IL-6 and IL-8. Among the 63 participants with clinical cold, less frequent use of cognitive reappraisal was associated with heightened production of nasal IL-1β, IL-6, and IL-8. In ancillary analyses, the composite of nasal cytokines was associated with the severity of one's subjective symptoms across the 5 days. Findings suggest that emotion regulation strategies, particularly cognitive reappraisal, influence illness trajectories during rhinovirus infection.

Transcriptomic Analysis Reveals Priming of The Host Antiviral Interferon Signaling Pathway by Bronchobini® Resulting in Balanced Immune Response to Rhinovirus Infection in Mouse Lung Tissue Slices

Rhinovirus (RV) is the predominant virus causing respiratory tract infections. Bronchobini^® is a low dose multi component, multi target preparation used to treat inflammatory respiratory diseases such as the common cold, described to ease severity of symptoms such as cough and viscous mucus production. The aim of the study was to assess the efficacy of Bronchobini^® in RV infection and to elucidate its mode of action. Therefore, Bronchobini^®’s ingredients (BRO) were assessed in an ex vivo model of RV infection using mouse precision-cut lung slices, an organotypic tissue capable to reflect the host immune response to RV infection. Cytokine profiles were assessed using enzyme-linked immunosorbent assay (ELISA) and mesoscale discovery (MSD). Gene expression analysis was performed using Affymetrix microarrays and ingenuity pathway analysis. BRO treatment resulted in the significant suppression of RV-induced antiviral and pro-inflammatory cytokine release. Transcriptome analysis revealed a multifactorial mode of action of BRO, with a strong inhibition of the RV-induced pro-inflammatory and antiviral host response mediated by nuclear factor kappa B (NFkB) and interferon signaling pathways. Interestingly, this was due to priming of these pathways in the absence of virus. Overall, BRO exerted its beneficial anti-inflammatory effect by priming the antiviral host response resulting in a reduced inflammatory response to RV infection, thereby balancing an otherwise excessive inflammatory response.

Clinical and molecular epidemiology of human rhinovirus infections in patients with hematologic malignancy

BACKGROUND

Human rhinoviruses (HRVs) are common causes of upper respiratory tract infection (URTI) in hematologic malignancy (HM) patients. Predictors of lower respiratory tract infection (LRTI) including the impact of HRV species and types are poorly understood.

OBJECTIVES

This study aims to describe the clinical and molecular epidemiology of HRV infections among HM patients.

STUDY DESIGN

From April 2012-March 2013, HRV-positive respiratory specimens from symptomatic HM patients were molecularly characterized by analysis of partial viral protein 1 (VP1) or VP4 gene sequence. HRV LRTI risk-factors and outcomes were analyzed using multivariable logistic regression.

RESULTS

One hundred and ten HM patients presented with HRV URTI (n=78) and HRV LRTI (n=32). Hypoalbuminemia (OR 3.0; 95% CI, 1.0-9.2; p=0.05) was independently associated with LRTI, but other clinical and laboratory markers of host immunity did not differ between patients with URTI versus LRTI. Detection of bacterial co-pathogens was common in LRTI cases (25%). Among 92 typeable respiratory specimens, there were 58 (64%) HRV-As, 12 (13%) HRV-Bs, and 21 (23%) HRV-Cs, and one Enterovirus 68. LRTI rates among HRV-A (29%), HRV-B (17%), and HRV-C (29%) were similar. HRV-A infections occurred year-round while HRV-B and HRV-C infections clustered in the late fall and winter.

CONCLUSIONS

HRVs are associated with LRTI in HM patients. Illness severity is not attributable to specific HRV species or types. The frequent detection of bacterial co-pathogens in HRV LRTIs further substantiates the hypothesis that HRVs predispose to bacterial superinfection of the lower airways, similar to that of other community-acquired respiratory viruses.

George K, Walsh TJ. Human rhinoviruses

Human rhinoviruses (HRVs), first discovered in the 1950s, are responsible for more than one-half of cold-like illnesses and cost billions of dollars annually in medical visits and missed days of work. Advances in molecular methods have enhanced our understanding of the genomic structure of HRV and have led to the characterization of three genetically distinct HRV groups, designated groups A, B, and C, within the genus Enterovirus and the family Picornaviridae. HRVs are traditionally associated with upper respiratory tract infection, otitis media, and sinusitis. In recent years, the increasing implementation of PCR assays for respiratory virus detection in clinical laboratories has facilitated the recognition of HRV as a lower respiratory tract pathogen, particularly in patients with asthma, infants, elderly patients, and immunocompromised hosts. Cultured isolates of HRV remain important for studies of viral characteristics and disease pathogenesis. Indeed, whether the clinical manifestations of HRV are related directly to viral pathogenicity or secondary to the host immune response is the subject of ongoing research. There are currently no approved antiviral therapies for HRVs, and treatment remains primarily supportive. This review provides a comprehensive, up-to-date assessment of the basic virology, pathogenesis, clinical epidemiology, and laboratory features of and treatment and prevention strategies for HRVs.

Effects of Echinaforce® treatment on ex vivo-stimulated blood cells

The herb Echinacea purpurea, also called purple coneflower, is regarded as an immune modulator. This study examined changes in cytokine production in blood samples from 30 volunteers before and during 8-day oral administration with an ethanolic extract of fresh Echinacea purpurea (Echinaforce(®)). Daily blood samples were ex vivo stimulated by LPS/SEB or Zymosan and analysed for a series of cytokines and haematological and metabolic parameters. Treatment reduced the proinflammatory mediators TNF-α and IL-1β by up to 24% (p<0.05) and increased anti-inflammatory IL-10 levels by 13% (p<0.05) in comparison to baseline. This demonstrated a substantial overall anti-inflammatory effect of Echinaforce(®) for the whole group (n=28). Chemokines MCP-1 and IL-8 were upregulated by 15% in samples from subjects treated with Echinaforce(®) (p<0.05). An analysis of a subgroup of volunteers who showed low pre-treatment levels of the cytokines MCP-1, IL-8, IL-10 or IFN-γ (n=8) showed significant stimulation of these factors upon Echinaforce(®) treatment (30-49% increases; p<0.05), whereas the levels in subjects with higher pre-treatment levels remained unaffected. We chose the term "adapted immune-modulation" to describe this observation. Volunteers who reported high stress levels (n=7) and more than 2 colds per year experienced a significant transient increase in IFN-γ upon Echinaforce(®) treatment (>50%). Subjects with low cortisol levels (n=11) showed significant down-regulation of the acute-phase proteins IL1-β, IL-6, IL-12 and TNF-α by Echinaforce(®) (range, 13-25%), while subjects with higher cortisol levels showed no such down-regulation. This is the first ex vivo study to demonstrate adapted immune-modulation by an Echinacea preparation. While Echinaforce(®) did not affect leukocyte counts, we speculate that the underlying therapeutic mechanism is based on differential multi-level modulation of the responses of the different types of leukocytes. Echinaforce(®) thus regulates the production of chemokines and cytokines according to current immune status, such as responsiveness to exogenous stimuli, susceptibility to viral infection and exposure to stress.

Oxymetazoline modulates proinflammatory cytokines and the T-cell stimulatory capacity of dendritic cells

Abstract:  The nasal decongestant oxymetazoline (OMZ) is frequently used in the topical treatment of rhinitis/sinusitis. As proinflammatory cytokines play a critical role in the development and maintenance of local inflammation, the aim of this study was to investigate the influence of OMZ on immune cells in order to diminish the mucosal infiltration of the nose. Peripheral blood mononuclear cells (PBMC) from buffy coats of healthy volunteers were isolated and stimulated in the presence or absence of OMZ. In addition, monocyte‐derived dendritic cells (DC) were generated and different concentrations of OMZ were added. DC phenotype and their T‐cell stimulatory properties were analysed. The vasoactive substance OMZ showed a concentration dependent inhibitory effect on T‐cell activation as well as a dominant effect on T‐cell stimulatory properties of DC. Low concentrations of OMZ inhibited the proliferation of polyclonally activated T cells. In addition, secretion of proinflammatory mediators such as the cytokines interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF α), IL‐6 and IL‐8 were inhibited in the presence of physiological doses of OMZ. Interestingly, the addition of IL‐6 to DC‐T‐cell co‐culture was able to completely restore T‐cell proliferation. In conclusion, these findings indicate that the anti‐inflammatory properties of OMZ are partially mediated by the inhibition of proinflammatory cytokines as well as reduced T‐cell stimulatory capacity of DC resulting in a repressed stimulation of T cells. Therefore, the therapeutic benefit of OMZ can be explained in part by its immunomodulating effects in the topical treatment of nasal inflammation.

Effect of clarithromycin on cytokines and chemokines in children with an acute exacerbation of recurrent wheezing: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Clarithromycin is postulated to possess immunomodulatory properties in addition to its antimicrobial activity.

OBJECTIVE

To evaluate the effect of clarithromycin on serum and nasopharyngeal cytokine and chemokine concentrations in children with an acute exacerbation of recurrent wheezing.

METHODS

Children with a history of recurrent wheezing or asthma and who presented with an acute exacerbation of wheezing were enrolled in a double-blind, randomized trial of clarithromycin vs placebo. Concentrations of tumor necrosis factor alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, RANTES, eotaxin, macrophage inflammatory protein 1alpha, macrophage inflammatory protein 1beta, and monocyte chemoattractant protein 1 were measured in serum and/or nasopharyngeal aspirates before, during, and after therapy. Mycoplasma pneumoniae and Chlamydophila pneumoniae infection were evaluated for by polymerase chain reaction and serologic testing.

RESULTS

Nasopharyngeal concentrations of TNF-alpha, IL-1beta, and IL-10 were significantly and persistently lower in children treated with clarithromycin compared with placebo. There tended to be a greater effect of clarithromycin on nasopharyngeal cytokine concentrations in patients with evidence of M. pneumoniae or C. pneumoniae infection. No significant differences were detected in serum cytokines for children treated with clarithromycin compared with placebo.

CONCLUSION

Clarithromycin therapy reduces mucosal TNF-alpha, IL-1beta, and IL-10 concentrations in children with an acute exacerbation of recurrent wheezing.

Vascular endothelial growth factor induction by rhinovirus infection

Vascular participation manifested by a runny nose (rhinorrhea) is a prominent feature of the acute consequences of rhinovirus infection. Vascular endothelial growth factor (VEGF) is an angiogenic factor that also induces potent increases in vascular permeability; it is a candidate mediator of rhinorrhea in response to rhinovirus infection as well as contributing to enhanced vascular leakage in rhinovirus-linked asthma exacerbations. It has been shown that rhinovirus induces significant increases in both VEGF protein and mRNA in primary airway fibroblasts [Ghildyal et al. (2005): J Med Virol 75:608-615]. The current studies assessed VEGF responses to rhinovirus in primary culture airway epithelium, in epithelial and fibroblast cell lines and in rhinovirus-infected nasal secretions. Epithelial and fibroblast cells were infected with rhinovirus serotype 16 and VEGF protein and isoforms assessed by ELISA and RT-PCR, respectively. VEGF protein was released by both epithelial and fibroblast cell lines and primary airway epithelial cells in culture but was not increased following rhinovirus infection. PCR products coding for four or five of the six known VEGF isoforms were produced (121, 145, 165 and 183, and/or 189 amino acids) in cell lines and primary culture cells, but no specific isoform was linked to rhinovirus infection. Nasal VEGF was also measured in a cohort of asthmatics with verified rhinovirus and respiratory syncytial virus (RSV) infection. VEGF was not raised following rhinovirus infection alone, but was increased significantly if concomitant RSV infection was present. The data suggest that fibroblasts rather than the epithelium may play a key role in VEGF mediated vascular responses after rhinovirus infection. This may aid recruitment of inflammatory cells and contribute to airway inflammation and bronchial obstruction.

Echinacea in the prevention of induced rhinovirus colds: a meta-analysis

BACKGROUND

The therapeutic effectiveness of Echinacea in the treatment and the prevention of colds has been debated. Studies of naturally occurring colds are hampered by variability in time from onset of symptoms to treatment and by heterogeneity in trial design. Experimental infection studies allow for the standardization of time to initiation of treatment, virus type and dose, and immune competence of volunteers.

OBJECTIVE

To determine whether the negative results obtained in previous studies of Echinacea were a consequence of efficacy or of inadequate sample size, we performed a meta-analysis of experimental rhinovirus infection studies on the efficacy of Echinacea extracts to prevent symptomatic development of an experimentally induced cold.

METHODS

We carried out a systematic search of English- and German-language literature using the MEDLINE, EMBASE, CAplus, BIOSIS, CABA, AGRICOLA, TOXCENTER, SCISEARCH, NAHL, and NAPRALERT, databases and the search terms Echinacea, black Sampson, coneflower, and Roter Sonnenbut. Matching documents were then searched for > or = 1 of the following terms: rhinovirus, RV, inoculation, Inokulation, induced, induziert, artificial, and artifiziell. Suitable studies were identified and pooled for analysis. The primary end point was the development of symptomatic clinical colds, as defined by the authors of the original studies. Results were reported as differences in the proportion of subjects with symptomatic episodes of a common cold, expressed as odds ratios (ORs) and 95% CIs. The secondary outcome was the difference in total symptom severity scores between treatment groups (assessed daily by integrating the severity scores of 8 individual cold-related symptoms that were rated on a scale from 0 [absent] to 4 [very severe]).

RESULTS

A total of 234 articles were identified through the literature search; 231 were excluded from the analysis because they related to studies of spontaneous common colds. Three suitable studies were selected for pooling of data. Based on the analysis, the likelihood of experiencing a clinical cold was 55% higher with placebo than with Echinacea (OR, 1.55 [95% CI, 1.02-2.36]; P<0.043). The absolute difference in total symptom scores between groups was -1.96 (95% CI, -4.83 to 0.90; P=NS).

CONCLUSIONS

This meta-analysis suggests that standardized extracts of Echinacea were effective in the prevention of symptoms of the common cold after clinical inoculation, compared with placebo. Further prospective, appropriately powered clinical studies are required to confirm this finding.

Emotional style, nasal cytokines, and illness expression after experimental rhinovirus exposure

Psychosocial factors moderate the expression of illness during upper respiratory virus infections but past attempts to define mediational pathways were not successful. Here, we used a model of experimental rhinovirus infection in humans to evaluate three proinflammatory cytokines for their potential role in mediating the previously documented association between positive emotional style and illness. After assessing emotional style in 327 healthy adults, each was exposed to one of two strains of rhinovirus and followed for 5 days in quarantine. Symptoms/signs, nasal lavage IL-1beta, IL-6, and IL-8 protein, and viral shedding were assessed at baseline and on each of the 5 days after exposure. Virus-specific antibody was assessed at baseline and 28 days after challenge. An analysis of the data for 234 subjects with documented infection showed that nasal IL-1beta, IL-6, and IL-8 protein levels were all associated with greater illness expression but IL-6 was by far the best predictor of nasal signs and symptoms. Lower positive emotional style was associated with greater objective and subjective markers of illness and these associations were decreased substantially by controlling for IL-6 but not for IL-1beta or IL-8. These results are consistent with the hypothesis that IL-6 acts as a biological mediator in linking positive emotional style to illness expression during rhinovirus infection.

Nasal cytokines as mediators of illness during the common cold

Identification of a pharmacologically targeted mediator of the common cold is a desirable, but, to date, elusive goal of current research. The roles of various mediators, such as histamine, leukotrienes, bradykinin, and, more recently, chemokines and cytokines, in the pathophysiology and development of complications of the common cold are the subject of previous and current investigations. Establishing causality of a mediator in the common cold has been difficult for a number of reasons, including the limitations of our research tools and protocols and the complexity of the inflammatory and immune pathways that participate during the common cold. The available evidence for mediation of the common cold is the subject of this manuscript.