Background
Hundreds of plant species release their pollen into the air every year during early spring. During that period, pollen allergic as well as non‐allergic patients frequently present to doctors with severe respiratory tract infections. Our objective was therefore to assess whether pollen may interfere with antiviral immunity.
Methods
We combined data from real‐life human exposure cohorts, a mouse model and human cell culture to test our hypothesis.
Results
Pollen significantly diminished interferon‐λ and pro‐inflammatory chemokine responses of airway epithelia to rhinovirus and viral mimics and decreased nuclear translocation of interferon regulatory factors. In mice infected with respiratory syncytial virus, co‐exposure to pollen caused attenuated antiviral gene expression and increased pulmonary viral titers. In non‐allergic human volunteers, nasal symptoms were positively correlated with airborne birch pollen abundance, and nasal birch pollen challenge led to downregulation of type I and ‐III interferons in nasal mucosa. In a large patient cohort, numbers of rhinoviruspositive cases were correlated with airborne birch pollen concentrations.
Conclusion
The ability of pollen to suppress innate antiviral immunity, independent of allergy, suggests that high‐risk population groups should avoid extensive outdoor activities when pollen and respiratory virus seasons coincide.
Background: Pollen exposure induces local and systemic allergic immune responses in sensitized individuals, but nonsensitized individuals also are exposed to pollen. The kinetics of symptom expression under natural pollen exposure have never been systematically studied, especially in subjects without allergy. Objective: We monitored the humoral immune response under natural pollen exposure to potentially uncover nasal biomarkers for in-season symptom severity and identify protective factors. Methods: We compared humoral immune response kinetics in a panel study of subjects with seasonal allergic rhinitis (SAR) and subjects without allergy and tested for cross-sectional and interseasonal differences in levels of serum and nasal, total, and Betula verrucosa 1-specific immunoglobulin isotypes; immunoglobulin free light chains; cytokines; and chemokines. Nonsupervised principal component analysis was performed for all nasal immune variables, and single immune variables were correlated with in-season symptom severity by Spearman test. Results: Symptoms followed airborne pollen concentrations in subjects with SAR, with a time lag between 0 and 13 days depending on the pollen type. Of the 7 subjects with nonallergy, 4 also exhibited in-season symptoms whereas 3 did not. Cumulative symptoms in those without allergy were lower than in those with SAR but followed the pollen exposure with similar kinetics. Nasal eotaxin-2, CCL22/MDC, and monocyte chemoattactant protein-1 (MCP-1) levels were higher in subjects with SAR, whereas IL-8 levels were higher in subjects without allergy. Principal component analysis and Spearman correlations identified nasal levels of IL-8, IL-33, and Betula verrucosa 1-specific IgG 4 (sIgG 4 ) and Betula verrucosa 1-specific IgE (sIgE) antibodies as predictive for seasonal symptom severity. Conclusions: Nasal pollen-specific IgA and IgG isotypes are potentially protective within the humoral compartment. Nasal levels of IL-8, IL-33, sIgG 4 and sIgE could be predictive biomarkers for pollen-specific symptom expression, irrespective of atopy.
Hintergrund und Fragestellungen: Die atopische Dermatitis ist der erste Schritt im sogenannten atopischen Marsch. Bei den meisten Betroffenen folgen zusätzlich noch allergische Rhinitis und Asthma. Die ersten Symptome lösen bereits Sorgen bei den Eltern betroffener Kinder aus, unter anderem jene um begleiten de Nahrungsmittelallergien. Die Koexistenz der atopischen Der matitis und Nahrungsmittelallergie vermindert die Lebensqua lität der Kinder und ihrer Eltern enorm.In der Pathogenese von Nahrungsmittelallergien spricht man nicht nur über genetische Veranlagung, das Immunsystem eines Kindes, die Hautbarriere und Umweltfaktoren, sondern auch über einen supersterilen Le bensstil, die erhöhte Anwen dung von Antibiotika, über die Geburt durch Kaiser schnitt und das "moderne" Mikrobiom als mögliche Aus löser. Jahrelang glaubte man, dass Kinder über die aufgenomme nen Lebensmittel in der Darmflora sensibilisiert wer den. Aktuelle Forschungen je
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