Targeted inhibition of allergen-induced histamine production by neutrophils.

Histamine is a critical inflammatory mediator in allergic diseases. We showed in a previous work that neutrophils from allergic patients produce histamine in response to allergens to which the patients were sensitized. Here, we investigate the molecular mechanisms involved in this process using peripheral blood neutrophils.

Neutrophils from allergic asthmatic patients produce and release metalloproteinase-9 upon direct exposure to allergens.

Background: Asthma is characterized by airway inflammation and remodelling in which matrix metalloproteinases (MMPs) play an important role. MMP-9 is the major MMP found in the bronchoalveolar lavage fluids and bronchial biopsies from patients with allergic asthma after allergen challenge, where it correlates with the count of neutrophils and macrophages. However, the cellular sources of MMP-9 in this inflammatory condition have not yet been clearly identified.

Neutrophil defensins: their possible role in allergic asthma.

Background: Neutrophil defensins, originally identified as broad-spectrum antimicrobial peptides, have been implicated in the regulation of inflammatory and immunological processes.

Objectives: To investigate whether the in vitro challenge of neutrophils from patients with bronchial asthma with allergens stimulated the release of alpha-defensins and whether levels released were dependent on lung infections.

Method: The neutrophils were cultivated with different agonists and the concentration of alpha-defensin in cell-free supernatant was measured with enzyme-linked immunosorbent assay (ELISA).

Cloning, expression and characterization of mugwort pollen allergen Art v 2, a pathogenesis-related protein from family group 1.

Mugwort (Artemisia vulgaris) belongs to the Compositae family, and is one of the main causes of allergy in late summer and autumn. The aim of the study was to characterize the allergen Art v 2 from mugwort pollen. Skin prick tests, performed in 19 patients allergic to mugwort and 10 control patients, showed an Art v 2 sensitization prevalence of 58%, whereas none false-positives were detected among control patients.