In:
Clinical & Experimental Allergy, Wiley, Vol. 42, No. 1 ( 2012-01), p. 76-84
Abstract:
Recently, it has been established that pollen grains contain Th2‐enhancing activities besides allergens. Objective The aim of this study was to analyse whether pollen carry additional adjuvant factors like microbes and what immunological effects they may exert. Methods Timothy pollen grains were collected and disseminated on agar plates, and the growing microorganisms were cultivated and defined. Furthermore, the immunologic effects of microbial products on DC and T cell responses were analysed. Results A complex mixture of bacteria and moulds was detected on grass pollen. Besides G ram‐negative bacteria that are known to favour Th1‐directed immune responses, moulds were identified as being sources of allergens themselves. Herein, we focused on G ram‐positive bacteria that were found in high numbers, e.g. B acillus cereus and B acillus subtilis . Contact of immature dendritic cells ( DC ) from grass pollen allergic donors with supernatants of homogenized G ram‐positive bacteria induced maturation of DC as measured by up‐regulation of CD 80, CD 83 and CD 86 and by enhanced production of IL ‐6, IL ‐12p40 and TNF ‐α, which was less pronounced compared with effects induced by lipopolysaccharide (LPS) . Consequently, stimulation of autologous CD 4 + T cells with supernatants of homogenized G ram‐positive bacteria plus grass pollen allergen‐pulsed DC led to an enhanced proliferation and production of IL ‐4, IL ‐13, IL ‐10, IL ‐17, IL ‐22 and IFN ‐γ production compared with T cells that were stimulated with allergen‐pulsed immature DC alone, whereas production of the transcription factor for regulatory T cells FoxP3 was not significantly affected. Conclusions and Clinical Relevance These data indicate that grass pollen is colonized by several microorganisms that influence the immune response differently. Similar to LPS , supernatants of homogenized Gram‐positive bacteria may serve as adjuvants by augmenting DC maturation and inflammatory Th1, Th2 and Th17 responses helping to initiate allergic immune responses.
Type of Medium:
Online Resource
ISSN:
0954-7894
,
1365-2222
DOI:
10.1111/cea.2011.42.issue-1
DOI:
10.1111/j.1365-2222.2011.03888.x
Language:
English
Publisher:
Wiley
Publication Date:
2012
detail.hit.zdb_id:
2186232-1
detail.hit.zdb_id:
2004469-0
