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Atopic donor status does not influence the uptake of the major grass pollen allergen, Phl p 5, by dendritic cells
- Ashjaei, Kazem, Palmberger, Dieter, Bublin, Merima, Bajna, Erika, Breiteneder, Heimo, Grabherr, Reingard, Ellinger, Isabella, Hoffmann-Sommergruber, Karin
- Journal of Immunological Methods 2015 v.424 pp. 120-130
- Helianthus annuus, T-lymphocytes, allergens, dendritic cells, endosomes, fluorescent antibody technique, grasses, humans, lipid transfer proteins, models, monocytes, pollen, staining
- Dendritic cells (DCs) are sentinels of the immune system for antigen recognition and uptake, as well as presentation to naïve T cells for stimulation or priming. Internalization and endocytic degradation of allergens by DCs are important steps required for T cell priming.In the current study we investigated binding and internalization of purified recombinant non-glycosylated grass pollen allergen, Phl p 5, and natural non-specific lipid transfer protein from sunflower, SF-nsLTP to human monocyte derived dendritic cells (MoDCs). Colocalization of Phl p 5 with low affinity (CD23) or high affinity receptor (FcεRI) was investigated by immunofluorescence staining. Likewise, localization of the allergens in early (EE) and late endosomes (LE) was detected by co-staining for early endosome antigen (EEA1) and lysosomal-associated membrane protein 1 (LAMP1).In our experimental setting we could demonstrate that Phl p 5 as well as SF-nsLTP bound to MoDCs from both, grass pollen allergic and non-allergic individuals. Competitive allergen uptake experiments demonstrated non-preferential and simultaneous uptake of Phl p 5 and SF-nsLTP by MoDCs. No overlap of signals from Phl p 5 and CD23 or FcεRI was detectable, excluding IgE-mediated uptake for this allergen. Both allergens, Phl p 5 and SF-nsLTP, were localized in early and late endosomes.The present study applied a set of methods to assess the allergen uptake by MoDCs in an in vitro model. No qualitative and quantitative differences in the allergen uptake of both, Phl p 5 and SF-nsLTP were detected in single and competitive assays.