?-Gal on the protein surface affects uptake and degradation in immature monocyte derived dendritic cells.

ABSTRACT: Red meat allergy is characterized by an IgE response against the carbohydrate galactose-?-1,3-galactose (?-Gal), which is abundantly expressed on glycoproteins from non-primate mammals. The mechanisms of how ?-Gal is processed and presented to the immune system to initiate an allergic reaction are still unknown. The aim of this study was to reveal whether the presence of ?-Gal epitopes on the protein surface influence antigen uptake and processing in immature monocyte-derived dendritic cells (iMDDCs). Immature MDDCs were prepared from healthy blood donors and red meat allergic patients. We found an increased internalization of ?-Gal carrying proteins over time in iMDDCs by flow cytometric analysis, which was independent of the donor allergic status. The uptake of ?-Gal carrying proteins was significantly higher than the uptake of non-?-Gal carrying proteins. Confocal microscopy revealed ?-Gal carrying proteins scattered around the cytoplasm in most iMDDCs while detection of proteins not carrying ?-Gal was negligible. Fluorescent detection of protein on SDS-PAGE showed that degradation of ?-Gal carrying proteins was slower than degradation of non-?-Gal carrying proteins. Thus, the presence of ?-Gal on the protein surface affects both uptake and degradation of the protein, and the results add new knowledge of ?-Gal as a clinically relevant food allergen.

SUBMITTER: Ristivojevic MK 

PROVIDER: S-EPMC6107510 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature