Antigen specific immunotherapy generates CD27+ CD35+ tolerogenic dendritic cells

•FA patients have lower frequencies of CD27+ B cells and TGF-β+ DCs.•More than 90% CD27+ B cells were also express CD35.•About 90% CD27+ CD35+ B cells expressed TGF-β.•CD27+ CD35+ B cells induce DCs to be tolerogenic DCs.

Background and aimsThe mechanism of antigen specific immunotherapy (ASIT) remains to be further understood. The present study aims to investigate the role of ASIT in the generation of tolerogenic dendritic cells (DC) in patients with food allergy (FA).MethodsTwenty patients with egg FA and 10 healthy subjects were recruited into this study. Blood samples were obtained from each subject before and after the ASIT and analyzed by flow cytometry.ResultsIn FA patients, the frequencies of CD27+ B cells and TGF-b+ DCs were significantly lower than that in healthy subjects. More than 90% CD27+ B cells also express CD35; about 90% CD27+ CD35+ B cells expressed TGF-b. Coculture of CD27+ CD35+ B cells with immature DCs generated TGF-b-expressing tolerogenic DCs; the latter was able to induce CD4+ CD25+ Foxp3+ regulatory T cells.ConclusionsTreatment with ASIT can induce TGF-b-expressing tolerogenic DCs in patients with FA.