Characterisation of allergen-specific responses of IL-10-producing regulatory B cells (Br1) in Cow Milk Allergy.

CD19+CD5+ regulatory B cells regulate immune responses by producing IL-10. IL-10-producing regulatory B cell (Br1) responses by allergen stimulation were investigated in human food allergy. Six milk allergy patients and eight milk-tolerant subjects were selected according to DBPCFC. PBMCs were stimulated by casein in vitro and stained for intracellular IL-10 and apoptosis. In response to allergen stimulation, Br1 decreased from 26.2+/-18.3 to 15.5+/-8.9% (p=0.031, n=6) in the milk allergy group and increased from 15.4+/-9.0 to 23.7+/-11.2% (p=0.023, n=8) in the milk-tolerant group. Apoptotic non-IL-10-producing regulatory B cells increased from 21.8+/-9.3 to 38.0+/-16.1% (p=0.031, n=6) in the milk allergy group and unchanged from 28.8+/-13.8 to 28.0+/-15.0% (p=0.844, n=8) in the milk-tolerant group. Br1 may be involved in the immune tolerance of food allergies by producing IL-10 and simultaneously undergoing apoptosis in humans. The exact roles for Br1 in immune tolerance needs to be further investigated.