CD 24 hi CD 27 ⁺ B cells from patients with allergic asthma have impaired regulatory activity in response to lipopolysaccharide

Summary Background Regulatory B cells have been identified that strongly reduce allergic and auto‐immune inflammation in experimental models by producing IL ‐10. Recently, several human regulatory B‐cell subsets with an impaired function in auto‐immunity have been described, but there is no information on regulatory B cells in allergic asthma. Objective In this study, the frequency and function of IL ‐10 producing B‐cell subsets in allergic asthma were investigated. Methods Isolated peripheral blood B cells from 13 patients with allergic asthma and matched healthy controls were analyzed for the expression of different regulatory B‐cell markers. Next, the B cells were activated by lipopolysaccharide ( LPS ), CpG or through the B‐cell receptor, followed by co‐culture with endogenous memory CD 4 + T cells and house dust mite allergen DerP1. Results Lower number of IL ‐10 producing B cells were found in patients in response to LPS , however, this was not the case when B cells were activated through the B‐cell receptor or by CpG. Further dissection showed that only the CD 24 hi CD 27 + B‐cell subset was reduced in number and IL ‐10 production to LPS . In response to DerP1, CD 4 + T cells from patients co‐cultured with LPS ‐primed total B cells produced less IL ‐10 compared to similar cultures from controls. These results are in line with the finding that sorted CD 24 hi CD 27 + B cells are responsible for the induction of IL ‐10 + CD 4 + T cells. Conclusions Taken together, these data indicate that CD 24 hi CD 27 + B cells from allergic asthma patients produce less IL ‐10 in response to LPS leading to a weaker IL ‐10 induction in T cells in response to DerP1, which may play a role in allergic asthma.