Upregulation of regulatory B and T cells in induced sputum following AIT

Introduction Regulatory B and T cells are considered to have a crucial impact on type 2 inflammation by producing regulatory cytokines, such as IL-10. By playing a significant role in suppressing immune responses, they are also seen as an important immunomodulating factors in allergic rhinitis and allergic asthma. Treatment with Allergen-specific Immunotherapy (AIT) seems to have various effects on a cellular and humoral base, which also affects regulatory cells. This study shows the differences of Breg and Treg levels in healthy subjects and allergic individuals and the development following AIT. Furthermore, it presents induced sputum as a possible clinical method to monitor immunomodulating processes on a local base.

Methods We collected PBMCs and induced sputum samples from 59 patients to investigate cell populations on a systemic level as well as at the local site of immune response in the lower airways. We included healthy controls (n = 24), allergic subjects with (n = 20) and without asthma (n = 15) including subgroups where we further analysed potential cellular effects of AIT in allergic patients with (n = 8) and without AIT (n = 7) as well as asthmatic patients with (n = 11) and without AIT (n = 9). B and T cell populations of blood and sputum samples were differentiated by flow cytometry.

Results CD19+IL10+ cells (Bregs) as well as CD3+CD4+Foxp3+ cells (Tregs) were significantly upregulated after AIT in allergic subjects. This effect could be shown as a systemic reaction in blood samples as well as in induced sputa. Flow cytometric analysis of induced sputum may therefore proof useful to display systemic and mucosal mechanisms of allergic diseases and their treatments.

Publication History

Article published online:
12 May 2023