Asthmatic farm children show increased CD3+Â CD8low T-cells compared to non-asthmatic farm children

Several studies report an important role of CD8+ cytotoxic T-cells in atopy. Farm children show protection against atopy development, partly explained by CD4+ T-cell subtypes. Additional effects of CD8+ T-cells are unknown being investigated in this study within the PASTURE/EFRAIM birth cohort in PBMCs from farming and non-farming 6-year-old (N = 76) German children. CD3+ CD8+ CD25+ T-cells were analyzed by flow cytometry. Genotyping of 17q21 locus-SNPs associated with childhood asthma was performed. No differences in CD8+ T-cell subsets were seen between farmers and non-farmers regardless of asthma. Among farm children, asthmatics displayed increased CD3+ CD8low(CD25+) T-cells compared to non-asthmatics. Asthmatic farm children exhibited a lower PI-induced stimulatory capacity of CD3+ CD8low(CD25+) cells and a lower IFN-γ secretion than non-asthmatic farm children. Among farm children with GSDMB and ORMDL3 risk alleles, asthmatics displayed higher CD3+ CD8low cells than non-asthmatics. Our data indicates a specific role of CD8low T-cells in asthmatic farm children.