Fig. 2: Smoking in asthma associates with increased peripheral blood CD4⁺CD45RO⁺ILC3 frequencies.

a Gating strategy for the three subsets of innate lymphoid cells (ILCs; Lineage⁻IL-7R⁺) in the blood. b Comparison of non-smoking and smoking asthma patients and non-smoking and smoking healthy individuals in terms of total ILC frequencies in the peripheral blood. Comparison of non-smoking and smoking asthma patients in terms of peripheral blood ILC1 (ST-2⁻C-kit⁻), ILC2 (ST-2⁺), and ILC3 (ST-2⁻C-kit⁺) (c), CD45RO⁺ ILC1, ILC2, and ILC3 (d, e), and CD4⁺CD45RO⁺ILC1 and CD4⁺CD45RO⁺ILC3 (f, g) frequencies. h Frequencies of CD45RA⁺, CD4⁻CD45RO⁺, and CD4⁺CD45RO⁺ total ILCs that co-express IL-17A. Each dot represents individual subject. Sample size of non-smoking healthy controls, n = 13; smoking healthy controls, n = 10; non-smoking asthma patients, n = 32; smoking asthma patients, n = 49 for Fig. 2b, non-smokers, n = 33; smokers, n = 52 for ILC1s, ILC2s in Fig. 2c and CD45RO⁺ILC1s, CD45RO⁺ILC2s in Fig. 2e, non-smokers, n = 32; smokers, n = 52 for ILC3s in Fig. 2c and CD45RO⁺ILC3s in Fig. 2e, non-smokers, n = 32; smokers, n = 49 for CD4⁺CD45RO⁺ILC1s and non-smokers, n = 32; smokers, n = 48 for CD4⁺CD45RO⁺ILC3s in Fig. 2g, CD45RA⁺ cells; n = 10, CD4⁻CD45RO⁺ cells; n = 10, CD4⁺CD45RO⁺ cells; n = 10 for Fig. 2h. The non-smokers and smokers in the asthma patients or healthy individuals were compared by multiple t-tests (Fig. 2b) or two-tailed Mann-Whitney U test (Fig. 2c, e, g). One-way ANOVA was conducted to compare the frequencies of IL-17A⁺ cells among CD45RA⁺, CD4⁻CD45RO⁺, and CD4⁺CD45RO⁺ ILCs (Fig. 2h). All data are presented as mean ± standard deviation. p < 0.05 is considered as significant.