FIGURE LEGENDS
Figure 1. Regulation of PD-L1 mRNA level in blood cells of pre-school children. (a) Experimental design of the blood and nasopharyngeal fluid (NPF) analysis of the healthy (n=21) and asthmatic (n=24) pre-school children of the PreDicta cohort in Erlangen.(b) PD-L1/HPRT mRNA expression in total blood cells of healthy and asthmatic children with a virus-induced (v) asthma phenotype at the baseline visit (n=10/11). (c) PD-L1/HPRT mRNA expression in total blood cells of healthy and asthmatic children (n=10/17). (d) PD-L1/HPRT mRNA expression in total blood cells of healthy and asthmatic children subdivided according to their FEV1% at the baseline visit (n=0/2/9/15). (e) Correlation of the PD-L1/HPRT mRNA level in total blood cells of asthmatic children with the FEV1% at the baseline visit. (f)PD-L1/HPRT mRNA expression in total blood cells of healthy and asthmatic children subdivided according to their PEF% at the baseline visit (n=5/6/5/10). (g)Correlation of the PD-L1/HPRT mRNA level in total blood cells of asthmatic children with the PEF% at the baseline visit. (h)Correlation of the PD-L1/HPRT mRNA level in total blood cells of asthmatic children with rhinovirus in their airways with the FEV1% (top) and PEF% (bottom) at the baseline visit. Data are presented as means ± SEMs. Two-tailed student t test (b, c) or ordinary one-way ANOVA (d, f) was used to calculate statistical significance. * p ≤ 0.05; ** p ≤ 0.01, *** p ≤ 0.001, **** p≤ 0.0001.

Figure 2. IFNβ correlated with better lung function in asthmatic children

(a, b) Correlation of the IFNβ level, measured in the supernatants of the untreated PBMC culture and the respective FEV1% (i) and PEF% (j) of asthmatic children with and without rhinovirus in their airways. Data are presented as means ± SEMs. Two-tailed student ttest (b, c) or ordinary one-way ANOVA (d, f) was used to calculate statistical significance. * p ≤ 0.05; ** p ≤ 0.01, *** p ≤ 0.001, **** p≤ 0.0001.
Figure 3. Correlation between PD-L1 mRNA level with IFNβ in healthy and asthmatic patients. Correlation of the PD-L1/HPRTmRNA level in total blood cells with the IFNβ level, measured in the supernatants of the respective untreated and with rhinovirus 1b re-stimulated PBMC culture, of healthy and asthmatic children.

Figure 4. PD-L1 is upregulated in blood cells of asthmatic children with high C-reactive protein (CRP) serum levels and correlated with RV in the airways

(a) PD-L1/HPRT mRNA expression in total blood cells of healthy and asthmatic children subdivided according to their CRP serum level (n=9/10/2). (b,c) Correlation of the PD-L1/HPRTmRNA level in total blood cells with the CRP serum level subdivided in healthy and asthmatic children with and without rhinovirus in their airways. Data are presented as means ± SEMs. Ordinary one-way ANOVA was used to calculate statistical significance. * p ≤ 0.05; ** p ≤ 0.01, *** p ≤ 0.001, **** p≤ 0.0001.