Rhinovirus Infection Induces Th2-Promoting Innate Cytokines in an Ex Vivo Precision Cut Lung Slice Model

Rhinovirus (RV) infection is associated with asthma exacerbations, but little is known about cellular response to virus leading to exacerbations. We hypothesized that RV39 infection of airways in precision cut lung slices (PCLS) from asthma subjects would induce a cytokine signature, including IL-25, IL-33, and TSLP. PCLS from subjects with (n=3) and without (n=5) history of asthma were prepared from cadaver lungs and cultured ex vivo. Explants were infected with RV39 at 300TCID50/slice, and viral loads were measured using qPCR. mRNA levels for IFN-l, IL-15, IL-33, IL-25, TSLP, and IL-13 were measured in a time course. Expression of mRNA was normalized to uninfected airways from the same subject and b-actin. mRNA results are expressed as means and standard deviation of DDCT. qPCR for RV39 confirmed active infection of PCLS at 24 hours (53,330 virions/mL cDNA, +/- 70,491). At 24 hours, mRNA expression of IL-15, IL-33, and IFN-l were similarly induced between asthmatics and controls. IL-25 (asthma 3.8+/- 3.78; control -2.4 +/- 5.08), TSLP (asthma 4.2 +/- 3.29; control -2.1+/- 3.69), and IL-13 (asthma 3.8 +/- 4.16; control -3.7 +/- 4.06) were induced only in PCLS from asthmatics and suppressed in controls. In PCLS airways from subjects with physician-diagnosed asthma, RV39 infection enhanced mRNA expression of IL-25, TSLP, and IL-13 along with typical cytokines required for innate immune defenses against virus. We suggest that IL-25 and TSLP increase IL-13 expression by mast cells, innate lymphoid type 2 cells, and/or T cells in PCLS airways of asthma subjects.