Figure 7. Involvement of IL-17RB⁺ iNKT cells in the development of RSV-induced AHR.

(A) Schematic showing the protocol for RSV-induced AHR. Mice were i.n. administered with RSV (10⁶ pfu) or PBS alone as a control 4 times at 10-day intervals. Mice were i.p. immunized with rec Gs/alum (50 µg/2 mg) 4 d after first RSV infections. Three days after the last RSV administration, mice were exposed i.n. to rec Gs and were measured 1 d later. (B) Development of RSV-induced AHR in BALB/c, but not in Jα18 ^−/− or Il17rb ^−/− mice. Changes in R_L are depicted. The RSV-infected, rec Gs immunized, BALB/c mice had a greatly increased AHR compared to the other three groups. Results are expressed as the mean ± SEM. * p<0.05 and ** p<0.01. (C, D) Total and differential cell counts (C) and cytokines (D) in BAL fluid. BAL fluid was collected 24 h after challenge of the mice depicted in (B) with intranasal rec Gs. Results are expressed as the mean ± SEM. * p<0.05 and ** p<0.01. (E) Histological examination of lung tissues by H&E and PAS staining. RSV infected, rec Gs immunized, BALB/c, Jα18 ^−/− or IL17rb ^−/−, mice were compared with control BALB/c mice (rec Gs alone). Bars indicate 100 µm. (F) AHR development after cell transfer of spleen IL-17RB⁺ iNKT cells into Jα18 ^−/− mice. Indicated cell numbers of sorted IL-17RB⁺, IL-17RB⁻ iNKT cells or total iNKT cells from spleen, or PBS control, were i.v. transferred into rec-Gs/alum-sensitized Jα18 ^−/− mice 24 h before RSV treatment (on the day 9, 19, and 29), and then challenged with rec Gs (24 h) and measurement of lung resistance (48 h). Each group of IL-17RB⁺ iNKT cell-transferred mice was compared to other three groups. * p<0.05, ** p<0.01 calculated by Kruskal Wallis test. The results represent one out of four experiments with five mice in each group.