Panels A to F show the lungs of rabbits immunolabeled with types I, III and V collagen by immunofluorescence. A decrease in the expression of collagens I (D), III (E) and V (F) in the peribronchovascular interstitium and in the septal interstitium of tolerated animals was observed when compared to immunized animals (A, B and C, respectively). Panels G, H and I show the differential gene expression of the mRNA for collagens I, III and V, respectively, in lung tissue of control and immunized animals and after the induction of nasal tolerance with collagen V. The box plot shows the distribution of all values between the bars (quartiles 25, 50 and 75 within the box), except extreme values (°1.5- to 3.0-fold the dimension of the box of the 75th percentile; *values that are more than 3-fold the dimension of the box of the 75th percentile). The Bonferroni test was used, and we considered the gene to be differentially expressed where p ≤ 0.05. TB = terminal bronchiole; V = Vessel; Magnification: A-F, 400×. Groups: CT-FA = Freund's adjuvant control; IM = immunized; IM-TOL = immunized.*Statistical significance.