Fig 2: Wilcoxon test revealing statistically significant difference between the relative numbers of different factors in cartilage. (a) A statistically significant difference between HBD-2 and HBD-4 in cartilage. (b) A statistically significant difference between HBD-2 and HBD-3 in cartilage. (c) A statistically significant difference between HBD-3 and IL-17A in cartilage. (d) A statistically significant difference between IL-17A and HBD-4 in cartilage. (e) A statistically significant difference between IL-17A and LL-37 in cartilage. C, cartilage; HBD-2, human ß defensin 2; HBD-3, human ß defensin 3; HBD-4, human ß defensin 4; LL-37, cathelicidine; IL-17A, interleukin 17A; o—outlier data—indicates a higher or lower relative number of positive cells which lie more than 1.5 but less than 3.0 times the interquartile range below the first quartile or above the third quartile.

Fig 3: Wilcoxon test revealing statistically significant difference between the relative numbers of different factors in bronchial epithelium. (a) A statistically significant difference between HBD-4 and HBD-3 in bronchial epithelium. (b) A statistically significant difference between HBD-2 and LL-37 in bronchial epithelium. (c) A statistically significant difference between HBD-2 and IL-17A in bronchial epithelium. (d) A statistically significant difference between LL-37 and HBD-4 in bronchial epithelium. (e) A statistically significant difference between HBD-4 and IL-17A in bronchial epithelium. BE, bronchial epithelium; HBD-2, human ß defensin 2; HBD-3, human ß defensin 3; HBD-4, human ß defensin 4; LL-37, cathelicidine; IL-17A, interleukin 17A; o—outlier data—indicates a higher or lower number of relative positive cells which lie more than 1.5 but less than 3.0 times the interquartile range below the first quartile or above the third quartile; *—extreme outlier data—indicates a higher or lower number of relative positive cells which lie more than 3.0 times the interquartile range below the first quartile or above the third quartile.

Fig 4: The postulated inflammatory positive feedback in neuroinflammation following SCI. IL-17 interacts with the corresponding receptors on the surfaces of certain target cells and induces the production of IL-6, IL-1ß, TNF-a, and CCL20. Subsequently, IL-6, IL-1ß, and TNF-a further stimulate IL-17 expression and differentiation of Th17 cells. The black solid line represents what we have proven in the present study. The purple dotted line represents what we have speculated from other studies

Fig 5: Immunohistochemical micrographs in lung tissue samples. (a) Numerous IL-17A positive cells in cartilage of 19-year-old male. IL-17A IMH, ×100; (b) moderate IL-17A positive structures in cartilage and none in connective tissue of 25-year-old male. IL-17A IMH, ×100.