NOD.Idd3/5 mice immunized with murine or human Jo-1 develop muscle inflammation and interstitial lung disease. (A) Representative muscle sections from NOD.Idd3/5 mice immunized with CFA emulsions of MA/MBP (panel a) or HA/MBP (panel b) demonstrate muscle fiber invasion/degeneration and endomysial inflammation (arrow, panel b). The table summarizes the frequency of muscle inflammation induced by MA/MBP or HA/MBP immunization in comparison to MBP inoculation (*p = 0.10, MA/MBP vs. MBP; **p = 0.09, HA/MBP vs. MBP—Fisher's exact test). (B) Micrographs and grading of lung inflammation 8 weeks following immunization of NOD.Idd3/5 mice. Co-administration of the OX40 agonist antibody OX86 is indicated along with the immunogen on the x-axis of the associated bar graph. Statistical comparison of lung severity scores incorporates all data from at least two independent experiments per cohort (nMA/MBP = 11, nHA/MBP = 10, nMBP = 8) and is again based on the Mann-Whitney U-test.