Fig. 3: Antibodies specific to the immunomodulatory domain in mice mimic some features of human anti-Jo-1-positive antisynthetase syndrome.

a Anti-HARS antibody titers in serum (left panel) and BALF (right panel) were measured by ECLIA. Immunized animals were all titer positive. The dotted line represents the limit of quantitation, and the bars represent the mean ± SEM. b Serum and BALF HARS were measured by ECLIA in control animals (naive), vehicle with control antigen, mouse HARS (mHARS), or mouse HARS WHEP domain (mWHEP). Serum HARS levels were reduced in both sets of immunizations (***p < 0.005, **p < 0.01; one-way ANOVA). BALF HARS levels were suppressed in immunized animals (**p < 0.01; one-way ANOVA). c Representative images of the right soleus from mice subjected to vehicle treatment (Sham Vax), mouse HARS or mouse HARS WHEP immunization followed by intramuscular (right tibialis anterior, gastrocnemius and quadriceps) injection with vehicle or cardiotoxin. Note the lack of immune cell infiltration in animals immunized with HARS WHEP in the absence of cardiotoxin, and also note the exacerbated inflammatory infiltrate in animals receiving cardiotoxin in the presence of antibodies against the HARS WHEP domain. x20 magnification. d Quantification of soleus muscle degeneration and inflammation based on the following semiquantitative scoring system: 0 = no significant lesion; minimal change = 1; mild change = 2; moderate change = 3; and marked change = 4. A score of 1 may, and often does, represent an incidental lesion that could be found randomly in normal animals. *p < 0.05, one-way ANOVA. e Representative H&E images of the lungs from animals that were naive or subjected to control immunization (Sham Vax), mHARS, or mWHEP immunization, and were then challenged with bleomycin. x10 magnification. f Upper left panel: the latency time required to become anesthetized by the inhaled anesthetic isoflurane was lengthened in animals challenged with bleomycin, suggesting impaired gas exchange in these animals. The latency time was even greater in animals immunized with mWHEP prior to bleomycin challenge. Upper right panel: the number of live cells isolated from the mediastinal lymph nodes of mice immunized with mWHEP and challenged with bleomycin is greater than the number present in sham-immunized bleomycin-challenged animals. Lower panels: the number of activated CD4 + (left) and CD8 + T cells (right) isolated from the mediastinal lymph nodes of mice immunized with mWHEP and challenged with bleomycin is greater than the number present in sham-immunized bleomycin-challenged animals. *p < 0.05, ***p < 0.001 one-way ANOVA followed by Dunnett’s post hoc vs. Vehicle vax/BLM challenged group.