After washing, 5 × 104–1 × 105 NK T cell hybridomas were cultured in the plate for 16–20 h, and IL-2 in the supernatant was measured by ELISA (BD PharMingen, San Diego, CA, USA). Liver tissues were

collected immediately from animals upon killing, fixed in 4% paraformaldehyde, embedded in paraffin, cut into 4-μm sections, deparaffinized, stained with haematoxylin Doxorubicin solubility dmso and eosin (H&E) and evaluated using light microscopy [36]. Scoring of liver inflammation was performed on coded H&E-stained sections of liver using a set of three indices by a ‘blinded’ pathologist (K.T.); indices including degrees of portal inflammation, parenchymal inflammation and bile duct damage were scored as: 0 = normal, no inflammation (or bile duct damage); 1 = minimal inflammation (or bile duct damage); 2 = mild inflammation (or bile duct damage); 3 = moderate inflammation (or bile duct damage); and 4 = severe inflammation (or bile duct damage). To examine the bile duct pathology, immunochemical staining was performed with a rabbit polyclonal antibody for cytokeratin

(CK) 19, which is an established marker Galunisertib supplier of biliary epithelial cells. Liver sections were immunostained using standard microwave protocol, as described previously [37]. In brief, after deparaffinization and microwave heating for antigen retrieval, rabbit polyclonal antibody against CK19 (Novus Biologicals, Littleton, CO, USA) was applied and incubated under intermittent microwave irradiation. After rinsing with TBS, Envision-peroxidase for rabbit polyclonal antibodies (Dako, Carpenteria, CA, USA) was applied and incubated under intermittent microwave treatment. As a substrate of peroxidase, 3,3′-diaminobenzidine (DAB; Vector, Burlingame, CA, USA) was applied for 5 min. Heamatoxylin was used as a counter-stain. Data are presented as the mean ± standard error of the mean (s.e.m.). over Two-sample comparisons were analysed using the two-tailed unpaired t-test.

The correlation between two parameters was analysed using Spearman’s correlation method. A value of P < 0·05 was considered statistically significant. As shown in Fig. 2a, the levels of anti-PDC-E2, measured as OD values in ELISA using 1:500 diluted serum samples, were significantly higher (P < 0·001) in E. coli-infected mice 4–12 weeks after bacterium infection when compared with the N. aro-infected mice and the uninfected control group. The level of anti-PDC-E2 peaked at 4 weeks after E. coli infection and then gradually decreased to the same level as that of N. aro-infected mice. Anti-PDC-E2 and anti-OGDC-E2 antibodies were detected in the serum of E. coli-infected mice but not N. aro-infected mice, while anti-BCOADC-E2 antibodies were not detected in either group (Fig. 2b). Next we validated the specificity of AMA by immunoblotting, which confirmed the presence of anti PDC-E2 antibodies in both E. coli- and N. aro-infected mice but not in control mice (Fig. 2c).