*4.3. Micro-CT*

The right hind paws of mice were scanned under anesthesia with i.p. ketamine (120 mg/kg; Calypsol, Gedeon Richter, Budapest, Hungary) and xylazine (6 mg/kg; Sedaxylan, Eurovet Animal Health, Bladel, The Netherlands) using a SkyScan 1176 in vivo micro-CT system (Bruker, Kontich, Belgium). A 0.5 mm Al filter was used, the voxel size was 17.5 μm, tube voltage was 50 kV, tube current was set to 500 μA. 3D reconstructions of the scans were made with the CT Analyzer software, and representative pseudocolor images were generated to highlight bone erosions and osteophyte formation.

#### *4.4. In Vitro Spleen Cell Culture*

Spleens were isolated and homogenized mechanically, then the spleen cells were cultured in DMEM supplemented with 10% fetal calf serum on 48-well plates (1.8 <sup>×</sup>106 cells in 600 <sup>μ</sup>L medium/well), in the presence or absence of 1.5 μg rhG1 antigen for 5 d. Supernatants were collected and stored in −20 ◦C and later used for ELISA measurements.

#### *4.5. Antigen-Specific Proliferation Assay*

Another part of the spleen cells were cultured in DMEM supplemented with 10% fetal calf serum, in the presence or absence of 1.5 <sup>μ</sup>g rhG1 antigen in triplicates on 96-well plates (3 <sup>×</sup> 105 cells in 200 μL medium/well) for 5 d. Promega CellTiter96® Nonradioactive Cell Proliferation Assay (Promega, Madison, WI, USA) was used to measure the proliferation rate according to the manufacturer's instructions.
