*2.1. Mice*

Male wild-type mice (8 weeks) on a BALB/c background were obtained from Charles River (Sulzfeld, Germany). Animals were fed a standard chow diet ad libitum with free access to water. All animal experiments were approved by the Regierung von Oberbayern (55.2-1-54-2532-48-2014), Germany.

#### *2.2. EAM Model*

To induce EAM, a purified synthetic peptide of the cardiac myosin heavy chain alpha (Ac-RSLKLMATLFSTYASADR, Caslo, Kongens Lyngby, Denmark) emulsified in complete Freund's adjuvant (CFA, Sigma-Aldrich, St. Louis, MO) was applied subcutaneously (200 μg of cardiac peptide per mouse) at day 1 and day 7. Equal volumes of CFA + PBS were administered for sham controls. In order to block LFA-1, we used a chimeric rat-mouse IgG1 anti-mouse CD11a monoclonal antibody (muM17, Genentech, San Francisco, CA) which was previously described [10]. The antibody was applied subcutaneously (5 μg/g body weight) starting from day 1 once a week until day 21. Control animals were treated with a matching IgG1 isotype antibody (Genentech, San Francisco, CA) or PBS. Sham-immunized controls were treated with PBS. On day 21, mice were sacrificed and hearts were subsequently removed for analysis.

#### *2.3. Histology and Heart Weight*/*Body Weight Ratio*

To evaluate the cardiac tissue histologically, mouse hearts were rinsed with PBS and fixated with PFA 4% (Roth, Karlsruhe, Germany). Analysis of the heart weight/body weight ratio was conducted using a microbalance (CP64-0CE, Sartorius, Göttingen, Germany) after carefully removing the pericardium, connective tissue, and vascular remains. Thereafter, hearts were dehydrated in a graded series of ethanol concentrations and subsequently embedded in paraffin (Sigma-Aldrich, St. Louis, MO, USA). To evaluate infiltration of leukocytes, sections were stained with hematoxylin (Roth) and eosin (Roth, H&E, day 21). The established EAM score (0: no inflammatory infiltrates; 1: small foci of <100 inflammatory cells between myocytes; 2: larger foci of >100 inflammatory cells; 3: >10% of a cross section shows infiltration of inflammatory cells; 4: >30% of a cross section shows infiltration of inflammatory cells) was used to evaluate leukocyte infiltration semi-quantitatively as previously described [2]. Analysis was performed in a blinded manner.
