Complement deposition was performed as described before(46 (link)). In brief, biotinylated antigens were coupled to FluoSphere NeutrAvidin beads (Thermo Fisher) and to form immune-complexes incubated with 10 μl 1:10 diluted plasma samples for 2h at 37°C. After non-specific antibodies were washed away, immune-complexes were incubated with guinea pig complement in GVB++ buffer (Boston BioProducts, MA, USA) for 20 min at 37°C. EDTA containing PBS (15mM) was used to stop the complement reaction and deposited C3 on beads was stained with anti-guinea pig C3-FITC antibody (MP Biomedicals, CA, USA, 1:100, polyclonal) and analyzed on an iQue analyzer (Intellicyt).