Rheumatoid Arthritis Synovial Explant Model

To examine RA synovial outgrowths, an ex vivo synovial tissue explant model was utilised [22 (link)]. A total of 50 μl of matrigel (Bio-sciences) was added to each well of a 96-well plate and incubated for 1 h at 37 °C. Following this, RA synovial tissue was sectioned and placed in matrigel wells with RPMI 1640 medium supplemented with 10 % FCS (Gibco-BRL), 10 ml of 1 mmol/l HEPES (Gibco-BRL), penicillin (100 units/ml; Bio-sciences), streptomycin (100 units/ml; Bio-sciences) and fungizone (0.25 μg/ml; Bio-sciences). RA explants were stimulated with TLR2 ligand Pam3CSK4 (1 μg/ml) over a time course of 1–15days. Supernatants were collected every 4 days and replenished with fresh media and experimental agents. Images were taken using a phase-contrast microscope (a Nikon TMS microscope (Nikon Corp., Tokyo, Japan) linked to a Canon S70 camera (Canon Inc., Tokyo, Japan)).