Modeling Autoimmune Arthritis in Mice

Following one week of acclimatization feeding, SPF DBA/1 mice (male, six-week-old, 18-20 g) were randomly divided into two groups (n = 6) as follows: the model group (MG, type II bovine collagen + Freund’s complete adjuvant/Freund’s incomplete adjuvant) and NC group (CG, saline). On day 0, the mice in the MG were subcutaneously injected with 100 μL of 1:1 type II bovine collagen and Freund’s complete adjuvant (Chondrex, Redmond, WA, USA) at multiple points of the caudal root. After 21 days, the same mice were injected with 1:1 type II bovine collagen + Freund’s incomplete adjuvant (Chondrex, Redmond, WA, USA). As per established scoring criteria [58 (link)], a score > 4 was considered to indicate successful modeling. Following successful modeling, peripheral blood was obtained from the mice, and PBMCs were isolated according to the instructions of the whole blood single nucleated cell isolation solution (Solarbio, Beijing, China). Total RNA was extracted by using TRIzol (Thermo Fisher, Waltham, MA, USA). This study was approved by the Guangzhou Medical University Ethics Committee.