Pharmacological Value of Murine Delayed‐type Hypersensitivity Arthritis: A Robust Mouse Model of Rheumatoid Arthritis in C57 BL /6 Mice

In this MiniReview, we summarize the body of knowledge on the delayed‐type hypersensitivity arthritis ( DTHA ) model, a recently developed arthritis model with 100% incidence, low variation and synchronized onset in C57 BL /6 (B6) mice, and compare it to other murine arthritis models. It is desirable to have robust arthritis models in B6 mice, as many transgene strains are bred on this background. However, several of the most widely used mouse model of arthritis cannot be induced in B6 mice without the drawback of lower incidence, reduced severity and higher variation, if at all. DTHA is induced by modifying a classical methylated bovine serum albumin ( mBSA )‐induced DTH response by administering a cocktail of anti‐type II collagen antibodies (anti‐ CII ) between immunization and challenge. Arthritis affects one, predefined paw in which acute inflammation and severe arthritis rapidly develop and peak after 4–7 days. Disease is self‐resolving over the course of around 3 weeks. Disease manifestations resemble those seen in other arthritis models and include bone erosion, cartilage destruction, oedema, pannus and new bone formation. Induction of DTHA is dependent on CD 4 + T cells while B cells are dispensable. The DTHA model is set apart from other murine arthritis models in that it can be induced in B6 mice with 100% incidence and with high and consistent severity. This is the clearest advantage of the model, as the mechanisms of disease and clinical manifestations can be found in other arthritis models. The model holds potential for future modifications that may improve the lack of chronicity.