Fig. 2

Principle of the development of arthritis. Hereditary and environmental factors synergistically trigger protein mutation or modification. First, the protein mutation results in the activation of immune cells such as macrophages (Møs) and dendritic cells (DCs), leading to hypersensitivity of these cells to TNF, LPS, IL-1, and so on. Second, after modification, the specific peptide of the protein is recognized by DCs, and DCs can also submit abnormal protein fragments to T cells, resulting in the activation of immune cells. Then, NF-κB and MAPK are activated. As a consequence of the activated NF-κB pathway, inflammasomes tend to assemble, pro-inflammatory cytokines and autoantibodies are produced, and immune cells infiltrate. Thereafter, localization of the inflammatory response occurs, and arthritis is initiated