TRISTETRAPROLIN (TTP) DEFICIENCY
Tristetraprolin (TTP) is a transcription factors that can bind to and destabilize mRNAs encoding TNF-α and granulocyte-macrophage colony-stimulating factor (GM-CSF). Mice deficient in TTP develop a complex syndrome characterized by cachexia, polyarticular arthritis, dermatitis, autoimmunity, and myeloid hyperplasia accompanied by extramedullary hematopoiesis (erythrocyte production outside of the bone marrow). TTP knockout mice exhibit exuberant inflammatory pannus and bony erosions. These mice also produce high titers of anti-DNA, and ANAs; however, rheumathoid factors are absent.