T Lymphocytes Degrade Fibronectin

Abstract
Mononuclear cells cause disappearance of fibronectin synthesized and released by fibroblasts. This disappearance of extracellular fibroblast fibronectin is accompanied by the appearance of components of 'lower' molecular weight indicating that a fibronectin-degrading enzymatic activity is responsible for the effect. Additional support for the existence of a fibronectin-degrading enzyme is that mononuclear cells degrade iodinated fibronectin attached to a collagen matrix. Furthermore, lymphocytes seem to mediate the degradation of fibronectin whereas monocytes rather act inhibitory.