T lymphocytes that infiltrate tumors and atherosclerotic plaques produce heparin-binding epidermal growth factor-like growth factor and basic fibroblast growth factor: A potential pathologic role

Despite significant infiltration into tumors and atherosclerotic plaques, the role oft lymphocytes in these pathological conditions is still unclear. We have demonstrated that tumor-infiltrating lymphocytes (TILs) and plaque- infiltrating lymphocytes (PILs) produce heparin-binding epidermal growth factor-like growth factor (HB-EGF) and basic fibroblast growth factor (bFGF) in vitro under nonspecific conditions and in vivo in tumors by immunohistochemical staining. HB-EGF and bFGF derived from TILs and PILs directly stimulated tumor cells and vascular smooth muscle cells (SMCs) in vitro, respectively, while bFGF displayed angiogenic properties. Therefore, T cells may play a critical role in the SMC hyperplasia of atherosclerosis and support tumor progression by direct stimulation and angiogenesis.