IMMUNOHISTOCHEMICAL LOCALIZATION OF TRANSFORMING GROWTH FACTOR-BETA(1) IN KAPOSIS-SARCOMA

Immunohistochemical localization of transforming growth factor beta 1 (TGF-beta 1) was studied in Kaposi's sarcoma (KS) tissues obtained fro m autopsy and biopsy materials of patients with and without acquired i mmunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) infection. There was no difference in the localization and distributio n of TGF-beta 1 in KS tissues regardless of the HIV-1 status of the pa tients. Rabbit polyclonal antibodies to synthetic peptides, correspond ing to the first 30 amino acids of mature TGF-beta 1 anti-LC(1-30), an d anti-CC(1-30), were used for localization of intracellular and extra cellular TGF-beta 1. An antibody to a peptide corresponding to amino a cids 266 to 278 of the TGF-beta 1. precursor sequence anti-Pre(266 to 278) was used to detect the TGF-beta 1 precursor and the latency-assoc iated peptide. Intracellular mature TGF-beta 1 was demonstrated in mon onuclear cells, presumably macrophages, within KS tumors but not in sp indle-shaped KS cells. Extracellular mature TGF-beta 1 was localized i n the basement membranes of blood vessels and fibrous capsules of KS t umors. Intracellular reactivity to anti-Pre was localized in vascular smooth muscle cells and pericytes within the tumor, in variable propor tions of spindle-shaped KS cells, and also in macrophage-like cells. T hese cells appear to be the production sites of TGF-beta 1, which may exert paracrine as well as autocrine proliferative effects. Copyright (C) 1995 by W.B. Saundes Company