EXPRESSION OF THE INTESTINAL T-LYMPHOCYTE-ASSOCIATED-MOLECULE RECOGNIZED BY THE HML-1 ANTIBODY ON MONONUCLEAR-CELLS FROM HPLV-I-INFECTED SUBJECTS

We investigated the expression of a monoclonal antibody (HML-1) define d antigen that appears on human intestinal T-lymphocytes in HTLV-l-rel ated disease, We studied 25 ATL, and 24 healthy HTLV-I carriers, Patie nts with acute ATL showed a variety of the expression of the HML-1 ant igen (range 0.4-74.8%). HML-1 expression on mononuclear cells (MNCs) i n blood from patients with chronic ATL ranged from 1.7-43.6% (mean 13. 5%). This level of expression was less than that of patients with acut e ATL, but not significantly, In patients with smoldering ATL, the deg ree of patients with acute ATL, but not significantly. In patients wit h smoldering AIL, the degree of expression ranged from 1.6-13.3% (mean 8.0%). In contrast to patients with acute ATL, MNCs from patients wit h acute myelogenous leukemia (AML), acute lymphocytic leukemia (ALL), and B-cell type chronic lymphocytic leukemia (B-CLL) did not express t he HML-1 antigen, except for the 2 patients with ALL. Healthy HTLV-I c arriers and healthy controls also were negative for HML-1 reactivity. In acute ATL, patients with gastrointestinal tract infiltration tended to have high expression of the HML-1 epitope. After stimulation with phytohemagglutinin (PHA), healthy HTLV-I carriers showed significantly increased expression of the HML-1 epitope (P < 0.05). Recently, the b eta 7 integrin family has been found to play a specific role in mucosa l localization or adhesion, and HML-1 protein was found to match the d educed beta 7 N-terminal sequence, We propose that the cellular gene r esponsible for HML-1 epitope expression may, like IL-2, lL-2R, etc., b e transactivated by infection with HTLV-I, and that HML-1 antigen gene expression by HTLV-I infection may lead to infiltration of ATL cells with highly expressed HML-1 epitope into the gut mucosa. (C) 1995 Wile y-Liss, Inc.