VARIATIONS IN THE EXPRESSION OF CELL-ADHESION MOLECULES ON LIVER-ASSOCIATED LYMPHOCYTES AND PERIPHERAL-BLOOD LYMPHOCYTES IN PATIENTS WITH AND WITHOUT LIVER METASTASIS

We evaluated the expression of the cell-adhesion molecules (CAM) that might be involved in liver-associated lymphocyte (LAL) contacts with o ther sinusoidal cells and/or be responsible for natural-killer(NI) and lymphokine-activated killer(LAK) activity in patients with liver meta stasis. The LAL population was isolated by sinusoidal high-pressure la vage from partial hepatectomies obtained from patients operated for me tastases (n = 13) and benign liver tumors (n = 9). Surface expression of the beta-2-integrin chains (CD11a, CD11b, CD11c and CD18), and the beta-1-integrin chains (CD49b, CD49d, CD49f and CD29), as well as that of members of the immunoglobulin superfamily (CD2, CD54, CD56 and CD5 8), were analyzed by one- or two-color flow cytometry. Quantitative an d qualitative differences were observed in both groups of patients in the expression of CAM between LAL and peripheral blood lymphocytes (PB L). LAL were characterized by an increase in the percentage of CD11b-, CD49b-, CD49d-, CD54-, CD56- and CD58-positive cells in comparison wi th PBL. Fluorescence values for CD2, CD11a, CD18 and CD56 were higher in LAL than in PBL. Moreover, the population expressing these antigens of differentiation presented a bimodal distribution (dim and bright): in LAL, as opposed to PBL, the percentage of cells with a bright phen otype was greater than of those with a dim one. The increase in CAM ex pression on LAL could be due to the influence of the liver sinusoidal micro-environment. Results were more unexpected for the comparison bet ween benign and malignant tumors. No difference was found in CAM expre ssion on LAL between these 2 categories. Consequently, it cannot be th is factor that explains the decrease in LAK activity of LAL in patient s with metastasis. (C) 1995 Wiley-Liss, Inc.