ADHESION MOLECULES AND CYTOKINE PRODUCTION

The exchange of cross-talks between cells relies on soluble factors or direct cell-cell contact. Soluble factors increase the expression of cell surface molecules that activate adjacent cells by direct contact to produce cytokines. In the lung, dendritic cells are potent inducers of T-cell proliferation, and the interaction between the two leads to the production of high amounts of TNF alpha and TNF beta. Of the mole cules involved in these biologic functions, LFA-3 CD11c, and the combi nation of beta(1) and beta(2), integrins are the most efficient. Howev er; blocking TNF alpha or TNF beta production does not af feet the all oreaction. The interaction between activated T cells and monocytes res ulted in a large production of IL-1 beta. In this reaction, CD69, CD2, and the beta 2, integrins (CD11a, b, c, and CD18) and also other mole cules such as a 25- to 35-kD glycoprotein play an important part. Fina lly, interaction between monocytes and fibroblasts leads to the produc tion of large amounts of collagenase and PGE(2) by fibroblasts. Cell-a ssociated IL-1, particularly IL-alpha 1 and membrane-bond TNF alpha, c an also play a crucial role in the process of cell-cell interaction. T his interaction may be controlled by inhibitors to IL-1 and TNF.