ETHANOL IMPAIRS CERTAIN ASPECTS OF NEUTROPHIL ADHESION INVITRO - COMPARISONS WITH INHIBITION OF EXPRESSION OF THE CD18 ANTIGEN

Since ethanol impairs polymorphonuclear leukocyte (PMNL) delivery to inflammatory sites, the effect of ethanol on PMNL adhesiveness was studied in vitro. Ethanol inhibited PMNL aggregation induced by formylmethionylleucylphenylalanine (FMLP) but not by phorbol myristate acetate (PMA), whereas responses to both stimuli were abolished by treating PMNL with monoclonal antibody 60.3 (against the adhesion protein CD18). This antibody also abrogated spontaneous and FMLP-stimulated PMNL adhesion to plastic, whereas ethanol reduced spontaneous but not FMLP-induced adherence. Chemotaxis in Boyden or agarose systems was not diminished by ethanol, but high concentrations of MAb 60.3 inhibited migration under agarose. Nonetheless, up-regulation of cell surface expression of CD18 (assessed by immunofluorescence flow cytometry) induced by FMLP or PMA was similarly reduced by ethanol. Thus, ethanol inhibited only certain aspects of PMNL adhesion, and although the stimulated up-regulation of CD18 expression was reduced it is unlikely that ethanol effects were mediated only by this inhibition.