Adhesion of neutrophils to epidermal cells: prerequisites for and blocking by anti-CD11b antibodies

γ in vitro is a prerequisite for neutrophil binding. Activation of neutrophils with N -formyl-methionyl-leucyl-phenylalanine (fMLP), tumor necrosis factor-α (TNF-α) or platelet activating factor (PAF) then leds to a three- to sixfold increase in neutrophil adhesion. This enhanced binding could be blocked by anti-CD11b monoclonal antibodies, whereas anti-CD11a and anti-CD11c antibodies exerted no significant effect. At a temperature of 6° C, 50% inhibition of neutrophil binding was observed. Complement factor C3 and fibrinogen, known ligands for CD11b/CD18, could not be detected on epidermal cells by immunohistochemistry. In summary, our study showed that enhanced binding of neutrophils to epidermal sections can be achieved by prestimulation of both the keratinocytes with interferon-γ and the neutrophils with fMLP, TNF-α and PAF. This adhesion was furthermore revealed to be dependent on the function of the leucocyte integrin CD11b/ CD18. Received: 21 April 1997