Dapsone and colchicine inhibit adhesion of neutrophilic granulocytes to epidermal sections.
A frozen section adhesion assay was used to study the influence of dapsone and colchicine on cell-cell adhesion between neutrophils and epidermal cells. Sections were prepared from small punch biopsies from healthy donors after preincubation with IFN-A. Freshly prepared neutrophils were activated with TNF-. or PAF after exposure to dapsone or colchicine, incubated on these sections, and the adhered cells were enumerated after washing. In the presence of dapsone (at concentrations of 0.1-80 Ig/ml) adherence of neutrophils could be blocked dose-dependently and 50% inhibition of adhesion was achieved at a concentration of 10 Ig/ml. Colchicine at concentrations of 10-200 ng/ml inhibited neutrophil binding with a clear correlation between inhibition and colchicine concentration. At a colchicine concentration of 110 ng/ml, 50% blocking was achieved. Since the function of CD11b/ paragraph signCD18 is necessary for neutrophil adhesion in this assay, we monitored CD11b expression on neutrophils after dapsone and colchicine exposure. CD11b expression on neutrophils was significantly reduced 5 h after incubation with dapsone at a concentration of 80 Ig/ paragraph signml, whereas no effects of colchicine on CD11b expression could be demonstrated. Our study showed that both drugs significantly inhibited adhesion between neutrophils and the epidermis.
Modschiedler
K
K
Department of Dermatology, University of Hamburg, Martinistr. 52, 20246 Hamburg, Germany.
Weller
M
M
Wörl
P
P
von den Driesch
P
P
D002448:Cell Adhesion / Q000187:drug effects*; D003078:Colchicine / Q000494:pharmacology*; D003622:Dapsone / Q000494:pharmacology*; D004817:Epidermis / Q000187:drug effects* / Q000502:physiology; D005434:Flow Cytometry; D005629:Frozen Sections; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D016177:Macrophage-1 Antigen / Q000032:analysis; D009504:Neutrophils / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D010972:Platelet Activating Factor / Q000494:pharmacology
D016177:Macrophage-1 Antigen; D010972:Platelet Activating Factor; D007371:Interferon-gamma; D003622:Dapsone; D003078:Colchicine