Interleukin-5 enhances the in vitro adhesion of human eosinophils, but not neutrophils, in a leucocyte integrin (CD11/18)-dependent manner.
Interleukin (IL-5) was found to enhance the adhesion of eosinophils, but not neutrophils, to both microvascular and large vein endothelial cells in a dose-dependent manner. Granulocyte/macrophage-colony-stimulating factor (GM-CSF) and platelet-activating factor (PAF) enhanced both eosinophil and neutrophil adhesion. Significant increases in eosinophil CR3 expression, but not LFA-1, were observed following pre-incubation with PAF, IL-3, IL-5 or GM-CSF. Neutrophil CR3 expression was increased significantly by pre-incubation with PAF or GM-CSF, but not IL-3 or IL-5. Enhanced adhesion to human microvascular endothelial cells (HMVEC) or human umbilical vein endothelial cells (HUVEC) was inhibited by (ranked in order of potency) anti-CR3 alpha = common beta-chain greater than LFA-1 alpha. Anti-p150,95 alpha had no measurable effect. Basal expression of eosinophil CR3 with monoclonal antibody inhibited IL-5-induced eosinophil hyperadherence to HUVEC in a manner almost identical to inhibition in the presence of excess anti-CR3. Thus, a conformational or affinity change in adhesion receptors following activation seems more important than a simple increase in numbers. No inhibition of unstimulated eosinophil adhesion to HMVEC or HUVEC by CD11/18 monoclonal antibody was observed. These findings demonstrate that IL-5 enhances eosinophil, but not neutrophil, adherence reactions, by a mechanism dependent, at least in part, on the CD11/18 family of adhesion glycoproteins.
Department of Allergy and Clinical Immunology, National Heart and Lung Institute, London, UK.
G M
GM
Walsh
A J
AJ
Wardlaw
A
A
Hartnell
C J
CJ
Sanderson
A B
AB
Kay
D015703:Antigens, CD / Q000502:physiology*; D018845:CD11 Antigens; D018821:CD18 Antigens; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D004804:Eosinophils / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D015848:Interleukin-5 / Q000494:pharmacology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D016177:Macrophage-1 Antigen / Q000032:analysis; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology
D015703:Antigens, CD; D018845:CD11 Antigens; D018821:CD18 Antigens; D015848:Interleukin-5; D016169:Lymphocyte Function-Associated Antigen-1; D016177:Macrophage-1 Antigen