IgA-induced chemokinesis of human polymorphonuclear neutrophils: requirement of their Fc-alpha receptor.
The influence of purified human immunoglobulins on the migration of human neutrophils (PMN) was measured in a 48-well micro chemotaxis chamber, with results expressed as percentages of maximal formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated chemotaxis. Both monomeric and polymeric IgA, of both subclasses, in monoclonal and polyclonal form, as well as secretory IgA and Fc-alpha, but not Fab-alpha fragments, enhanced PMN migration when present either in the lower or in both compartments of the chamber (chemokinesis) at concns as low as 0.1 mg/ml. IgM and IgE had no such effect. In contrast, IgG was chemotactic at low concn (0.1 mg/ml). Both monomeric and polymeric IgA decreased the maximally induced FMLP-chemotaxis, but IgA increased chemotaxis induced by suboptimal levels of FMLP. Binding of 3[H]-FMLP to PMN was not affected. Cytofluorographic analysis revealed that, under the conditions of the assay, IgA did bind to 93% of PMN. Thus, the various forms of IgA have a dual effect on human PMN mobility: (1) increase PMN random migration (chemokinesis); and (2) decrease the maximal FMLP-induced chemotaxis. Our data support the requirement of binding of IgA to the Fc-alpha receptor of PMN for expression of these activities. This effect of IgA on PMN mobility may be relevant in IgA deficiency states.
Sibille
Y
Y
Department of Internal Medicine, Catholic University of Louvain, Brussels, Belgium.
Delacroix
D L
DL
Merill
W W
WW
Chatelain
B
B
Vaerman
J P
JP
D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D002465:Cell Movement; D002634:Chemotaxis, Leukocyte; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007128:Immunoglobulin Fragments / Q000276:immunology; D007136:Immunoglobulins / Q000276:immunology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology / Q000502:physiology*; D011961:Receptors, Fc / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C036832:Fc(alpha) receptor; D007070:Immunoglobulin A; D007128:Immunoglobulin Fragments; D007136:Immunoglobulins; D011961:Receptors, Fc; D009240:N-Formylmethionine Leucyl-Phenylalanine