Impact of priming on the response of neutrophils to human neutrophil alloantigen-3a antibodies.
BACKGROUND
Human neutrophil alloantigen-3a (HNA-3a) antibodies can induce transfusion-related acute lung injury (TRALI). The severity of TRALI varies largely among the affected patients. Severe comorbidity seems to increase the susceptibility for TRALI, potentially by priming of neutrophils. Thus, the impact of neutrophil priming on HNA-3a antibody-mediated neutrophil aggregation and CD11b surface expression was investigated.


METHODS
Neutrophils were primed using formyl-methionyl-leucyl-phenylalanine (fMLP) or bacterial lipopolysaccharide (LPS). Granulocyte aggregation and CD11b surface expression were evaluated by the granulocyte agglutination test and by flow cytometry (FC), respectively. Priming-induced changes in the surface expression of choline transporter-like protein 2 (CTL2) and the CTL2 mRNA expression were assessed by FC and quantitative real-time polymerase chain reaction, respectively.


RESULTS
Priming of neutrophils lowered the amount of HNA-3a antibodies required for inducing granulocyte aggregation in a dose-dependent manner by 50% to 75%. The priming agent concentration necessary for this response differed between donors. Priming slightly enhanced binding of HNA-3a antibodies to neutrophils. However, CTL2 de novo synthesis was not induced after priming with LPS, indicating that increased HNA-3a antibody binding was likely caused by translocation of intracellular CTL2 to the surface or by increased affinity of HNA-3a antibodies to CTL2. HNA-3a antibodies influenced CD11b surface expression on neutrophils only marginally, which was also not potentiated by priming with fMLP or LPS.


CONCLUSIONS
This study provides experimental evidence supporting the "threshold model" of TRALI. Priming of neutrophils with fMLP or LPS increases their aggregation response to HNA-3a antibodies by lowering the required antibody amount.
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.|Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.
Tom
T
Berthold
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.|Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.
Stefan
S
Muschter
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.
Nicole
N
Schubert
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.
Jan
J
Wesche
Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.
Sabine
S
Ameling
Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany.
Alexander
A
Teumer
German Red Cross Blood Donation Service West, Hagen, Germany.
Angelika
A
Reil
German Red Cross Blood Donation Service West, Hagen, Germany.
Jürgen
J
Bux
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.
Tamam
T
Bakchoul
Department of Transfusion Medicine, Institute for Immunology and Transfusion Medicine, Greifswald, Germany.
Andreas
A
Greinacher
D000372:Agglutination Tests; D017951:Antigen Presentation / Q000276:immunology*; D016824:Antigens, Human Platelet / Q000276:immunology* / Q000494:pharmacology; D039481:CD11b Antigen / Q000378:metabolism; D002449:Cell Aggregation / Q000276:immunology; D002478:Cells, Cultured; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects / Q000502:physiology*; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000276:immunology / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects / Q000276:immunology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*
C044561:3a alloantigen, human; D016824:Antigens, Human Platelet; D039481:CD11b Antigen; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; C484524:SLC44A2 protein, human; D009240:N-Formylmethionine Leucyl-Phenylalanine