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Human neutrophil antigen‐3a antibodies induce neutrophil stiffening and conformational activation of CD11b without shedding of L‐selectin
Author(s) -
Berthold Tom,
Glaubitz Michael,
Muschter Stefan,
Groß Stefan,
Palankar Raghavendra,
Reil Angelika,
Helm Christiane A.,
Bakchoul Tamam,
Schwertz Hansjörg,
Bux Jürgen,
Greinacher Andreas,
Delcea Mihaela
Publication year - 2015
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.13299
Subject(s) - integrin alpha m , antibody , fibrinogen , immunology , pathogenesis , neutrophil extracellular traps , cd18 , flow cytometry , chemistry , granulocyte , p selectin , cell adhesion molecule , selectin , platelet , microbiology and biotechnology , inflammation , medicine , platelet activation , biology , biochemistry
BACKGROUND HNA‐3a antibodies induce severe transfusion‐related acute lung injury (TRALI) in which neutrophils play a major role. As neutrophil passage through the pulmonary microvasculature is a critical step in the pathogenesis of TRALI, we investigated the impact of HNA‐3a antibodies on two important factors that could impair granulocyte passage through lung capillaries: the elasticity of neutrophils and the expression and activation of adhesion molecules. STUDY DESIGN AND METHODS The impact of HNA‐3a antibodies on the elasticity of neutrophils was investigated using atomic force microscopy (AFM). Neutrophils were settled on poly‐2‐hydroxyethyl‐methacrylate–coated glass slides before treatment with anti‐HNA‐3a plasma samples, control plasma, or control plasma containing formyl‐methionyl‐leucyl‐phenylalanine (fMLP). Elasticity measurements were carried out in a temperature‐controlled perfusion chamber using an atomic force microscopy (AFM) device. The impact of HNA‐3a antibodies on the surface expression of total CD11b, activation of CD11b, and L‐selectin (CD62L) shedding was investigated by flow cytometry. The functional impact of HNA‐3a antibodies on neutrophil adhesion was assessed using fibrinogen‐coated plates. RESULTS HNA‐3a antibodies induced stiffening of neutrophils (+24% ‐ 40%; p < 0.05) to a similar extent as fMLP. This effect was blocked by treatment of neutrophils with cytochalasin D. While total surface expression of CD11b and L‐selectin on neutrophils was largely unaffected, HNA‐3a antibodies induced alloantigen‐specific activation of CD11b (+72% ‐ 107%; p < 0.05) and increased adhesion of neutrophils to fibrinogen. CONCLUSION Accumulation of neutrophils in the pulmonary microvasculature during severe TRALI is likely mediated by increased rigidity and CD11b‐mediated adhesion of neutrophils leading to retention of neutrophils.