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EFFECT OF INTERFERON‐γ ON THE NEUTROPHIL FUNCTIONAL PROPERTIES
Author(s) -
Duarte Ana Paula Ferreira,
Souza Ivani Aparecida,
Ramos Verônica Santos,
Torres Anelize Sgorlon Pinheiro,
Antunes Edson
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.lb387
Subject(s) - cytokine , immunology , peripheral blood mononuclear cell , chemistry , microbiology and biotechnology , biology , in vitro , biochemistry
Interferon γ (IFN‐g) is a cytokine produced by natural killer T cells implicated in innate and acquired immune response during bacterial infections. Higher levels of this cytokine are suggested to suppress the hematopoiesis, leading to leukopenia that is clinically observed after the resolution of severe infectious. Evidence shows that IFN‐g induces MHC class II overexpression in human circulating neutrophils (NE) and reduces Staphylococcus aureus ‐mouse induced NE infiltration. Our preliminary results have been showing that staphylococcal enterotoxins (SEs; type A and B) are able to inhibit human NE properties such as adhesion and chemotactic response. Whereas, IFN‐g release is reported to contribute to pathological events induced by SEs the aim of the present study was investigate the effect of IFN‐g on the functional properties of human NE. Blood was collected from healthy volunteers after approval from the local ethics committee (Protocol No 61370616.3.0000.5412). Blood samples were placed on isotonic Percoll solution. After centrifugation, the mononuclear cell layer was removed and the pellet containing erythrocytes and granulocytes was aspirated and subjected to isotonic lysis. After lysis cells (98% NE) were resuspended to 4 × 10 6 cells/ml and submitted to in vitro incubation with IFN‐g (10000 IU/ml; 30 min). Adhesion assays were carried out in 96‐well plates pre‐coated with recombinant human VCAM‐1 and ICAM‐1 for 30 min in the presence of interleukin‐8 (IL‐8). The NE adhesion was calculated by measuring myeloperoxidase (MPO) activity on adherent cells. NE migration assay was performed using a 48‐well microchemotaxis Boyden chamber. Prior NE in vitro incubation with IFN‐g reduces human NE adhesion in VCAM‐1 (Control: 4.7 ± 0.5; untreated NE + IL‐8: 6.7 ± 0.6; IFN‐g treated NE+IL‐8: 4.8 ± 0.66 optic density/NE × 10 6 cells; ) or ICAM‐1(Control: 4.3 ± 0.5; untreated NE + IL‐8: 6.1 ± 0.6; IFN‐g treated NE+IL‐8: 3.9 ± 0.48 optic density/NE × 10 6 cells) coated plates. Similar results were observed for NE chemotactic activity (Control: 18.7 ± 0.8; untreated NE +IL‐8: 52.9 ± 2.7; IFN‐g treated NE+IL‐8: 36.4 ± 1.6 NE per high‐power field). These findings support the hypothesis that IFN‐g modulates the inhibitory effects of Staphylococcal enterotoxins on NE functional properties. Support or Funding Information CAPES‐Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (1676187). This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .