The Anti-Apoptotic Effect of Respiratory Syncytial Virus on Human Peripheral Blood Neutrophils is Mediated by a Monocyte Derived Soluble Factor
Christopher M Coleman*, 1, Karen Plant1, Susan Newton2, Lynsey Hobson1, Moira K.B Whyte3, Mark L Everard4
Identifiers and Pagination:Year: 2011
First Page: 114
Last Page: 123
Publisher Id: TOVJ-5-114
Article History:Received Date: 10/5/2011
Revision Received Date: 7/7/2011
Acceptance Date: 27/7/2011
Electronic publication date: 18/10/2011
Collection year: 2011
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http: //creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Respiratory Syncytial Virus (RSV) causes annual epidemics of respiratory disease particularly affecting infants. The associated airway inflammation is characterized by an intense neutrophilia. This neutrophilic inflammation appears to be responsible for much of the pathology and symptoms. Previous work from our group had shown that there are factors within the airways of infants with RSV bronchiolitis that inhibit neutrophil apoptosis. This study was undertaken to determine if RSV can directly affect neutrophil survival.
Neutrophils were isolated from citrated venous blood (collected from healthy adult volunteers) by discontinuous plasma: Percoll gradient centrifugation and, in some experiments, further purified by negative immunomagnetic bead selection. The effect of RSV on neutrophil survival was measured by Annexin V-PE /To-Pro-3 staining and by morphological changes, using Dif-Quick staining of cytospins.
Inhibition of neutrophil apoptosis was observed in neutrophils isolated by standard plasma:Percoll gradient when exposed to RSV but not in ultra pure neutrophil preparations. Adding monocytes back to ultra purified preparations restored the effect. The inhibition of apoptosis was observed with both active and UV inactivated virus. The effect is dependent on a soluble factor and appears to be dependent on CD14 receptors on the monocytes.