title: Differential changes in gene expression in human neutrophils following TNF-α stimulation: Up-regulation of anti-apoptotic proteins and down-regulation of proteins involved in death receptor signaling.
abstract: Responses of human neutrophils to TNF-α are complex and multifactorial. Exposure of human neutrophils to TNF-α in vitro primes the respiratory burst, delays apoptosis and induces the expression of several genes including chemokines, and TNF-α itself. This study aimed to determine the impact of TNF-α exposure on the expression of neutrophil genes and proteins that regulate apoptosis. Quantitative PCR and RNA-Seq, identified changes in expression of several apoptosis regulating genes in response to TNF-α exposure. Up-regulated genes included TNF-α itself, and several anti-apoptotic genes, including BCL2A1, CFLAR (cFLIP) and TNFAIP3, whose mRNA levels increased above control values by between 4-20 fold (n = 3, P < 0.05). In contrast, the expression of pro-apoptotic genes, including CASP8, FADD and TNFRSF1A and TNFRSF1B, were significantly down-regulated following TNF-α treatment. These changes in mRNA levels were paralleled by decreases in protein levels of caspases 8 and 10, TRADD, FADD, TNFRSF1A and TNFRSF1B, and increased cFLIP protein levels, as detected by western blotting. These data indicate that when neutrophils are triggered by TNF-α exposure, they undergo molecular changes in transcriptional expression to up-regulate expression of specific anti-apoptotic proteins and concomitantly decrease expression of specific proteins involved in death receptor signaling which will alter their function in TNF-α rich environments.
authors.affiliation: Institutes of Integrative BiologyUniversity of LiverpoolLiverpoolUnited Kingdom; Immunology Unit & Center of Excellence in Immunology and Immune-mediated DiseaseDepartment of Microbiology, Faculty of Medicine, Chulalongkorn UniversityBangkokThailand.
authors.forename: Direkrit
authors.initials: D
authors.lastname: Chiewchengchol
authors.affiliation: Institutes of Integrative Biology University of Liverpool Liverpool United Kingdom.
authors.forename: Helen L
authors.initials: HL
authors.lastname: Wright
authors.affiliation: Institutes of Integrative Biology University of Liverpool Liverpool United Kingdom.
authors.forename: Huw B
authors.initials: HB
authors.lastname: Thomas
authors.affiliation: Institutes of Integrative Biology University of Liverpool Liverpool United Kingdom.
authors.forename: Connie W
authors.initials: CW
authors.lastname: Lam
authors.affiliation: Institutes of Integrative Biology University of Liverpool Liverpool United Kingdom.
authors.forename: Kate J
authors.initials: KJ
authors.lastname: Roberts
authors.affiliation: Immunology Unit & Center of Excellence in Immunology and Immune-mediated Disease Department of Microbiology, Faculty of Medicine, Chulalongkorn University Bangkok Thailand.
authors.forename: Nattiya
authors.initials: N
authors.lastname: Hirankarn
authors.affiliation: Translational Medicine University of Liverpool Liverpool United Kingdom.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Beresford
authors.affiliation: Ageing and Chronic Disease University of Liverpool Liverpool United Kingdom.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Moots
authors.affiliation: Institutes of Integrative Biology University of Liverpool Liverpool United Kingdom.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Edwards
keywords: Death receptor signaling; TNF receptors; neutrophils