IFN-γ alters the expression of diverse immunity related genes in a cell culture model designed to represent maturing neutrophils

• Published in: PloS one 2017-10, Vol.12 (10), p.e0185956-e0185956
• Main Authors: Ellison, Michael A, Gearheart, Christy M, Porter, Christopher C, Ambruso, Daniel R
• Format: Article
• Language: English
• Subjects: Apoptosis; Biocompatibility; Biology and Life Sciences; Biomedical materials; Blood; Blotting, Western; Bone marrow; Cell culture; Cell death; Cell Line; Cell migration; Chemotaxis; Chemotaxis, Leukocyte; Chronic granulomatous disease; CYBB protein; Cytokines; Exposure; Gene expression; Gene Expression Regulation; Genes; Humans; Immune response; Immunity; Immunity, Innate - genetics; Interferon; Interferon-gamma - physiology; Leukemia; Leukocytes (neutrophilic); Lymphocytes; Major histocompatibility complex; Maturation; Medicine and Health Sciences; Microbicides; Muramidase - metabolism; Myeloid cells; NAD(P)H oxidase; NADPH Oxidases - metabolism; Neutrophils; Neutrophils - cytology; Neutrophils - enzymology; Neutrophils - immunology; Oligonucleotide Array Sequence Analysis; Osteopetrosis; Pattern recognition; Pediatrics; Peroxidase - metabolism; Phagocytosis; Proteins; Radioactive half-life; Reactive oxygen species; Signal Transduction; Transcription; γ-Interferon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0185956

The cytokine interferon-γ (IFN-γ) is approved as a drug to treat chronic granulomatous disease (CGD) and osteopetrosis and is also used in hyperimmunoglobulin E syndromes. Patients with CGD have defects in proteins of the NOX2 NADPH oxidase system. This leads to reduced production of microbicidal ROS by PMNs and recurrent life threatening infections. The goal of this study was to better understand how IFN-γ might support phagocyte function in these diseases, and to obtain information that might expand potential uses for IFN-γ. Neutrophils mature in the bone marrow and then enter the blood where they quickly undergo apoptotic cell death with a half-life of only 5-10 hours. Therefore we reasoned that IFN-γ might exert its effects on neutrophils via prolonged exposure to cells undergoing maturation in the marrow rather than by its brief exposure to short-lived circulating cells. To explore this possibility we made use of PLB-985 cells, a myeloblast-like myeloid cell line that can be differentiated into a mature, neutrophil-like state by treatment with various agents including DMSO. In initial studies we investigated transcription and protein expression in PLB-985 cells undergoing maturation in the presence or absence of IFN-γ. We observed IFN-γ induced differences in expression of genes known to be involved in classical aspects of neutrophil function (transmigration, chemotaxis, phagocytosis, killing and pattern recognition) as well as genes involved in apoptosis and other mechanisms that regulating neutrophil number. We also observed differences for genes involved in the major histocompatibility complex I (MHCI) and MHCII systems whose involvement in neutrophil function is controversial and not well defined. Finally, we observed significant changes in expression of genes encoding guanylate binding proteins (Gbps) that are known to have roles in immunity but which have not as yet been linked to neutrophil function. We propose that changes in the expression within these classes of genes could help explain the immune supportive effects of IFN-γ. Next we explored if the effect of IFN-γ on expression of these genes is dependent on whether the cells are undergoing maturation; to do this we compared the effects of IFN-γ on cells cultured with and without DMSO. For a subset of genes the expression level changes caused by IFN-γ were much greater in maturing cells than non-maturing cells. These findings indicate that developmental changes associated with cell maturati