Respiratory syncytial virus-induced cytokine production by neonatal macrophages.
The induction of immunoregulatory cytokines IL-1 beta, IL-6, IL-12, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) was studied with neonatal (cord blood) monocyte-derived macrophages (MDM) after in vitro infection with respiratory syncytial virus (RSV). The expression of mRNAs for these cytokines in RSV-infected MDM was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). The activities of these cytokines were assayed by ELISA. Significant increase of expression of mRNA for IL-6, IL-12, TNF-alpha and IFN-gamma occurred within 2 h after infection and decreased within 6 h after infection. At 20 h after infection the MDM produced and secreted moderate levels of IL-6 and TNF-alpha; however, no IL-12 and IFN-gamma activities were detected. Moderate IL-1 beta mRNA was expressed before RSV infection, and its expression increased at 2 h after infection. However, no detectable IL-1 beta was secreted in culture fluids. These observations suggest that RSV-infected neonatal macrophages produce and secrete IL-6 and TNF-alpha quickly during the eclipse phase of RSV infection and therefore may play a prominent role in the initiation of the immune response to RSV.
Tsutsumi
H
H
Department of Paediatrics, Sapporo Medical University School of Medicine, Japan.
Matsuda
K
K
Sone
S
S
Takeuchi
R
R
Chiba
S
S
D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D005312:Fetal Blood; D006801:Humans; D007231:Infant, Newborn; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D012136:Respiratory Syncytial Viruses / Q000276:immunology*
D016207:Cytokines; D012333:RNA, Messenger