Interleukin-1 receptor antagonist inhibits interleukin-8 expression in A549 respiratory epithelial cells infected in vitro with a replication-deficient recombinant adenovirus vector.
In an earlier study, we showed that a recombinant adenovirus vector with deletions in the E1 and E3 regions of the viral genome (AV1LacZ4) induces expression of interleukin (IL)-8 in A549 cells (a human respiratory cell line). IL-8 can be induced through several pathways, including activation by IL-1. We tested the hypothesis that the induction of IL-8 by the AV1LacZ4 adenovirus is accomplished by means of the IL-1/IL-8 activation pathway, which could be blocked by IL-1 receptor antagonist (IRAP). Viral infections of A549 cells were performed at a multiplicity of infection (MOI) of 50 in the presence and absence of IRAP (50 ng/ml). A549 cells were also stimulated with tumor necrosis factor (TNF)-alpha (100 ng/ml), a known stimulant of IL-8, in the presence and absence of IRAP. IL-8 expression was evaluated by Northern blot analysis and enzyme-linked immunosorbent assay. Levels of IL-8 protein and messenger RNA (mRNA) were greater in the infected cells than in the uninfected ones at 24, 48, and 96 h (P < 0.01). Virus-infected cells treated with IRAP expressed 75% less IL-8 mRNA and protein (P < 0.01) than did untreated cells, whereas IRAP pretreatment of TNF-alpha-stimulated cells did not affect IL-8 production. IL-1 production by the virus-infected cells was detectable by concentration of the supernatants and reverse transcription-polymerase chain reaction. We conclude that IL-8 is produced by virus vector-infected cells, partly through IL-1 activation that can be downregulated by IRAP.
Schwarz
Y A
YA
Division of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel. schwarz@tasmc.health.gov.il
Amin
R S
RS
Stark
J M
JM
Trapnell
B C
BC
Wilmott
R W
RW
D000256:Adenoviridae / Q000235:genetics*; D001980:Bronchi / Q000187:drug effects*; D003673:Defective Viruses / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004847:Epithelial Cells / Q000187:drug effects; D005822:Genetic Vectors; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000494:pharmacology / Q000502:physiology; D016209:Interleukin-8 / Q000378:metabolism*; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors*; D011994:Recombinant Proteins / Q000378:metabolism; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000494:pharmacology*; D013997:Time Factors; D014407:Tumor Cells, Cultured
C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D016209:Interleukin-8; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; D012795:Sialoglycoproteins