Analysis of gene expression in Lassa virus-infected HuH-7 cells.
The pathogenesis of Lassa fever is poorly understood. As the liver is a major target organ of Lassa virus, gene expression in Lassa virus-infected HuH-7 cells, a differentiated human hepatoma cell line, was studied. Cellular mRNA levels were measured at the late phase of acute infection, when virtually all cells expressed large amounts of nucleoprotein, and virus RNA concentration had reached>10(8) copies (ml supernatant)-1. Two types of transcription array were used: cDNA-based macroarrays with a set of 3500 genes (Atlas Human 1.2 arrays; Clontech) and oligonucleotide-based microarrays covering 18,400 transcripts (Human Genome U133A array; Affymetrix). Data analysis was based on statistical frameworks controlling the false-discovery rate. Atlas array data were considered relevant if they could be verified by U133A array or real-time RT-PCR. According to these criteria, there was no evidence for true changes in gene expression. Considering the precision of the U133A array and the number of replicates tested, potential expression changes due to Lassa virus infection are probably smaller than twofold. To substantiate the array data, beta interferon (IFN-beta) gene expression was studied longitudinally in Lassa virus-infected HuH-7 and FRhK-4 cells by using real-time RT-PCR. IFN-beta mRNA levels increased only twofold upon Lassa virus infection, although there was no evidence that the virus inhibited poly(I:C)-induced IFN-beta gene expression. In conclusion, Lassa virus interferes only minimally with gene expression in HuH-7 cells and poorly induces IFN-beta gene transcription.
Müller
Stefanie
S
Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany.
Geffers
Robert
R
Mucosal Immunity Group, German Research Centre for Biotechnology, 38124 Braunschweig, Germany.
Günther
Stephan
S
Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany.
D006528:Carcinoma, Hepatocellular; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D015967:Gene Expression Regulation, Viral; D006801:Humans; D007836:Lassa virus / Q000235:genetics* / Q000302:isolation & purification; D008113:Liver Neoplasms; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012367:RNA, Viral