Transcriptome studies on Streptococcus pneumoniae, illustration of early response genes to THP-1 human macrophages.
Pathogen-host interaction plays an essential role in pathogenicity. In this study, we investigated transcriptomes of one Streptococcus pneumoniae TIGR4-derived unencapsulated strain upon exposure to THP-1 human macrophage-like cells for 0.5 h, 1 h and 3 h, respectively. Expression of most genes was up-regulated and the changes of selected genes were validated by qRT-PCR. To characterize the functions of the identified genes, one locus of genes (SP1057-SP1063) was deleted in TIGR4 by insertion replacement mutagenesis. Compared to the wild-type strain, the constructed mutant exhibited lower binding and internalization activities to the THP-1 macrophages at early incubation time periods (0.5 h and/or 1 h) but not at 3 h. However, no change was observed in the intracellular survival assays. These data indicate that the SP1057-SP1063 locus is involved in the early stage of interaction with host macrophages. Further sequence and PCR analyses suggest that the SP1057-SP1063 locus was acquired by lateral transfer.
Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3. xinming.song@usask.ca
Xin-Ming
XM
Song
Wayne
W
Connor
Karsten
K
Hokamp
Lorne A
LA
Babiuk
Andrew A
AA
Potter
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D054884:Host-Pathogen Interactions; D006801:Humans; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology / Q000382:microbiology*; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*
D001426:Bacterial Proteins