Analysis of Chlamydia pneumoniae infection in mononuclear cells by reverse transcription-PCR targeted to chlamydial gene transcripts
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Published on: June 10, 2020
Laura Mannonen1, Eveliina Markkula, Mirja Puolakkainen
1Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland. laura.mannonen@helsinki.fi
Abstract:
Chlamydia pneumoniae (C. pneumoniae) is an important etiological agent of respiratory infections including pneumonia. C. pneumoniae DNA can be detected in peripheral blood mononuclear cells indicating that monocytes can assist the spread of infection to other anatomical sites. Persistent infection established at these sites could promote inflammation and enhance pathology. Thus, the mononuclear cells are in a strategic position in the development of persistent infection. To investigate the intracellular replication and fate of C. pneumoniae in mononuclear cells, we have established an in vitro model in the human Mono Mac 6 cell line. In the present study, we analyzed the transcription of 11 C. pneumoniae genes in Mono Mac 6 cells during infection by real-time RT-PCR. Our results suggest that the transcriptional profile of the studied genes in monocytes is different from that seen in epithelial cells. Furthermore, our study shows that genes related to secretion are transcribed, and secreted bacterial proteins are also translated during infection of monocytes, creating novel opportunities for the management of chlamydial infection of monocytes.
Insights
Chlamydia pneumoniae (C. pneumoniae) infection in monocytes differs from epithelial cells, with key secretion genes transcribed and translated. This suggests new therapeutic targets for persistent chlamydial infections.
Area of Science:
- Microbiology
- Immunology
- Molecular Biology
Background:
- Chlamydia pneumoniae (C. pneumoniae) is a significant cause of respiratory infections like pneumonia.
- C. pneumoniae DNA in peripheral blood mononuclear cells suggests monocytes facilitate systemic infection spread.
- Persistent C. pneumoniae infections in monocytes may drive inflammation and pathology.
Purpose of the Study:
- To investigate the intracellular replication and fate of C. pneumoniae within monocytes.
- To establish and utilize an in vitro model using the human Mono Mac 6 cell line for studying C. pneumoniae in monocytes.
- To analyze the transcriptional activity of C. pneumoniae genes during monocyte infection.
Main Methods:
- Established an in vitro infection model using the human Mono Mac 6 cell line.
- Infected Mono Mac 6 cells with C. pneumoniae.
- Analyzed the transcription of 11 C. pneumoniae genes using real-time RT-PCR.
Main Results:
- The transcriptional profile of C. pneumoniae genes in monocytes differs from that observed in epithelial cells.
- Genes associated with bacterial secretion pathways are transcribed during monocyte infection.
- Secreted bacterial proteins are translated, indicating active bacterial processes within monocytes.
Conclusions:
- Monocytes play a critical role in the lifecycle and potential persistence of C. pneumoniae.
- The distinct gene expression in monocytes presents unique targets for therapeutic intervention.
- Understanding C. pneumoniae gene transcription in monocytes opens new avenues for managing chlamydial infections.
