Analysis of Gene Transcription Changes Following Chlamydia pneumoniae Infection of THPl Monocytes May Have Relevance to Alzheimer\u27s Disease

There is increasing evidence that neuroinflammation caused by infectious agents is an important etiologic factor in neurodegenerative diseases including Alzheimer\u27s disease (AD). One infectious agent that has been associated with AD is Chlamydia pneumoniae (Cpn). Cpn DNA can be detected within peripherally circulating mononuclear cells and there is evidence that infected mononuclear cells could be involved in chronic infection and contribute to inflammation at numerous anatomical sites, including the brain. Understanding Cpn genetic changes progressing from an acute to a chronic infection within monocytes may help to further elucidate. the role of Cpn infected monocytes with regard to the neurodegeneration observed within AD. In this study, monocytes were infected in vitro with Cpn (either AR39 or CWL029) for 24, 48, 72, 96, or 120 hours. Subsequently, we investigated transcriptional gene changes of 7 Cpn genes using RT- PCR. We found a significant drop in gene expression at later time points in 3 of the genes. Our results demonstrate differences in gene expression from acute to chronic infection that perhaps indicate a trend towards persistence. However, our data does not unequivocally support that these gene changes are representative of the progression from acute to persistent infection. Future studies are required to resolve these differences and determine important gene changes that indicate persistent Cpn infection within monocytes