Real time PCR for detection of Chlamydophila pneumoniae in peripheral blood mononuclear cells of patients with multiple sclerosis

Chlamydia trachomatis and Chlamydia pneumoniae Interaction with the Host: Latest Advances and Future Prospective

Research in Chlamydia trachomatis and Chlamydia pneumoniae has gained new traction due to recent advances in molecular biology, namely the widespread use of the metagenomic analysis and the development of a stable genomic transformation system, resulting in a better understanding of Chlamydia pathogenesis. C. trachomatis, the leading cause of bacterial sexually transmitted diseases, is responsible of cervicitis and urethritis, and C. pneumoniae, a widespread respiratory pathogen, has long been associated with several chronic inflammatory diseases with great impact on public health. The present review summarizes the current evidence regarding the complex interplay between C. trachomatis and host defense factors in the genital micro-environment as well as the key findings in chronic inflammatory diseases associated to C. pneumoniae.

Chlamydophila pneumoniae Infection and Its Role in Neurological Disorders

Chlamydophila pneumoniae is an intracellular pathogen responsible for a number of different acute and chronic infections. The recent deepening of knowledge on the biology and the use of increasingly more sensitive and specific molecular techniques has allowed demonstration of C. pneumoniae in a large number of persons suffering from different diseases including cardiovascular (atherosclerosis and stroke) and central nervous system (CNS) disorders. Despite this, many important issues remain unanswered with regard to the role that C. pneumoniae may play in initiating atheroma or in the progression of the disease. A growing body of evidence concerns the involvement of this pathogen in chronic neurological disorders and particularly in Alzheimer's disease (AD) and Multiple Sclerosis (MS). Monocytes may traffic C. pneumoniae across the blood-brain-barrier, shed the organism in the CNS and induce neuroinflammation. The demonstration of C. pneumoniae by histopathological, molecular and culture techniques in the late-onset AD dementia has suggested a relationship between CNS infection with C. pneumoniae and the AD neuropathogenesis. In particular subsets of MS patients, C. pneumoniae could induce a chronic persistent brain infection acting as a cofactor in the development of the disease. The role of Chlamydia in the pathogenesis of mental or neurobehavioral disorders including schizophrenia and autism is uncertain and fragmentary and will require further confirmation.

Chlamydia pneumoniae induces T cell apoptosis through glutathione redox imbalance and secretion of TNF-alpha

Chlamydia pneumoniae persistent infection has been implicated in the pathogenesis of several chronic inflammatory diseases including atherosclerosis, and we hypothesized that modulation of the apoptosis of macrophages and/or T cells by C. pneumoniae infection may contribute to the development of such diseases. We therefore evaluated apoptosis, cytokine response, and redox status in human primary T cells and macrophages infected with C. pneumoniae. In addition, co-cultures of T cells and macrophages infected with C. pneumoniae were also carried out. Apoptosis, and levels of glutathione (GSH), glutathione disulfide (GSSG), and tumour necrosis factor (TNF)-alpha were measured by flow cytometry, high performance liquid chromatography and enzyme-linked immunosorbent assay. C. pneumoniae induced apoptosis in T cells as well as in co-cultures of T cells and infected macrophages by marked decrease in GSH/GSSG ratio and increased production of TNF-alpha, respectively. The results demonstrate that interaction of C. pneumoniae with T cells and/or macrophages characterized by interference with redox status, and secretion of tumour necrosis factor-alpha culminates in the induction of T cell apoptosis and survival of infected macrophages. In conclusion, the inappropriate T cell response against C. pneumoniae and survival of infected macrophages could explain the persistence of this intracellular obligate pathogen in the host-organism; it may contribute to the development of chronic inflammatory diseases, although further studies are needed to clarify such a complex mechanism.

Chlamydia Pneumoniae and Chronic Diseases with a Great Impact on Public Health

Chlamydia pneumoniae is recognised as a common cause of respiratory tract infections and has recently been implicated in several extrapulmonary chronic diseases, with great impact on public health, such as atherosclerosis, multiple sclerosis and Alzheimer's disease. The involvement of C. pneumoniae in such diseases may be correlated to characteristic features of this pathogen, including intracellular growth and ability to induce persistent forms. C. pneumoniae persistent forms are inherently more suited to evade the host immune response and are more difficult to eradicate by antibiotics. Our preliminary experimental findings show that interaction of C. pneumoniae with macrophages and/or T cells characterized by interference with TNF-α production, and redox state, culminates in the induction of T cell apoptosis and survival of infected macrophages. Based on our evidence, the poor cooperation between T cells and macrophages could lead to an inappropriate immune response against C. pneumoniae that may therefore promote the development of extrapulmonary chronic diseases.

No evidence of involvement of Chlamydia pneumoniae in lung cancer by means of quantitative real-time polymerase chain reaction

Chlamydia pneumoniae, an obligate intracellular pathogen, is well-known as etiological agent of acute respiratory infections; the repeated or prolonged exposure to chlamydial antigens may promote the persistence of C. pneumoniae in the respiratory tract leading to chronic diseases, such as chronic obstructive pulmonary disease and asthma. The predilection of C. pneumoniae to cause respiratory tract infections combined with its persistent nature suggest that it might play a role in lung cancer. The aim of our study is to evaluate the involvement of C. pneumoniae in pathogenesis of lung cancer. We therefore investigated the presence of C. pneumoniae DNA in tumor lung tissues by using real-time PCR assay. Simultaneously, tumor and healthy tissues from the same patient with primary carcinoma lung were analyzed. C. pneumoniae DNA was not detected in a single lung tumor tissue by means of an highly sensitive, and specific real-time PCR assay based on FRET hybridization probes. In conclusion, this study does not support the involvement of C. pneumoniae in the pathogenesis of lung cancer, suggesting that further investigations are needed to clarify other potential causative factors for the development of this malignancy.

Chlamydophila pneumoniae DNA and mRNA transcript levels in peripheral blood mononuclear cells and cerebrospinal fluid of patients with multiple sclerosis

Chlamydophila pneumoniae DNA and mRNA transcripts were investigated by PCR and RT-PCR in fresh CSF and PBMC specimens co-cultured in Hep-2 cell lines and collected from 14 patients with definite RR MS and 19 patients with other inflammatory (OIND) and non-inflammatory (NIND) neurological controls. A positivity for C. pneumoniae DNA and mRNA was detected in CSF and PBMCs of 9 RR MS patients (64.2%) with evidence of disease activity, whereas only 3 controls were positive for Chlamydial DNA. These preliminary findings suggest that C. pneumoniae may occur in a persistent and metabolically active state at both peripheral and intrathecal levels in MS, but not in OIND and NIND.