Chlamydial Heat Shock Protein Research Articles

Highlights of This Issue

Two studies in this issue address the development of informative astrocytoma and glioblastoma (GBM) biomarkers. In the first study, Santosh and colleagues evaluated insulin-like growth factor binding protein isoforms 2, 3, and 5 (IGFBP-2,-3, and -5) in astrocytoma samples. The authors report that mRNA and protein expression levels of these three IGFBP isoforms were associated with increasing grades of astrocytoma malignancy. In the second study, Sreekanthreddy and colleagues used information from glioma microarray databases to identify informative serum biomarkers. The authors identify several novel serum biomarkers for glioblastoma. Specifically, they report that high serum osteopontin (OPN) levels are a poor prognostic indicator in GBMs.There are significant differences in the levels of carcinogenic tobaccospecific nitrosamines (TSNA) found in cigarettes from different countries. In this study, Ashley and colleagues evaluated how TSNA levels in used cigarette butts relate to the amounts of salivary nitrosamines and urinary nitrosamine metabolites of smokers from four different countries. The study reports a direct association between salivary nitrosamine and urinary nitrosamine metabolite levels. In addition, levels of both were significantly reduced in subjects smoking cigarettes with lower TSNA levels (from Canada and Australia) compared to smokers of high TSNA cigarettes (from the United States). These findings provide incentive for countries to adopt known tobacco curing practices that can lower cigarette TSNA levels.Although the bacterium, Chlamydia pneumoniae has been implicated in lung carcinogenesis, the lack of a validated marker for chronic C. pneumoniae infection has hampered the precise estimation of its role in lung cancer. Chaturvedi and colleagues studied the relationship between C. pneumoniae infection and prospective lung cancer risk by assaying the presence of antibodies against Chlamydial heat shock protein-60 (CHSP-60). They report that individuals seropositive for CHSP-60 antibodies had significantly increased lung cancer risk. CHSP-60-related risk did not differ significantly by lung cancer histology or smoking, and CHSP-60 seropositivity was associated with increased risk 2 to 5 years prior to lung cancer diagnosis. This work highlights the potential for lung cancer risk reduction through treatments targeting chronic pulmonary infection and inflammation.To help identify biomarkers that reliably monitor oxidative stress levels in humans, Il'yasova and colleagues report on the responsiveness of urinary biomarkers in breast cancer patients undergoing doxorubicinbased chemotherapy. The study monitored five urinary biomarkers of oxidative lipid modification: four F2-isoprostanes and one oxidative product of uric acid (allantoin). This study found that in all subjects, the levels of all five urinary biomarkers increased following doxorubicin chemotherapy. These encouraging findings suggest the use of these biomarkers to measure oxidative stress levels in humans.

Deficiency of XIAP Leads to Sensitization for Chlamydophila pneumoniae Pulmonary Infection and Dysregulation of Innate Immune Response in Mice

Obligate intracellular Chlamydophila pneumoniae induce apoptosis resistance in host cells to escape eradication by immune effector cells. Apoptosis resistance depends on the increased expression and stabilization of cellular inhibitor of apoptosis proteins (cIAPs) and X-linked inhibitor of apoptosis protein (XIAP). Here we investigated the role of XIAP in experimental pulmonary infection of mice with C. pneumoniae. XIAP knock out (KO) mice were sensitized for C. pneumoniae infection compared with wild type mice. XIAP was involved in lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and endotoxin shock. Hyper-secretion of tumor necrosis factor-alpha and lower NO in LPS-treated KO mouse macrophages revealed its regulatory role in inflammatory responses. Unexpectedly, activating stimuli like LPS, tumor necrosis factor-alpha, or interferon-gamma very efficiently induced apoptotic cell death in KO macrophages but not in wild type macrophages. Cell survival transcription factor nuclear factor kappaB (NF-kappaB) p65 levels were reduced in lungs and pulmonary macrophages of infected KO mice. Furthermore, a reduced CD8 T cell population and their increased sensitivity for concanavalin A and chlamydial HSP60 stimulation revealed a defect in CD8 T cells in XIAP KO mice. These data demonstrated a role of XIAP for the integrity of both innate and cellular immune responses during C. pneumoniae infection.

Characterization of Humoral Immune Responses to Chlamydial HSP60, CPAF, and CT795 in Inflammatory and Severe Trachoma

Chlamydia trachomatis (Ct) remains the leading global cause of preventable blindness. There are limited data on humoral immune responses in trachoma. Evaluating these responses is important for understanding host-pathogen interactions and informing vaccine design. Antibodies to chlamydial heat shock protein 60 (cHSP60) have been associated with infertility and trachomatous scarring. Other proteins, including chlamydial protease-associated factor (CPAF) and a hypothetical protein unique to the family Chlamydiaceae, CT795, elicit strong immune responses in urogenital infections, but their role in trachomatous disease is unknown. This study was conducted to expand on previous cHSP60 findings and evaluate the association of CPAF and CT795 antibodies with ocular Ct infection and disease. Clinical trachoma grading was performed, and conjunctival samples were obtained from individuals with trachomatous trichiasis (TT; one or more inturned eyelashes) or inflammatory trachoma without trichiasis and control subjects without disease, all of whom resided in trachoma-endemic regions of Nepal. Ct infection was determined using commercial PCR. IgG and IgA tear antibodies against cHSP60, CT795, and CPAF fusion proteins were measured by quantitative ELISA. Significantly higher IgG antibody levels were found against cHSP60, CPAF, and CT795 in the inflammatory cases compared with levels in the controls (P < 0.005 for all three). Ct infection was independently associated with IgG antibodies against all three immunogens in the inflammatory cases but not in the controls (P = 0.025, P = 0.03 and P = 0.017, respectively). Only IgG antibodies against CPAF were significantly elevated among the TT cases (P = 0.013). Among individuals with trachoma, IgG antibody responses to CPAF are likely to be both a marker and risk factor for inflammatory trachoma and severe trachomatous disease.

Comparison of five commercial serological tests for the detection of anti-Chlamydia trachomatis antibodies

Screening for Chlamydia trachomatis-specific antibodies is valuable in investigating recurrent miscarriage, tubal infertility and extrauterine pregnancy. We compared here the performance of immunofluorescence (IF) to four other commercial tests in detecting IgG antibodies directed against C. trachomatis: two enzyme-linked immunosorbent assays (ELISAs) using the major outer membrane protein (MOMP) as the antigen, commercialised respectively by Medac and R-Biopharm (RB), one ELISA using the chlamydial heat shock protein 60 (cHSP60) as the antigen (Medac), as well as a new automated epifluorescence immunoassay (InoDiag). A total of 405 patients with (n = 251) and without (n = 154) miscarriages were tested by all five tests. The prevalence of C. trachomatis-specific IgG antibodies as determined by the IF, cHSP60-Medac, MOMP-Medac, MOMP-RB and InoDiag was 14.3, 23.2, 14.3, 11.9 and 26.2%, respectively. InoDiag exhibited the highest sensitivity, whereas MOMP-RB showed the best specificity. Cross-reactivity was observed with C. pneumoniae using IF, MOMP-RB and InoDiag, and Parachlamydia acanthamoebae using the cHSP60 ELISA test. No cross-reactivity was observed between C. trachomatis and the other Chlamydiales (Neochlamydia hartmannellae, Waddlia chondrophila and Simkania negevensis). Given its high sensitivity, the new automated epifluorescence immunoassay from InoDiag represents an interesting alternative. The MOMP-based ELISA of R-Biopharm should be preferred for large serological studies, given the high throughput of ELISA and its excellent specificity.

Immunopathogenic consequences of Chlamydia trachomatis 60 kDa heat shock protein expression in the female reproductive tract

Chlamydia trachomatis is an obligate intracellular bacterium that infects chiefly urogenital and ocular epithelial cells. In some infected women the microorganism migrates to the upper reproductive tract resulting in a chronic, but asymptomatic, infection. The immune response to this infection, production of interferon-gamma and pro-inflammatory cytokines, results in interruption of chlamydial intracellular replication. However, the Chlamydia remains viable and enters into a persistent state. In this form, most chlamydial genes are inactive. An exception is the gene coding for the 60 kDa heat shock protein (hsp60), which is synthesized in increased amounts and is released into the extracellular milieu. The chronic release of chlamydial hsp60 induces a local pro-inflammatory immune response in fallopian tube epithelia and results in scar formation and tubal occlusion. In addition, long-term exposure of the maternal immune system to the chlamydial hsp60 eventually results in the release of tolerance and generation of an immune response that recognizes regions of the chlamydial hsp60 that are also present in the human hsp60. Production of cross-reacting antibodies and cell-mediated immunity to the human hsp60 is detrimental to subsequent pregnancy outcome and may also possibly increase susceptibility to atherosclerosis, autoimmune disorders, or malignancies.

Corrigendum to: Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells

Corrigendum to: Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells

Role of Activins and Inducible Nitric Oxide in the Pathogenesis of Ectopic Pregnancy in Patients with or withoutChlamydia trachomatisInfection

Chlamydia trachomatis infection can lead to pelvic inflammatory disease, ectopic pregnancy (EP), infertility, and chronic pelvic pain in women. Activins and inducible nitric oxide synthase (iNOS) are produced by the human fallopian tube, and we speculate that tubal activins and iNOS may be involved in the immune response to C. trachomatis in humans and their pathological alteration may result in tubal pathology and the development of EP. Blood and fallopian tubes were collected from 14 women with EP. Sera were analyzed by enzyme-linked immunosorbent assay to detect antibodies against chlamydial heat shock protein 60 (chsp60) and the major outer membrane protein of C. trachomatis. Confirmation of C. trachomatis serology was made using the microimmunofluorescence test. The patients were classified into three groups according to their serological results, and immunohistochemistry and quantitative reverse transcription-PCR were performed to investigate the expression of candidate molecules by tubal epithelial cells among the three groups. This is the first study to show an increase in the expression of activin betaA subunit, type II receptors, follistatin, and iNOS within the human fallopian tube of EP patients who were serologically positive for C. trachomatis. A similar expression profile was observed in the fallopian tubes with detectable antibodies only against chsp60. These results were shown at the mRNA and protein levels. We suggest that tubal activin A, its type II receptors, follistatin, and NO could be involved in the microbial-mediated immune response within the fallopian tube, and their pathological expression may lead to tubal damage and the development of EP.

Cervical Epithelial Cells from Chlamydia trachomatis-Infected Sites Coexpress Higher Levels of Chlamydial Heat Shock Proteins 60 and 10 in Infertile Women than in Fertile Women

Background/Aims: The objective of the present study was to examine the possible relationship between the chlamydial heat shock proteins (cHSP) 60 and 10 expression and the damaging sequelae of a Chlamydia trachomatis infection, such as infertility. Methods: Seven fertile and 7 infertile female patients infected with C. trachomatis attending the gynecology outpatient department of Safdarjung hospital (New Delhi, India) were enrolled. The relative transcript levels and intracellular expression of cHSP60 and cHSP10 in cervical cells were assessed using real-time RT-PCR and flow cytometry, respectively. Results: Quantitative real-time RT-PCR analysis showed that transcript levels of both cHSP60 (p = 0.007) and cHSP10 (p = 0.0006) were higher in infertile women than in fertile women. Flow cytometric analysis showed significantly higher intracellular levels of cHSP60 (p = 0.0006) and cHSP10 (p = 0.0041) in fertile women infected with Chlamydia than in infertile women. However, the percentage of double-positive cells (both cHSP60- and cHSP10-expressing cells) were higher (p = 0.0006) in infertile women than in fertile women. Conclusion: Our results suggest that cHSP60 and cHSP10 have a different pattern of expression in infertile women compared to fertile women reflecting a probable difference in the metabolic state of Chlamydia with the presence of an abnormal cryptic form of C. trachomatis in infertile women.

Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells

Clinically, Chlamydia pneumoniae infection and its heat shock protein 60 (cHSP60) may contribute to atherogenesis; however, its underlying mechanisms are largely unknown. The objective of this study was to determine whether cHSP60 could cause endothelial dysfunction in human coronary artery endothelial cells (HCAECs) and porcine coronary arteries. When HCAECs were treated with recombinant cHSP60, endothelial nitric oxide synthase (eNOS) mRNA and protein levels, enzyme activities, cellular NO levels, mRNA stability, and promoter activities were significantly decreased. Superoxide anion production was significantly increased due to the inhibition of mitochondrial membrane potential and catalase and superoxide dismutase (SOD) activities as well as activation of NADPH oxidase. Antioxidant seleno-l-methionine (SeMet) or SOD mimetic MnTBAP effectively blocked cHSP60-induced eNOS downregulation. In addition, cHSP60 activated mitogen-activated protein kinases (MAPKs) including p38, c-Jun-N-terminal kinase/stress-activated protein kinase, and extracellular signal-regulated kinases. Specific chemical inhibitors or their dominant-negative mutant forms of these MAPKs effectively blocked cHSP60-induced eNOS downregulation. cHSP60-induced eNOS downregulation and oxidative stress were also demonstrated in porcine coronary artery rings in vitro. Functionally, endothelium-dependent vasorelaxation was significantly reduced in cHSP60-treated vessels. cHSP60 directly induces eNOS downregulation through oxidative stress and MAPK activation in both HCAECs and porcine coronary arteries, thereby causing endothelial dysfunction.

Cytokine Polymorphisms and Severity of Tubal Damage in Women withChlamydia‐Associated Infertility

Chronic inflammation induced by Chlamydia trachomatis can lead to tubal factor infertility (TFI). To investigate the genetic basis of chlamydial TFI and various manifestations of tubal damage, we studied functional polymorphisms in selected cytokine genes (IL-10 -1082 A/G, -819 T/C, and -592 A/C; IFN-gamma +874 T/A; TNF-alpha -308 G/A; TGF-beta1 codons 10 T/C and 25 G/C; and IL-6 -174 G/C) in 114 women with laparoscopically verified TFI (hereafter known as "cases") and in 176 controls. Evidence of past infection with C. trachomatis was demonstrated in 96 cases by use of a combined test for humoral and cell-mediated immune responses to chlamydial elementary bodies (EBs) and chlamydial heat-shock protein 60 antigens. We found that the IL-10 -1082 AA genotype and the TNF-alpha -308 A allele increased the risk of severe tubal damage in women with infertility associated with C. trachomatis (odds ratio [OR], 7.3 [95% confidence interval {CI}, 1.3-42] and 4.0 [95% CI, 1.0-16], respectively), suggesting that differences in these genes contribute to the wide spectrum of disease manifestations.

Infectious agents and lymphoma development: molecular and clinical aspects

This review is focused on the role of infectious agents in the development of some lymphoma entities. Associations involving bacterial infections mostly regard marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT)-type. Some paradigmatic examples of these associations include the Helicobacter pylori-related gastric MALT lymphoma and the more recently reported links between Chlamydophila psittaci and ocular adnexal MALT lymphomas and Borrelia burgdorferi and cutaneous MALT lymphomas. The well-documented association between Epstein-Barr virus infection and related lymphoproliferative disorders are analysed as an example of lymphotropic virus with tumourigenic activity. Molecular, biological and clinical features as well as therapeutic implications of these associations are analysed and future perspectives in this field are discussed.

Determination of chlamydial load and immune parameters in asymptomatic, symptomatic and infertile women

The regulation of immune response and chlamydial infectious load in the cervix of human females is largely unknown. Infectious load in terms of inclusion-forming units (IFUs) was determined by quantitative cultures in Chlamydia-positive women, in asymptomatic women, women with mucopurulent cervicitis (MPC) and women with fertility disorders (FD). CD4(+), CD8(+), CD14(+) cells, myeloid and plasmacytoid dendritic cells (mDCs and pDCs) in the cervix were quantified by flow cytometry. Cervical cytokines, levels of beta-estradiol and C-reactive protein (CRP) in serum and cervical immunoglobulin A antibody to chlamydial major outer membrane protein antigen, chlamydial heat shock protein 60 and 10 antigens were measured by an enzyme-linked immunosorbent assay. In asymptomatic women, chlamydial load showed significant positive correlations with CD4, mDCs, interleukin-12 (IL-12) and IL-2; however, negative correlations were found with CD8 and IL-8 levels. In women with MPC, chlamydial IFUs correlated positively with CD8, pDC number, IL-8, CRP and interferon-gamma (IFN-gamma). In women with FD, chlamydial load showed a significant positive correlation with the pDC number, IL-10 and estradiol level and a negative correlation with CD4 and IFN-gamma. Overall, these results suggest that the interplay between chlamydial infectious load and host immune responses may be the deciding factor for the clinical condition presented during Chlamydia trachomatis infection.

Induction of Interleukin-18 in Atherosclerotic Patients: A Role for Chlamydia pneumoniae

Objectives: The present work explored gene expression and spontaneous induction of the inflammatory cytokine interleukin-18 (IL-18) in atherosclerotic patients. In addition, the effect of the chlamydial antigen heat shock protein 60 (HSP60) and lipopolysaccharide (LPS) on the induction of this mediator was examined. Subjects and Methods: Detection of IL-18 mRNA and protein level were assessed by in situ hybridization and immunohistochemistry, respectively, in 15 patients with coronary artery disease undergoing angiograms and 15 matching controls. Results: These experiments showed significantly high levels of spontaneously expressed IL-18 mRNA and high protein levels in patients compared to healthy controls (p < 0.0005). Cells stimulated with chlamydial HSP60 (CHSP60) and LPS showed a significantly high expression of IL-18 at the mRNA level (p < 0.0005 for CHSP60 and p < 0.005 for LPS) and an increased production of IL-18 at protein level (p < 0.0005 for CHSP60 and p < 0.005 for LPS). Conclusion: This study demonstrated de novo synthesis of the inflammatory cytokine IL-18 in atherosclerosis and, furthermore, that chlamydial antigens might play a role in the immunopathological events in this disease by generating more inflammatory mediators such as IL-18.

Multiple site sampling does not increase the sensitivity of Chlamydia trachomatis detection in infertility patients

Persistent Chlamydia trachomatis infections are associated with tubal pathology. We studied whether sampling from multiple sites would increase the identification of the infections. Prospective cohort study. Tertiary care facility. Two hundred two infertile women. Smears were taken from the cervix, urethra, high vagina, fimbriae and the Douglas cavity. Blood samples were collected and tubal patency was assessed by pertubation with lipiodol and methylene blue. Detection of C. trachomatis DNA, detection of IgA and IgG antibodies against C. trachomatis, and antibodies against chlamydial heat-shock protein 60, tubal patency. Chlamydia trachomatis was detected in 2 of 202 patients, for an overall prevalence of 1%. In both patients PCR results were positive in the cervical, vaginal, and urethral specimens. Chlamydia trachomatis IgG, IgA, and chlamydial heat-shock protein 60 IgG were significantly more prevalent in women with distal tubal pathology than in those without (26/40 [65.0%] vs. 16/162 [9.9%], 9/40 [22.5%] vs. 7/162 [4.3%], and 34/40 [85.0%] vs. 34/162 [21.0%]). Bacterial colonization was found in 1 of 202 samples from the Douglas cavity. Routine DNA testing for C. trachomatis should be confined to cervical sampling. The association between tubal pathology and seropositivity of IgG, IgA, and cHSP60 IgG was confirmed but did not add clinically valuable information during the diagnostic workup of infertility patients.

The Association of C (–260)→T Polymorphism in CD14 Promoter andChlamydia pneumoniaeInfection in Ischemic Stroke Patients

The C (-260) --> T polymorphism has been reported to regulate CD14 gene expression. It has also been implicated in atherosclerotic diseases, and in addition, it could be a genetic factor responsible for interindividual differences in the susceptibility to Chlamydia pneumoniae infection. This case-control study is aimed at evaluating the association between CD14 promoter polymorphisms, frequency of persistent C pneumoniae infection, and anti-chlamydial heat shock protein 60 (cHsp60) induction in stroke patients. Persistent C pneumoniae infection was observed in 43.3% of control subjects and 53.3% of patients (P = .005). The odds ratio of persistent infection was 3.25 for the CC genotype in stroke patients (P = .018). However, the serologic positive responses to cHsp60 in people with the TT genotype were significantly lower in stroke patients (9.3% vs 38.6%; P < .001). Our findings suggest that persistent C pneumoniae infection is independently associated with stroke in CC genotypes and the lowering of cHsp60 antibody levels in TT genotypes.

Aberrant chlamydial developmental forms in the gastrointestinal tract of pigs spontaneously and experimentally infected with Chlamydia suis

The phenomenon of persistence is well known from in vitro studies, where it is associated with the production of aberrant bodies, but its occurrence in vivo is less well documented. The objective of this study was to search for aberrant bodies in intestinal tissues from pigs, describe their ultrastructure, and investigate the suitability of immunohistochemical staining for chlamydial heat shock protein 60 (cHSP60) to detect such forms. Intestinal tissues derived from pigs naturally and experimentally infected with Chlamydia ( C.) suis were examined by immunohistochemistry, transmission electron microscopy and immunogold electron microscopy. The chlamydial species involved in the natural infection were determined using an Array Tube Microarray to C. suis and Chlamydophila abortus. Ultrastructurally, aberrant bodies were detected in the gut of both naturally and experimentally infected pigs. Immunogold electron microscopy showed that the aberrant bodies were labeled less strongly than the normal forms by antibodies against LPS and cHSP60 respectively. It was concluded that aberrant bodies occur in vivo in pigs and that the gnotobiotic pig model might be suitable for the study of chlamydial persistence in vivo. The antibody against cHSP60 does not appear to be suitable to specifically detect such forms.

Lipopolysaccharide stimulation of trophoblasts induces corticotropin-releasing hormone expression through MyD88

We hypothesized that intrauterine infection may lead to placental corticotrophin-releasing hormone (CRH) expression via Toll-like receptor signaling. To test this hypothesis JEG3 cells were stimulated with lipopolysaccharide (LPS), chlamydial heat shock protein 60, and interleukin (IL)-1. CRH expression was assessed by reverse transcription polymerase chain reaction (RT-PCR). The signaling mechanisms that were involved were examined in transient transfection experiments with beta-galactosidase, CRH-luciferase, cyclic adenosine monophosphate (AMP) response element-luciferase, dominant-negative (DN)-myeloid differentiation primary response gene (MyD88) and DN-toll-IL-1-receptor domain containing adapter inducing interferon (TRIF) vectors. Luciferase activity was determined by luciferase assay. Beta-galactosidase assay was performed to determine transfection efficiency. LPS, chlamydial heat shock protein 60, and IL-1 stimulation led to CRH expression in the JEG3 cells. LPS-induced CRH expression was not due to the autocrine effect of LPS-induced IL-1 because the supernatant from LPS-conditioned JEG3 cells did not induce CRH expression in the naïve cells. DN-MyD88, but not DN-TRIF, blocked the LPS-induced CRH expression. The cAMP response element did not play a role in LPS-induced CRH expression. Toll-like receptor signaling 4 may induce placental CRH expression through MyD88.

Chlamydia trachomatis-Specific Heat Shock Proteins 60 Antibodies can Serve as Prognostic Marker in Secondary Infertile Women

The magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. A predictive serological test for upper genital tract infection would be a desirable diagnostic tool as C. trachomatis infection may lead to various immunopathological sequelae such as infertility, or ectopic pregnancy. Female patients (n = 198) attending gynecology outpatient department of Safdarjung hospital were enrolled for the study and clinically characterized into four groups on the basis of their symptoms; discharge, chronic cervicitis, primary and secondary infertility. Serological detection of C. trachomatis was done by ELISA using specific peptide sequences of major outer membrane protein (MOMP), Chlamydia heat shock protein (cHSP60 and 10). Significant high seropositivity to chlamydial anti-cHSP60 antibodies were detected in patients with secondary infertility. A significant percent of chlamydial reinfection was observed in patients having secondary infertility (82.6%; p < 0.01) and chronic cervicitis (64.28%; p < 0.05). Considering IgG MOMP ELISA as a test standard, anti-cHSP60 antibodies showed higher sensitivity (90.91%) and specificity (89.47%) than cHSP10 ELISA (75.6% and 73.87%) in the secondary infertile group. Further anti-cHSP60 antibodies' detection had a sensitivity of 67.33% and a specificity of 90.67% in secondary infertile women when compared with DFA and PCR. Our data suggest that detection of anti-cHSP60 antibodies would help in early prognosis of immunopathological sequelae in C. trachomatis-infected women and thereby in instituting appropriate therapy for controlling C. trachomatis infection at an early stage.

Inflammatory- and immune responses in relation to bacterial replication in mice following re-infections with Chlamydophila pneumoniae

Investigation of chronic infections with Chlamydophila pneumoniae. BALB/c mice were repeatedly infected with C. pneumoniae and tested during a 1-year period. Production of histamine, IFN-gamma, IL-6 and antibodies was monitored by ELISA. Live bacteria were cultured and DNA was detected by PCR. Cellular immunity was tested by ELISPOT. After re-infections, culture positivity and persistence of DNA in lungs and blood were shorter. Detection of DNA at late time points indicated persistent infection in a few mice. Histamine was produced after primary and re-infections, and the level correlated with the number of viable bacteria in lung. IFN-gamma, IL-6 levels, IgG2/IgG1 ratio, IgA titres, and level of chlamydial heat-shock protein antibodies were higher after re-infections. IgM antibodies were demonstrated even after re-infections. High number of IFN-gamma-producing splenocytes was observed after the third inoculation. These results promote an understanding of the patho- and immune mechanisms after C. pneumoniae re-infections.

In infertile women, cells from Chlamydia trachomatis infected site release higher levels of interferon-gamma, interleukin-10 and tumor necrosis factor-alpha upon heat shock protein stimulation than fertile women

BackgroundThe magnitude of reproductive morbidity associated with sexually transmitted Chlamydia trachomatis infection is enormous. Association of antibodies to chlamydial heat shock proteins (cHSP) 60 and 10 with various disease sequelae such as infertility or ectopic pregnancy has been reported. Cell-mediated immunity is essential in resolution and in protection to Chlamydia as well as is involved in the immunopathogenesis of chlamydial diseases. To date only peripheral cell mediated immune responses have been evaluated for cHSP60. These studies suggest cHSPs as important factors involved in immunopathological condition associated with infection. Hence study of specific cytokine responses of mononuclear cells from the infectious site to cHSP60 and cHSP10 may elucidate their actual role in the cause of immunopathogenesis and the disease outcome.MethodsFemale patients (n = 368) attending the gynecology out patient department of Safdarjung hospital, New Delhi were enrolled for the study and were clinically characterized into two groups; chlamydia positive fertile women (n = 63) and chlamydia positive infertile women (n = 70). Uninfected healthy women with no infertility problem were enrolled as controls (n = 39). cHSP60 and cHSP10 specific cytokine responses (Interferon (IFN)-gamma, Interleukin (IL)-10, Tumor Necrosis Factor (TNF)-alpha, IL-13 and IL-4) were assessed by ELISA in stimulated cervical mononuclear cell supernatants.ResultscHSP60 and cHSP10 stimulation results in significant increase in IFN-gamma (P = 0.006 and P = 0.04 respectively) and IL-10 levels (P = 0.04) in infertile group as compared to fertile group. A significant cHSP60 specific increase in TNF-alpha levels (P = 0.0008) was observed in infertile group as compared to fertile group. cHSP60 and cHSP10 specific IFN-gamma and IL-10 levels were significantly correlated (P < 0.0001, r = 0.54 and P = 0.004, r = 0.33 respectively) in infertile group.ConclusionOur results suggest that exposure to chlamydial heat shock proteins (cHSP60 and cHSP10) could significantly affect mucosal immune function by increasing the release of IFN-gamma, IL-10 and TNF-alpha by cervical mononuclear cells.