Lymphocyte proliferative responses to chlamydial antigens in human chlamydial eye infections

Bioinformatics Analysis of Potential Candidates for Therapy of TDRD7 Deficiency-Induced Congenital Cataract

AIMS

The aim of this study was to identify potential candidates and explore the possible mechanism in congenital cataract induced by tudor domain-containing 7 (TDRD7) deficiency.

METHODS

The gene expression profile GSE25812 generated from 18 samples was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between disease and normal groups were identified. Then, gene ontology and pathway enrichment analysis of DEGs were performed. The protein-protein interaction (PPI) network and transcription factor (TF) regulatory network were constructed. The modules in the PPI network were identified. Significant target genes were selected from the TF regulatory network.

RESULTS

A total of 329 DEGs were obtained, and downregulated DEGs were significantly enriched in biological processes including defense response and immune response. In the PPI network, high-degree genes of complement component 1, q subcomponent, A/B/C chain (C1QA/C1QB/C1QC), lymphocyte antigen 86 (LY86) and neuroblastoma RAS viral oncogene homolog (NRAS) were identified. From the TF regulatory network, the heat shock 27 kDa protein 1 (HSPB1) was the target of the estrogen receptor 1, and LY86 was the target of the v-myc avian myelocytomatosis viral oncogene homolog.

CONCLUSION

HSPB1, NRAS, immune response, defense response and the related genes LY86, C1QA/C1QB/C1QC may play an important role in the development of congenital cataract induced by TDRD7 deficiency. However, further experiments are still needed.

Chlamydia vaccine candidates and tools for chlamydial antigen discovery

The failure of the inactivated Chlamydia-based vaccine trials in the 1960s has led researchers studying Chlamydia to take cautious and rational approaches to develop safe and effective chlamydial vaccines. Subsequent research efforts focused on three areas. The first is the analysis of the immunobiology of chlamydial infection in animal models, with supporting clinical studies, to identify the immune correlates of both protective immunity and pathological responses. Second, recent radical improvements in genomics, proteomics and associated technologies have assisted in the implementation of creative approaches to search for suitable vaccine candidates. Third, progress in the analysis of host response and adjuvanticity regulating both innate and adaptive immunity at the mucosal site of infection has led to progress in the design of optimal delivery and adjuvant systems for enhancing protective immunity. Considerable progress has been made in the first two areas but research efforts to better define the factors that regulate immunity at mucosal sites of infection and to develop strategies to boost protective immunity via immunomodulation, effective delivery systems and potent adjuvants, have remained elusive. In this article, we will summarize progress in these areas with a focus on chlamydial vaccine antigen discovery, and discuss future directions towards the development of a safe and effective chlamydial vaccine.

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility

BACKGROUND

To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI).

METHODS

Blood samples were taken from 88 women with TFI and 163 control women. C. trachomatis and chlamydial heat shock protein 60 (CHSP60)-specific immunoglobulin G (IgG) antibodies were analysed using enzyme-linked immunosorbent assay (ELISA) kits. Proliferative reactivity of peripheral blood mononuclear cells was studied in vitro against Chlamydia elementary body (EB) and recombinant CHSP60 antigens.

RESULTS

C. trachomatis-specific IgG antibodies were found more frequently (43.2 versus 13.5%), and the antibody levels were higher in the TFI cases than in the controls (P < 0.001). C. trachomatis EB-induced lymphocyte responses were positive in 81.8% of the TFI cases and 58.9% of the controls (P < 0.001). Similarly, CHSP60-induced lymphocyte responses were found in 45.5% of the TFI cases and 30.7% of the controls (P < 0.001). CHSP60 antibody test was the best single test predicting TFI. Compared to cases with all four markers negative, the estimated risk for TFI was 4.1 (95% CI 1.4-11.9) among those with one positive marker and 19.9 (95% CI 6.9-57.4) among those with three to four positive markers.

CONCLUSION

Our results show that TFI prediction model can be improved by combining tests for humoral and CMI response to chlamydial antigens.

Trachoma: new assault on an ancient disease

Trachoma is the leading infectious cause of blindness worldwide. The World Health Organization (WHO) estimated that approximately 5.9 million persons are blind or have severe vision-loss as a result of trachoma, and another 10 million are at high risk. Trachoma preferentially affects the most deprived communities, and within these communities, women and children bear the brunt of the burden. In recent years, there has been a renewed focus on research and heightened enthusiasm for strengthening trachoma control programs in afflicted countries. WHO has convened an alliance of member countries, non-governmental organizations, and other partners for the Global Elimination of Blinding Trachoma by the year 2020, and endorsed the multi-faceted SAFE strategy for trachoma control. SAFE-Surgery, Antibiotics, Face-washing, and Environmental improvement-has incorporated sound research on elements likely to reduce trachoma, and trachomatis blindness, in endemic communities. This review summarizes current knowledge about trachoma and its causative agent, Chlamydia trachomatis, the epidemiology and risk factors for trachoma as a prelude to reviewing the SAFE strategy. While ongoing research to support the knowledge base for SAFE must continue to be a priority, the full implementation of SAFE is the best hope for countries to reduce the global burden of blindness from this preventable cause.

Current problems of perinatal Chlamydia trachomatis infections

Chlamydia trachomatis has been recognized as a pathogen of trachoma, nongonococcal urethritis, salpingitis, endocervicitis, pelvic inflammatory disease, inclusion conjunctivitis of neonates, follicular conjunctivitis of adults, infantile pneumonia and associated conditions. Chlamydial infections during pregnancy may also cause a variety of perinatal complications. Different antigenic strains of C. trachomatis from endocervical, nasopharyngeal and conjunctival origins have been associated with different clinical conditions. Control programs emphasizing early diagnosis, targeted screening, and effective treatment will lead to an eventual decline in the incidence of perinatal chlamydial infection. This review focuses on current problems of perinatal C. trachomatis infections in the aspects of microbiological and immunological pathogenesis.

Cell-mediated immune response during primary Chlamydia pneumoniae infection

The development of Chlamydia pneumoniae-specific cell-mediated immunity was studied during a primary C. pneumoniae infection. The immune response was detected as positive lymphocyte proliferation and secretion of interferon gamma. C. pneumoniae-induced activation of both CD4(+) and CD8(+) T cells was detected in the early phase of infection, but activation of only CD4(+) T cells was detected in the later stage.

Chlamydia pneumoniae-specific cell-mediated and humoral immunity in healthy people

In this work, cell-mediated immunity to Chlamydia pneumoniae was studied in 157 healthy individuals using lymphoproliferative assay and serum antibodies were analysed by microimmunofluorescence techniques. The C. pneumoniae-specific IgG antibodies were elevated more frequently and the geometric mean titres for IgG (67.5 versus 44.1; P = 0.05) and IgA (14.9 versus 11.3; P = 0.025) antibodies were significantly higher in males than in females. However, no gender-dependent differences were observed in cellular reactivity to C. pneumoniae, since the median cellular responses were similar (stimulation indices 7.5) in men and women. Although the cell-mediated and humoral responses to C. pneumoniae did not correlate clearly, elevated IgG antibodies were associated with slightly higher lymphocyte proliferation in comparison to all subjects (15.5 versus 7.5) and significantly stronger in comparison to those with persistently elevated IgA (> 80) antibodies (15.5 versus 3.5; P = 0.023). Further studies are needed to evaluate a possible role of reduced cellular reactivity in the cause of chronic C. pneumoniae infection.

Subjects recovering from human ocular chlamydial infection have enhanced lymphoproliferative responses to chlamydial antigens compared with those of persistently diseased controls

Cell-mediated immune responses to chlamydial and common recall antigens were measured in 26 subjects whose clinical signs of trachoma persisted over 6 months of follow-up and in 21 subjects whose clinical signs resolved spontaneously over the same period. Seven-day lymphocyte proliferative responses to chlamydial but not common recall antigens were significantly greater in subjects whose disease resolved spontaneously. There was, however, no detectable difference between the two groups in gamma interferon levels in supernatants from lymphocyte cultures stimulated with these antigens. These results are consistent with the hypothesis that cell-mediated immune responses play an important role in the clearance of ocular chlamydial infection in humans.

Cell-mediated immunity to Chlamydia pneumoniae measured as lymphocyte blast transformation in vitro

The purpose of the present study was to analyze Chlamydia pneumoniae-induced, antigen-specific, cell-mediated immunity. Peripheral blood mononuclear cells of four persons infected with C. pneumoniae Kajaani 6 and 17 healthy volunteers were stimulated with antigen composed of whole elementary bodies of C. pneumoniae Kajaani 6 (CP-Ag). Definitive antigen-specific lymphoproliferation (LP) responses were developed after recent infection. The LP responses of healthy people to CP-Ag varied considerably. There was no clear correlation between LP responses to CP-Ag and those to an antigen prepared from Chlamydia trachomatis serotype L2 (r > or = 0.50, P < 0.1). A larger study is required to demonstrate whether the LP responses to CP-Ag can be used for the diagnosis of C. pneumoniae infection.