1
|
Hagemann JB, Simnacher U, Marschall MT, Maile J, Soutschek E, Wellinghausen N, Essig A. Analysis of humoral immune responses to recombinant Chlamydia pneumoniae antigens. Int J Infect Dis 2019; 91:232-239. [PMID: 31841725 DOI: 10.1016/j.ijid.2019.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES Chlamydia pneumoniae is a difficult to diagnose respiratory pathogen. This study was performed to systematically characterize humoral immune responses to selected C. pneumoniae antigens in order to provide novel serodiagnostic perspectives for clinical and epidemiological issues. METHODS Based on a literature search, gene library screening, and serological proteome analysis, 15 immunogenic surface-associated, virulence-associated, and hypothetical C. pneumoniae antigens were selected, recombinantly expressed, and lined on a nitrocellulose strip. Specific IgM and IgG reactivity was measured in a total of 172 PCR- and micro-immunofluorescence testing (MIF)-characterized serum samples from patients with respiratory infections. A theoretical model was conceived to approximate a putative course of C. pneumoniae antigen expression and assess the potential of early and late antigens. RESULTS While surface antigens performed poorly, the virulence-associated TARP was a reliable antigen for IgM detection, with a sensitivity of 80.0% and a diagnostic specificity of 90.2%. The hypothetical protein YwbM proved powerful for IgG detection with MIF-correlative sensitivities of up to 94.4% and a diagnostic specificity of 95.1%. CONCLUSIONS This study provides new insights into antibody profiles to immunogenic proteins in C. pneumoniae infection. The study findings offer antigen candidates for more reliable and standardized serological investigations of C. pneumoniae infections, including studies on seroprevalence and epidemiology.
Collapse
Affiliation(s)
- Jürgen Benjamin Hagemann
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany.
| | - Ulrike Simnacher
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Miriam Theresia Marschall
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| | - Julia Maile
- Mikrogen Diagnostik, Floriansbogen 2, D-82061 Neuried, Germany
| | - Erwin Soutschek
- Mikrogen Diagnostik, Floriansbogen 2, D-82061 Neuried, Germany
| | | | - Andreas Essig
- Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Albert-Einstein-Allee 23, D-89081 Ulm, Germany
| |
Collapse
|
2
|
Zocevic A, Vorimore F, Marhold C, Horvatek D, Wang D, Slavec B, Prentza Z, Stavianis G, Prukner-Radovcic E, Dovc A, Siarkou VI, Laroucau K. Molecular characterization of atypical Chlamydia and evidence of their dissemination in different European and Asian chicken flocks by specific real-time PCR. Environ Microbiol 2012; 14:2212-22. [DOI: 10.1111/j.1462-2920.2012.02800.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
3
|
Bermudez-Fajardo A, Stark AK, El-Kadri R, Penichet ML, Hölzle K, Wittenbrink MM, Hölzle L, Oviedo-Orta E. The effect of Chlamydophila pneumoniae Major Outer Membrane Protein (MOMP) on macrophage and T cell-mediated immune responses. Immunobiology 2011; 216:152-63. [DOI: 10.1016/j.imbio.2010.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 06/09/2010] [Accepted: 06/11/2010] [Indexed: 01/31/2023]
|
4
|
Slepenkin A, Enquist PA, Hägglund U, de la Maza LM, Elofsson M, Peterson EM. Reversal of the antichlamydial activity of putative type III secretion inhibitors by iron. Infect Immun 2007; 75:3478-89. [PMID: 17470544 PMCID: PMC1932962 DOI: 10.1128/iai.00023-07] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
INPs, which are chemically synthesized compounds belonging to a class of acylated hydrazones of salicylaldehydes, can inhibit the growth of Chlamydiaceae. Evidence has been presented that in Yersinia and Chlamydia INPs may affect the type III secretion (T3S) system. In the present study 25 INPs were screened for antichlamydial activity at a concentration of 50 muM, and 14 were able to completely inhibit the growth of Chlamydia trachomatis serovar D in McCoy and HeLa 229 cells. The antichlamydial activities of two of these INPs, INPs 0341 and 0400, were further characterized due to their low cytotoxicity. These compounds were found to inhibit C. trachomatis in a dose-dependent manner; were not toxic to elementary bodies; were cidal at a concentration of > or =20 microM; inhibited all Chlamydiaceae tested; and could inhibit the development of C. trachomatis as determined by the yield of progeny when they were added up to 24 h postinfection. INP 0341 was able to affect the expression of several T3S genes. Compared to the expression in control cultures, lcrH-1, copB, and incA, all middle- to late-expressed T3S genes, were not expressed in the INP 0341-treated cultures 24 to 36 h postinfection. Iron, supplied as ferrous sulfate, as ferric chloride, or as holo-transferrin, was able to negate the antichlamydial properties of the INPs. In contrast, apo-transferrin and other divalent metal ions tested were not able to reverse the inhibitory effect of the INPs. In conclusion, the potent antichlamydial activity of INPs is directly or indirectly linked with iron, and this inhibition of Chlamydia has an effect on the T3S system of this intracellular pathogen.
Collapse
Affiliation(s)
- Anatoly Slepenkin
- Department of Pathology and Laboratory Medicine, Medical Science Building, Room D-440, University of California-Irvine, Irvine, CA 92697-4800, USA
| | | | | | | | | | | |
Collapse
|
5
|
Sharma J, Bosnic AM, Piper JM, Zhong G. Human antibody responses to a Chlamydia-secreted protease factor. Infect Immun 2004; 72:7164-71. [PMID: 15557641 PMCID: PMC529132 DOI: 10.1128/iai.72.12.7164-7171.2004] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have previously identified a chlamydia-secreted protein (designated chlamydial proteasome/protease-like activity factor, or CPAF) in the cytosol of chlamydia-infected cells. Although CPAF is known to degrade host transcription factors required for major histocompatibility complex antigen expression in cultured cells, it is not clear whether CPAF is produced and maintains similar functions in humans infected with chlamydial organisms. We now report that CPAF does not preexist in chlamydial organisms and that CPAF synthesis requires live organism replication in cultured cells. Mice inoculated with live, but not mice inoculated with dead, chlamydial organisms produced a strong antibody response to CPAF, correlating CPAF-specific antibody production with CPAF synthesis in animals. Sera from women diagnosed with Chlamydia trachomatis cervicitis displayed higher levels of antibodies to CPAF than to either chlamydial major outer membrane protein or heat shock protein 60, suggesting that CPAF is both produced and immunogenic during human chlamydial infection.
Collapse
Affiliation(s)
- Jyotika Sharma
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | | | | | | |
Collapse
|
6
|
Wehrl W, Brinkmann V, Jungblut PR, Meyer TF, Szczepek AJ. From the inside out - processing of the Chlamydial autotransporter PmpD and its role in bacterial adhesion and activation of human host cells. Mol Microbiol 2004; 51:319-34. [PMID: 14756775 DOI: 10.1046/j.1365-2958.2003.03838.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Polymorphic membrane protein (Pmp)21 otherwise known as PmpD is the longest of 21 Pmps expressed by Chlamydophila pneumoniae. Recent bioinformatical analyses annotated PmpD as belonging to a family of exported Gram-negative bacterial proteins designated autotransporters. This prediction, however, was never experimentally supported, nor was the function of PmpD known. Here, using 1D and 2D PAGE we demonstrate that PmpD is processed into two parts, N-terminal (N-pmpD), middle (M-pmpD) and presumably third, C-terminal part (C-pmpD). Based on localization of the external part on the outer membrane as shown by immunofluorescence, immuno-electron microscopy and immunoblotting combined with trypsinization, we demonstrate that N-pmpD translocates to the surface of bacteria where it non-covalently binds other components of the outer membrane. We propose that N-pmpD functions as an adhesin, as antibodies raised against N-pmpD blocked chlamydial infectivity in the epithelial cells. In addition, recombinant N-pmpD activated human monocytes in vitro by upregulating their metabolic activity and by stimulating IL-8 release in a dose-dependent manner. These results demonstrate that N-PmpD is an autotransporter component of chlamydial outer membrane, important for bacterial invasion and host inflammation.
Collapse
Affiliation(s)
- Wolfgang Wehrl
- Max-Planck Institute for Infection Biology, Department of Molecular Biology, Schumannstr. 21/22, 10117 Berlin, Germany
| | | | | | | | | |
Collapse
|
7
|
Cunningham AF, Ward ME. Characterization of human humoral responses to the major outer membrane protein and OMP2 of Chlamydophila pneumoniae. FEMS Microbiol Lett 2004; 227:73-9. [PMID: 14568150 DOI: 10.1016/s0378-1097(03)00650-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Chlamydophila pneumoniae infection is associated with a range of diseases including pneumonia, asthma and heart disease. Although an obligate intracellular pathogen, high levels of antigen-specific antibody are induced and serology is frequently used to diagnose these infections. Proteins targeted by the humoral response include the major outer membrane protein (MOMP) and outer membrane protein 2 (OMP2). Using human anti-chlamydial sera we have defined the B cell epitopes recognized on MOMP and OMP2. Peptides from MOMP, unlike OMP2, were not strongly recognized. Two of these epitopes when linked to an inert carrier reacted strongly with high-titer anti-C. pneumoniae sera.
Collapse
Affiliation(s)
- Adam F Cunningham
- Department of Molecular Microbiology, University of Southampton, Tremona Rd, Southampton, SO16 6YD, UK.
| | | |
Collapse
|
8
|
Klein M, Kötz A, Bernardo K, Krönke M. Detection of Chlamydia pneumoniae-specific antibodies binding to the VD2 and VD3 regions of the major outer membrane protein. J Clin Microbiol 2003; 41:1957-62. [PMID: 12734234 PMCID: PMC154690 DOI: 10.1128/jcm.41.5.1957-1962.2003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although Chlamydia pneumoniae is an important human pathogen, the antigens eliciting a specific humoral immune response remain elusive. We scrutinized several recombinant chlamydial surface proteins for species-specific recognition by a panel of human sera previously tested for the presence of anti-C. pneumoniae and anti-C. trachomatis antibodies by microimmunofluorescence and enzyme-linked immunosorbent assay. The 15-kDa cysteine-rich protein (CrpA), porin-b (PorB), 9-kDa outer membrane protein (OMP3), 60-kDa outer membrane protein (OMP2), and four fragments of the major outer membrane protein (MOMP) representing each variable domain (VD) were overexpressed in Escherichia coli, affinity purified, and employed for Western blot analysis. None of the sera tested contained antibodies recognizing PorB and OMP3 of C. pneumoniae. Sera from C. pneumoniae-immune patients cross-reacted with OMP2 of C. trachomatis, and sera from C. trachomatis-immune patients cross-reacted with CrpA of C. pneumoniae, indicating that some of chlamydial surface molecules share antigenic epitopes. In contrast, the VD2, as well as the VD3, regions of the MOMP of C. pneumoniae were only recognized by C. pneumoniae-positive sera, suggesting the existence of species-specific epitopes. The identification of such epitopes of cell surface molecules provides new insights into C. pneumoniae-specific immune responses and may be of value for the improvement of C. pneumoniae-specific diagnostic assay systems based on defined recombinant antigens.
Collapse
Affiliation(s)
- Marcus Klein
- Institute for Medical Microbiology, Immunology, and Hygiene, University of Cologne, 50935 Cologne, Germany.
| | | | | | | |
Collapse
|
9
|
Slepenkin A, Motin V, de la Maza LM, Peterson EM. Temporal expression of type III secretion genes of Chlamydia pneumoniae. Infect Immun 2003; 71:2555-62. [PMID: 12704128 PMCID: PMC153279 DOI: 10.1128/iai.71.5.2555-2562.2003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia pneumoniae has been shown to possess at least 13 genes that are homologous with other known type III secretion (TTS) systems. Upon infection of HEp-2 cells with C. pneumoniae, the expression of these genes was followed by reverse transcriptase PCR throughout the developmental cycle of this obligate intracellular pathogen. In addition, expression was analyzed when C. pneumoniae was grown in the presence of human gamma interferon (IFN-gamma). The groEL-1, ompA, and omcB genes were used as markers for the early, middle, and late stages of the developmental cycle, respectively, and the inhibition of expression of the fstK gene was used as a marker for the effect of IFN-gamma on the maturation of C. pneumoniae. In the absence of IFN-gamma, the TTS genes were expressed as follows: early stage (1.5 to 8 h), yscC, yscS, yscL, yscJ and lcrH-2; middle stage (by 12 to 18 h), lcrD, yscN, and yscR; and late stage (by 24 h), lcrE, sycE, lcrH-1, and yscT. Of the genes expressed early, the lcrH-2 gene was detected the earliest, at 1.5 h. Expression of the yscU gene was not detected at any of the time points examined. Under the influence of IFN-gamma, the cluster of TTS genes that were normally not expressed until the middle to late stages of the developmental cycle, namely, lcrD, lcrE, and sycE, as well as lcrH-1, were down-regulated, and expression could not be detected up to 48 h. In contrast, the expression of the other TTS genes appeared to be unchanged in the presence of IFN-gamma. The lcrH-1 and lcrH-2 genes differed from one another in both their temporal expression and response to IFN-gamma. In other TTS systems, these genes code for proteins that function in regulation of effector protein synthesis as well as serve as chaperones for proteins that provide for the translocation of the effector proteins into the host cell. In summary, the expression pattern of the TTS genes of C. pneumoniae examined suggests that they are temporally regulated throughout the developmental cycle. Furthermore, paralleling the inhibition of the maturation of the reticulate body to the elementary body, TTS genes expressed in the later stages of the cycle appear to be down-regulated when the organism is grown in the presence of IFN-gamma.
Collapse
Affiliation(s)
- Anatoly Slepenkin
- Department of Pathology, University of California, Irvine, Irvine 92697-4800, USA
| | | | | | | |
Collapse
|
10
|
Haralambieva IH, Iankov ID, Petrov DP, Mladenov IV, Mitov IG. Monoclonal antibody of IgG isotype against a cross-reactive lipopolysaccharide epitope of Chlamydia and Salmonella Re chemotype enhances infectivity in L-929 fibroblast cells. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2002; 33:71-6. [PMID: 12052561 DOI: 10.1111/j.1574-695x.2002.tb00575.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A murine monoclonal antibody (MAb) 202D7 of IgG3 isotype recognizes a lipopolysaccharide (LPS) epitope of Chlamydia spp. and cross-reacts with the Re chemotype LPS of Salmonella and Escherichia coli. The antibody exhibits strong complement activating properties and stimulates phagocytosis of Salmonella enterica serovar Minnesota Re mutant by murine macrophages. Salmonella Re mutants are non-invasive for cell monolayers but still can enter and replicate in L-929 murine fibroblast cells. The entry of bacteria within the cells increases five-fold in the presence of MAb 202D7. The antibody mediates attachment and enhances five-fold the infectivity of Chlamydia pneumoniae into L-929 cells, which suggests a possible IgG-mediated mechanism of entry and survival of the pathogen in fibroblast cells.
Collapse
Affiliation(s)
- Iana H Haralambieva
- Department of Microbiology, Medical University of Sofia, Zdrave 2 street, 1431, Sofia, Bulgaria
| | | | | | | | | |
Collapse
|
11
|
Tapia O, Slepenkin A, Sevrioukov E, Hamor K, de la Maza LM, Peterson EM. Inclusion fluorescent-antibody test as a screening assay for detection of antibodies to Chlamydia pneumoniae. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2002; 9:562-7. [PMID: 11986260 PMCID: PMC119991 DOI: 10.1128/cdli.9.3.562-567.2002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A study was conducted to determine the ability of the inclusion immunofluorescence assay (inclusion IFA) to act as a screening test to detect samples with antibodies to Chlamydia pneumoniae; microimmunofluorescence (MIF) was used as the "gold standard." In addition, the inclusion IFA was compared using HEp-2 cells infected with either C. pneumoniae CM-1 or Chlamydia trachomatis serovar E. A total of 331 serum samples representing a range of MIF titers were evaluated. The sensitivities of the inclusion IFA for detecting samples with C. pneumoniae MIF titers of > or = 16 were 96.9 and 74.8% with C. pneumoniae- and C. trachomatis-infected cells, respectively. For samples with an elevated C. pneumoniae MIF titer of > or = 512, the sensitivities of the C. pneumoniae- and C. trachomatis-based inclusion IFA were 97.0 and 8.8%, respectively. These results suggest that the inclusion IFA is not a genus-specific test, as evidenced by the failure of the C. trachomatis-infected cells to detect a significant number of samples with C. pneumoniae antibodies. Samples that had elevated C. pneumoniae inclusion IFA and MIF titers but that were found negative (titer, <16) by the C. trachomatis inclusion IFA were further tested by an in vitro neutralization assay for functional antibodies that might not have been detected by the serological assays. The in vitro neutralization results corroborated the serological results in that all seven sera tested had a neutralization titer for C. pneumoniae (range, 20 to 225), while all but one failed to have any effect on the infectivity of C. trachomatis serovar E. While the C. pneumoniae inclusion IFA had a high sensitivity for detecting chlamydial antibodies, depending on whether it was used as a screening test for detecting samples with low (> or = 16) or elevated (> or = 512) MIF titers, its specificity ranged from 53.4 to 77.1%. In conclusion, the inclusion IFA with C. pneumoniae-infected cells was best suited as a sensitive screening test for identifying specimens with elevated MIF titers (those associated with a possible acute infection with C. pneumoniae).
Collapse
Affiliation(s)
- Olga Tapia
- Department of Pathology, University of California-Irvine, Irvine, California 92697-4800, USA
| | | | | | | | | | | |
Collapse
|
12
|
Montigiani S, Falugi F, Scarselli M, Finco O, Petracca R, Galli G, Mariani M, Manetti R, Agnusdei M, Cevenini R, Donati M, Nogarotto R, Norais N, Garaguso I, Nuti S, Saletti G, Rosa D, Ratti G, Grandi G. Genomic approach for analysis of surface proteins in Chlamydia pneumoniae. Infect Immun 2002; 70:368-79. [PMID: 11748203 PMCID: PMC127649 DOI: 10.1128/iai.70.1.368-379.2002] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia pneumoniae, a human pathogen causing respiratory infections and probably contributing to the development of atherosclerosis and heart disease, is an obligate intracellular parasite which for replication needs to productively interact with and enter human cells. Because of the intrinsic difficulty in working with C. pneumoniae and in the absence of reliable tools for its genetic manipulation, the molecular definition of the chlamydial cell surface is still limited, thus leaving the mechanisms of chlamydial entry largely unknown. In an effort to define the surface protein organization of C. pneumoniae, we have adopted a combined genomic-proteomic approach based on (i) in silico prediction from the available genome sequences of peripherally located proteins, (ii) heterologous expression and purification of selected proteins, (iii) production of mouse immune sera against the recombinant proteins to be used in Western blotting and fluorescence-activated cell sorter (FACS) analyses for the identification of surface antigens, and (iv) mass spectrometry analysis of two-dimensional electrophoresis (2DE) maps of chlamydial protein extracts to confirm the presence of the FACS-positive antigens in the chlamydial cell. Of the 53 FACS-positive sera, 41 recognized a protein species with the expected size on Western blots, and 28 of the 53 antigens shown to be surface-exposed by FACS were identified on 2DE maps of elementary-body extracts. This work represents the first systematic attempt to define surface protein organization in C. pneumoniae.
Collapse
Affiliation(s)
- Silvia Montigiani
- Chiron SpA, 53100 Siena. Sezione di Microbiologia DMCSS, University of Bologna, 40138 Bologna, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Schumacher A, Lerkerød AB, Seljeflot I, Sommervoll L, Holme I, Otterstad JE, Arnesen H. Chlamydia pneumoniae serology: importance of methodology in patients with coronary heart disease and healthy individuals. J Clin Microbiol 2001; 39:1859-64. [PMID: 11326004 PMCID: PMC88039 DOI: 10.1128/jcm.39.5.1859-1864.2001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Most publications on the relationship between infection with Chlamydia pneumoniae and coronary heart disease (CHD) propose an association, but negative studies are also reported. Seroepidemiological studies vary in the use of different serological methods, different cutoff limits, different sampling times in relation to acute cardiac events, and different clinical stages of CHD. We wanted to compare three different commercially available methods for measuring Chlamydia antibodies to see how the choice of method influenced the prevalence of seropositive individuals in CHD patients and in healthy individuals and to see if sampling time in relation to an acute cardiac event or the stage of atherothrombotic disease influenced the results. Blood samples from 197 CHD patients and 197 individually matched healthy control individuals were tested at baseline and after 6 months; the mean age was 55 years in both groups, and 18% were women. Among the CHD patients, 166 were included at a median of 16 days after an acute cardiac event and 31 had chronic disease with the latest acute event being >3 months earlier. The difference in prevalence of antibodies between the CHD patients and the healthy controls was significant when Chlamydia lipopolysaccharide antibodies were measured, while no significant differences between the study groups were observed by the two methods detecting Chlamydia pneumoniae major outer membrane protein antibodies. The number of seropositive individuals was quite similar at inclusion and 6 months later, and no significant differences were observed between patients with a recent cardiac event and those with a more remote cardiac event. We conclude that the choice of serological method is of major importance when evaluating a possible relationship between C. pneumoniae and CHD.
Collapse
Affiliation(s)
- A Schumacher
- Department of Microbiology and Department of Medicine, Vestfold Central Hospital, Halfdan Wilhelmsens allé 17, post box 2168, Postterminalen, 3103 Tønsberg, Norway.
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Although Chlamydia pneumoniae and Chlamydia psittaci are well-established causes of community-acquired pneumonia, little is known about the role of Chlamydia species in upper respiratory tract infections. C. pneumoniae may play a role in the pathogenesis of acute otitis media. Although C. pneumoniae has been isolated from the middle-ear fluid of children with otitis, children in whom the organism was isolated from middle-ear fluid improved despite being treated with antibiotics that are not active against C. pneumoniae. Although many patients with community-acquired pneumonia caused by C. pneumoniae have symptoms suggestive of sinusitis, there is only one report of isolation of the organism from the maxillary sinus of a patient with sinusitis. Studies of the association with pharyngitis are all based on serology, which often has a poor correlation with isolation of the organism by culture.
Collapse
|
15
|
Rasmussen-Lathrop SJ, Koshiyama K, Phillips N, Stephens RS. Chlamydia-dependent biosynthesis of a heparan sulphate-like compound in eukaryotic cells. Cell Microbiol 2000; 2:137-44. [PMID: 11207570 DOI: 10.1046/j.1462-5822.2000.00039.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One hypothesis for the mechanism of chlamydial interaction with its eukaryotic host cell invokes a trimolecular mechanism, whereby a Chlamydia-derived glycosaminoglycan bridges a chlamydial acceptor molecule and a host receptor enabling attachment and invasion. We show that a heparan sulphate-specific monoclonal antibody specifically binds a glycosa-minoglycan localized to the surface of the chlamydial organism and effectively neutralizes infectivity of both C. trachomatis and C. pneumoniae. In addition to the ability of this antibody to neutralize infectivity, direct visualization using immunofluorescence demonstrated staining of chlamydial organisms localized to the intracellular vacuole. The chlamydial-associated glycosaminoglycan was specifically labelled with [14C]-glucosamine, and the labelled compound was immunoprecipitated and resolved by gel electrophoresis. The chlamydial-associated glycosaminoglycan is a high-molecular-weight compound similar in size to heparin or heparan sulphate and was sensitive to cleavage by heparan sulphate lyase. These data demonstrate that a glucosamine-containing sulphated polysaccharide is produced within the intracellular vacuole containing chlamydiae and is a target for antibody-mediated neutralization of infectivity.
Collapse
Affiliation(s)
- S J Rasmussen-Lathrop
- The Francis I. Proctor Foundation, University of California, San Francisco 94143, USA
| | | | | | | |
Collapse
|
16
|
Essig A, Simnacher U, Susa M, Marre R. Analysis of the humoral immune response to Chlamydia pneumoniae by immunoblotting and immunoprecipitation. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:819-25. [PMID: 10548570 PMCID: PMC95782 DOI: 10.1128/cdli.6.6.819-825.1999] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chlamydia pneumoniae is a widely spread agent of respiratory tract infections in humans. A reliable serodiagnosis of the disease is hampered by the poor knowledge about immunodominant antigens in C. pneumoniae infections. We applied a novel strategy to identify immunogenic proteins of C. pneumoniae TW183 combining metabolic radiolabeling of de novo-synthesized chlamydial antigens with immunoprecipitation. By this technique C. pneumoniae antigens of approximately 160, 97 to 99, 60 to 62, 40, 27, and 15 kDa were detected in the vast majority of sera from patients with a current C. pneumoniae infection. By immunoblotting purified elementary bodies of C. pneumoniae TW183 with the same sera, only the 60- to 62-kDa antigen could be detected consistently. Sequential immunoprecipitation performed at different stages of the chlamydial developmental cycle revealed that the 60- to 62-kDa antigen is strongly upregulated after 24 to 48 h of host cell infection and is presented as a major immunogen in both C. pneumoniae-infected patients and mice. We conclude that, due to its high sensitivity and concurrent preservation of conformational epitopes, metabolic radiolabeling of chlamydial antigens combined with immunoprecipitation may be a useful method to reveal important immunogens in respiratory C. pneumoniae infection which might have been missed by immunoblot analysis.
Collapse
Affiliation(s)
- A Essig
- Department of Medical Microbiology and Hygiene, University of Ulm, D-89081 Ulm, Germany.
| | | | | | | |
Collapse
|
17
|
Peterson EM, de la Maza LM, Brade L, Brade H. Characterization of a neutralizing monoclonal antibody directed at the lipopolysaccharide of Chlamydia pneumoniae. Infect Immun 1998; 66:3848-55. [PMID: 9673271 PMCID: PMC108433 DOI: 10.1128/iai.66.8.3848-3855.1998] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Identification of protective epitopes is one of the first steps in the development of a subunit vaccine. One approach to accomplishing this is to identify structures or epitopes by using monoclonal antibodies (MAb) that can attenuate infectivity in vitro and in vivo. To date attempts to use this approach with Chlamydia pneumoniae have failed. This report is the first description of a MAb directed to the lipopolysaccharide (LPS) of Chlamydia that neutralizes both in vitro and in vivo the infectivity of C. pneumoniae. MAb CP-33, an immunoglobulin G2b (IgG2b), was identified from a fusion using splenocytes from mice immunized with C. pneumoniae TW-183. By Western blot analysis, MAb CP-33 exhibited genus-specific reactivity in that it recognized the LPSs of C. pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci. MAb CP-33 did not react with 15 genera of gram-negative and gram-positive bacteria and Candida albicans. By using isolated LPS of Re mutants of Escherichia coli, Salmonella enterica serovar Minnesota, and recombinants expressing the 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) transferase gene kdtA of C. trachomatis, MAb CP-33 was shown to require for binding the presence of the genus-specific trisaccharide epitope alphaKdo(2-->8)alphaKdo(2-->4)alphaKdo. By employing synthetic oligosaccharides and neoglycoconjugates in an enzyme immunoassay (EIA) and EIA inhibition, it was further shown that MAb CP-33 differed from the extensively investigated prototype chlamydial LPS MAb S25-23. Most likely, MAb CP-33 recognizes a conformational epitope in which the alphaKdo(2-->8)alphaKdo(2-->4)alphaKdo trisaccharide is an essential structural component. When tested in an in vitro neutralization assay, MAb CP-33 gave a 50% neutralization titer of 8 ng/ml against C. pneumoniae TW-183. However, this MAb did not neutralize other C. pneumoniae strains, C. trachomatis, or C. psittaci. C. pneumoniae TW-183 was treated with either MAb CP-33 or a control IgG and then used to inoculate mice by the respiratory route. Five days after inoculation, there was a difference between the mice inoculated with the control IgG-treated inoculum and those inoculated with the MAb CP-33-treated organisms as to the number of mice infected as well as the number of inclusion-forming units recovered from lung cultures (P < 0.05). In summary, a Chlamydia-specific LPS MAb was able to neutralize in vitro the infectivity of C. pneumoniae TW-183.
Collapse
Affiliation(s)
- E M Peterson
- Department of Pathology, University of California, Irvine, Irvine, California 92697-4800, USA.
| | | | | | | |
Collapse
|
18
|
Hammerschlag MR. Current knowledge of Chlamydia pneumoniae and atherosclerosis. Eur J Clin Microbiol Infect Dis 1998; 17:305-8. [PMID: 9721957 DOI: 10.1007/bf01709451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
19
|
Kutlin A, Tsumura N, Emre U, Roblin PM, Hammerschlag MR. Evaluation of Chlamydia immunoglobulin M (IgM), IgG, and IgA rELISAs Medac for diagnosis of Chlamydia pneumoniae infection. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1997; 4:213-6. [PMID: 9067658 PMCID: PMC170504 DOI: 10.1128/cdli.4.2.213-216.1997] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Chlamydia pneumoniae is an important pathogen responsible for a variety of respiratory diseases in humans. Cell culture remains the most specific method for C. pneumoniae diagnosis, but it is labor-intensive and time-consuming. Thus, serology, particularly microimmunofluorescence (MIF) testing, is frequently utilized. However, the MIF test has a significant subjective component. We evaluated a new serological test: Chlamydia Immunoglobulin M (IgG, IgA, and IgM rELISAs Medac, based on a recombinant Chlamydia-specific lipopolysaccharide (LPS) fragment, for the diagnosis of C. pneumoniae infection. The results of this study demonstrated that the use of rELISAs Medac with single sera does not appear to be sensitive or specific for diagnosis of C. pneumoniae infection compared to culture. In children, sensitivities of the rELISAs compared to culture did not exceed 34.2%, and the specificities ranged from 68.4% (IgG) to 91.2% (IgA). In adults, the sensitivities of the rELISAs were slightly higher, up to 77.8% (IgA or IgG), but the specificities ranged from a very low 20.8% for IgA or IgG to 81.1% for IgM. When multiple sera were tested, the results of the rELISAs Medac correlated with culture results in five of eight (62.5%) patients. However, this offers only a retrospective diagnosis, which makes it difficult to manage these patients prospectively.
Collapse
Affiliation(s)
- A Kutlin
- Department of Pediatrics, State University of New York at Brooklyn 11203-2098, USA
| | | | | | | | | |
Collapse
|
20
|
Immunopathogenesis of Chlamydia pneumoniae Infections in children. Infect Dis Obstet Gynecol 1996; 4:128-30. [PMID: 18476082 PMCID: PMC2364485 DOI: 10.1155/s1064744996000282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/1996] [Accepted: 10/01/1996] [Indexed: 11/18/2022] Open
|