scholarly journals Immunization with an acellular vaccine consisting of the outer membrane complex of Chlamydia trachomatis induces protection against a genital challenge.

1997 ◽  
Vol 65 (8) ◽  
pp. 3361-3369 ◽  
Author(s):  
S Pal ◽  
I Theodor ◽  
E M Peterson ◽  
L M de la Maza
2012 ◽  
Vol 195 (5) ◽  
pp. 951-957 ◽  
Author(s):  
S. Hou ◽  
L. Lei ◽  
Z. Yang ◽  
M. Qi ◽  
Q. Liu ◽  
...  

2010 ◽  
Vol 192 (22) ◽  
pp. 6017-6024 ◽  
Author(s):  
Ding Chen ◽  
Lei Lei ◽  
Chunxue Lu ◽  
Ahmad Galaleldeen ◽  
P. John Hart ◽  
...  

ABSTRACT Human antibody recognition of Chlamydia trachomatis plasmid-encoded Pgp3 protein is dependent on the native conformation of Pgp3. The structural basis for the conformation dependence and the function of Pgp3 remain unknown. Here, we report that Pgp3 trimerization is required for the recognition of Pgp3 by human antibodies. In a native polyacrylamide gel, Pgp3 purified from a bacterial expression system migrated as stable trimers that were dissociated into monomers only by treatment with urea or sodium dodecyl sulfate (SDS) but not nonionic detergents. Human antibodies recognized trimeric but not monomeric Pgp3, suggesting that Pgp3 is presented to the human immune system as trimers during C. trachomatis infection. The endogenous Pgp3 secreted into the chlamydial outer membrane complex or host cell cytosol is always trimerized. Intact Pgp3 trimers were eluted from the outer membrane complex by a combination of nonionic detergents with reducing agents but not by the presence of either alone. These observations have provided important information for further understanding the role of Pgp3 in chlamydial pathogenesis and potentially optimizing Pgp3 as a subunit vaccine candidate antigen.


2021 ◽  
Vol 15 (8) ◽  
pp. e0009655
Author(s):  
Ehsan Ghasemian ◽  
Aleksandra Inic-Kanada ◽  
Astrid Collingro ◽  
Lamiss Mejdoubi ◽  
Hadeel Alchalabi ◽  
...  

Trachoma is a blinding disease caused by repeated conjunctival infection with different Chlamydia trachomatis (Ct) genovars. Ct B genovars have been associated with more severe trachoma symptoms. Here, we investigated associations between Ct genovars and bacterial loads in ocular samples from two distinct geographical locations in Africa, which are currently unclear. We tested ocular swabs from 77 Moroccan children (28 with trachomatous inflammation-follicular (TF) and 49 healthy controls), and 96 Sudanese children (54 with TF and 42 healthy controls) with a Ct-specific real-time polymerase chain reaction (PCR) assay. To estimate bacterial loads, Ct-positive samples were further processed by multiplex real-time qPCR to amplify the chromosomal outer membrane complex B and plasmid open reading frame 2 of Ct. Genotyping was performed by PCR-based amplification of the outer membrane protein A gene (~1120 base pairs) of Ct and Sanger sequencing. Ct-positivities among the Moroccan and Sudanese patient groups were 60·7% and 31·5%, respectively. Significantly more Sudanese patients than Moroccan patients were genovar A-positive. In contrast, B genovars were significantly more prevalent in Moroccan patients than in Sudanese patients. Significantly higher Ct loads were found in samples positive for B genovars (598·596) than A genovar (51·005). Geographical differences contributed to the distributions of different ocular Ct genovars. B genovars may induce a higher bacterial load than A genovars in trachoma patients. Our findings emphasize the importance of conducting broader studies to elucidate if the noted difference in multiplication abilities are genovar and/or endemicity level dependent.


2000 ◽  
Vol 186 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Per Holse Mygind ◽  
Gunna Christiansen ◽  
Peter Roepstorff ◽  
Svend Birkelund

2010 ◽  
Vol 192 (11) ◽  
pp. 2852-2860 ◽  
Author(s):  
Xiaoyun Liu ◽  
Mary Afrane ◽  
David E. Clemmer ◽  
Guangming Zhong ◽  
David E. Nelson

ABSTRACT The extracellular chlamydial infectious particle, or elementary body (EB), is enveloped by an intra- and intermolecular cysteine cross-linked protein shell called the chlamydial outer membrane complex (COMC). A few abundant proteins, including the major outer membrane protein and cysteine-rich proteins (OmcA and OmcB), constitute the overwhelming majority of COMC proteins. The identification of less-abundant COMC proteins has been complicated by limitations of proteomic methodologies and the contamination of COMC fractions with abundant EB proteins. Here, we used parallel liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analyses of Chlamydia trachomatis serovar L2 434/Bu EB, COMC, and Sarkosyl-soluble EB fractions to identify proteins enriched or depleted from COMC. All well-described COMC proteins were specifically enriched in the COMC fraction. In contrast, multiple COMC-associated proteins found in previous studies were strongly enriched in the Sarkosyl-soluble fraction, suggesting that these proteins are not COMC components or are not stably associated with COMC. Importantly, we also identified novel proteins enriched in COMC. The list of COMC proteins identified in this study has provided reliable information for further understanding chlamydial protein secretion systems and modeling COMC and EB structures.


2010 ◽  
Vol 79 (1) ◽  
pp. 518-526 ◽  
Author(s):  
Michael J. McConnell ◽  
Juan Domínguez-Herrera ◽  
Younes Smani ◽  
Rafael López-Rojas ◽  
Fernando Docobo-Pérez ◽  
...  

ABSTRACTAcinetobacter baumanniicauses pneumonias, bacteremias, and skin and soft tissue infections, primarily in the hospitalized setting. The incidence of infections caused byA. baumanniihas increased dramatically over the last 30 years, while at the same time the treatment of these infections has been complicated by the emergence of antibiotic-resistant strains. Despite these trends, no vaccines or antibody-based therapies have been developed for the prevention ofA. baumanniiinfection. In this study, an outer membrane complex vaccine consisting of multiple surface antigens from the bacterial membrane ofA. baumanniiwas developed and tested in a murine sepsis model. Immunization elicited humoral and cellular responses that were able to reduce postinfection bacterial loads, reduce postinfection proinflammatory cytokine levels in serum, and protect mice from infection with human clinical isolates ofA. baumannii. A single administration of the vaccine was able to elicit protective immunity in as few as 6 days postimmunization. In addition, vaccine antiserum was used successfully to therapeutically rescue naïve mice with established infection. These results indicate that prophylactic vaccination and antibody-based therapies based on an outer membrane complex vaccine may be viable approaches to preventing the morbidity and mortality caused by this pathogen.


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