P-217 Role of Adhesin of Outer Membrane Protein Chlamydia pneumoniae in Collagen Type-IV Degradation

ABSTRACT Detection of antibodies to an outer membrane protein 2 (OMP2) by enzyme-linked immunosorbent assay (ELISA) by using either the Chlamydia trachomatis- or the Chlamydia pneumoniae-specific protein was investigated. OMP2 is an immunodominant antigen giving rise to antibody responses in humans infected with different C. trachomatis serovars (A to C and D to K) or with C. pneumoniae, which could be detected by OMP2 ELISA. OMP2 ELISA is not species specific, but antibody titers were usually higher on the homologous protein. The sensitivity of this assay was high but varied according to the “gold standard” applied. Levels of antibody to C. pneumoniae OMP2 as detected by ELISA seem to return to background or near-background values within a shorter period of time compared to antibodies to C. pneumoniae detected by microimmunofluorescence (MIF), making it more likely that positive results in ELISA reflect recent infection. Thus, OMP2 ELISA has distinct advantages over MIF and commercially available ELISAs and might be a useful tool for the serodiagnosis of chlamydial infection.

Download Full-text

The role of Toll-like receptor 4 in eliciting acquired immune responses against nontypeable Haemophilus influenzae following intranasal immunization with outer membrane protein

International Journal of Pediatric Otorhinolaryngology ◽

10.1016/j.ijporl.2009.08.015 ◽

2009 ◽

Vol 73 (12) ◽

pp. 1657-1665 ◽

Cited By ~ 14

Author(s):

Takashi Hirano ◽

Satoru Kodama ◽

Munehito Moriyama ◽

Toshiaki Kawano ◽

Masashi Suzuki

Keyword(s):

Membrane Protein ◽

Immune Responses ◽

Haemophilus Influenzae ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Toll Like Receptor ◽

Nontypeable Haemophilus Influenzae ◽

Toll Like Receptor 4 ◽

Acquired Immune Responses

Download Full-text

Super-Resolution Fluorescence Microscopy Reveals Clustering Behaviour of Chlamydia pneumoniae’s Major Outer Membrane Protein

Biology ◽

10.3390/biology9100344 ◽

2020 ◽

Vol 9 (10) ◽

pp. 344

Author(s):

Amy E. Danson ◽

Alex McStea ◽

Lin Wang ◽

Alice Y. Pollitt ◽

Marisa L. Martin-Fernandez ◽

...

Keyword(s):

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Chlamydia Pneumoniae ◽

Inflammatory Diseases ◽

Super Resolution ◽

Homology Model ◽

Major Outer Membrane Protein ◽

Membrane Complex ◽

Antimicrobial Studies

Chlamydia pneumoniae is a Gram-negative bacterium responsible for a number of human respiratory diseases and linked to some chronic inflammatory diseases. The major outer membrane protein (MOMP) of Chlamydia is a conserved immunologically dominant protein located in the outer membrane, which, together with its surface exposure and abundance, has led to MOMP being the main focus for vaccine and antimicrobial studies in recent decades. MOMP has a major role in the chlamydial outer membrane complex through the formation of intermolecular disulphide bonds, although the exact interactions formed are currently unknown. Here, it is proposed that due to the large number of cysteines available for disulphide bonding, interactions occur between cysteine-rich pockets as opposed to individual residues. Such pockets were identified using a MOMP homology model with a supporting low-resolution (~4 Å) crystal structure. The localisation of MOMP in the E. coli membrane was assessed using direct stochastic optical reconstruction microscopy (dSTORM), which showed a decrease in membrane clustering with cysteine-rich regions containing two mutations. These results indicate that disulphide bond formation was not disrupted by single mutants located in the cysteine-dense regions and was instead compensated by neighbouring cysteines within the pocket in support of this cysteine-rich pocket hypothesis.

Download Full-text