Surface-exposed Epitopes on the Major Outer-membrane Protein of Chlamydia trachomatis Defined with Peptide Antisera

Abstract

The surface exposure of computer-predicted, linear B-cell epitopes on the major outer-membrane protein (MOMP) of Chlamydia trachomatis serovar B was assessed using antibodies raised against synthetic peptides in conjunction with immunogold transmission electron microscopy. Several of the chosen peptides elicited antibodies which reacted with both denatured and native MOMP. The majority of the exposed epitopes were found within the variable segments of MOMP. For each of the epitopes identified, the extent of their surface accessibility varied both among individual organisms and different developmental forms. Evidence for two distinct subspecies-specific epitopes within VS4 is presented.

Nucleotide sequence and taxonomic value of the major outer membrane protein gene of Chlamydia pneumoniae IOL-207

“…We speculate that the unique peptide ANELP in the equivalent position in C. pneumoniae MOMP is also surface exposed and this may represent a type-specific region. In VS 4 of the B complex serovars of C. trachomatis there are two known subspecies-and one species-specific epitope (Baehr et al, 1988;Conlan et al, 1988Conlan et al, , 1989. We are unable to identify a clear counterpart in C. pneumoniae.…”

Immunoreactivity of the 60 kDa cysteine-rich proteins of Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae expressed in Escherichia coli

“…The MOMP, which is found in both EBs and RBs, is thought to act as a porin (Bavoil etal., 1984) and has a role in the attachment and uptake of EBs by host cells. It is also recognized as an exposed surface molecule possessing infection-neutralizing epitopes (Collett e t al., 1989 ;Zhang e t al., 1989 ;Conlan et al, 1989 ;Conlan et al, 1990;Peterson e t al., 1990). Polyacrylamide gel analysis of C. tracbomatis proteins has shown that the 60 kDa CrP occurs as a singlet in the trachoma biovar and as a 60/62 kDa doublet in the LGV biovar (Batteiger e t d., 1985).…”

Isolation of recombinant fragments of the major outer-membrane protein of Chlamydia trachomatis: their potential as subunit vaccines

“…Hence, this reactivity is unlikely to account for the observed species-specific labelling of intact chlamydiae. However, VS IV appears to be immunologically complex, as two surface-exposed, subspecies-specific epitopes flank each side of the speciesspecific region (Conlan et al, 1988(Conlan et al, , 1989b.…”

“…Surface-exposed epitopes of MOMP on intact chlamydiae were detected by transmission electron microscopy (TEM) using immunogold as previously described (Conlan et al, 1989b). Test antisera were used at dilutions of 1 : 10 and 1 : 50; the protein G-gold conjugate was used at 1 : 10.…”

“…Immunoblotting. Immunoblotting of chlamydia was done as previously described (Conlan et al, 1989b). Primary rabbit antisera were used at 1 : 200 dilution; mAbs were used at 1 : 1000 dilution and were detected with goat anti-mouse IgG (H + L), alkaline phosphatase conjugate (Bio-Rad, 1 : 3000).…”