New monoclonal antibodies to the Chlamydia trachomatis main outer membrane protein and their immunobiological properties

ABSTRACT Monoclonal antibodies (MAbs) to the Chlamydia trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP) were characterized for their ability to neutralize the infectivity of this organism in vitro and in vivo. One of the MAbs (MoPn-23) recognizes a nonlinear epitope in the MOMP, MAb MoPn-40 binds to a linear epitope in the variable domain 1 (VD1), and MAb MoPn-32 recognizes the chlamydial lipopolysaccharide. MAb MoPn-23 neutralized 50% of the infectivity of Chlamydia, as measured in vitro by using HAK (FcγIII−) and HeLa-229 (FcγIII+) cells at a concentration 100 times lower than MAb MoPn-40. MAb MoPn-32 had no neutralizing ability. In comparison to the control normal mouse immunoglobulin G, passive immunization of BALB/c mice with MAb MoPn-23 resulted in a highly significant protection against an intranasal (i.n.) challenge as determined by the change in body weight, the weight of the lungs, and the yield of Chlamydia inclusion-forming units (IFU) from the lungs. Passive immunization with MAb MoPn-40 resulted in a lower degree of protection, and MAb MoPn-32 afforded no protection. MAb MoPn-23 was also tested for its ability to protect wild-type (WT) and severe combined immunodeficient (SCID) C.B-17 mice against an i.n. challenge. Protection based on total body weight, lung weight, and yield of Chlamydia IFU was as effective in SCID as in WT C.B-17 mice. In conclusion, antibodies to MOMP can protect mice against a chlamydial infection in the presence or absence of T and B cells.

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Antigenic analysis of the major outer membrane protein of Chlamydia trachomatis with murine monoclonal antibodies.

Infection and Immunity ◽

10.1128/iai.53.3.530-533.1986 ◽

1986 ◽

Vol 53 (3) ◽

pp. 530-533 ◽

Cited By ~ 16

Author(s):

B E Batteiger ◽

W J Newhall ◽

P Terho ◽

C E Wilde ◽

R B Jones

Keyword(s):

Monoclonal Antibodies ◽

Chlamydia Trachomatis ◽

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Major Outer Membrane Protein ◽

Antigenic Analysis ◽

Murine Monoclonal Antibodies

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Chlamydia trachomatis major outer membrane protein variants escape neutralization by both monoclonal antibodies and human immune sera.

Infection and Immunity ◽

10.1128/iai.65.1.317-319.1997 ◽

1997 ◽

Vol 65 (1) ◽

pp. 317-319 ◽

Cited By ~ 9

Author(s):

M F Lampe ◽

K G Wong ◽

L M Kuehl ◽

W E Stamm

Keyword(s):

Monoclonal Antibodies ◽

Chlamydia Trachomatis ◽

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Major Outer Membrane Protein ◽

Human Immune ◽

Protein Variants

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Subinhibitory Concentrations of Antimicrobial Agents Reduce the Uptake of Legionella pneumophila into Acanthamoeba castellanii and U937 Cells by Altering the Expression of Virulence-Associated Antigens

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.11.2870 ◽

1998 ◽

Vol 42 (11) ◽

pp. 2870-2876 ◽

Cited By ~ 8

Author(s):

P. Christian Lück ◽

Jürgen W. Schmitt ◽

Arne Hengerer ◽

Jürgen H. Helbig

Keyword(s):

Monoclonal Antibodies ◽

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Legionella Pneumophila ◽

Antimicrobial Agents ◽

Acanthamoeba Castellanii ◽

Host Cells ◽

Uncharacterized Protein ◽

Subinhibitory Concentrations

ABSTRACT We determined the MICs of ampicillin, ciprofloxacin, erythromycin, imipenem, and rifampin for two clinical isolates of Legionella pneumophila serogroup 1 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay and by quantitative culture. To test the influence of subinhibitory concentrations (sub-MICs) of antimicrobial agents on Legionella uptake into Acanthamoeba castellanii and U937 macrophage-like cells, both strains were pretreated with 0.25 MICs of the antibiotics for 24 h. In comparison to that for the untreated control, subinhibitory concentrations of antibiotics significantly reducedLegionella uptake into the host cells. Measurement of the binding of monoclonal antibodies against several Legionellaantigens by enzyme-linked immunoassays indicated that sub-MIC antibiotic treatment reduced the expression of the macrophage infectivity potentiator protein (Mip), the Hsp 60 protein, the outer membrane protein (OmpM), an as-yet-uncharacterized protein of 55 kDa, and a few lipopolysaccharide (LPS) epitopes. In contrast, the expression of some LPS epitopes recognized by monoclonal antibodies 8/5 and 30/4 as well as a 45-kDa protein, a 58-kDa protein, and the major outer membrane protein (OmpS) remained unaffected.

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