Combinations of monoclonal antibodies to anthrax toxin manifest new properties in neutralization assays

Monoclonal antibodies (MAbs) are potential therapeutic agents against Bacillus anthracis toxins, since there is no current treatment to counteract the detrimental effects of toxemia. In hopes of isolating new protective MAbs to the toxin component lethal factor (LF), we used a strain of mice (C57BL/6) that had not been used in previous studies, generating MAbs to LF. Six LF-binding MAbs were obtained, representing 3 IgG isotypes and one IgM. One MAb (20C1) provided protection from lethal toxin (LeTx) in an in vitro mouse macrophage system but did not provide significant protection in vivo. However, the combination of two MAbs to LF (17F1 and 20C1) provided synergistic increases in protection both in vitro and in vivo. In addition, when these MAbs were mixed with MAbs to protective antigen (PA) previously generated in our laboratory, these MAb combinations produced synergistic toxin neutralization in vitro. But when 17F1 was combined with another MAb to LF, 19C9, the combination resulted in enhanced lethal toxicity. While no single MAb to LF provided significant toxin neutralization, LF-immunized mice were completely protected from infection with B. anthracis strain Sterne, which suggested that a polyclonal response is required for effective toxin neutralization. In total, these studies show that while a single MAb against LeTx may not be effective, combinations of multiple MAbs may provide the most effective form of passive immunotherapy, with the caveat that these may demonstrate emergent properties with regard to protective efficacy.

Medienart:

E-Artikel

Erscheinungsjahr:

2013

Erschienen:

2013

Enthalten in:

Zur Gesamtaufnahme - volume:81

Enthalten in:

Infection and immunity - 81(2013), 6 vom: 14. Juni, Seite 1880-8

Sprache:

Englisch

Beteiligte Personen:

Pohl, Mary Ann [VerfasserIn]
Rivera, Johanna [VerfasserIn]
Nakouzi, Antonio [VerfasserIn]
Chow, Siu-Kei [VerfasserIn]
Casadevall, Arturo [VerfasserIn]

Links:

Volltext

Themen:

Anthrax Vaccines
Anthrax toxin
Antibodies, Bacterial
Antibodies, Monoclonal
Antigens, Bacterial
Bacterial Toxins
Journal Article
Research Support, N.I.H., Extramural

Anmerkungen:

Date Completed 08.08.2013

Date Revised 21.10.2021

published: Print-Electronic

GENBANK: KC592294, KC592295

Citation Status MEDLINE

doi:

10.1128/IAI.01328-12

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM225941716