In:
PLOS ONE, Public Library of Science (PLoS), Vol. 18, No. 2 ( 2023-2-16), p. e0281879-
Abstract:
Bacillus anthracis overcomes host immune responses by producing capsule and secreting toxins. Production of these virulence factors in response to entering the host environment was shown to be regulated by atxA , the major virulence regulator, known to be activated by HCO 3 - and CO 2 . While toxin production is regulated directly by atxA , capsule production is independently mediated by two regulators; acpA and acpB . In addition, it was demonstrated that acpA has at least two promotors, one of them shared with atxA . We used a genetic approach to study capsule and toxin production under different conditions. Unlike previous works utilizing NBY, CA or R-HCO 3 - medium under CO 2 enriched conditions, we used a sDMEM-based medium. Thus, toxin and capsule production can be induced in ambient or CO 2 enriched atmosphere. Using this system, we could differentiate between induction by 10% NRS, 10% CO 2 or 0.75% HCO 3 - . In response to high CO 2 , capsule production is induced by acpA based response in an atxA -independent manner, with little to no toxin (protective antigen PA) production. atxA based response is activated in response to serum independently of CO 2 , inducing toxin and capsule production in an acpA or acpB dependent manner. HCO 3 - was also found to activate atxA based response, but in non-physiological concentrations. Our findings may help explain the first stages of inhalational infection, in which spores germinating in dendritic cells require protection (by encapsulation) without affecting cell migration to the draining lymph-node by toxin secretion.
Type of Medium:
Online Resource
ISSN:
1932-6203
DOI:
10.1371/journal.pone.0281879
DOI:
10.1371/journal.pone.0281879.g001
DOI:
10.1371/journal.pone.0281879.g002
DOI:
10.1371/journal.pone.0281879.g003
DOI:
10.1371/journal.pone.0281879.g004
DOI:
10.1371/journal.pone.0281879.g005
DOI:
10.1371/journal.pone.0281879.g006
DOI:
10.1371/journal.pone.0281879.g007
DOI:
10.1371/journal.pone.0281879.t001
DOI:
10.1371/journal.pone.0281879.t002
DOI:
10.1371/journal.pone.0281879.t003
DOI:
10.1371/journal.pone.0281879.t004
DOI:
10.1371/journal.pone.0281879.s001
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2023
detail.hit.zdb_id:
2267670-3
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