Cáceres CS, Gallo GL, Colocho FA, Silva JE, Garay JA, Mattar Domínguez MA. Vegetative forms of Clostridium chauvoei trigger apoptotic and inflammatory responses on macrophages.
Anaerobe 2022;
77:102616. [PMID:
35931287 DOI:
10.1016/j.anaerobe.2022.102616]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 10/12/2021] [Accepted: 07/20/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND
Clostridium chauvoei is a gram-positive, spore-forming, strictly anaerobic bacterium that causes blackleg, a disease that affects cattle by inducing fulminant myonecrosis, thereby leading to high and constant losses of cattle. Macrophages (Mɸs) are depleted in tissues infected with the vegetative form of C. chauvoei, but the mechanism remains partially known. Consequently, Mɸs may be a critical target in the pathogenicity of C. chauvoei.
AIM
The objective of this work was to study the mechanism of death of mouse-primary Mɸs infected in vitro for 24 h with the vegetative form of C. chauvoei.
METHODS
Mouse peritoneal Mɸs were infected in vitro with different multiplicities of infection (MOIs) of C. chauvoei (i.e., 5:1, 20:1, and 100:1). After 24 h post-infection, cell viability (MTT reduction assay), apoptosis (apoptotic bodies, DNA ladder, and Annexin V assays), and inflammatory cell response (iNOS and TNF-α expression) were assessed.
RESULTS
All the MOIs investigated decreased cell viability. An MOI of 20:1 caused the highest production of apoptotic bodies and an electrophoretic DNA-ladder pattern typical of an apoptosis cell death process. These results were corroborated using the Annexin V-flow cytometry assay. Concurrently with apoptotic cell death, Mϕs expressed iNOS and TNF-α.
CONCLUSION
Inflammation-mediated apoptosis of Mϕs can be a potential mechanism of evasion of the immune response used by C. chauvoei in tissues for depleting phagocytic cells at the site of infection.
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