AIP56: A Novel Bacterial Apoptogenic Toxin

Toxins

Manuel T. Silva¹  Nuno M. S. dos Santos¹ 

[1] IBMC-Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823. 4150-180 Porto, Portugal;

关键词: Photobacterium damselae subsp. piscicida;    AIP56;    AB toxin;    apoptosis;    secondary necrosis;   

DOI  :  10.3390/toxins2040905

来源: mdpi

【 摘 要 】

Photobacterium damselae subsp. piscicida (Phdp) is a Gram-negative pathogen agent of an important fish septicemia. The key virulence factor of Phdp is the plasmid-encoded exotoxin AIP56, which is secreted by exponentially growing pathogenic strains. AIP56 has 520 amino acids including an N-terminal cleavable signal peptide of 23 amino acid residues, two cysteine residues and a zinc-binding region signature HEXXH that is typical of most zinc metallopeptidases. AIP56 induces in vitro and in vivo selective apoptosis of fish macrophages and neutrophils through a caspase-3 dependent mechanism that also involves caspase-8 and -9. In vivo, the AIP56-induced phagocyte apoptosis progresses to secondary necrosis with release of cytotoxic phagocyte molecules including neutrophil elastase. Fish injected with recombinant AIP56 die with a pathology similar to that seen in the natural infection.

【 授权许可】

CC BY   
© 2010 by the authors; licensee MDPI, Basel, Switzerland