Autor(es):
Cassona, Carolina P. ; Ramalhete, Sara ; Amara, Khira ; Candela, Thomas ; Kansau, Imad ; Denève-Larrazet, Cécile ; Janoir-Jouveshomme, Claire ; Mota, Luís Jaime ; Dupuy, Bruno ; Serrano, Mónica ; Henriques, Adriano O.
Data: 2024
Identificador Persistente: http://hdl.handle.net/10362/182741
Origem: Repositório Institucional da UNL
Assunto(s): Spores, Bacterial/metabolism; Clostridioides difficile/genetics; Bacterial Toxins/metabolism; Humans; Bacterial Proteins/metabolism; Gene Expression Regulation, Bacterial; Animals; Chlorocebus aethiops; Vero Cells; Enterotoxins/metabolism; Medicine (miscellaneous); Biochemistry, Genetics and Molecular Biology(all); Agricultural and Biological Sciences(all)
Descrição
Funding Information: We thank Simon Cutting for the gift of the anti-CotD antibody and Aimee Shen for the gift of the anti-GerS and anti-GPR antibodies. We thank Georges Haustant for help with the spore cytopathic assays. This work was supported by grant PEst-OE/EQB/LA0004/2011 from the \u201CFunda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia\u201D (FCT) to A.O.H. This work was also financially supported by Project LISBOA-01-0145-FEDER-007660 (\u201CMicrobiologia Molecular, Estrutural e Celular\u201D) funded by FEDER funds through COMPETE2020 - \u201CPrograma Operacional Competitividade e Internacionaliza\u00E7\u00E3o\u201D (POCI), by national funds through the FCT (\u201CFunda\u00E7\u00E3o para a Ci\u00EAncia e a Tecnologia\u201D), and by program IF of the FCT (IF/00268/2013/CP1173/CT0006) to M.S. C.C. (PD/BD/52212/2013), S.R. (SFRH/BD/45459/08) and K.A. (PD/BD/148398/2019) were the recipients of doctoral fellowships from the FCT. Publisher Copyright: © The Author(s) 2024.
Clostridioides difficile causes a wide range of intestinal diseases through the action of two main cytotoxins, TcdA and TcdB. Ingested spores germinate in the intestine establishing a population of cells that produce toxins and spores. The pathogenicity locus, PaLoc, comprises several genes, including those coding for TcdA/B, for the holin-like TcdE protein, and for TcdR, an auto-regulatory RNA polymerase sigma factor essential for tcdA/B and tcdE expression. Here we show that tcdR, tcdA, tcdB and tcdE are expressed in a fraction of the sporulating cells, in either the whole sporangium or in the forespore. The whole sporangium pattern is due to protracted expression initiated in vegetative cells by σD, which primes the TcdR auto-regulatory loop. In contrast, the forespore-specific regulatory proteins σG and SpoVT control TcdR production and tcdA/tcdB and tcdE expression in this cell. We detected TcdA at the spore surface, and we show that wild type and ΔtcdA or ΔtcdB spores but not ΔtcdR or ΔtcdA/ΔtcdB spores are cytopathic against HT29 and Vero cells, indicating that spores may serve as toxin-delivery vehicles. Since the addition of TcdA and TcdB enhance binding of spores to epithelial cells, this effect may occur independently of toxin production by vegetative cells.
