PMID:22239957

Citation	Sabbadini, PS, Assis, MC, Trost, E, Gomes, DL, Moreira, LO, Dos Santos, CS, Pereira, GA, Nagao, PE, Azevedo, VA, Hirata Júnior, R, Dos Santos, AL, Tauch, A and Mattos-Guaraldi, AL (2012) Corynebacterium diphtheriae 67-72p hemagglutinin, characterized as the protein DIP0733, contributes to invasion and induction of apoptosis in HEp-2 cells. Microb. Pathog. 52:165-76
Abstract	Although Corynebacterium diphtheriae has been classically described as an exclusively extracellular pathogen, there is growing evidence that it may be internalized by epithelial cells. The aim of the present report was to investigate the nature and involvement of the surface-exposed non-fimbrial 67-72 kDa proteins (67-72p), previously characterized as adhesin/hemagglutinin, in C. diphtheriae internalization by HEp-2 cells. Transmission electron microscopy and bacterial internalization inhibition assays indicated the role of 67-72p as invasin for strains of varied sources. Cytoskeletal changes with accumulation of polymerized actin in HEp-2 cells beneath adherent 67-72p-adsorbed microspheres were observed by the Fluorescent actin staining test. Trypan blue staining method and Methylthiazole tetrazolium reduction assay showed a significant decrease in viability of HEp-2 cells treated with 67-72p. Morphological changes in HEp-2 cells observed after treatment with 67-72p included vacuolization, nuclear fragmentation and the formation of apoptotic bodies. Flow cytometry revealed an apoptotic volume decrease in HEp-2 cells treated with 67-72p. Moreover, a double-staining assay using Propidium Iodide/Annexin V gave information about the numbers of vital vs. early apoptotic cells and late apoptotic or secondary necrotic cells. The comparative analysis of MALDI-TOF MS experiments with the probes provided for 67-72p CDC-E8392 with an in silico proteome deduced from the complete genome sequence of C. diphtheriae identified with significant scores 67-72p as the protein DIP0733. In conclusion, DIP0733 (67-72p) may be directly implicated in bacterial invasion and apoptosis of epithelial cells in the early stages of diphtheria and C. diphtheriae invasive infection.
Links	PubMed Online version:10.1016/j.micpath.2011.12.003
Keywords	Actins/metabolism; Apoptosis; Cell Line; Cell Survival; Corynebacterium diphtheriae/genetics; Corynebacterium diphtheriae/pathogenicity; Endocytosis; Hemagglutinins/genetics; Hemagglutinins/metabolism; Hepatocytes/microbiology; Hepatocytes/physiology; Humans; Protein Multimerization; Virulence Factors/genetics; Virulence Factors/metabolism
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
CORDI:Y733		GO:0030047 : actin modification	ECO:0000270:		P		figure 5A demonstrated the "cytoskeletal changes with accumulation of polymerized actin in Hep-2 cells" by the presence of the protein 67-72p	complete CACAO 4884

References

See Help:References for how to manage references in GONUTS.