[Pathogenic activity modulation of Escherichia coli TL+ toxin with an isolated protein of Giardia intestinalis and a synthetic peptide].
It is know that a protein from Giardia intestinalis works as a substrate for V. cholerae and Escherichia coli. The toxic activity of both activates protein G form intestinal mucosa with a pathogenic activity results. In the present study, the pathogenic activity of subunit A of Vibrio cholerae toxin (ADP-ribosyltranferase) using isolated fragments from: Giardia intestinalis and a synthetic peptide were used as modulators in vivo.


METHODS
Adult Neo Zealand males rabbits with ileal loop were prepared and different mixtures of heat labile enterotoxin obtained from Escherichia coli H10407 and ARF protein isolated by electrofocusing from Giardia intestinalis Portland I were inoculated in the loops. The toxin activity was evaluated by luminal liquid secretion and cyclic AMP concentration in tissues (each loop).


RESULTS
ADP ribosyltranferase activity was modulated, due to a decreased of luminal secretion and cAMP in tissues. Such results were seen when synthetic peptide and subunit A from Vibrio cholerae were used.


CONCLUSIONS
The ADP ribosyltranferase activity of heat labile Escherichia coli and Vibrio cholerae toxins were modified by in vitro and in vivo interaction with ARF protein, which modified pathogenic effect over rabbits intestinal epithelium.
Jiménez-Cardoso
E
E
Laboratorio de Investigación en Parasitología, Hospital Infantil de México.
Eligio-García
L
L
Jiménez-Cardoso
J M
JM
Angeles-Anguiano
E
E
Tobilla-Mercado
J M
JM
Castañeda
G
G
D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D002772:Cholera Toxin / Q000378:metabolism*; D004768:Enterotoxins / Q000378:metabolism*; D004926:Escherichia coli / Q000472:pathogenicity*; D029968:Escherichia coli Proteins; D016829:Giardia lamblia / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000382:microbiology; D008297:Male; D015800:Protozoan Proteins / Q000378:metabolism*; D011817:Rabbits
D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D015800:Protozoan Proteins; D002772:Cholera Toxin; C027538:heat-labile enterotoxin, E coli; D020727:ADP-Ribosylation Factors