Evaluation of colostrum-derived human mammary-associated serum amyloid A3 (M-SAA3) protein and peptide derivatives for the prevention of enteric infection:in vitroand in murine models of intestinal disease

Autor: Pat G. Casey, Colin Hill, Annika Weber, Michael Cronin, Sarah O'Flaherty, Thomas L. McDonald, R.P. Ross, Cormac G. M. Gahan, Fergus Shanahan, Gillian E. Gardiner
Rok vydání: 2009
Předmět:
Zdroj: FEMS Immunology & Medical Microbiology. 55:404-413
ISSN: 1574-695X
0928-8244
DOI: 10.1111/j.1574-695x.2009.00539.x
Popis: In vitro experiments confirmed that a 10-mer peptide derived from human mammary-associated serum amyloid A3 (M-SAA3) protected intestinal epithelial cells from enteropathogenic Escherichia coli (EPEC) adherence. The entire 42-mer human M-SAA3 protein was even more effective, reducing EPEC binding by 72% relative to untreated cells (P0.05), compared with 25% and 57% reductions for the human 10-mer and Lactobacillus GG, respectively. However, none of the M-SAA3 peptides reduced Salmonella invasion in vitro (P0.05). Each of the M-SAA3 10-mer peptides and the 42-mer was then administered orally to mice at 500 mug day(-1) for 4 days before deliberate infection with either Citrobacter rodentium (mouse model of EPEC) or Salmonella Typhimurium. None of the peptides protected against Salmonella infection and the 42-mer may even increase infection, as there was a trend towards increased Salmonella counts in the liver and small intestine in 42-mer-treated mice compared with those in sodium acetate-treated control mice. Citrobacter counts were reduced in the caecum of mice administered the 42-mer relative to a scrambled 10-mer (P0.05), but not compared with the sodium acetate control and no reductions were observed in the faeces or colon. Overall, although promising anti-infective activity was demonstrated in vitro, neither the 42-mer M-SAA3 protein nor a 10-mer peptide derivative prevented enteric infection in the animal models tested.
Databáze: OpenAIRE