Toward a better understanding of the basis of the molecular mimicry of polysaccharide antigens by peptides: the example of Shigella flexneri 5a.

Title:

Toward a better understanding of the basis of the molecular mimicry of polysaccharide antigens by peptides: the example of Shigella flexneri 5a.

identifier:	1244666
description:	epitope description:KRHFLSQRQ host organism:Mus musculus antibody name:C5, I3
aggregation:	instance of dataset
availability:	available
primaryPublications:	16251186

study type:	b cell assays
subject species:

fullName:	Marie-Jeanne Clé ment Antoine Fortuné Armelle Phalipon Vé ronique Marcel-Peyre Catherine Simenel Anne Imberty Muriel Delepierre Laurence A Mulard

method:	antigen inhibition

name:	Toward a better understanding of the basis of the molecular mimicry of polysaccharide antigens by peptides: the example of Shigella flexneri 5a.
description:	This peptide was derived from a nonamer phage display random peptide library by screening with a protective IgA mAb specific for O-polysaccharide from Shigella flexneri 5a LPS. No anti-polysaccharide Abs were elicitied upon phage-peptide immunization. Structural studies suggest that the failure to generate a functional mimic is due to is its lack of a stable conformation. Two protective IgA mAbs raised against S.flexneri, specific for the O-antigen (O-Ag) part of LPS, are tested for the inhibition of LPS recognition by this peptide. For one of the mAbs (I3), an IC50 value of 70±11μM was obtained. The other mAb (C5) has an IC50 0.03±0.01μM. Due to the multivalency of LPS and the dimeric nature of IgAs the IC50 is not a true measurement of affinity. NMR structural studies of this peptide complexed with the mAbs showed that whether mIgA I3 or IgA C5 was concerned, p22 residues in direct contact with the mAbs were identical. They included the His3 azole protons, Phe4 aromatic protons, as well as Leu5 methyl protons.

name:	iedb
homePage:	http://www.iedb.org

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