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Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA.

Authors :
Fusco WG
Choudhary NR
Stewart SM
Alam SM
Sempowski GD
Elkins C
Leduc I
Source :
Monoclonal antibodies in immunodiagnosis and immunotherapy [Monoclon Antib Immunodiagn Immunother] 2015 Apr; Vol. 34 (2), pp. 73-82.
Publication Year :
2015

Abstract

Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrA(I)) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine.

Details

Language :
English
ISSN :
2167-9436
Volume :
34
Issue :
2
Database :
MEDLINE
Journal :
Monoclonal antibodies in immunodiagnosis and immunotherapy
Publication Type :
Academic Journal
Accession number :
25897604
Full Text :
https://doi.org/10.1089/mab.2014.0054