Serotype-specific engineered glycoproteins as novel antigenic target for diagnosis of hemolytic uremic syndrome

MELLI LJ; CIOCCHINI A. E.; CAILLAVA AJ; IWASHKIW JA; CHINEN I; RIVAS M; FELDMAN M. F.; COMERCI D. J; UGALDE, J. E.

Buenos Aires

Simposio; First Argentinian Symposium of Glycobiology, "GlycoAR 2014"; 2014

Hemolytic Uremic Syndrome (HUS) is a disease characterized by acute renal failure, hemolytic anemia and thrombocytopenia. HUS is a critical health problem in Argentina since it is the main cause of acute renal failure in children and the second cause of chronic renal failure. With over 100 serotypes, Shiga Toxin Escherichia coli (STEC) is the main causal agent of the disease, being the most prevalent serotypes STEC O157:H7 (75,4%), O145:NM (12,9%) and O121:H19 (1,8%). Here, we present a set of serotype-specific recombinant glycoproteins as new diagnostic tools for diagnosis of HUS. O157-AcrA, O145-AcrA and O121-AcrA were produced and purified with high yields in non-pathogenic E. coli cells co-expressing the OTase PglB, the protein acceptor AcrA of Campylobacter jejuni and the corresponding O-polysaccharide gene cluster. Indirect immunoassays based on the detection of anti O-polysaccharide IgG/M antibodies in serum samples were developed coupling the antigens to ELISA plates. As a proof of concept, we analyzed serum samples from HUS pediatric patients and control sera and demonstrated that the detected antibody response is specifically directed towards the O-polysaccharide moiety of the glycoproteins and that with these antigens it is possible to clearly diagnose the disease even in culture-negative HUS patients.