Anti-Blood Group Lewis A monoclonal antibody, clone 9NG

Human ovarian cyst glycoproteins (HOC, cyst gps) isolated from pseudomucinous type of human ovarian cyst fluids is one of the richest and pioneer sources for studying biosynthesis, structures and functional roles of blood group ABH, Le(a,b,x,y), sLe(a) and sLe(x) active glycoproteins. After 70(+) years of exploration, four top highlights are shared. (i) an updated concept of glycotopes and their internal structures in cyst gps was composited; (ii) the unknown codes of new genes in secreted cyst gps were unlocked as Le(x) and Le(y); (iii) recognition profiles of cyst glycans and a sialic acid-rich (18%) glycan with lectins and antibodies were shown. (iv) Co-expression of Blood Group A/ A-Le(b/y) and B/B-Le(b/y) active Glycotopes in the same glycan chains were isolated and illustrated. These are the most advanced achievements since 1980.

We have previously reported clinical data to suggest that colonization factor I (CFA/I) fimbriae of enterotoxigenic Escherichia coli (ETEC) can bind to Lewis a (Le(a)), a glycan epitope ubiquitous in the small intestinal mucosa of young children (< 2 years of age), and individuals with a genetic mutation of FUT2. To further elucidate the physiological binding properties of this interaction, we engineered Chinese Hamster Ovary (CHO-K1) cells to express Le(a) or Le(b) determinants on both N- and O-glycans. We used our glyco-engineered CHO-K1 cell lines to demonstrate that CfaB, the major subunit of ETEC CFA/I fimbriae, as well as four related ETEC fimbriae, bind more to our CHO-K1 cell-line expressing Le(a), compared to cells carrying Le(b) or the CHO-K1 wild-type glycan phenotype. Furthermore, using in-silico docking analysis, we predict up to three amino acids (Glu(25), Asn(27), Thr(29)) found in the immunoglobulin (Ig)-like groove region of CfaB of CFA/I and related fimbriae, could be important for the preferential and higher affinity binding of CFA/I fimbriae to the potentially structurally flexible Le(a) glycan. These findings may lead to a better molecular understanding of ETEC pathogenesis, aiding in the development of vaccines and/or anti-infection therapeutics.