The immunogenicity of the tumor-associated antigen Lewis(y) may be suppressed by a bifunctional cross-linker required for coupling to a carrier protein.
A Lewis(y) (Le(y)) tetrasaccharide modified by an artificial aminopropyl spacer was synthesized by a highly convergent approach that employed a levulinoyl ester and a 9-fluorenylmethoxycarbonate for temporary protection of the hydroxy groups and a trichloroethyloxycarbonyl as an amino protecting group. The artificial aminopropyl moiety was modified by a thioacetyl group, which allowed efficient conjugation to keyhole limpet hemocyanin (KLH) modified by electrophilic 4-(maleimidomethyl)cyclohexane-1-carboxylate (MI). Mice were immunized with the KLH-MI-Le(y) antigen. A detailed analysis of sera by ELISA established that a strong immunoglobulin G (IgG) antibody response was elicited against the linker region. The use of a smaller and more flexible 3-(bromoacetamido)propionate for the attachment of Le(y) to KLH not only reduced the IgG antibody response against the linker but also led to a significantly improved immune response against the Le(y) antigen. This study shows that highly antigenic linkers suppress antibody responses to weak antigens such as self-antigens.
Buskas
Therese
T
Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602-4712, USA.
Li
Yanhong
Y
Boons
Geert-Jan
GJ
D000906:Antibodies / Q000276:immunology; D002236:Carbohydrate Conformation; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D006868:Hydrolysis; D007114:Immunization; D007125:Immunogenetics; D007983:Lewis Blood Group Antigens / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D008301:Maleimides / Q000737:chemistry; D009369:Neoplasms / Q000235:genetics* / Q000276:immunology*; D011134:Polysaccharides / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011485:Protein Binding
D000906:Antibodies; D002352:Carrier Proteins; D003432:Cross-Linking Reagents; D007983:Lewis Blood Group Antigens; C094162:Lewis Y antigen; D008301:Maleimides; D011134:Polysaccharides; C043592:maleimide