| Autor: |
Donahue TC; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States., Zong G; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States., O'Brien NA; Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States., Ou C; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States., Gildersleeve JC; Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States., Wang LX; Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States. |
| Abstrakt: |
N-Glycosylation plays an important role in many biological recognition processes. However, very few N-glycan-specific antibodies are available for functional studies and potentially for therapeutic development. In this study, we sought to synthesize bacteriophage Qβ conjugates with representative N-glycans and investigate their immunogenicity for raising N-glycan-specific antibodies. An array of Qβ glycoconjugates bearing five different human N-glycans and two different chemical linkers were synthesized, and the immunization of the N-glycan-Qβ conjugates was performed in mice. We found that the N-glycan-Qβ conjugates raised significant IgG antibodies that recognize N-glycans, but, surprisingly, most of the glycan-dependent antibodies were directed to the shared chitobiose core and were nonspecific for respective N-glycan structures. The linker chemistry was found to affect antibody specificity with adipic acid-linked N-glycan-Qβ immunogens raising antibodies capable of recognizing both the N -acetylglucosamine (GlcNAc) moieties of the chitobiose core. In contrast, antibodies raised by N-glycan-Qβ immunogens with a triazole linker preferentially recognized the innermost N -acetylglucosamine moiety at the reducing end. We also found that sialylation of the N-glycans significantly suppressed the immune response. Furthermore, the N-glycan-Qβ immunogens with an adipic acid linker elicited higher glycan-specific antibody titers than the N-glycan-triazole-Qβ immunogens. These findings delineate several challenges in eliciting mammalian N-glycan-specific antibodies through the conventional glycoconjugate vaccine design and immunization. |
