Enhancing Immunogenicity Through Structure Guided Design and Glycoengineering

Raghavan Varadarajan in collaboration with Sudha Kumari, both of the Indian Institute of Science in India and Nico Callewaert of the VIB-UGent Center for Medical Biotechnology in Belgium will modify the microorganism, Pichia pastoris, used to produce lower-cost vaccines in low-resource settings, to generate more effective vaccines. Many vaccines are composed of pathogen-derived proteins that require production inside other cells. Although P. pastoris can produce these antigens at a lower cost than mammalian or insect cells, the viral proteins it produced for the SARS-CoV-2 vaccine were hyperglycosylated and poorly immunogenic, unlike those produced in mammalian cells. They will express different antigen forms in mammalian cells, and in different Pichia hosts, to determine whether altering glycosylation and protein size affects immunogenicity. They will also glycoengineer Pichia hosts to determine whether they can produce more effective vaccines. Ultimately, this approach could improve vaccine production for COVID-19 and other viruses.