Evaluation of carrier proteins upon binding to the HB-EGFR and its variants
Spring 2021 Graduate Student Award in Innovative Evolutionary Medicine
Vaccines are used as a preventative measure against infection. Conjugate vaccines are specifically comprised of a piece of a virus or bacteria that is attached to a carrier protein that allows for an enhanced immune response. A common carrier protein in conjugate vaccines is cross-reactive material 197 (CRM197). The enhanced immune response is caused by CRM197 binding to a specific receptor called the heparin binding epidermal growth factor receptor (HB-EGFR), and then becoming internalized into an immune cell, such as a dendritic cell. Over time, certain amino acids (the building blocks of proteins) have changed in the sequence of the HB-EGFR in certain populations due to evolution. Sometimes changes in the sequence of a protein can affect how well molecules bind to it. Since CRM197 is used in FDA-approved vaccines like Prevnar13 and Menveo, understanding how these changes in the receptor influence the biochemical properties (binding and internalization into the cell) of CRM197-based vaccines is important. The potential differences in binding and internalization may result in an altered protective effect for individuals that have the changes in amino acids. In addition, we wanted to assess the protective potential that two different carrier proteins (CRM197 and an antibody that binds to the HB-EGFR) have on a murine coronavirus. The antibody has the potential to be used as an alternative carrier protein to CRM197; especially if the changes in the amino acid sequence of the HB-EGFR lead to a diminished protective effect.