Sortase-mediated modification of αDEC205 affords optimization of antigen presentation and immunization against a set of viral epitopes
Author(s)Ploegh, Hidde; Swee, Lee Kim; Guimaraes, Carla P.; Sehrawat, Sharvan; Spooner, Eric; Barrasa, M. Inmaculada; ... Show more Show less
MetadataShow full item record
A monoclonal antibody against the C-type lectin DEC205 (αDEC205) is an effective vehicle for delivery of antigens to dendritic cells through creation of covalent αDEC205–antigen adducts. These adducts can induce antigen-specific T-cell immune responses or tolerance. We exploit the transpeptidase activity of sortase to install modified peptides and protein-sized antigens onto the heavy chain of αDEC205, including linkers that contain nonnatural amino acids. We demonstrate stoichiometric site-specific labeling on a scale not easily achievable by genetic fusions (49 distinct fusions in this report). We conjugated a biotinylated version of a class I MHC-restricted epitope to unlabeled αDEC205 and monitored epitope generation upon binding of the adduct to dendritic cells. Our results show transfer of αDEC205 heavy chain to the cytoplasm, followed by proteasomal degradation. Introduction of a labile dipeptide linker at the N terminus of a T-cell epitope improves proteasome-dependent class I MHC-restricted peptide cross-presentation when delivered by αDEC205 in vitro and in vivo. We also conjugated αDEC205 with a linker-optimized peptide library of known CD8 T-cell epitopes from the mouse γ-herpes virus 68. Animals immunized with such conjugates displayed a 10-fold reduction in viral load.
DepartmentMassachusetts Institute of Technology. Department of Biology; Whitehead Institute for Biomedical Research
Proceedings of the National Academy of Sciences of the United States of America
National Academy of Sciences (U.S.)
Swee, L. K., C. P. Guimaraes, S. Sehrawat, E. Spooner, M. I. Barrasa, and H. L. Ploegh. “Sortase-mediated modification of DEC205 affords optimization of antigen presentation and immunization against a set of viral epitopes.” Proceedings of the National Academy of Sciences 110, no. 4 (January 22, 2013): 1428-1433.
Final published version