Enhancement of MHC-I Antigen Presentation Via Architectural Control of PH-Responsive, Endosomolytic Polymer Nanoparticles
Protein-based vaccines offer a number of important advantages over organism-based vaccines but generally elicit poor CD8+ T cell responses. We have previously demonstrated that pH-responsive, endosomolytic polymers can enhance protein antigen delivery to major histocompatibility complex class I (MHC-I) antigen presentation pathways thereby augmenting CD8+ T cell responses following immunization. Here, we describe a new family of nanocarriers for protein antigen delivery assembled using architecturally distinct pH-responsive polymers. Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to synthesize linear, hyperbranched, and core-crosslinked copolymers of 2-(N,N-diethylamino)ethyl methacrylate (DEAEMA) and butyl methacrylate (BMA) that were subsequently chain extended with a hydrophilic N,N-dimethylacrylamide (DMA) segment copolymerized with thiol-reactive pyridyl disulfide (PDS) groups. In aqueous solution, polymer chains assembled into 25 nm micellar nanoparticles and enabled efficient and reducible conjugation of a thiolated protein antigen, ovalbumin. Polymers demonstrated pH-dependent membrane-destabilizing activity in an erythrocyte lysis assay, with the hyperbranched and cross-linked polymer architectures exhibiting significantly higher hemolysis at pH ≤ 7.0 than the linear diblock. Antigen delivery with the hyperbranched and cross-linked polymer architecture enhanced in vitro MHC-I antigen presentation relative to free antigen, whereas the linear construct did not have a discernible effect. The hyperbranched system elicited a four- to fivefold increase in MHC-I presentation relative to the cross-linked architecture, demonstrating the superior capacity of the hyperbranched architecture in enhancing MHC-I presentation. This work demonstrates that the architecture of pH-responsive, endosomolytic polymers can have dramatic effects on intracellular antigen delivery, and offers a promising strategy for enhancing CD8+ T cell responses to protein-based vaccines.
J. T. Wilson et al., "Enhancement of MHC-I Antigen Presentation Via Architectural Control of PH-Responsive, Endosomolytic Polymer Nanoparticles," AAPS Journal, vol. 17, no. 2, pp. 358-369, Springer New York LLC, Mar 2015.
The definitive version is available at https://doi.org/10.1208/s12248-014-9697-1
Materials Science and Engineering
Keywords and Phrases
MHC-I antigen presentation; pH-responsive nanoparticle; polymer architecture; RAFT polymerization; vaccine
International Standard Serial Number (ISSN)
Article - Journal
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