Polymer micelles with pyridyl disulfide-coupled antigen travel through lymphatics and show enhanced cellular responses following immunization.
Poly(ethylene glycol)-stabilized poly(propylene sulfide) core (PEG-PPS) nanoparticles (NPs) smaller than 50 nm efficiently travel to draining lymph nodes and interact with antigen-presenting cells (APCs) to induce potent immune responses following intradermal immunization. To determine if a similar system could be developed that could be more easily and reproducibly prepared and eliminated faster in vivo, we created block copolymers of PEG-bl-PPS capable of self-assembling into 25-35 nm micelles (MCs). Biodistribution studies showed that these MCs were able to travel to draining lymph nodes, where they preferentially interacted with APCs. To couple cysteine-containing antigens to the surface of the MCs, a new polymer was synthesized with a terminal pyridyl disulfide (PDS), forming PDS-PEG-bl-PPS-benzyl. When mice were immunized in conjunction with free CpG as an adjuvant, ovalbumin-conjugated MCs (MC-Ova) generated more (2.4-fold) Ova-specific CD8(+) T cells in the blood and higher (1.7-fold) interferon-gamma levels from splenocytes upon restimulation than in mice immunized with free Ova and CpG. When comparing this MC platform to our PEG-PPS NPs with disulfide-linked Ova, no significant differences were found in the measured responses. These results indicate that PDS-functionalized MCs are efficient antigen delivery vehicles that enhance immune responses compared to immunization with free protein.
Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Jackson K
JK
Eby
Karen Y
KY
Dane
Conlin P
CP
O'Neil
Sachiko
S
Hirosue
Melody A
MA
Swartz
Jeffrey A
JA
Hubbell
D000818:Animals; D000941:Antigens / Q000008:administration & dosage*; D004220:Disulfides / Q000737:chemistry*; D007271:Injections, Intradermal; D042601:Lymphatic Vessels / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008823:Micelles; D011108:Polymers; D011725:Pyridines / Q000737:chemistry*; D014018:Tissue Distribution
D000941:Antigens; D004220:Disulfides; D008823:Micelles; D011108:Polymers; D011725:Pyridines