Different-Sized Gold Nanoparticle Activator/ Antigen Increases Dendritic Cells Accumulation in Liver-Draining Lymph Nodes and CD8+ T Cell Responses Qianqian Zhou, Yulong Zhang, Juan Du, Yuan Li, Yong Zhou, Qiuxia Fu, Jingang Zhang, Xiaohui Wang,* and Linsheng Zhan* Beijing Institute of Transfusion Medicine, Beijing Key Laboratory of Blood Safety and Supply Technologies, TaiPing Road 27, 100039 Beijing, P. R. China S Supporting Information *
ABSTRACT: The lack of efficient antigen and activator delivery systems, as well as the restricted migration of dendritic cells (DCs) to secondary lymph organs, dramatically limits DC-based adoptive immunotherapy. We selected two spherical gold nanoparticle (AuNP)-based vehicles of optimal size for activator and antigen delivery. Their combination (termed the NanoAu-Cocktail) was associated with the dual targeting of CpG oligonucleotides (CpGODNs) and an OVA peptide (OVAp) to DC subcellular compartments, inducing enhanced antigen cross-presentation, upregulated expression of costimulatory molecules and elevated secretion of T helper1 cytokines. We demonstrated that the intravenously transfused NanoAu-Cocktail pulsed DCs showed dramatically improved in vivo homing ability to lymphoid tissues and were settled in T cell area. Especially, by tissuedistribution analysis, we found that more than 60% of lymphoid tissues-homing DCs accumulated in liver-draining lymph nodes (LLNs). The improved homing ability of NanoAu-Cocktail pulsed DCs was associated with the high expression of chemokine receptor 7 (CCR7) and rearrangement of the cytoskeletons. In addition, by antigen-specific tetramers detection, NanoAu-Cocktail pulsed DCs were proved able to elicit strong antigen-specific CD8+ T cell responses, which provided enhanced protection from viral invasions. This study highlights the importance of codelivering antigen/adjuvant using different sized gold nanoparticles to improve DC homing and therapy. KEYWORDS: dendritic cells, gold nanoparticles, migration, immunotherapy production of IL-12p70)5 and (ii) the restricted in vivo homing ability of adopted DCs (only 5% or less) caused by inferior migratory responses to lymph node-associated chemokines.6 To benefit from DC immunotherapy on a large scale, novel approaches for targeting antigens and immune-stimulatory agents to DCs, as well as the in vivo DC trafficking potential and response to chemokine gradients, should be extensively explored. Recent years have witnessed rapid and remarkable progress in nanotechnology and nanomaterials, giving rise to a dramatic expansion of biomedical applications and providing novel platforms to construct new generations of vaccine adjuvants. Nanosized materials (NMs), such as carbon nanotubes,7
D
endritic cells (DCs) play a central role in both innate and adaptive immune responses and mediate host antitumor or pathogen immune responses.1 The “gold standard” of adoptive DC therapy strategies involves ex vivo loading of DCs with whole tumor or pathogen-associated antigens, activating the cells with an IL-1β/TNF-α/IL-6/PGE2 “cytokine-cocktail” and then subsequently reinjecting the DCs into patients to activate T cells in vivo.2 Although a considerable number of patients have been treated with DCbased vaccines thus far, only a fraction of these patients showed vaccine-induced immune responses, and an even small proportion (10−15%) exhibited a clinical response.3,4 Numerous clinical and fundamental studies during the past two decades have helped define major factors resulting in the failure of adoptive DC therapy to induce sufficient acquired immunity. These include: (i) insufficient antigen and activator delivery to facilitate DC cross-presentation and full maturation (low level © XXXX American Chemical Society
Received: December 8, 2015 Accepted: January 11, 2016
A
DOI: 10.1021/acsnano.5b07716 ACS Nano XXXX, XXX, XXX−XXX
Article
www.acsnano.org
Article
ACS Nano
Figure 1. (A) Schematics of the chemical modification strategies used to conjugate CpG-ODNs and OVAp onto the surface of AuNPs through the Au−S bond. (B) TEM microimages of prepared gold nanoparticles observed at an acceleration voltage of 80 kV. Scale bar = 200 nm. (C) Absorption spectra of prepared AuNPs colloidal solutions recorded in the wavelength range from 400 to 900 nm.
polypropylene sulfide (PPS),8,9 polyethylenimine (PEI),10 silica,11 hydrogels,12,13 and gold nanoparticles (AuNPs),14,15 have been designed as nanocarriers to deliver antigen-combined immunomodulatory compounds to local DCs to promote antitumor or pathogen immunity. These products are known as nanovaccines and display several advantages for efficient targeting of DCs; for example, a high payload and extended half-life of the conjugated molecules,16 pathogen-like appearances for enhanced uptake by DCs, and a high ability to promote local DC homing to lymph nodes.17 As nanovaccines, engineered NMs (ENMs) are usually used in conventional vaccination approaches (directly injected into the recipients) with the objective of targeting and activating the antigenpresenting cells (APCs) in situ.18 For adoptive dendritic cell therapy, the accurate delivery of cells to target organs or migration to lymph nodes is essential to the success of treatments.6 Although nanovaccines have been demonstrated to codeliver antigen/adjuvant to DCs and elicit enhanced immune responses,16,17 questions regarding the effects of nanocarriers on adoptive DC in vivo migration and distribution, as well as the molecular mechanisms, remain to be sufficiently addressed. As nanocarriers, gold nanostructures possess unique properties such as tunable surface chemistry, high biocompatibility, and an easily controllable size and shape.14,15 In the design of nanovaccines, the size or diameter of the ENM is one of the most important factors that affects the induced immune responses, which in turn determines the immunogenic payload delivered per nanoparticle,8 the ability of particles to reach the appropriate DC subset in the lymphoid tissue,17 the outcomes of interactions between nanoparticles and APCs, and the
polarization of T cell responses.19,20 Small nanoparticles (
