TRAIL-expressing cell membrane nanovesicles as an anti-inflammatory platform for rheumatoid arthritis therapy

Abstract

Rheumatoid arthritis (RA) is one of the most common chronic autoimmune diseases. Although the progress made with current clinical use of biologic disease-modifying antirheumatic drugs (bioDMARDs), the response rate of RA treatment remains ungratified, primarily due to intricacy interactions of multiple inflammatory cytokines and the awkward drug delivery. Thus, it is of great importance to neutralize cytokines and actively deliver therapeutic agents to RA joints for the purpose of promoting in situ activity. Herein, we proposed and validated a nanoparticle-based broad-spectrum anti-inflammatory strategy for RA management by fusing TRAIL-anchored cell membranes onto drug-loaded polymeric cores (TU-NPs), which makes them ideal decoys of inflamed macrophage-targeted biological molecules. Upon intravenous injection of TU-NPs into collagen-induced arthritic mice, the fluorescence/photoacoustic dual-modal imaging revealed higher accumulations and longer retention of TU-NPs in inflamed joints. In vivo therapeutic evaluations suggested that these nanoparticles could neutralize cytokines, suppress synovial inflammation, and provide strong chondroprotection against joint damage by targeting and deep penetration into the inflamed tissues. Overall, our work provides a novel strategy to treat RA with a strong potential for clinical translation.

Introduction

Rheumatoid arthritis (RA) is one of the most devastating autoimmune disease with systemic inflammation and progressive disability, causing a serious threat to human health [1,2]. It primarily involves inflammatory cells infiltration, pannus formation, bone erosion and cartilage destruction [3,4]. At present, the precise mechanism of RA is still unknown. The main clinical agents for RA treatment currently are disease-modifying antirheumatic drugs (DMARDs) including anti-inflammatory biologics and synthetic small chemicals [5,6], but it commonly brings severe adverse effects such as osteoporosis, liver function failure and even lymphoma due to its nonspecific targeting and the complexity of inflammatory network [7,8]. Despite much progress has been made in treating RA, notably with the application of biologic DMARDs that target interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α) or CD20 [[9], [10], [11]], the recent therapies still remain insufficient. One of the reasons for the dilemma is that the production of inflammatory cytokines in RA is a complexed system determined by numerous synovial infiltrated cells. Even a therapeutic blockade of one cytokine may not be enough to relieve its symptoms [12,13]. In clinics, chemical synthetic or biologic DMARDs have only partial therapeutic response for a large proportion of patients [[14], [15], [16], [17]]. Therefore, there is an urgent need to develop a novel anti-inflammatory strategy or drug delivery system to improve the therapeutic index and alleviate the adverse effects of RA treatment [[18], [19], [20], [21]].

Nowadays, with the advancement of cell membrane-based nanotechnology, cell membrane-coated nanoparticles (NPs) have been developed as a practical therapeutic platform [13,22,23]. In addition to achieving high drug accumulation in the target sites, cell membrane-coated NPs can efficaciously reduce the elimination and enhance the circulation time of nanoparticles [24,25]. Furthermore, the combined NPs are manufactured by surface coating natural cell membranes onto synthesized NPs and can mimic the source cells, which empowers them with the ability to bind and neutralize multitudinous and intricate pathological factors [13,26]. For example, cancer cell membrane-coated NPs have been used for homologous targeting to deliver antineoplastic drugs, improve the intravital half-time of drugs and decrease the toxicity on normal tissues [26,27]. Moreover, erythrocyte membrane- or macrophage-derived NPs have been widely used to absorb toxins during the period of exogenous bacterial infection and pathological autoantibodies that would otherwise cause serious autoimmune disease [28].

Encouraged by the progress of cell membrane based-camouflaged nanotechnology in biotherapies, we proposed a strategy that uses cell- mimicking NPs as an anti-inflammatory platform to address the challenges of RA treatment. Furthermore, decorating cell membranes with specific ligands that target inflammatory tissues or cells may enhance the drug delivery efficacy [24,29]. Nonetheless, gene engineering is a versatile platform that can be used to specifically express the targeting ligand onto the cell membrane without interfering with the existed membrane proteins, whereas chemical modification is hardly to achieve it. Herein, we developed a flexible approach to express tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) onto the cell membrane to target the actived M1 macrophages in the inflammatory sites of RA. Among the inflammatory cells, inflammatory M1 macrophages play a crucial role in the progression of RA because it can subsequently release inflammatory cytokines and chemokines to activate or recruit other immune cells [18,19]. Moreover, M1 macrophages can also adhere to the pannus of inflamed vascular tissue and participate in endothelium and synovium inflammation in the synovial joint environment, which ultimately cause bone erosion and cartilage destruction [20,21]. Because of the upregulated death receptor-5 (DR5) [30,31], TRAIL-expressing cell membrane-coated NPs could induce apoptosis of M1 macrophages while simultaneously targeting delivery of antirheumatic drugs to inflammatory tissues.

In this study, considering the fact that several inflammatory cytokines such as TNF-α can bind its receptor on the vascular endothelial cell to promote the formation of pannus, which is responsible for perpetuating RA progression [32,33], we prepared umbilical vein endothelial cell (UVEC) membrane-coated drug loaded NPs and functionalized them with inflammation-targeting ligands TRAIL (TU-NPs) through genetic bioengineering for antirheumatic drugs delivery. Notably, we chose hydroxychloroquine (HCQ), a first-line antirheumatic drug with low adverse effects, as a model payload to synthesize HCQ -NPs, U-NPs and TU-NPs. The capacity of TU-NPs for inducing differentiated M1 macrophage apoptosis was identified with immunofluorescence (IF), and neutralizing the inflammatory cytokines was evaluated by ELISA. We also compared TU-NP targeting ability to RA with that of bare U-NPs through advanced imaging technology. Finally, the therapeutic efficacy of TU-NPs was evaluated in the collagen-induced arthritis (CIA) mouse model.