Department for Immunology and Immunoparasitology, Institute for the Application of Nuclear Energy, University of Belgrade, Belgrade, Serbia.
Center for Biomedical Sciences, Medical Faculty Foča, University of East Sarajevo, Foča, Bosnia and Herzegovina.
Int J Nanomedicine. 2022 Jul 23;17:3191-3216. doi: 10.2147/IJN.S362038. eCollection 2022.
Phosphonates, like 3-AminoPropylphosphonic Acid (ApA), possess a great potential for the therapy of bone tumours, and their delivery via cellulose nanocrystals (CNCs) seems a promising approach for their increased efficacy in target tissues. However, the immunological effects of CNC-phosphonates have not been investigated thoroughly. The main aim was to examine how the modification of CNCs with phosphonate affects their immunomodulatory properties in human cells.
Wood-based native (n) CNCs were modified via oxidation (ox-CNCs) and subsequent conjugation with ApA (ApA-CNCs). CNCs were characterised by atomic force microscopy (AFM) and nanoindentation. Cytotoxicity and immunomodulatory potential of CNCs were investigated in cultures of human peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (MoDCs)/T cells co-cultures by monitoring phenotype, cytokines production, allostimulatory and Th/Treg polarisation capacity.
AFM showed an increase in CNCs' thickens, elasticity modulus and hardness during the modification with ApA. When applied at non-toxic doses, nCNCs showed a tolerogenic potential upon internalisation by MoDCs, as judged by their increased capacity to up-regulate tolerogenic markers and induce regulatory T cells (Treg), especially when present during the differentiation of MoDCs. In contrast, ox- and ApA-CNCs induced oxidative stress and autophagy in MoDCs, which correlated with their stimulatory effect on the maturation of MoDCs, but also inhibition of MoDCs differentiation. ApA-CNC-treated MoDCs displayed the highest allostimulatory and Th1/CTL polarising activity in co-cultures with T cells. These effects of ApA-CNCs were mediated via GABA-B receptor-induced lowering of cAMP levels in MoDCs, and they could be blocked by GABA-B receptor inhibitor. Moreover, the Th1 polarising and allostimulatory capacity of MoDCs differentiated with ApA-CNC were largely preserved upon the maturation of MoDCs, whereas nCNC- and ox-CNC-differentiated MoDCs displayed an increased tolerogenic potential.
The delivery of ApA via CNCs induces potent DC-mediated Th1 polarisation, which could be beneficial in their potential application in tumour therapy.
膦酸酯类化合物，如 3-氨基丙基膦酸（ApA），在骨肿瘤治疗方面具有巨大的潜力，而通过纤维素纳米晶体（CNC）来输送它们似乎是提高其在靶组织中疗效的一种有前途的方法。然而，CNC-膦酸盐的免疫效应尚未得到充分研究。本研究的主要目的是研究通过膦酸酯修饰 CNC 如何影响其在人类细胞中的免疫调节特性。
通过氧化（ox-CNCs）和随后与 ApA 缀合（ApA-CNCs）对木质素基天然（n）CNCs 进行修饰。通过原子力显微镜（AFM）和纳米压痕对 CNCs 进行表征。通过监测人外周血单核细胞（PBMCs）和单核细胞衍生的树突状细胞（MoDC）/T 细胞共培养物中的表型、细胞因子产生、共刺激和 Th/Treg 极化能力，研究 CNCs 的细胞毒性和免疫调节潜力。
AFM 显示，在 ApA 修饰过程中，CNCs 的厚度、弹性模量和硬度增加。当以非毒性剂量应用时，nCNCs 在被 MoDCs 内化时表现出耐受原性潜力，这可以通过它们上调耐受原性标记物和诱导调节性 T 细胞（Treg）的能力来判断，尤其是在 MoDCs 分化期间存在时。相比之下，ox-CNCs 和 ApA-CNCs 在 MoDCs 中诱导氧化应激和自噬，这与它们对 MoDCs 成熟的刺激作用相关，但也抑制了 MoDCs 的分化。在与 T 细胞的共培养物中，用 ApA-CNC 处理的 MoDCs 显示出最高的共刺激和 Th1/CTL 极化活性。这些 ApA-CNC 的作用是通过 GABA-B 受体诱导的 MoDCs 中 cAMP 水平降低介导的，并且可以被 GABA-B 受体抑制剂阻断。此外，用 ApA-CNC 分化的 MoDCs 的 Th1 极化和共刺激能力在 MoDCs 成熟后基本保持不变，而用 nCNC 和 ox-CNC 分化的 MoDCs 则显示出增加的耐受原性潜力。
通过 CNC 输送 ApA 可诱导有效的 DC 介导的 Th1 极化，这在其在肿瘤治疗中的潜在应用中可能是有益的。
