團聚化金奈米粒子對卵白蛋白免疫小鼠後天免疫反應的影響

Abstract

金奈米粒子因具多項優越的物理特性，使其應用於生醫領域大受歡迎。近來研究指出，金奈米粒子作為腫瘤抗原載體及免疫佐劑，應用於腫瘤免疫治療極具潛力。然而，金奈米粒子對免疫系統之影響仍有待釐清。本研究利用卵白蛋白（ovalbumin; OVA）免疫小鼠之模式探討金奈米粒子對抗原專一性免疫反應之作用。商品化之奈米金粒子的粒徑為50奈米，其溶液需調整離子濃度以進行靜脈注射，此時會產生2種粒徑大小之團聚化金奈米粒子溶液，其粒徑分別為86奈米以及86奈米及309奈米混合之奈米金溶液。BALB/c小鼠於第1至10天每天以靜脈注射給予團聚化金奈米粒子(1 mg/kg)，於第2天給予OVA免疫，於第9天進行血清中OVA特異性抗體及T細胞反應性之分析。第10天於小鼠足墊皮下注射OVA誘發遲發型過敏反應。並於24小時後量測足墊腫脹變化及組織病理檢查。實驗結果顯示靜脈投予金奈米粒子增加脾臟指數（spleen index）及脾臟中CD11b+ 細胞的比例。金奈米粒子對脾臟細胞代謝活性並無影響，但促進脾臟細胞表現OVA專一性之IFN-γ。金奈米粒子也促進脾臟細胞以脂多醣(lipopolysaccharide; LPS)刺激所分泌之IL-1β、IL-10和TNF-α表現量。血清中OVA專一性抗體及遲發型過敏反應則未受影響。本研究之結果指出金奈米粒子影響OVA免疫小鼠之部分免疫反應，包含增加脾臟指數和脾臟CD11b的細胞族群，以及促進脾臟細胞表現IFN-γ、IL-1β、IL-10和TNF-α。

Gold nanoparticles (AuNPs) possess a number of unique physical properties that make them appealing for medical applications. Recently, AuNPs have been developed for cancer immunotherapy as immune adjuvants and vehicles for delivery of cancer antigens However, the influence of AuNPs on the immune system remains mostly unclear. The objective of the present study was to investigate the effect of AuNPs on antigen-specific immunity in ovalbumin (OVA)-sensitized mice. A commercial preparation of AuNPs whose particle size is 50 nm was employed in the present study. The AuNPs solution formed two sizes of agglomerates (86 nm AuNPs, and 86 nm and 309 nm mixed AuNPs) after electrolyte adjustment for intravenous (IV) administration. BALB/c mice were daily administered with the agglomerated AuNPs (1 mg/kg) by IV injection from day 1-10. The mice were intraperitoneally sensitized with ovalbumin (OVA) absorbed to alum on day 2. Serum levels of OVA-specific antibodies and T cell reactivity were examined on day 9. Delayed-type hypersensitivity (DTH) reaction was elicited by OVA challenge subcutaneously to the footpad of OVA-sensitized mice on day 10. Local inflammatory reactions were examined by measuring footpad swelling and histological analysis 24 h after the OVA challenge. Administration with AuNPs increased the spleen index and the population of CD11b+ cells in the spleen. The production of interferon (IFN)-γ by splenocytes re-stimulated with OVA in culture was markedly enhanced by AuNPs, whereas the metabolic activity of OVA-stimulated splenoyctes was unaffected. In addition, AuNPs enhanced the production of IL-1β, IL-10 and TNF-α by splenocytes stimulated with lipopolysaccharide (LPS). Serum levels of OVA-specific antibodies and DTH reaction were unaltered by AuNPs treatment. Collectively, the results demonstrated that systemic exposure to AuNPs affected some aspects of immunity in OVA-sensitized mice, including the increase of the spleen index and splenic CD11b+ population, and the enhancement of the production of IFN-γ, IL-1β, IL-10 and TNF-α by splenocytes.