2014年12月26日訊 /生物谷BIOON/ --兩種不同的方法的組合,即病毒治療及免疫治療組合顯示出治療胰腺癌的「巨大潛力」。
一項由英國慈善胰腺癌症研究基金會資助的研究調查是否溶瘤牛痘病毒(經修飾以選擇性地感染和殺死癌細胞的病毒)通過裝備能調節機體免疫系統的一個基因後,能否更有效治療胰腺癌。
雖然實驗研究表明組合後既可以殺死癌細胞,也可以提振針對癌症再生的免疫力。但溶瘤病毒在臨床試驗並沒有表現良好的治療功效,因為免疫系統在他可以發揮有效前會攻擊病毒。
研究團隊用白介素-10(IL-10)基因的拷貝裝備溶瘤牛痘病毒,一旦癌細胞感染牛痘病毒後,牛痘病毒會表達IL-10。這一蛋白質已知可以抑制免疫應答,研究者希望這會讓病毒在體內持續更長時間。
很多病毒利用IL-10逃避宿主的免疫系統,所以我們調查這種組合策略是否提高病毒的有效性。該研究小組在細胞系中發現,牛痘病毒裝備IL-10後,不會影響牛痘病毒的抗癌作用。然後,他們將牛痘病毒單獨使用,牛痘病毒與IL-10組合比較,比較兩組對小鼠胰腺癌以及一組轉基因小鼠(以使其發生胰腺癌)的治療有效性。六周後,用相結合方法治療的小鼠中有87.5%小鼠體內腫瘤被完全清除,42.8%的牛痘病毒單獨處理小鼠體內腫瘤被完全清除。研究人員說:這些都是令人振奮的結果,但我們仍然有幾個問題,在小鼠中IL-10如何抑制抗病毒免疫,增強抗腫瘤免疫的,究竟IL-10如何使這種情況發生的仍不清楚。(生物谷Bioon.com)
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A Vaccinia virus armed with interleukin-10 is a promising therapeutic agent for treatment of murine pancreatic cancer
Louisa Chard, et al.
Purpose:Vaccinia virus (VV) has strong potential as a novel therapeutic agent for treatment of pancreatic cancer (PaCa). We investigated whether arming VV with IL10 could enhance the antitumor efficacy with the view that IL10 might dampen the host immunity to the virus, increasing viral persistence thus maximising the oncolytic effect and antitumor immunity associated with VV. Experimental Design:The antitumor efficacy of IL10-armed VV (VVLTK-IL10) and control VVTK was assessed in pancreatic cancer cell lines, mice bearing subcutaneous PaCa tumors and a PaCa transgenic mouse model. Viral persistence within the tumors was examined and immune depletion experiments as well as immunophenotyping of splenocytes were carried out to dissect the functional mechanisms associated with the viral efficacy. Results:Compared to unarmed VVLTK, VVLTK-IL10 had a similar level of cytotoxicity and replication in vitro in murine pancreatic cancer cell lines, but rendered a superior anti-tumor efficacy in the subcutaneous pancreatic cancer model and a K-ras-p53 mutant-transgenic PaCa model after systemic delivery, with induction of long-term antitumor immunity. The antitumor efficacy of the VV was dependent on CD4+ and CD8+, but not NK cells. Clearance of VVLTK-IL10 was reduced at early time points compared to the control virus. Treatment with VVLTK-IL10 resulted in a reduction in virus-specific, but not tumor-specific CD8+ cells compared to VVLTK. Conclusions:These results suggest that VVLTK-IL10 has strong potential as an antitumor therapeutic for PaCa.