結合

結合 MIP-1α 基因轉殖之腫瘤細胞疫苗與樹突細胞疫苗以抑制腫瘤生長 之研究

 Mouse macrophage inflammatory protein (mMIP) -1α 是屬於 C-C chemokines 的一員，吸引的對象細胞 包括巨噬細胞和淋巴球等，進而造成發炎反應；已知 MIP-1α 的表現能在腫瘤生長處，協同宿主的 抗原呈現細胞 (antigen-presenting cells, APCs) 引發具專一性的抗腫瘤細胞毒殺反應；依此特性製 作 mMIP-1α 轉殖的腫瘤細胞疫苗，再結合體外處理的 APCs ，設計出複合式疫苗，預期對老鼠的腫 瘤細胞生長能夠有加強抑制的效果。利用核酸轉殖 (transfection) 的技術，將一個含有 mMIP-1α 基 因的載體送入老鼠的腫瘤細胞， CT26 (BALB/c) 及 B16F10 (C57BL/6J) ，並利用酵素聯結免疫吸 附分析測試 (ELISA) 篩選出能持續表現 mMIP-1α 的單株細胞；自老鼠的股骨、脛骨取出骨髓細胞

，加入 mGM-CSF 、 mIL-4 等細胞激素刺激其中的單核球分化成為樹突細胞 (dendritic cells, DCs) 。 我們的假設為：先以 mMIP-1α 轉殖的腫瘤細胞疫苗注射老鼠，使其在注射部位產生發炎反應，隔 天再於同一位置注射經體外處理後攜帶有腫瘤抗原的樹突細胞疫苗，預期接受此種複合性疫苗的老 鼠更能有效降低或抑制腫瘤細胞的生長，表示 mMIP-1α 不但能在體內增加週邊 DCs 浸潤到疫苗注 射部位，其所引起的發炎反應也可進一步刺激、活化額外注入的 DCs ，進一步增強抑制腫瘤生長 的免疫反應。

 我們的實驗結果顯示，不論是 BALB/c 或 C57BL/6J 老鼠，在單獨注射 mMIP-1α 轉殖的腫瘤細胞疫 苗時，對腫瘤細胞的生長都沒有明顯的抑制效果，但是在注射樹突細胞疫苗時，抑制腫瘤生長的效 果明顯增強，而在結合兩種疫苗後，發現其效果略勝於單獨注射樹突細胞疫苗；同時我們將兩疫苗 注射於同點與不同點的結果相比較，在 BALB/c 老鼠並沒有看出差異，但在 C57BL/6J 老鼠的結果 發現注射於同一點所產生的抑制能力較強，顯示兩種疫苗之間是有互相加成的效果。結論是，樹突 細胞疫苗對腫瘤生長的抑制已經有很好的效果，雖然 mMIP-1α 轉殖的腫瘤細胞疫苗沒有如預期的 結果，但當兩者結合後，仍達到加成的效果；也許未來能以樹突細胞疫苗為主，配合不同條件的 m MIP-1α 或其他趨化激素轉殖的腫瘤細胞疫苗做研究，期待找出更強的疫苗組合，以達到抑制腫瘤 生長的效果。

Study on the Inhibition of Tumor Growth by MIP-1α-transfected Tumor Cell Vaccine and Dendritic Cell Vaccine

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Mouse macrophage inflammatory protein (mMIP) -1α is a member of the C-C chemokines. It attracts cells including macrophages, lymphocytes and others, and can induce inflammatory re sponses. It has been reported that the manifestation of MIP-1α can coordinate the antigen pres enting cells (APCs) of host to induce specific anti-tumor cytotoxicity in the place where tumor grows.

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Our hypothesis is that if we injected mMIP-1α-transfected tumor cell vaccine into mice subcut

aneously, we can induce inflammation at the site of injection. If we then inject DC which alrea

dy carries tumor antigens at the same site, the inflammatory environment might further promot

e the maturation and activation of these injected, antigen-pulsed DC. We expect that mice treat

ed with this kind of complex vaccines can effectively reduce or suppress the growth of tumor

cells. Our results indicate that in both BALB/c and C57BL/6J mice, injection of mMIP-1α-tra

nsfected tumor cell vaccine alone did not significantly inhibit tumor growth. Injection of DCs

vaccine increased the efficiency of inhibition on tumor growth. When we combined these two

vaccines, the efficiency was slightly better than injection with DC vaccine alone. We have fou

nd that the efficiency of tumor inhibition was better if the two vaccines were injected at the sa

me site in C57BL/6J mice, but not in BALB/c mice. In conclusion, mMIP-1α-transfected tumo

r cell vaccine alone did not demonstrate the expected efficiency of tumor inhibition, however,

DC vaccine appeared to suppress tumor growth in our systems. After we combined the two ki

nds of vaccine, the efficiency of tumor inhibition was doubled. These results suggest that we c

an manipulate DC vaccines and tumor cell vaccines, which are modified with mMIP-1α or oth

er chemokines, in the future to find out a more powerful vaccination strategy for effective inhi

bition of tumor growth.