因腫瘤微環境極為複雜，而且可能隨著腫瘤生長與外在刺激，如接受放射治療 (RT)，而改變。本研究的主要目標在應用原位生長的老鼠腦瘤模型精細的探究，腫瘤前、中、後期各種免疫細胞數量變化，以進一步釐清免疫細胞在腫瘤與接受放射治療後的變化與扮演的角色。實驗中利用流式細胞儀與抗體將細胞分群，所觀看的細胞群有由源自於骨髓細胞的macrophages、microglia、 monocytic 與 neutrophilic - MDSC，另外還有lymphocytes中的helper T細胞、 cytotoxic Ｔ細胞和regulatory T細胞；實驗發現腦瘤中的microglia與腦室中的microglia形態不同，甚至認為與macrophages功能類似；而MDSC的功能為抑制T細胞，且發現M-MDSC與N-MDSC兩群細胞在腫瘤前後期的重要性不同。另外還發現RT過後會造成MDSC數量的下降，而同時T細胞的數量會上升，如果在此時能加入免疫治療，效果可能更佳。此研究也同時觀察了周邊器官的免疫細胞群隨著腫瘤生長的變化趨勢，嘗試這去了解這些細胞是否可以作為腫瘤生長或治療的預測指標。
另外，利用帶有冷光基因的腫瘤細胞，進行免疫T細胞的毒殺實驗，研究發現由有種植腫瘤的老鼠所取下的CD8+ T細胞，其毒殺腫瘤細胞的效率似乎被腫瘤所釋放的因子影響而降低了，但是放射治療過後其對癌細胞毒殺的效率有增加的趨勢。更進一步地探究腫瘤的生長是否會影響T細胞的增生效率，從帶有腫瘤老鼠取出的CD8+ T細胞其增生效率有顯著被抑制的趨勢，但CD4+的增生不會降低反而是增加，由此可發現腫瘤細胞對於CD4+與CD8+T細胞而言，是會有不同的影響，也可由此推論CD4+ T細胞與CD8+T細胞對腫瘤細胞的影響可能也不完全一樣。希望可以藉由此研究更進一步的瞭解免疫細胞在腫瘤裡面所扮演的角色，甚至在哪個時期進行合併免疫治療可以達到最好的效果。

Tumor microenvironment is pretty complex and it might be changed during tumor progression or following therapy. To examine the effect of stroma cells on the behaviors of tumor growth, the relative relationship among tumor cells, brain resident cells, such as microglia, and infiltrating cells, such as monocytic (CD45+CD11b+) or lymphocytic (CD45+CD11b-) lineage cells, was analyzed by flow cytometry. Not only tumor area, peripheral organs, including spleen, blood, and lymph nodes were also examined. The preliminary data showed that microglia had different pattern in ventricles and in the tumor. Furthermore, we found that the change of two subtypes of myeloid derived suppressor cells (MDSCs), Ly6G+ neutrophilic MDSC (N-MDSC) and Ly6G- monocytic MDSC (M-MDSC), was in opposite direction during tumor progression. The increase of M-MDSCs is associated with the increase of tumor size while the N-MDSC is decreased. More interestingly, the population of MDSC is closely related to the change of T cells, in particular after radiotherapy.
We also established a brain tumor reporter cell line, ALTS1C1-Luc. We used this cell line to prove that CD8+ T cell had cytotoxicity to tumor cells and this efficiency would be influenced by bearing tumor and radiotherapy. The effect of bearing tumor and radiotherapy on T cell proliferation was also studied. Results show that bearing tumor and radiotherapy have distinctive effect on the cytotoxicity of CD8+ and the proliferation potential of CD4+ T cells.

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