科普專欄–薯不揀單 - 深入淺出–以免疫治療(Immunotherapy)手段醫治癌細胞(二)

上集講述了PD1/PDL1在醫治癌細胞免疫治療方面的重要性，接下來我們將會繼續深入探討問題。1398Please respect copyright.ＰＥＮＡＮＡPBa0QeK9kB
1398Please respect copyright.ＰＥＮＡＮＡuZz91jScAD
上集：https://www.penana.com/article/4711251398Please respect copyright.ＰＥＮＡＮＡXxxBKlsMNB
1398Please respect copyright.ＰＥＮＡＮＡaPxMl3P2Bw
1398Please respect copyright.ＰＥＮＡＮＡzHGWJlr5Q8
1398Please respect copyright.ＰＥＮＡＮＡwb7YjDmDSx
（圖1）雖然阻擋PD1/PDL1可以增強T cell辨認癌細胞的能力，但另一個重要的問題是，如何確保有足夠的T cell殺滅癌細胞呢?1398Please respect copyright.ＰＥＮＡＮＡZx5JIDfBgw
1398Please respect copyright.ＰＥＮＡＮＡ65ZSRBnQaJ
就算成功糾正免疫系統細胞懂得把癌細胞辨認為外來之物，但免疫系統細胞數量不足的話，依然是不會達到重大效果的。1398Please respect copyright.ＰＥＮＡＮＡe2ZRXflSFa
1398Please respect copyright.ＰＥＮＡＮＡcN4LYUDoai
換句話說，我們需要一道能夠提升針對癌細胞的T cell數量手段。1398Please respect copyright.ＰＥＮＡＮＡYWbgUsnvre
1398Please respect copyright.ＰＥＮＡＮＡWCgngoF3uO
1398Please respect copyright.ＰＥＮＡＮＡFH6yATQzg1
1398Please respect copyright.ＰＥＮＡＮＡ6xHxJa5GCR
（圖2）T cell的產生數量，接近可以說是由Antigen Presenting Cells(APC)來決定;1398Please respect copyright.ＰＥＮＡＮＡ8vpQGMzs81
APC可以睇成為一堆負責把癌細胞獨特Neoantigen帶來T cell面前的細胞。1398Please respect copyright.ＰＥＮＡＮＡ3ubt2XPqUd
1398Please respect copyright.ＰＥＮＡＮＡn4Rx09Z3Lq
忘記甚麼是Neoantigen的話，可重溫上一集。1398Please respect copyright.ＰＥＮＡＮＡBlWFm4roX6
1398Please respect copyright.ＰＥＮＡＮＡiWq1D5iH29
當APC展示癌細胞的Neoantigen予T cell的receptor後，另一個必需的動作就是T cell表面的CD28與APC表面的B7合併。1398Please respect copyright.ＰＥＮＡＮＡD3SSux6qg6
1398Please respect copyright.ＰＥＮＡＮＡwRpLA1pvYT
只要兩者條件達成的話，負責對付對應癌細胞的T cell數量及效力便會大增。1398Please respect copyright.ＰＥＮＡＮＡoNfaTAeVaf
1398Please respect copyright.ＰＥＮＡＮＡGlNeZu8Nfo
1398Please respect copyright.ＰＥＮＡＮＡMLC2CnQPT0
1398Please respect copyright.ＰＥＮＡＮＡv4qfPGoWq9
（圖3）然而，當T cell數量產生至一定程度的時候，T cell便會產生出CTLA4。CTLA4會搶奪CD28的位置，與B7合併。1398Please respect copyright.ＰＥＮＡＮＡweqMHkbSYa
1398Please respect copyright.ＰＥＮＡＮＡDxS6d2XIV5
而當CTLA4與B7合併後，T cell所產生的數量及威力就會大減。1398Please respect copyright.ＰＥＮＡＮＡuHsXJQxBqq
1398Please respect copyright.ＰＥＮＡＮＡISJkBlKufl
這個CTLA4產生的機制是與生俱來的，目的就是為了避免產生過量的T cell，以免身體會產生不良反應。1398Please respect copyright.ＰＥＮＡＮＡJpoHdK01ph
1398Please respect copyright.ＰＥＮＡＮＡ4RExx3zAik
1398Please respect copyright.ＰＥＮＡＮＡslF1k1NhJr
（圖4）只不過的是，現時癌細胞大敵當前，燃眉之急就是要調動大量的T cell前往討伐癌細胞。1398Please respect copyright.ＰＥＮＡＮＡUx9OYFSxwN
1398Please respect copyright.ＰＥＮＡＮＡbCggCUu9Yv
為此，我們重施應對PD1/PDL1故技，利用抗體阻擋CTLA4，確保CD28及B7持續合併，不斷產生效力高強的T cell。1398Please respect copyright.ＰＥＮＡＮＡt2Z64Ci6M3
1398Please respect copyright.ＰＥＮＡＮＡH1KBnpff6d
1398Please respect copyright.ＰＥＮＡＮＡXY2xaiITXf
（圖5）簡略的總結來說，為了確保有足夠的T cell消滅癌細胞，我們不惜採用阻擋CTLA4的抗體，號令身體持續產生效力高強的T cell。1398Please respect copyright.ＰＥＮＡＮＡqzh4wSgeaY
而另一邊廂，我們亦同時利用阻擋PD1/PDL1的抗體，確保T cell能夠順利把癌細胞辨認成為外來物，將其制裁。1398Please respect copyright.ＰＥＮＡＮＡY1pTdYGLQN
1398Please respect copyright.ＰＥＮＡＮＡL3EgEXRDVk
這CTLA4抗體及PD1/PDL1抗體的雙管齊下療法，將能大大提升免疫治療的效率。1398Please respect copyright.ＰＥＮＡＮＡ2ssm8H393p
1398Please respect copyright.ＰＥＮＡＮＡ8FNLNoUZgR
但是，並不是所有病人也能依靠這方法而得益，原因是T cell沒法能夠順利抵達癌細胞的位置以及滲入癌細胞的內部作有效的消滅。1398Please respect copyright.ＰＥＮＡＮＡW42tQAVrpL
1398Please respect copyright.ＰＥＮＡＮＡMttgjDlbms
這一方面，我們將會在下一篇免疫治療的最終章再作探討。1398Please respect copyright.ＰＥＮＡＮＡoktguOLwRq
1398Please respect copyright.ＰＥＮＡＮＡFPk8xYVAGu
1398Please respect copyright.ＰＥＮＡＮＡCOPJ4KJ2Sr
如果想我快啲出文的話，請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark，這對我非常之重要。1398Please respect copyright.ＰＥＮＡＮＡMgc4Q9AGZb
1398Please respect copyright.ＰＥＮＡＮＡh4KrByMYmN
Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc1398Please respect copyright.ＰＥＮＡＮＡMFANseFf1V
1398Please respect copyright.ＰＥＮＡＮＡOpcxt0sNHL
同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」，以課金的方式推動我繼續搜羅資料寫文，多謝。1398Please respect copyright.ＰＥＮＡＮＡYIFQGTGQc0
1398Please respect copyright.ＰＥＮＡＮＡZ0gTqIgdbC
Link:1398Please respect copyright.ＰＥＮＡＮＡLax0s19zwv
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1398Please respect copyright.ＰＥＮＡＮＡfAqT4y65nZ
1398Please respect copyright.ＰＥＮＡＮＡwUhyTqIfFo
1398Please respect copyright.ＰＥＮＡＮＡ0DONDXFvNM
有興趣接收科普資訊的話，歡迎follow IG: potatopigtongue。1398Please respect copyright.ＰＥＮＡＮＡw9zQMbvjaS