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。1417Please respect copyright.ＰＥＮＡＮＡztOZ5zJURo
1417Please respect copyright.ＰＥＮＡＮＡBrYQkW386t
上集：https://www.penana.com/article/4711251417Please respect copyright.ＰＥＮＡＮＡPp12GXBAWY
1417Please respect copyright.ＰＥＮＡＮＡ5nbAnLKq8i
1417Please respect copyright.ＰＥＮＡＮＡsi1pMDEsvz
1417Please respect copyright.ＰＥＮＡＮＡxhZ1bFqwAS
（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?1417Please respect copyright.ＰＥＮＡＮＡaGeZGI985n
1417Please respect copyright.ＰＥＮＡＮＡWPuHo0LmSL
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。1417Please respect copyright.ＰＥＮＡＮＡ5KKTtbeCL6
1417Please respect copyright.ＰＥＮＡＮＡSaobGXRgXP
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。1417Please respect copyright.ＰＥＮＡＮＡO7Qsabt2RE
1417Please respect copyright.ＰＥＮＡＮＡWIfVfAUnEW
1417Please respect copyright.ＰＥＮＡＮＡB3netPbMWc
1417Please respect copyright.ＰＥＮＡＮＡ1FeuEVHBqJ
（圖2）T cell的產生數量，接近可以說是由Antigen Presenting Cells(APC)來決定;1417Please respect copyright.ＰＥＮＡＮＡkO5wWc9mP0
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。1417Please respect copyright.ＰＥＮＡＮＡAghWexP0Uq
1417Please respect copyright.ＰＥＮＡＮＡW7Mm8xseQs
忘記甚麼是Neoantigen的話，可重溫上一集。1417Please respect copyright.ＰＥＮＡＮＡE3duVsjFrN
1417Please respect copyright.ＰＥＮＡＮＡymKYrQ2mFK
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。1417Please respect copyright.ＰＥＮＡＮＡM1y1rq66Sj
1417Please respect copyright.ＰＥＮＡＮＡSLtzZptmkX
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。1417Please respect copyright.ＰＥＮＡＮＡPgUQ55k2Y0
1417Please respect copyright.ＰＥＮＡＮＡVvC0kl9XBk
1417Please respect copyright.ＰＥＮＡＮＡeYTR2yeGNO
1417Please respect copyright.ＰＥＮＡＮＡCU34dlnpl2
（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。1417Please respect copyright.ＰＥＮＡＮＡTGLsQniKV9
1417Please respect copyright.ＰＥＮＡＮＡ2ywYW1xNqB
而當CTLA4與B7合併後，T cell所產生的數量及威力就會大減。1417Please respect copyright.ＰＥＮＡＮＡ3e2hiFG94f
1417Please respect copyright.ＰＥＮＡＮＡPrj7IQaHSe
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。1417Please respect copyright.ＰＥＮＡＮＡk0aCpXOpfa
1417Please respect copyright.ＰＥＮＡＮＡnzMzRWU3pm
1417Please respect copyright.ＰＥＮＡＮＡsJs33dZrlH
（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。1417Please respect copyright.ＰＥＮＡＮＡTqG3IcmgsN
1417Please respect copyright.ＰＥＮＡＮＡmjqhvfnZs0
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。1417Please respect copyright.ＰＥＮＡＮＡkYmHl0XKQJ
1417Please respect copyright.ＰＥＮＡＮＡJIqVYLildk
1417Please respect copyright.ＰＥＮＡＮＡ04BR2JrjiW
（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。1417Please respect copyright.ＰＥＮＡＮＡVj8qB4TFBV
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。1417Please respect copyright.ＰＥＮＡＮＡusJg7eWwqQ
1417Please respect copyright.ＰＥＮＡＮＡj4YerARJBE
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。1417Please respect copyright.ＰＥＮＡＮＡ3JR5Ehy5Ww
1417Please respect copyright.ＰＥＮＡＮＡslaZ1kB7Fd
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。1417Please respect copyright.ＰＥＮＡＮＡccvUouHXXq
1417Please respect copyright.ＰＥＮＡＮＡwJxtRYX8m7
這一方面，我們將會在下一篇免疫治療的最終章再作探討。1417Please respect copyright.ＰＥＮＡＮＡ77jm16LKYd
1417Please respect copyright.ＰＥＮＡＮＡSvsEeNsxIl
1417Please respect copyright.ＰＥＮＡＮＡNJ1N5imJwE
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。1417Please respect copyright.ＰＥＮＡＮＡyEd1VaGB25
1417Please respect copyright.ＰＥＮＡＮＡTh3M09OTIM
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/toc1417Please respect copyright.ＰＥＮＡＮＡblB0buONix
1417Please respect copyright.ＰＥＮＡＮＡGXvv2WnxqN
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。1417Please respect copyright.ＰＥＮＡＮＡvVdRavd67X
1417Please respect copyright.ＰＥＮＡＮＡQK4IhkZjAo
Link:1417Please respect copyright.ＰＥＮＡＮＡR5JnGzGvQD
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1417Please respect copyright.ＰＥＮＡＮＡEK2QOrieMd
1417Please respect copyright.ＰＥＮＡＮＡW4f5P01N3Z
1417Please respect copyright.ＰＥＮＡＮＡFr9x5buzlj
有興趣接收科普資訊的話，歡迎follow IG: potatopigtongue。1417Please respect copyright.ＰＥＮＡＮＡOVLpg9xVbD