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。1341Please respect copyright.PENANA5S41aOLGGL
1341Please respect copyright.PENANArzHxxeD9eu
上集:https://www.penana.com/article/4711251341Please respect copyright.PENANAQp6cTqZZAf
1341Please respect copyright.PENANAl33CqgOtKd1341Please respect copyright.PENANATAx6o4z8xH
1341Please respect copyright.PENANADQLx3ZXAwZ
(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?1341Please respect copyright.PENANAfspllR2AEZ
1341Please respect copyright.PENANAtxPnZMMUTF
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。1341Please respect copyright.PENANA0h18djNHCI
1341Please respect copyright.PENANAuzpx9EdCJX
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。1341Please respect copyright.PENANALXiIIzoHeD
1341Please respect copyright.PENANAmmDbM2IET11341Please respect copyright.PENANA58RnmRnHZQ
1341Please respect copyright.PENANAjtoDl7nj72
(圖2)T cell的產生數量,接近可以說是由Antigen Presenting Cells(APC)來決定;1341Please respect copyright.PENANApHtkO5QA5q
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。1341Please respect copyright.PENANAOEKKZUsswb
1341Please respect copyright.PENANArK0oCjYqf2
忘記甚麼是Neoantigen的話,可重溫上一集。1341Please respect copyright.PENANAcUlEd3crXW
1341Please respect copyright.PENANALKhejjur9p
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。1341Please respect copyright.PENANAUmm5QNRAY8
1341Please respect copyright.PENANAYydCMQuLWa
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。1341Please respect copyright.PENANAhDbMNsap1M
1341Please respect copyright.PENANAt8UFEvtXSd1341Please respect copyright.PENANAFkPxmFGYtx
1341Please respect copyright.PENANAU1F7GXtLSG
(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。1341Please respect copyright.PENANAH1AgSBgDqN
1341Please respect copyright.PENANAzsdVF9xwsG
而當CTLA4與B7合併後,T cell所產生的數量及威力就會大減。1341Please respect copyright.PENANA5zK4QFU8aN
1341Please respect copyright.PENANAEphSUBnidU
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。1341Please respect copyright.PENANAH9o6msebCJ1341Please respect copyright.PENANAi5Lt8GOVio
1341Please respect copyright.PENANAIN1pEaqYXW
(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。1341Please respect copyright.PENANA7tRUPyhCDZ
1341Please respect copyright.PENANArEon7fLTd2
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。1341Please respect copyright.PENANAmL40eKXiqu1341Please respect copyright.PENANA6eT8ySN0Pr
1341Please respect copyright.PENANAVYYrl9E3p6
(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。1341Please respect copyright.PENANAzWqKMYn7fQ
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。1341Please respect copyright.PENANAFNtPj1NDoJ
1341Please respect copyright.PENANAaQAZ9uCOmu
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。1341Please respect copyright.PENANAZkAGAhEQCD
1341Please respect copyright.PENANA0h1SQQY0VD
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。1341Please respect copyright.PENANAexHdOnkdru
1341Please respect copyright.PENANAHa4vxv5ci2
這一方面,我們將會在下一篇免疫治療的最終章再作探討。1341Please respect copyright.PENANArWlVawxPH9
1341Please respect copyright.PENANAlFxbkTPROU
1341Please respect copyright.PENANAuJhMb9T9fv
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。1341Please respect copyright.PENANAjaJZYZzzwD
1341Please respect copyright.PENANAzaEBJo59Wr
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/toc1341Please respect copyright.PENANA8PcIgsStpQ
1341Please respect copyright.PENANACaKoJ6HuFP
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。1341Please respect copyright.PENANATw4M8RW5xj
1341Please respect copyright.PENANA70tTrP8zU3
Link:1341Please respect copyright.PENANAIptQshAvmV
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1341Please respect copyright.PENANAFaTahWKIqj
1341Please respect copyright.PENANAMbLo5SXXuL
1341Please respect copyright.PENANAbMMaQbzZiS
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。1341Please respect copyright.PENANAl0q8uJvm61