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。1366Please respect copyright.PENANAybYvaNB9j3
1366Please respect copyright.PENANAPdYJaIHtM3
上集:https://www.penana.com/article/4711251366Please respect copyright.PENANAmf03w8ZIhv
1366Please respect copyright.PENANApP4GtY7UE81366Please respect copyright.PENANAe8oaoHbKqO
1366Please respect copyright.PENANAgM7YJByUwg
(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?1366Please respect copyright.PENANASvBiTXOHR3
1366Please respect copyright.PENANAGOXI0CLHsT
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。1366Please respect copyright.PENANA4LKoWrn7lp
1366Please respect copyright.PENANA4OPxHGytir
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。1366Please respect copyright.PENANAGnP59Ihd5c
1366Please respect copyright.PENANAzTXJlgab151366Please respect copyright.PENANAf12wjasUVr
1366Please respect copyright.PENANAO1RRK0ACmR
(圖2)T cell的產生數量,接近可以說是由Antigen Presenting Cells(APC)來決定;1366Please respect copyright.PENANAcq1sWHIlgp
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。1366Please respect copyright.PENANAPFbXnfN5oT
1366Please respect copyright.PENANAUInK347krG
忘記甚麼是Neoantigen的話,可重溫上一集。1366Please respect copyright.PENANAK03qOEHqwm
1366Please respect copyright.PENANA9Rvvekq2cM
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。1366Please respect copyright.PENANAiW5PNxOKlD
1366Please respect copyright.PENANA3SJBmUl0fn
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。1366Please respect copyright.PENANAlW0sgVhxQL
1366Please respect copyright.PENANA75CX0GhmFx1366Please respect copyright.PENANAI96wD4g31L
1366Please respect copyright.PENANAtGR0rG1kFp
(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。1366Please respect copyright.PENANA2g7DRgWCwS
1366Please respect copyright.PENANApf6XSBc0QT
而當CTLA4與B7合併後,T cell所產生的數量及威力就會大減。1366Please respect copyright.PENANAkikyS8d1fK
1366Please respect copyright.PENANAG9cNbgg1gy
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。1366Please respect copyright.PENANAKAkTXsHWJQ1366Please respect copyright.PENANAciPUFlbBEw
1366Please respect copyright.PENANAgk12Nb4Vzo
(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。1366Please respect copyright.PENANA2GSOBKqsYJ
1366Please respect copyright.PENANACESLueNjaq
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。1366Please respect copyright.PENANAf6tMeqF5tR1366Please respect copyright.PENANA9kUU7PlpKf
1366Please respect copyright.PENANA9ngSDumy4r
(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。1366Please respect copyright.PENANAyDy7arEbAo
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。1366Please respect copyright.PENANA7Rn5u3of8t
1366Please respect copyright.PENANAyCL1UtyTDj
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。1366Please respect copyright.PENANAQL4CIPBtXc
1366Please respect copyright.PENANAOP9Iquzx1r
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。1366Please respect copyright.PENANAA6TsxMcGEX
1366Please respect copyright.PENANASOnRWqpc4B
這一方面,我們將會在下一篇免疫治療的最終章再作探討。1366Please respect copyright.PENANA1CJhieGjfP
1366Please respect copyright.PENANAf06iQtdNDK
1366Please respect copyright.PENANAYVu4580PLk
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。1366Please respect copyright.PENANABoTpMwwsEJ
1366Please respect copyright.PENANAyyxwUQznpy
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/toc1366Please respect copyright.PENANAQG5Y1S1hAm
1366Please respect copyright.PENANA22ziRxzW9h
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。1366Please respect copyright.PENANASJTfj8yNCr
1366Please respect copyright.PENANABtHdnfnw55
Link:1366Please respect copyright.PENANAITqwHbQpsK
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1366Please respect copyright.PENANACmyd1ClAaB
1366Please respect copyright.PENANA5RvgJqBzzt
1366Please respect copyright.PENANAzFkfYR34VG
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。1366Please respect copyright.PENANAPevZMgpeQH