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。1400Please respect copyright.PENANADWvwBiY6Df
1400Please respect copyright.PENANAOVzNiIrqvG
上集:https://www.penana.com/article/4711251400Please respect copyright.PENANAKEvvrWQ2nA
1400Please respect copyright.PENANAEW9FuYcCd41400Please respect copyright.PENANA09ahO6CVIM
1400Please respect copyright.PENANAyhLSIOgghK
(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?1400Please respect copyright.PENANAcaU7pRTm0k
1400Please respect copyright.PENANAwcjrg5H3Eq
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。1400Please respect copyright.PENANAFzoUfVAi6H
1400Please respect copyright.PENANAfqXk91ZP2O
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。1400Please respect copyright.PENANAYgwiwnMnZY
1400Please respect copyright.PENANAz7GcdfwG751400Please respect copyright.PENANAls4HtbZuGb
1400Please respect copyright.PENANAjfEeL6M363
(圖2)T cell的產生數量,接近可以說是由Antigen Presenting Cells(APC)來決定;1400Please respect copyright.PENANAfpPlHdEW0s
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。1400Please respect copyright.PENANAivTw74Iywq
1400Please respect copyright.PENANA2V1i2XmCcS
忘記甚麼是Neoantigen的話,可重溫上一集。1400Please respect copyright.PENANA05QTzQyqu0
1400Please respect copyright.PENANAUYFdvGFpf7
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。1400Please respect copyright.PENANAe2c1VfvGEa
1400Please respect copyright.PENANA6ggPRVSV5L
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。1400Please respect copyright.PENANAHSFgyKnKSt
1400Please respect copyright.PENANAI8oQ74ijdr1400Please respect copyright.PENANAZhCBC6Cqp4
1400Please respect copyright.PENANAKTLpygos54
(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。1400Please respect copyright.PENANALjwuYkz4Zy
1400Please respect copyright.PENANAaPadd1yPfJ
而當CTLA4與B7合併後,T cell所產生的數量及威力就會大減。1400Please respect copyright.PENANAgRg3BaK7QC
1400Please respect copyright.PENANAtYUcwlZ9ur
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。1400Please respect copyright.PENANAmXyfNX07Oa1400Please respect copyright.PENANA6SefwATf9G
1400Please respect copyright.PENANATwfHlNnu2K
(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。1400Please respect copyright.PENANAeylY4dicQh
1400Please respect copyright.PENANAr60k0E1bES
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。1400Please respect copyright.PENANAweV3RcBWsX1400Please respect copyright.PENANA88AElI2i3o
1400Please respect copyright.PENANAYdubkKeze3
(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。1400Please respect copyright.PENANArQw4JumjAi
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。1400Please respect copyright.PENANAgnop3fENET
1400Please respect copyright.PENANAqwrRUoWvAU
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。1400Please respect copyright.PENANAYhP9WR4fi3
1400Please respect copyright.PENANACwHNdzaNP3
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。1400Please respect copyright.PENANA6AF2eO1I9d
1400Please respect copyright.PENANA8a6FvEC0Co
這一方面,我們將會在下一篇免疫治療的最終章再作探討。1400Please respect copyright.PENANAOVL6ifyGh5
1400Please respect copyright.PENANAG747tgiyhZ
1400Please respect copyright.PENANAAtNDlnVfvf
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。1400Please respect copyright.PENANAKpY8K7K0qU
1400Please respect copyright.PENANAljTl6RfzzK
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/toc1400Please respect copyright.PENANAT0lRZxgLdR
1400Please respect copyright.PENANAdBELUKB2oD
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。1400Please respect copyright.PENANASREiWcWpq3
1400Please respect copyright.PENANALxbZamuWcB
Link:1400Please respect copyright.PENANAncQmcZsn9C
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1400Please respect copyright.PENANAjJ7upNbwqW
1400Please respect copyright.PENANAuP0bZLeQYe
1400Please respect copyright.PENANARcxNI7mCL5
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。1400Please respect copyright.PENANAWwv6Z1z1Wi