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。1381Please respect copyright.PENANAyn2rSK9QkO
1381Please respect copyright.PENANAzsy0LTnSLp
上集:https://www.penana.com/article/4711251381Please respect copyright.PENANAdm1DGp3JRu
1381Please respect copyright.PENANAb16RukokCf1381Please respect copyright.PENANAZiHzeeJNQF
1381Please respect copyright.PENANAPKhfljqqrZ
(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?1381Please respect copyright.PENANACzGcCTPsjO
1381Please respect copyright.PENANArKTGVUxgYZ
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。1381Please respect copyright.PENANAqcV5qWmaRh
1381Please respect copyright.PENANA1xVBY6X8s5
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。1381Please respect copyright.PENANAhxBlPfVcwS
1381Please respect copyright.PENANAbXT14CxkfG1381Please respect copyright.PENANA8264IuEU9U
1381Please respect copyright.PENANAOjTZIdgG34
(圖2)T cell的產生數量,接近可以說是由Antigen Presenting Cells(APC)來決定;1381Please respect copyright.PENANA6SntWX9GIU
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。1381Please respect copyright.PENANAPoph1uF56r
1381Please respect copyright.PENANAqTJslf49DR
忘記甚麼是Neoantigen的話,可重溫上一集。1381Please respect copyright.PENANAx2f2duw0Qb
1381Please respect copyright.PENANAAj6taswQB9
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。1381Please respect copyright.PENANAgEGAUykSJ1
1381Please respect copyright.PENANA0oJH8fW5xi
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。1381Please respect copyright.PENANA45fzAgKytt
1381Please respect copyright.PENANASTR53Ls1Yc1381Please respect copyright.PENANAd0n4or0vik
1381Please respect copyright.PENANAhBa8vbIQiN
(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。1381Please respect copyright.PENANAsOC7xqljqF
1381Please respect copyright.PENANAmAHtVws5Q9
而當CTLA4與B7合併後,T cell所產生的數量及威力就會大減。1381Please respect copyright.PENANASF5UxgiyLy
1381Please respect copyright.PENANA8HpZGRvKdr
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。1381Please respect copyright.PENANAiLfz09oJS31381Please respect copyright.PENANAHRx7gAZDxL
1381Please respect copyright.PENANAGFSejqls0w
(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。1381Please respect copyright.PENANArmJPFauTj3
1381Please respect copyright.PENANAWH6iC6Eg6V
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。1381Please respect copyright.PENANASEnGlgElf71381Please respect copyright.PENANASQZacmrdJ2
1381Please respect copyright.PENANAF4z5WY69zB
(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。1381Please respect copyright.PENANAmZ9SBhOM4J
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。1381Please respect copyright.PENANAhpPDm0k5LE
1381Please respect copyright.PENANAOV9pPtXwmp
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。1381Please respect copyright.PENANAHYXl0rhtzK
1381Please respect copyright.PENANAIYsMEMycY5
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。1381Please respect copyright.PENANAULw7Zz7fGe
1381Please respect copyright.PENANArrw86wQzMx
這一方面,我們將會在下一篇免疫治療的最終章再作探討。1381Please respect copyright.PENANAKzYcgjzRvQ
1381Please respect copyright.PENANAMAdjUDdlJm
1381Please respect copyright.PENANAInxOSjjIaI
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。1381Please respect copyright.PENANAIPp4c2EA1V
1381Please respect copyright.PENANAgJ543a330Z
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/toc1381Please respect copyright.PENANAKYDelvahor
1381Please respect copyright.PENANAg9RCJMsLaj
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。1381Please respect copyright.PENANAaptGwT8zrs
1381Please respect copyright.PENANAwO3jenVCGF
Link:1381Please respect copyright.PENANAnPK3qhpCNu
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1381Please respect copyright.PENANAGgWaO7MGVk
1381Please respect copyright.PENANA3pH5j7UwA5
1381Please respect copyright.PENANA6p4eSbLMpv
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。1381Please respect copyright.PENANARmaQz9NspS