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。1289Please respect copyright.PENANAsN5kfUUTPS
1289Please respect copyright.PENANAIZx70AAHFx
上集:https://www.penana.com/article/4711251289Please respect copyright.PENANAslOvHw1uK1
1289Please respect copyright.PENANACZqwZfAUpq1289Please respect copyright.PENANATPxcAw63y8
1289Please respect copyright.PENANA8VM9Vtzhyz
(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?1289Please respect copyright.PENANAaXmpU1qk1M
1289Please respect copyright.PENANA8II3qYnbtY
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。1289Please respect copyright.PENANAsxN4CYjpe7
1289Please respect copyright.PENANAT3Wm982nfD
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。1289Please respect copyright.PENANALWpf09jlG7
1289Please respect copyright.PENANAON6bDqMIjj1289Please respect copyright.PENANAAoSAdIyWyr
1289Please respect copyright.PENANAstJd6gTMZv
(圖2)T cell的產生數量,接近可以說是由Antigen Presenting Cells(APC)來決定;1289Please respect copyright.PENANAizrS5yVsTt
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。1289Please respect copyright.PENANAOCmIpaTXRs
1289Please respect copyright.PENANAuFBS839pM1
忘記甚麼是Neoantigen的話,可重溫上一集。1289Please respect copyright.PENANA4rSjoVBxkS
1289Please respect copyright.PENANA11UfQJXRkd
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。1289Please respect copyright.PENANA8yeqdv61Xu
1289Please respect copyright.PENANA5r4qyLitIt
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。1289Please respect copyright.PENANAcFoZKIFY6V
1289Please respect copyright.PENANAS4nGxIxQhD1289Please respect copyright.PENANAQQ2uNt8hhm
1289Please respect copyright.PENANANozyGKJrcg
(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。1289Please respect copyright.PENANAfOiCNSJzTl
1289Please respect copyright.PENANAOmJ9MnRRQb
而當CTLA4與B7合併後,T cell所產生的數量及威力就會大減。1289Please respect copyright.PENANA9OWhiisZzz
1289Please respect copyright.PENANArbAgbEw8h2
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。1289Please respect copyright.PENANASUFu1qTCJp1289Please respect copyright.PENANAsEajM8yXZx
1289Please respect copyright.PENANAUzG3JIpyjb
(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。1289Please respect copyright.PENANARmijjOzPfm
1289Please respect copyright.PENANABe89oV0XVx
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。1289Please respect copyright.PENANADNfdBuYTxM1289Please respect copyright.PENANA9UtjMPbjDU
1289Please respect copyright.PENANApUiKXvGaEN
(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。1289Please respect copyright.PENANA5F0OGU5Uwo
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。1289Please respect copyright.PENANARMafnkva6O
1289Please respect copyright.PENANAZRn1KF4zSg
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。1289Please respect copyright.PENANAfg2WkLuHk8
1289Please respect copyright.PENANAFlOAhiNCVy
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。1289Please respect copyright.PENANAjBxUeU68Rj
1289Please respect copyright.PENANAtShh0e0EXp
這一方面,我們將會在下一篇免疫治療的最終章再作探討。1289Please respect copyright.PENANAScpVRyW2on
1289Please respect copyright.PENANAjxASVk19aN
1289Please respect copyright.PENANAXldfxV56Ni
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。1289Please respect copyright.PENANAqeEPC6NYTn
1289Please respect copyright.PENANA6ewDgwgImc
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/toc1289Please respect copyright.PENANAJxSqOwix6g
1289Please respect copyright.PENANAU4nR38Vo50
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。1289Please respect copyright.PENANAl0HY9ht0xN
1289Please respect copyright.PENANAZ8FWa5HBoh
Link:1289Please respect copyright.PENANAzftDLCOivD
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio1289Please respect copyright.PENANAKQlxp3dsse
1289Please respect copyright.PENANAZnIUJ75aci
1289Please respect copyright.PENANAXHX7qgU4zh
有興趣接收科普資訊的話,歡迎follow IG: potatopigtongue。1289Please respect copyright.PENANA2Z41d6anrQ