在CBPS1383/1387Am/m 小鼠腸道發炎反應之T細胞分析

Profiling T cells in intestinal inflammation CBPS1383/1387Am/m mice

許毓華(Yu-Hua Hsu)

指導教授 ： 繆希椿

國立臺灣大學/醫學院/免疫學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702139

摘要

CREB (cAMP response element-binding protein) 結合蛋白(CBP)是一種轉錄共活化因子，可利用本身的組蛋白乙醯轉移酶(HAT)直接調控轉綠作用的進行，並且與多種蛋白有交互作用。當CBP產生突變在人類會造成魯賓斯坦-泰必氏綜合症(Rubinstein-Taybi syndrome, RTS)。在小鼠的胸腺細胞條件式剔除CBP，會有異常的胸腺發育，而且CD8細胞會表現出作用、記憶與先天性型態，並且在接受刺激後能大量快速產生伽瑪干擾素 (interferon-γ)。先前研究證實，CBP 胺基酸1382與1386位置 (老鼠為胺基酸1383與1387位置) 的絲氨酸會被進入細胞核的IKKα磷酸化而增進 CBP HAT的活性，而在此兩胺基酸位點突變的CBP較傾向與P53結合而不傾向與NF-κB結合。在突變CBP knock-in小鼠 (CBPS1383/1387Am/; AA 小鼠) 中，發現會有自發性腸炎的現象，並且其症狀與人類發炎性腸炎相似。因此我們假設在AA小鼠中，腸道發炎是由於異常的T細胞而造成的。在本研究中，我們證實AA小鼠的胸腺細胞數相對於野生型是較少的，但是在腸系膜淋巴結 (mLNs) 中，不論是CD4或是CD8 T細胞數都是上升的。在脾臟中與野生型相比，AA小鼠初始T細胞是顯著性下降且作用性T細胞是顯著性上升的。而在CD4與CD8 T細胞產生細胞激素的能力方面WT小鼠與AA小鼠是相似的，並且初始T細胞分化為TH1、TH2與TH17的能力也是沒有顯著性差異的。此外發炎型細胞激素與抗菌蛋白在AA小鼠大腸黏液層都是上升的，另外在DSS引起的腸道發炎模式中，AA小鼠的 mLNs 會有較多免疫細胞，並且將AA小鼠與WT小鼠混合飼養後，mLNs中的免疫細胞數目沒有顯著差異。

關鍵字

CREB結合蛋白 ； T 細胞 ； 腸炎

並列摘要

CREB (cAMP response element-binding protein) binding protein (CBP) is a transcriptional co-activator. It regulates transcription directly with its intrinsic histone acetyltransferase (HAT) domian. Mutation of CBP in human causes Rubinstein-Taybi syndrome (RTS), an autosomal-dominant disease. Moreover, T cell development in CBP conditional knock-out mice is abnormal. CBP deficient CD8 single-positive (SP) thymocytes possess an effector-, memory-, or innate-like T-cell phenotype and rapidly produce interferon-γ upon stimulation. Previous study indicated that nuclear IKKα phosphorylates CBP at Ser-1382 and Ser-1386 (mouse amino acids 1383 and 1387) and enhance CBP HAT activity. Mutant CBP was shown to switch binding preference from NF-κB to p53. Mutant CBP knock-in mice, CBPS1383/1387Am/m (AA) mice, were generated. They spontaneously develop colitis with features of human inflammatory bowel disease. Because CBP plays a crucial role in T cell development, we hypothesize that abnormal T cells cause chronic intestinal inflammation in the mutated CBP knock-in mice. In this study, the aim is to clarify the role of T cells in intestinal inflammation in AA mice. The results showed that the cell number of thymus was lower in AA mice than WT mice. However, T cells, including CD4 and CD8 T cells, were significantly increased in mesenteric lymph nodes (mLNs) of AA mice. Furthermore, naïve T cells were significantly decreased and effector T cells were significantly increased in AA mice. However, the cytokine-producing ability of T cells was similar in WT and AA mice and the serine phosphorylated CBP did not affect naïve CD4 T cells differentiate into TH1, TH2 and TH17 cells. Moreover, inflammatory cytokines and anti-microbial peptides (AMPs) were enhanced in colon mucus layer of AA mice. AA mice exhibited more immune cells in mLNs compared to WT mice after DSS treatment. In addition, AA mice had similar immune cell population in mLNs to WT mice according to DSS co-house study.

並列關鍵字

CBP ； T cell ； colitis ； IBD

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