專 題 討 論

Final reporter

江承堯

S46931067

Macrophage Surface Expression of Annexins I and II in the Phagocytosis of Apoptotic Lymphocytes

摘要  

吞噬死亡細胞的作用是一個維持體內環境恆定的重要機制,當細胞進行細胞凋亡的過程時,細胞膜內葉的 phosphatidylserine(PS)會曝露於細胞膜外葉,並且傳遞一個”吃我”的信號給巨噬細胞。吞噬細胞辨識並且攝入死亡細胞噬一個可以壓抑自體免疫反應及發炎反應的發生,而在這一篇文獻中告訴我們巨是細胞表面所表現的Annexin I及 Annexin II在吞噬作用的發生扮演重要的角色。凋亡的Jurkat T cells以及周邊T cells但是不包括胸腺細胞可以被anti-annexin I所染上,但不會被anti-annexin II所染上。凋亡細胞被巨噬細胞吞噬的作用可以被anti-annexin I,anti-annexin II的單株抗體所抑制,或是將巨噬細胞先用同樣的單株抗體處理過之後也可以看到同樣的效果,但吞噬作用卻不會被anti-annexin V所抑制。然而透過調理作用巨噬細胞吞噬紅血球噬不需要annexin分子的參與。對凋亡的目標細胞作與巨噬細胞相似的單株抗體前處理後,卻對巨噬細胞的吞噬作用沒有影響。EGTA是一種鈣離子的敖合劑,會將環境中的鈣離子抓掉,用EGTA來處理凋亡的細胞可以抑制巨噬細胞對凋亡細胞吞噬能力。因此annexins分子家族在巨噬細胞吞噬凋亡細胞的過程中扮演了一個橋樑,他們在這過程中扮演著ligand與receptor的角色。

結果

(1) Binding of anti-annexin mAbs to live J774 and EP macrophage

(2) Binding of anti-annexin mAbs to live U937

(3) Phagocytosis of apoptotic mouse thymocytes in the presence of anti-annexin mAbs.

(4) Phagocytosis of apoptotic mouse thymocytes by differentiated U937 macrophages

(5) Phagocytosis of PS-expressing or opsonized erythrocytes by EP macrophages in the presence of anti-

annexin mAbs

(6) Phagocytosis of apoptotic thymocytes after pretreatment of either macrophage or target cells with anti-annexin mAbs

(7) Binding of anti-annexin mAbs to apoptotic Jurkat cells

(8) Phagocytosis of Jurkat cells after pretreatment of either macrophage or target cells with anti-annexin mAbs or EGTA

(9) Expression of annexins by apoptotic thymocytes and apoptotic Jurkat cells

(10) Binding of anti-annexin mAbs to apoptotic human peripheral T lymphocytes.

Summary

參考文獻

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3.Fan, X., et al. 2004. Macrophage surface expression of annexins I and II in

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