生物谷報道：結(jié)核分枝菌是一種能引發(fā)肺結(jié)核的細菌，世界上有1/3的人口被這種細菌所感染,，基本上每1秒種就有一個新感染案例,，從而造成全球性的健康問題。如今,，研究人員在6月號的《自然—免疫學(xué)》期刊上報告說,，他們發(fā)現(xiàn)結(jié)核分枝菌分泌出的一種蛋白質(zhì)能夠嚴重抑制早期的免疫反應(yīng)。
以前的研究發(fā)現(xiàn),，結(jié)核分枝細菌分泌的ESAT-6蛋白質(zhì)與免疫系統(tǒng)對結(jié)核分枝細菌的無效反應(yīng)有關(guān),，如今,，Joyoti Basu和同事評估了這種蛋白質(zhì)的功能。Toll樣受體(TLRs)是機體通過感知病原微生物體并激活細胞直接產(chǎn)生免疫防御的天然免疫受體,，Basu等發(fā)現(xiàn),，純化的ESAT-6能阻斷特定的免疫受體蛋白質(zhì)——Toll樣受體的信號，產(chǎn)生這種機制的關(guān)鍵是ESAT-6與一種Toll受體——TLR2在巨噬細胞表面上的特定相互作用,，巨噬細胞是一種重要的免疫前哨,。他們發(fā)現(xiàn)，通過與TLR2的結(jié)合,，ESAT-6誘導(dǎo)出一種關(guān)閉所有Toll樣受體功能的信號,。
研究人員指出，阻斷ESAT-6與TLR2間的相互作用也許是一種治療肺結(jié)核的潛在方法,，而模擬ESAT-6與TLR2間的相互作用將有助于抑制過度的炎癥反應(yīng),。
Figure 1 - ESAT-6 inhibits LPS-driven production of IL-12p40.
(a) ELISA of IL-12p40 in the supernatants of RAW cells treated with LPS (1 g/ml) alone or with CFP-10 (C; 5 g/ml) or ESAT-6–CFP-10 complex (E–C; 5 g/ml) or varying concentrations (horizontal axes) of recombinant ESAT-6 protein purified from E. coli. (b) ELISA of IL-12p40 in supernatants of RAW cells treated with LPS and 0, 1 or 3 g/ml of recombinant ESAT-6 protein purified from HEK293 cells. (c,d) ELISA of IL-6 (c) or TNF (d) in supernatants of RAW cells treated with LPS, recombinant ESAT-6 protein purified from E. coli, or both. Data are the mean + s.d. of three experiments.
原文出處：
Nature Immunology June 2007, Volume 8 No 6
Direct extracellular interaction between the early secreted antigen ESAT-6 of Mycobacterium tuberculosis and TLR2 inhibits TLR signaling in macrophages - pp610 - 618
Sushil Kumar Pathak, Sanchita Basu, Kunal Kumar Basu, Anirban Banerjee, Shresh Pathak, Asima Bhattacharyya, Tsuneyasu Kaisho, Manikuntala Kundu & Joyoti Basu
doi:10.1038/ni1468
相關(guān)基因：
TLR2
Official Symbol TLR2 and Name: toll-like receptor 2 [Homo sapiens]
Other Aliases: CD282, TIL4
Other Designations: toll/interleukin 1 receptor-like 4
Chromosome: 4; Location: 4q32
Annotation: Chromosome 4, NC_000004.10 (154824890..154846692)
MIM: 603028
GeneID: 7097
