當(dāng)細(xì)菌侵入身體時(shí),，免疫細(xì)胞會(huì)迅速出現(xiàn)在感染區(qū)與“敵人”斗爭(zhēng),，但是，當(dāng)細(xì)菌被消滅后,，這些免疫細(xì)胞如何撤退呢,？研究人員在4月號(hào)的《自然—免疫學(xué)》上報(bào)告說(shuō)：免疫細(xì)胞從血液中的撤退需要一種以上的分子。新發(fā)現(xiàn)也許有助于研究人員尋找治療炎癥疾病的靶標(biāo),。
淋巴細(xì)胞是一種免疫細(xì)胞,，它們以與血液流動(dòng)相同的速度在血管內(nèi)穿梭。當(dāng)身體被感染或受傷時(shí),，淋巴細(xì)胞迅速聚集到受傷點(diǎn),，因此，它們?cè)谌蝿?wù)完成后也需要撤離血管,。淋巴細(xì)胞使用一種L-選擇蛋白(L-selectin)來(lái)識(shí)別和抓住特定類型的復(fù)合糖蛋白——O-glycans,，O-glycans 位于受感染血管壁。
Minoru Fukuda和同事發(fā)現(xiàn),，小鼠的淋巴細(xì)胞也能識(shí)別N-glycans糖蛋白發(fā)出的撤離信號(hào),。人類的淋巴細(xì)胞是否也具有同樣的識(shí)別和撤離功能呢？這有待研究人員進(jìn)一步探索,。如果人類的淋巴確實(shí)具有類似功能,，研究炎癥疾病治療方法的科學(xué)家們就需要尋找更多的指示淋巴細(xì)胞撤離的靶標(biāo)。
部分英文原文：
Published online: 4 March 2007; | doi:10.1038/ni1442
Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment
Junya Mitoma1, 6, 7, Xingfeng Bao1, 7, Bronislawa Petryanik2, Patrick Schaerli3, Jean-Marc Gauguet3, Shin-Yi Yu4, Hiroto Kawashima1, Hideo Saito1, Kazuaki Ohtsubo5, Jamey D Marth5, Kay-Hooi Khoo4, Ulrich H von Andrian3, John B Lowe2 & Minoru Fukuda1
1 Glycobiology Program, Cancer Research Center, Burnham Institute for Medical Research, La Jolla, California 92037, USA.
2 Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
3 CBR Institute for Biomedical Research and Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.
4 Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.
5 Howard Hughes Medical Institute and Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA.
6 Present address: Division of Glyco-Signal Research, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba, Sendai, Miyagi 981-8558, Japan.
7 These authors equally contributed to this work.
Correspondence should be addressed to Minoru Fukuda [email protected]
Lymphocyte homing is mediated by specific interaction between L-selectin on lymphocytes and the carbohydrate ligand 6-sulfo sialyl Lewis X on high endothelial venules. Here we generated mice lacking both core 1 extension and core 2 branching enzymes to assess the functions of O-glycan-borne L-selectin ligands in vivo. Mutant mice maintained robust lymphocyte homing, yet they lacked O-glycan L-selectin ligands. Biochemical analyses identified a class of N-glycans bearing the 6-sulfo sialyl Lewis X L-selectin ligand in high endothelial venules. These N-glycans supported the binding of L-selectin to high endothelial venules in vitro and contributed in vivo to O-glycan-independent lymphocyte homing in wild-type and mutant mice. Our results demonstrate the critical function of N-glycan-linked 6-sulfo sialyl Lewis X in L-selectin-dependent lymphocyte homing and recruitment.
