生物谷：免疫細(xì)胞是怎樣捕獲和運(yùn)送來(lái)自外來(lái)病原體的蛋白質(zhì)的呢,？研究人員在7月在線(xiàn)出版的《自然—免疫學(xué)》（Nature Immunology）中說(shuō)，他們尋找了問(wèn)題的答案,。
在發(fā)動(dòng)“反攻”前,，免疫細(xì)胞首先需要“看到”外來(lái)抗原。但在充滿(mǎn)免疫細(xì)胞的淋巴結(jié)中發(fā)送這樣一個(gè)信號(hào)是個(gè)挑戰(zhàn),。淋巴結(jié)是免疫系統(tǒng)的一個(gè)集散地,，被抗體或特定的血蛋白質(zhì)（也被稱(chēng)為補(bǔ)充物）所裝飾的外來(lái)抗原進(jìn)入淋巴結(jié)中。Jason Cyster和同事發(fā)現(xiàn),，一種特別的免疫細(xì)胞在淋巴結(jié)表面上捕獲了這些經(jīng)裝飾的復(fù)合體,，并將它們引導(dǎo)到通向抗體產(chǎn)生器B細(xì)胞的傳送帶上。然后,，B細(xì)胞與外來(lái)抗原競(jìng)相發(fā)送出深藏于淋巴結(jié)中的特定抗原細(xì)胞,，將它們激活，從而啟動(dòng)免疫系統(tǒng)應(yīng)對(duì)入侵的外來(lái)者,。
這種抗原捕獲和傳送的系統(tǒng)是如此錯(cuò)綜復(fù)雜,，通過(guò)警告侵略者的出現(xiàn)，它確保了免疫系統(tǒng)快速而有效地處理潛在的外來(lái)侵略者,。（科學(xué)時(shí)報(bào)）
原始出處:
Nature Immunology
Published online: 29 July 2007 | doi:10.1038/ni1494
Subcapsular encounter and complement-dependent transport of immune complexes by lymph node B cells
Tri Giang Phan1, Irina Grigorova1, Takaharu Okada1,2 & Jason G Cyster1
Abstract
The mechanism of B cell–antigen encounter in lymphoid tissues is incompletely understood. It is also unclear how immune complexes are transported to follicular dendritic cells. Here, using real-time two-photon microscopy we noted rapid delivery of immune complexes through the lymph to macrophages in the lymph node subcapsular sinus. B cells captured immune complexes by a complement receptor–dependent mechanism from macrophage processes that penetrated the follicle and transported the complexes to follicular dendritic cells. Furthermore, cognate B cells captured antigen-containing immune complexes from macrophage processes and migrated to the T zone. Our findings identify macrophages lining the subcapsular sinus as an important site of B cell encounter with immune complexes and show that intrafollicular B cell migration facilitates the transport of immune complexes as well as encounters with cognate antigen.
Howard Hughes Medical Institute and Department of Microbiology and Immunology, University of California, San Francisco, California 94143, USA.
Present address: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Nishikyo-ku, Kyoto, Japan.
Correspondence to: Jason G Cyster1 e-mail: [email protected]
