美國研究人員最近鑒別出一種在B淋巴細(xì)胞分裂,、增殖過程中所必需的關(guān)鍵蛋白,。科學(xué)家說,，這項發(fā)現(xiàn)將能幫助開發(fā)針對多發(fā)性骨髓瘤等疾病的新療法,。
大量、快速生成B淋巴細(xì)胞等免疫細(xì)胞是構(gòu)建免疫系統(tǒng)的關(guān)鍵,。但如果B淋巴細(xì)胞的分裂,、增殖得不到控制，就可能引發(fā)多發(fā)性骨髓瘤等疾??；如果B淋巴細(xì)胞攻擊目標(biāo)錯誤，就可能引發(fā)自體免疫性疾病。
美國加州大學(xué)圣迭戈分校醫(yī)學(xué)院的研究人員8日在《自然·免疫學(xué)》雜志網(wǎng)絡(luò)版上說,，他們發(fā)現(xiàn)一種名為CD98hc的蛋白可影響B(tài)淋巴細(xì)胞分裂,、增殖，這種蛋白在幾乎所有脊椎動物身體中都存在,，但科學(xué)家一直不清楚它在免疫過程中的作用,。
論文第一作者約瑟夫·坎托說，過去人們在靜息淋巴細(xì)胞過程中發(fā)現(xiàn)這種蛋白的含量較低,，因此用它做活化標(biāo)記物,。但現(xiàn)在發(fā)現(xiàn)，當(dāng)B淋巴細(xì)胞受抗原刺激,，比如在阻止細(xì)菌入侵機(jī)體時,，CD98hc蛋白的含量會激增。
進(jìn)一步的實驗發(fā)現(xiàn),，缺乏這種蛋白的小鼠對病原體不會產(chǎn)生正常的抗體反應(yīng),。
坎托說，當(dāng)缺乏CD98hc蛋白時,，B淋巴細(xì)胞就不能快速分裂,。這表明，CD98hc蛋白在大量增加B淋巴細(xì)胞,、促發(fā)免疫反應(yīng)過程中發(fā)揮著不可缺少的作用,。
研究人員推測，人們將來也許可以通過抑制CD98hc蛋白,，阻止B淋巴細(xì)胞異常增殖或阻止B淋巴細(xì)胞發(fā)生錯誤攻擊,，進(jìn)而阻止多發(fā)性骨髓瘤等疾病的發(fā)生。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature Immunology 8 March 2009 | doi:10.1038/ni.1712
CD98hc facilitates B cell proliferation and adaptive humoral immunity
Joseph Cantor1, Cecille D Browne2, Raphael Ruppert3, Chloé C Féral4, Reinhard F?ssler3, Robert C Rickert2 & Mark H Ginsberg1
The proliferation of antigen-specific lymphocytes and resulting clonal expansion are essential for adaptive immunity. We report here that B cell–specific deletion of the heavy chain of CD98 (CD98hc) resulted in lower antibody responses due to total suppression of B cell proliferation and subsequent plasma cell formation. Deletion of CD98hc did not impair early B cell activation but did inhibit later activation of the mitogen-activated protein kinase Erk1/2 and downregulation of the cell cycle inhibitor p27. Reconstitution of CD98hc-deficient B cells with CD98hc mutants showed that the integrin-binding domain of CD98hc was required for B cell proliferation but that the amino acid–transport function of CD98hc was dispensable for this. Thus, CD98hc supports integrin-dependent rapid proliferation of B cells. We propose that the advantage of adaptive immunity favored the appearance of CD98hc in vertebrates.
1 Department of Medicine, University of California San Diego, La Jolla, California, USA.
2 Program of Inflammatory Disease Research, Infectious and Inflammatory Disease Center, Burnham Institute for Medical Research, La Jolla, California, USA.
3 Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany.
4 Institut National de la Santé et de la Recherche Médicale, Nice-Sophia Antipolis University, Nice, France.
