Smirnova Anna S, Andrade-Oliveira Vinicius, Gerbase-DeLima Maria
Immunogenetics Division, Department of Pediatrics, Universidade Federal de Sao Paulo, R. Loefgreen 1235, 04040-031 São Paulo, SP, Brazil.
Mol Immunol. 2008 Feb;45(4):1179-83. doi: 10.1016/j.molimm.2007.07.028. Epub 2007 Sep 6.
The TNF superfamily ligands BAFF and APRIL and receptors BCMA, TACI and BAFF-R play an important role in the regulation of B cell immunity. A number of functionally important splice isoforms have already been characterized for these molecules, stimulating the search for new transcript variants (TVs). Here we report two new BAFF TVs and three BCMA TVs, all potentially codifying new proteins. BAFF TVs were expressed in peripheral blood mononuclear cells (PBMC) of nearly all the individuals studied, decreasing in level when PBMC were activated by PMA and ionomycin. They were also detected in PBMC cytoplasmic RNA. Low levels of the BAFF TVs in all lymphocyte subpopulations analyzed suggest that their main source in PBMC are monocytes. BCMA TVs were observed only in some CD19+ cell samples. Functional studies concerning interaction between isoforms of BAFF, APRIL and their receptors are needed for elucidation of their significance in the immune response.
肿瘤坏死因子超家族配体BAFF和APRIL以及受体BCMA、TACI和BAFF-R在B细胞免疫调节中发挥重要作用。这些分子已经鉴定出许多具有功能重要性的剪接异构体，这促使人们寻找新的转录变体（TVs）。在此，我们报告了两种新的BAFF TV和三种BCMA TV，它们都可能编码新的蛋白质。BAFF TV在几乎所有研究个体的外周血单核细胞（PBMC）中表达，当PBMC被佛波酯（PMA）和离子霉素激活时其水平降低。它们也在PBMC细胞质RNA中被检测到。在所有分析的淋巴细胞亚群中BAFF TV水平较低，这表明它们在PBMC中的主要来源是单核细胞。BCMA TV仅在一些CD19+细胞样本中观察到。需要对BAFF、APRIL及其受体异构体之间的相互作用进行功能研究，以阐明它们在免疫反应中的意义。
