TGF-BETA-1 INDUCES GERM-LINE TRANSCRIPTS OF BOTH IGA SUBCLASSES IN HUMAN LYMPHOCYTES-B
TGF-BETA-1 INDUCES GERM-LINE TRANSCRIPTS OF BOTH IGA SUBCLASSES IN HUMAN LYMPHOCYTES-B
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DOI：
10.1093/intimm/3.11.1099
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发表时间：
1991-11-01
影响因子：
4.4
通讯作者：
SMITH, CIE
中科院分区：
文献类型：
--
作者：
ISLAM, KB;NILSSON, L;SMITH, CIE
免疫球蛋白（IG）类转换之前，生殖系转录诱导。 在这份报告中，我们表明，转化生长因子β（TGF-β）诱导的伊加亚类（IgA 1和IgA 2）在卡他布兰汉氏菌（BC）激活的人脾B细胞的生殖系成绩单。 在用TGF-β处理的培养物中可以看到两条种系带，一条约为1.85 kb，另一条约为1.6 kb。 约1.85 kb的条带含有膜型生殖系转录物的mRNA。 该条带与生产性分泌形式的α-mRNA共迁移。 另一种约1.6 kb的较短形式在大小上与任何已知形式的生产性α-mRNA不相关，并且含有生殖系α-mRNA的分泌形式。 α-生殖系转录物的诱导伴随着μ和γ-mRNA的伴随抑制。 我们还确定了转换α（S-alpha）区域上游约0.5 kb内推定的I-alpha序列（根据公认的命名法指定）的位置。 TGF-β刺激的脾B细胞中IgA亚类特异性mRNA的相对比例与美洲商陆有丝分裂原（PWM）刺激的脾单核细胞（MNC）中观察到的分布模式一致，IgA 1和IgA 2 mRNA分别为89%和11%。 这些结果表明TGF-β在调节人B淋巴细胞中伊加类转换中的作用。
Immunoglobulin (Ig) class switching appears to be preceded by induction of germ-line transcripts. In this report, we demonstrate that transforming growth factor beta (TGF-beta) induces germ-line transcripts of both the IgA subclasses (IgA1 and IgA2) in Branhamella catarrhalis (BC)-activated human spleen B cells. Two germ-line bands, one of approximately 1.85 kb and the other of approximately 1.6 kb, could be seen in cultures treated with TGF-beta. The approximately 1.85 kb band contains mRNA for a germ-line transcript of the membrane form. This band co-migrates with the productive secreted form of alpha-mRNA. The other, shorter form of approximately 1.6 kb did not correlate in size with any known form of productive alpha-mRNA and contained the secreted form of germ-line alpha-mRNA. The induction of alpha-germ-line transcripts was accompanied by a concomitant suppression of mu and gamma-mRNA. We have also identified the location of a putative I-alpha sequence (designated according to the generally accepted nomenclature) within approximately 0.5 kb upstream to the switch alpha (S-alpha) region. The relative proportions of IgA-subclass-specific mRNA in TGF-beta-stimulated spleen B cells are concordant with the distribution pattern seen in pokeweed mitogen (PWM)-stimulated spleen mononuclear cells (MNC), which was 89 and 11% for the IgA1 and the IgA2 mRNA respectively. These results suggest a role of TGF-beta in regulating IgA class switching in human B lymphocytes.