Molecular genetic features reflecting the preference for isotype switching to IgA expression by Peyer's patch germinal center B cells.
Molecular genetic features reflecting the preference for isotype switching to IgA expression by Peyer's patch germinal center B cells.
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分子遗传特征反映了派尔氏斑生发中心 B 细胞对同种型转换至 IgA 表达的偏好。
DOI：
10.1093/intimm/3.12.1253
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发表时间：
1991
影响因子：
4.4
通讯作者：
Cebra,JJ
中科院分区：
文献类型：
--
作者：
Weinstein,PD;Schweitzer,PA;Cebra-Thomas,JA;Cebra,JJ
事实证明，通过体内或体外方法评估生发中心 (GC) B 细胞（包括来自派尔氏集结 (PP) 的 B 细胞）的功能潜力都很困难。因此，我们没有将分泌的 Ig 产物作为功能潜力的指标进行评估，而是寻求通过原位杂交来检测与来自 PP 的 GC B 细胞中各种 Ig 重链相关的 mRNA。我们发现 PP 的 GC 包含绝大多数 B 细胞，并且具有易于检测的 mRNAα 水平。这些水平介于小型静息 B 细胞和浆母细胞之间。当 PP B 细胞富集带有 GC 标记的细胞时，约 50% 含有 mRNAα，40% 含有 mRNAα。 sigA+B 细胞的类似富集使 50% 的细胞具有易于检测的 mRNAα，并且很少有 mRNAμ 呈阳性。这些 mRNA 的大小与编码 μ 链和 α 链的膜和分泌形式的 mRNA 的大小相似。使用针对 α 开关区域 5' 序列的探针进行 Northern 分析，无法检测到 Cα 种系转录本。最后，来自 PP 的 GC 和 slgA+ 细胞也显示出 Cα 的 CHgenes 5' 的部分基因组 DNA 缺失。因此，似乎大多数表达 mRNAα 的 GC 细胞已经在 DNA 水平上经历了与 Cα 的常规 VDJ 重组，以便转而表达 IgA。我们的研究结果反映了 PP 中 GC 细胞对转换为 IgA 的异常偏好。
It has proven difficult to evaluate the functional potential of germinal center (GC) B cells, including those from Peyer′s patches (PP), by eitherin vivoorin vitromethods. Thus, rather than assess secreted Ig product as an indicator of functional potential we have instead sought to detect mRNAs related to the various Ig heavy chains in GC B cells from PP byin situhybridization. We have found that the GCs of PP contain the vast majority of B cells with easily detectable levels of mRNAα. These levels are intermediate between those of small resting B cells and plasmablasts. When PP B cells are enriched for cells bearing GC markers, ∼50% contain mRNAα and 40% mRNAα. Similar enrichment for sigA+B cells gave 50% of cells with easily detectable mRNAα and few if any positive for mRNAμ. The sizes of these mRNAs were similar to those encoding the membrane and secretory form of μ and α chains. No Cα germ-line transcripts could be detected by Northern analyses using a probe for sequences 5′ to the α switch regions. Finally, GC and slgA+cells from PP also showed the absence of a portion of their genomic DNA for CHgenes 5′ of Cα. Thus, it seems likely that most of the GC cells expressing mRNAα have undergone conventional VDJ recombination to Cα at the DNA level in order to switch to the expression of IgA. Our findings reflect the extraordinary preference for switching to IgA by GC cells in PP.