Reaction of germinal centers in the T-cell-independent response to the bacterial polysaccharide alpha(1-->6)dextran.
Reaction of germinal centers in the T-cell-independent response to the bacterial polysaccharide alpha(1-->6)dextran.
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T 细胞独立反应中生发中心对细菌多糖 α(1-->6) 葡聚糖的反应。
DOI：
10.1073/pnas.91.7.2502
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发表时间：
1994
影响因子：
11.1
通讯作者：
E. A. Kabat
中科院分区：
文献类型：
--
作者：
Denong Wang;Sandra M. Wells;Alan M. Stall;E. A. Kabat
用α（1->6）葡聚糖（DEX）（一种天然细菌多糖）初次免疫BALB/c小鼠，诱导了一种意想不到的脾B细胞应答模式。在第4天抗体分泌B细胞反应达到峰值后，葡聚糖-抗葡聚糖免疫复合物的沉积（如葡聚糖和葡聚糖抗体染色所示）发生并持续存在于脾滤泡中，直至免疫后至少第四周。抗原特异性B细胞在这些卵泡中出现并增殖，导致第11天发育为DEX特异性生发中心，其特征在于存在DEX+花生凝集素阳性（PNA+）细胞的不同区域。此时，荧光激活的细胞分选仪分析也显示DEX+ PNA+脾B细胞的独特群体的出现。相反，DEX+ PNA-细胞，其特征在于强烈的细胞质染色，存在于脾滤泡外，在第4天至第5天达到峰值，并持续到至少第28天。这些细胞的频率与DEX特异性抗体分泌细胞相关，如通过ELISA斑点测定所检测的。因此，除了预期的血浆细胞应答外，典型的T细胞非依赖性II型抗原DEX也令人惊讶地促进抗原特异性生发中心的形成。这些观察结果提出了关于生发中心在T细胞非依赖性免疫反应中的作用的基本问题。
Primary immunization of BALB/c mice with alpha(1-->6)dextran (DEX), a native bacterial polysaccharide, induces an unexpected pattern of splenic B-cell responses. After a peak of antibody-secreting B-cell response at day 4, deposition of dextran-anti-dextran immune complexes, as revealed by staining with both dextran and antibodies to dextran, occurs and persists in splenic follicles until at least the fourth week after immunization. Antigen-specific B cells appear and proliferate in such follicles, leading by day 11 to development of DEX-specific germinal centers as characterized by the presence of distinct regions of DEX+ peanut agglutinin-positive (PNA+) cells. At this time, fluorescence-activated cell sorter analysis also reveals the appearance of a distinct population of DEX+ PNA+ splenic B cells. In contrast, DEX+ PNA- cells, characterized by intense cytoplasmic staining, are present outside of splenic follicles, peak at day 4 to day 5, and persist until at least day 28. The frequency of these cells correlates with DEX-specific antibody-secreting cells, as detected by the ELISA-spot assay. Thus, in addition to the expected plasma cellular response, the typical T-cell-independent type II antigen, DEX, surprisingly also elicits the formation of antigen-specific germinal centers. These observations raise fundamental questions about the roles of germinal centers in T-cell-independent immune responses.