ANTIBODY DIVERSITY IN RESPONSES TO POLYSACCHARIDE VACCINES

简单多糖，如细菌莱万（BL），不与 蛋白引起胸腺非依赖性（TI）反应。 虽然TI 反应是克隆限制性的，抗体库，可以是 新克隆型的出现证明， 在用多糖-蛋白质复合物免疫的小鼠中产生。 的 本研究的重点是确定的机制或事件 哪一种潜在的抗体被真正表达了。 我们早先 检查IgG抗体等电聚焦（IEF）模式的研究 在遗传上确定的小鼠中， 菌株表明，IgG反应的复杂性受到调节， 至少一个C57 BL/6基因，命名为谱型调节基因1 (Sr1），并且不与Igh基因复合体、MHC或毛色相关。 正在进行的工作集中在将Sr 1基因定位到小鼠中， 染色体 将一大组（BALB/c X C57 BL/6）F1小鼠回交至 BALB/c已经繁殖，用BL免疫，并表型为Sr 1阳性或 血清中抗菊粉抗体IEF分析为阴性。 脾 从所有回交1（BC 1）小鼠中分离DNA。 使用 简单序列重复（SSR）-PCR，BC 1小鼠的基因分型为 位于1号到19号染色体上的遗传标记。 我们的数据表明 Sr 1和常染色体之间的连接，并且该结果得到以下结果的支持： CXB重组近交系的表型和基因型分析。 BC 1小鼠和其他CXB菌株的基因分型正在进行中。 我们 计划繁殖更多的BC 1小鼠，并检查基因型和表型 一个同源菌株，缺乏C57 BL/6基因的区域，我们有 确定为Sr 1的可能位置。 关于TCRb/TCRd的最新研究 双基因敲除小鼠已经证实对BL的反应是TI， 反应 一个调控基因（Sr 1）的定位和表征 免疫后抗体多样性的表达 多糖抗原将有助于更好地了解 多糖免疫应答及抗体调节 多样性

Simple polysaccharides, such as bacterial levan (BL), not conjugated to protein elicit a thymus independent (TI) response. Although the TI response is clonally restricted, the repertoire of antibodies that can be produced is much greater as evidenced by the appearance of new clonotypes produced in mice immunized with polysaccharide-protein complexes. The focus of this investigation is on the mechanisms or events that determine which of the potential antibodies is actually expressed. Our earlier studies examining the isoelectric focusing (IEF) pattern of IgG antibodies produced in response to immunization with BL in genetically defined mouse strains demonstrated that the complexity of the IgG response is regulated by at least one C57BL/6 gene, designated spectrotype regulation gene 1 (Sr1 ), and is not linked to the Igh gene complex, MHC, or coat color. Work in progress is focused on mapping the Sr1 gene to a murine chromosome. A large group of (BALB/c X C57BL/6)F1 mice backcrossed to BALB/c has been bred, immunized with BL, and phenotyped as Sr1 positive or negative by IEF analysis of anti-inulin antibodies in the serum. Spleen DNA has been isolated from all of the backcross 1 (BC1) mice. Using simple sequence repeat (SSR)-PCR, the BC1 mice have been genotyped at genetic markers located on chromosomes 1 through 19. Our data indicate linkage between Sr1 and an autosome and this result is supported by phenotype and genotype analyses of CXB recombinant inbred lines. Genotyping of the BC1 mice and additional CXB strains is in progress. We plan to breed additional BC1 mice and examine the genotype and phenotype of a congenic strain which lacks C57BL/6 genes in the region we have identified as a possible location for Sr1. Recent studies with TCRb/TCRd double knockout mice have confirmed that the response to BL is a TI response. Mapping and characterization of a gene (Sr1 ) which regulates the expression of antibody diversity following immunization with a polysaccharide antigen will contribute to a betterunderstanding of the immune response to polysaccharides and of the regulation of antibody diversity.