MECHANISTIC ANALYSIS OF PREFERENTIAL DHRSS TARGETING

V(D)J重组是重组信号序列的靶点 它们被发现与功能免疫受体基因紧邻 细分市场。虽然D/H段两侧的RSS看起来是相等的，但它们 不是随机使用的。我们发现小鼠的D/H基因重排 删除的频率至少是倒置的1000倍。在……里面 人B细胞D/H/J/H缺失重排倾向10-100倍 过度反转重排。人工复合基板 证明了D/H-J/H中3‘D/H RSS的强偏倚 重排可以在细胞系中重演，并依赖于 几个因素包括紧挨着的编码序列 D/H RSS，D/H段本身的重组伙伴。这些 数据表明，某些RSS组合更好地针对重组 比其他人更好。 倒置的D/H片段编码带正电荷的残基 速度是法线方向上D/H段的两倍。数据表单 几个不同的调查人员已经证明了以下内容：1)一个 抗DNA特异性与正电荷重的关系 链CDR3/S；2)发现倒置的D/H基因片段的倾向 抗DNA抗体。由于D/H倒置重排相对 罕见，高频率D/H倒置在具有特异性的抗体中 作为进一步研究的DNA依据。 因此，这项建议的目标是划定独联体和转运体-- 行动元素，针对特定的12/23 RSS组合使用 优先连接5‘D/H RSS到V/H RSS和3’D/H RSS到J/H。 并确定D/H RSS靶向在自身免疫中是否失调 条件。

V(D)J recombination is targeted by recombination signal sequences (RSS) which are found immediately adjacent to functional immune receptor gene segments. While the RSS flanking D/H segments appear to be equivalent they are not randomly utilized. We have found that murine D/H genes rearrange at least 1000 times more frequently by deletion than by inversion. In human B cells, deletion D/H/J/H rearrangement is favored by 10-100 fold over inversional rearrangement. Artificial recombination substrates demonstrate that the strong bias for the 3' D/H RSS in D/H-J/H rearrangement can be recapitulated in cell lines, and is dependent on several factors including the coding sequence immediately adjacent to the D/H RSS, the recombination partner to which the D/H segment itself. These data suggest that certain RSS combinations target recombination better than others. Inverted D/H segments encodes positively charged residues at approximately twice the rate as D/H segments in the normal orientation. Data forms several different investigators have demonstrated the following: 1) an association between anti-DNA specificity and positively charged heavy chain CDR3/s; and 2) a propensity to find inverted D/H gene segments in anti-DNA antibodies. Since inverted D/H rearrangements are relatively rare, the high frequency of D/H inversions in antibodies with specificity for DNA warrants further study. Thus, the objectives of this proposal are to delineate the cis and trans- acting elements which target specific 12/23 RSS combinations using the preferential joining of the 5'D/H RSS to V/H RSS and 3' D/H RSS to J/H. and to determine whether D/H RSS targeting is dysregulated in autoimmune conditions.