Use of molecular modeling and site-directed mutagenesis to define the structural basis for the immune response to carbohydrate xenoantigens.
Use of molecular modeling and site-directed mutagenesis to define the structural basis for the immune response to carbohydrate xenoantigens.
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DOI：
10.1186/1471-2172-8-3
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发表时间：
2007-03-12
期刊：
影响因子：
3
通讯作者：
Cramer DV
中科院分区：
文献类型：
--
作者：
Kearns-Jonker M;Barteneva N;Mencel R;Hussain N;Shulkin I;Xu A;Yew M;Cramer DV
针对碳水化合物的天然抗体排斥猪异种移植物。它们最初以种系构型表达，并由少量结构相关的种系祖细胞编码。转基因猪器官的移植可以防止超急性排斥反应，但延迟性移植物排斥反应仍会发生，部分原因是体液反应。编码诱导的异种抗体的IgVH基因主要（非排他地）来源于VH 3家族中的生殖系祖细胞。我们先前已经在患者和灵长类动物中鉴定了编码VH 3异种抗体的免疫球蛋白重链基因。在这份手稿中，我们完成了诱导的异种抗体的结构分析，通过鉴定IgVH基因编码的小比例的VH 4异种抗体和种系祖细胞编码异种抗体轻链。该信息已用于使用计算机模拟建模来定义异种抗体/碳水化合物结合位点。VH 4 -59基因编码VH 4家族中的抗体，所述抗体在人类患者中诱导，从而产生活性异种抗体应答。异种抗体的轻链由DPK 5和HSIGKV 134编码。通过测序分析获得的结构信息用于创建计算机模拟模型。VH 3家族异种抗体的异种抗体/碳水化合物相互作用的关键接触位点包括位点31、33、50、57、58中的氨基酸和IgVH基因的CDR 3区。定点诱变表明预测接触位点的突变改变了与碳水化合物异种抗原的结合。计算机模拟模型表明，CDR 3区直接影响结合。在早期和延迟的异种移植物反应期间诱导的异种抗体主要由VH 3家族中的基因编码，其中一小部分由VH 4生殖系祖细胞编码。该限制性基团可以通过轻链、重链和CDR 3的独特典型结构来鉴定。计算机模拟模型准确地描述了这种结构，正如定点突变所证实的那样。使用计算机模拟模型的计算机模拟药物设计现在可以应用于开发可能提高异种移植器官存活率的新药。
Natural antibodies directed at carbohydrates reject porcine xenografts. They are initially expressed in germline configuration and are encoded by a small number of structurally-related germline progenitors. The transplantation of genetically-modified pig organs prevents hyperacute rejection, but delayed graft rejection still occurs, partly due to humoral responses. IgVH genes encoding induced xenoantibodies are predominantly, not exclusively, derived from germline progenitors in the VH3 family. We have previously identified the immunoglobulin heavy chain genes encoding VH3 xenoantibodies in patients and primates. In this manuscript, we complete the structural analysis of induced xenoantibodies by identifying the IgVH genes encoding the small proportion of VH4 xenoantibodies and the germline progenitors encoding xenoantibody light chains. This information has been used to define the xenoantibody/carbohydrate binding site using computer-simulated modeling. The VH4-59 gene encodes antibodies in the VH4 family that are induced in human patients mounting active xenoantibody responses. The light chain of xenoantibodies is encoded by DPK5 and HSIGKV134. The structural information obtained by sequencing analysis was used to create computer-simulated models. Key contact sites for xenoantibody/carbohydrate interaction for VH3 family xenoantibodies include amino acids in sites 31, 33, 50, 57, 58 and the CDR3 region of the IgVH gene. Site-directed mutagenesis indicates that mutations in predicted contact sites alter binding to carbohydrate xenoantigens. Computer-simulated modeling suggests that the CDR3 region directly influences binding. Xenoantibodies induced during early and delayed xenograft responses are predominantly encoded by genes in the VH3 family, with a small proportion encoded by VH4 germline progenitors. This restricted group can be identified by the unique canonical structure of the light chain, heavy chain and CDR3. Computer-simulated models depict this structure with accuracy, as confirmed by site-directed mutagenesis. Computer-simulated drug design using computer-simulated models may now be applied to develop new drugs that may enhance the survival of xenografted organs.
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影响因子：
6.2
作者：
Cramer, DV;Wu, GD;Borie, D
通讯作者：
Borie, D
影响因子：
5.6
作者：
de Bono, B;Madera, M;Chothia, C
通讯作者：
Chothia, C
DOI：
10.1006/clin.1998.4603
发表时间：
1998-12-01
期刊：
CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY
影响因子：
--
作者：
Adderson, EE;Shackelford, PG;Carroll, WL
通讯作者：
Carroll, WL
影响因子：
6.2
作者：
Borie, DC;Cramer, DV;Makowka, L
通讯作者：
Makowka, L
影响因子：
6.2
作者：
COTTERELL, AH;COLLINS, BH;PLATT, JL
通讯作者：
PLATT, JL