IMMUNOCHEMISTRY OF GONOCOCCAL LIPOOLIGOSACCHARIDE

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。该项目继续研究模仿人类糖鞘糖脂(GSL)的脂寡糖(LOS)如何使淋球菌能够传播，以找到预防它的方法。低的是外膜糖脂，它的糖基部分由近端的基底区和三个短的远端链组成，分别称为_、_和_。许多链低聚糖在结构上与Lacto-(Lac-R)、Globo-(P_(Gb3)和P_(Pl))、副链-(LNnT)和神经节糖基(GalNAc_1-LNnT)系列GSL的结构相同。LOS参与上皮细胞的附着和侵袭，以及免疫清除机制的逃避。淋病期间脱落的淋球菌造成较大的淋病损失。由MS1lmkC--一种用于人体实验的菌株--产生的较高的M_LOS具有聚乳糖胺结构。多聚乳糖胺化可解释该变异体较高的M_2分子，但不能解释其他变异体的高M_2分子。一些血清耐药淋球菌株延长LOS链，形成平行于α链-乳糖的-乳糖，而脑膜炎双球菌可延长-链。我们正在构建由临床分离株产生的更高的M_LOS：由Ser1菌株产生的LOS，以及似乎具有更高阶(Gb4和P-1)球糖低聚糖的LOS，它们分别与副大叶糖和神经节糖基LOS同位。我们特别想知道较高的M_LOS是否有平行的GSL样触角，可以使上皮细胞受体交联。我们将继续依靠质谱学技术，但也将利用高pH阴离子交换色层分析。我们对淋球菌LOS的脂类成分知之甚少。这一信息是必要的，因为脂类部分影响糖类部分的构象，从而影响后者结合包括抗体在内的糖蛋白的能力。来自降解的LOS叶的可用结构信息未探索已知的O-酰基类脂部分的不均一性。我们将描述淋球菌类脂部分在菌株之间的异质性，并对选定菌株的类脂基团进行更完整的结构分析。单抗已被广泛应用于淋病发病机制的研究中，作为糖结构的替代物。然而，我们还没有区分已知糖类结构的单抗，更不用说那些尚未发现的单抗了。我们计划扩大我们的单抗资料库，以包括更多的特异性。这些单抗对于完整研究LOS在发病机制中的作用是必要的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project continues studies of how liooligosaccharide (LOS) mimicry of human glycosphingolipids (GSL) enables the transmission of Neisseria gonorrhoeae in order to find ways to prevent it. LOW are outer membrane glycolipids that have a glycose moiety that consists of proximal Basal Region and three short distal chains, termed _, _, and _. Many _ chain oligosaccharides are structurally identical to those of lacto- (Lac-R), globo- (P_(Gb3) and P1), paraglobo- (lacto-N-neotetraose (LNnT)), and gangliosyl (GalNAc_1-LNnT) series GSL. LOS are involved in attachment to and invasion of epithelial cells, and in evasion of immune clearance mechanisms. Gonococci shed during gonorrhoea make larger LOS. The higher M_ LOS made by MS1lmkC -- a strain used in human experimentation -- have polylactosamine structures. Polylactosaminylation explains the higher M_ molecules of this variant, but not those of others. Some serum resistant (ser_) gonococcal strains extend the LOS _ chain to form an _-lactose that is parallel to the _-lactose of the a chain, and meningococci can extend the _ chain. We are structuring higher M_ LOS made by clinical isolates: LOS made by ser_ strains, and LOS that appear to have higher order (Gb4 and P-1) globosyl oligosaccharides that are isobaric with paraglobosyl and gangliosyl LOS, respectively. We particularly want to know whether higher M_ LOS have parallel GSL-like antennae that could crosslink epithelial cell receptors. We will continue to rely on mass spectrometric techniques, but will also utilize high pH anion exchange chromatographic analyses. We know little about the lipoidal moieties of gonococcal LOS. This information is needed because the lipoidal moiety influences the conformation of the glycose moiety in ways that affect the latter's ability to bind glycoproteins, including antibodies. Available structural information from degraded LOS leaves unexplored the known O-acyl lipoidal moiety heterogeneity. We will profile gonococcal lipoidal moiety heterogeneity among strains, and perform more complete structural analysis on the lipoidal groups from select strains. Mabs have been used extensively in studies of gonococcal pathogenesis as surrogates for glycose structures. However, we do not have mAbs that discriminate among known glycose structures, much less for those that have yet to be found. We plan to expand our library of mAbs to include additional specificities. These mAbs will be necessary for complete studies of the role of LOS in pathogenesis.