Ravindranath Mepur H, Muthugounder Sakunthala, Saravanan Thiruverkadu S, Presser Naftali, Morton Donald L
Laboratory of Glycoimmunotherapy, John Wayne Cancer Institute, 2200 Santa Monica Boulevard, Santa Monica, CA 90404-2302, USA.
Ann N Y Acad Sci. 2005 Jun;1050:229-42. doi: 10.1196/annals.1313.024.
Gangliosides have a hydrophilic sugar chain that contains antigenic determinants and a hydrophobic ceramide. In humans, gangliosides elicit a T-cell independent IgM response; antiganglioside IgM autoantibodies may be pentameric or polymeric. A correlation between specific neuropathies and antiganglioside autoantibodies has been confirmed. Although many neurologists attempt to lower titers of antiganglioside autoantibodies, oncologists are developing strategies to augment production of IgM antibodies that will remove immunosuppressive gangliosides from the circulation of patients and target gangliosides and kill tumor cells. Antiganglioside IgM antibodies can cause leakage of the blood-nerve barrier in a concentration-dependent and complement-independent manner, bind to neuronal gangliosides to create a neuromuscular block and serve as a marker of axonal damage in neuropathies such as multiple sclerosis. They are also a promising biomarker of early prostate cancer. There is a need to validate the protocol for enzyme-linked immunosorbent assay (ELISA) of antiganglioside IgM autoantibodies. This validation must consider the purity of gangliosides from different commercial sources, the coating of gangliosides onto a solid matrix in a manner that maximizes exposure of oligosaccharide epitopes to IgM paratopes, techniques to minimize background noise and eliminate nonspecific antibody binding, and carefully defined positive and negative controls. The validated protocol also must include a simple formula to estimate titers for several replicas. Finally, antibody titers must be converted to natural logs for statistical appraisal.
神经节苷脂具有一个包含抗原决定簇的亲水性糖链和一个疏水性神经酰胺。在人类中，神经节苷脂引发T细胞非依赖性IgM反应；抗神经节苷脂IgM自身抗体可能是五聚体或多聚体。特定神经病变与抗神经节苷脂自身抗体之间的相关性已得到证实。尽管许多神经科医生试图降低抗神经节苷脂自身抗体的滴度，但肿瘤学家正在制定策略来增加IgM抗体的产生，这些抗体将从患者循环中清除免疫抑制性神经节苷脂，并靶向神经节苷脂并杀死肿瘤细胞。抗神经节苷脂IgM抗体可导致血神经屏障以浓度依赖性和补体非依赖性方式渗漏，与神经元神经节苷脂结合形成神经肌肉阻滞，并作为多发性硬化症等神经病变中轴突损伤的标志物。它们也是早期前列腺癌有前景的生物标志物。需要验证抗神经节苷脂IgM自身抗体的酶联免疫吸附测定（ELISA）方案。这种验证必须考虑来自不同商业来源的神经节苷脂的纯度、以最大限度地使寡糖表位暴露于IgM互补位的方式将神经节苷脂包被到固体基质上、最小化背景噪声和消除非特异性抗体结合的技术，以及精心定义的阳性和阴性对照。经过验证的方案还必须包括一个简单的公式来估计几个复制品的滴度。最后，抗体滴度必须转换为自然对数用于统计评估。
