Immunochemical and genetical studies on B cell abnormality in patients with immunoglobulin deficiencies

本文从免疫球蛋白产生功能分析、膜糖蛋白天冬酰胺连接糖链分析、免疫球蛋白产生基因分析等方面对免疫球蛋白缺乏症患者的B细胞异常进行了免疫化学和遗传学研究。结果如下：(1)免疫球蛋白产生功能：用Poke杂草有丝分裂原、Epstein Barr病毒和考万-L对B细胞或T细胞功能进行检测，结果表明，许多患者B细胞功能紊乱，且患者B细胞功能障碍存在较大的异质性。(2)膜糖蛋白的天冬酰胺连接糖链，用肼裂解和序贯外切糖苷酶消化法进行研究。结果表明，在B细胞中，分化程度越高的B细胞，其二天线糖链与二分体N-乙酰氨基葡萄糖(GlcNAc)结合的糖链越多，与GlcNAc 2-Gt；4 Man结合的三触角糖链越多，四触角糖链越多。T细胞没有二角化GlcNAc的二触角糖链。另一方面，正常B细胞和免疫缺陷B细胞在结构上没有显著差异。这些结果表明，含有二分体GlcNAc的二天线糖链与B细胞功能有关。(3)免疫球蛋白产生基因：在健康淋巴细胞和免疫缺陷淋巴细胞上，用硫氰酸胍-硫氰酸法获得它们的mRNA，并用细胞自由翻译的方法合成免疫球蛋白。免疫球蛋白检测采用免疫印迹等方法。结果表明，正常人和免疫缺陷者均合成了IgM。这一结果表明，某些患者的免疫球蛋白合成可能受到了mRNA水平后的途径的干扰。

Abnormalities of B cells from patients with immunoglobulin deficiencies wewe immunochemically and genetically investigated in points of (1) analysis of immunoglobulin productive function (2) analysis of asparagine linked sugar chains of membrane glycoproteins (3) analysis of gene of immunoglobulin production. The results obtained were as follow.(1) Immunoglobulin productive function; B cell or T cell function was investigated using Poke weed mitogen,Epstein Barr virus and Cowan l. As the results,it was clear that in many patients B cell function was disturbed,and moreover there was much heterogeneity in B cell dysfunctions of patients.(2) Asparagine linked sugar chain of membrane glycoprotein; This was studied by methods of hydrazinolysis and sequential exoglycosidase digestion. As the results,it was clear that,in B cells ,more differentiated B cells had the biantennary sugar chain with bisect N-acetylglucosamine(GlcNAc), more triantennary sugar chain with GlcNAc 2->4 Man bound and more tetraantennary sugar chains. T cells did not have the biantennary sugar chain with bisect GlcNAc. On the other hand,there was no significant difference between healthy B cells and immunodeficient B cells in structures. From these results, it is suggested that the biantennary sugar chain with bisect GlcNAc is concerning to B cell functions.(3) Gene of immunoglobulin production; On healthy lymphocytes and immunodeficient lymphocytes, their mRNA were obtained by the method of guanidium-thiocyanate,and immunoglobulin was synthesized by the method of cell free translation from the mRNA. The immunoglobulin was detected by the Western-blotting method and so on. As the results, IgM was synthesized in both healthy and immunodeficient persons. From this result,it is suggested that the pathway after mRNA level may be disturbed in immunoglobulin synthesis on certain patients.