抗日本血吸虫保护性免疫若干无损伤性量化指标的研究

STUDIES ON NONINVASIVE QUANTITATIVE INDEXES IN PERSONS VACCINATED BY SCHISTOSOMA JAPONICUM

为寻找能无损伤地量化提示抗日本血吸虫疫苗接种后保护作用的测定指标，试从三个方面进行了探索：①通过获取可排除活动性新感染．从而提示免疫保护性存在的高特异、高性能单抗免疫探针，测量宿主体内的循环抗原（CAg）组分，经3农杂交瘤细胞融合、筛选，制备了5株具诊断效能的（IgM）单抗，发现组合应用这些单抗为捕获兼测示抗体，明显优于单个应用．其中IE＋11H＋12G组合显示了在目前多种组合中最佳检测效能．采用Dot－ELISA及新建立的斑点金免疫渗滤法，在样本数（n）分别为184和104的两组健康人群中，分别显示了94．6％及95．2％的高特异性，而在139例及69例两批慢性血吸虫感染者，该两法也分别达到了可以接受的54．7％和60．8％的阳性检出率，也已获得了1株IgG_3同型单抗，A9．初步测试具有较好诊查效果，正在进一步作出鉴定;②为建立采用优质纯化抗原的标准系列，利于定量值测CAg的灵敏度，我们采用Mono－Q高压液相技术纯化分离了SEAj的活性组分，已初步用为测量CAg组分的定量标准参考系列；③通过方法学的改进，借助于BIO－TECH自动酶标仪，建立了测量与抗力相关的特异性IgE及疾病相关的特异性IgG_4的动态ELISA或经标化的终点列读常规，在243例慢性血吸虫病血样测读基础上，经100例健康人测试，?

Aiming at searching non-invasive quantitative criteria to indicate successful vaccinationagainst Schistosoma-infection, 3 approaches were undertaken: ro To obtain potent immuneprobes having high specificity to rule out newly acquired active infections, 5 monoclonal antibodies (McAbs) with diagnostic potency were obtained via 3 times of hybridoma fusions andscreening. Combined use of these McAbs as capture as well as detecting antib0dies wasfound better than singly use of the McAbs. When used in Dot-ELISA and a newly estab-lished Dot Immunogold Filtration Assay, the best combinations of IE + 11H+ 12G, in thepresent case, was shown to give high spcificities of 94. 6% (n= 184) and 95. 2% (n= 104)respectively in normal individuals with relatively fine and acceptable positive rate of 54. 7%and 60. 8% in chronic patients (n= 139,n = 69 respectively). Moreover, a new McAb, codedas A9, of IgG3 isotype recognizing egg-associated epitope was obtained. Promising results indiagnostic using has been revealed in preliminary studies and further trials is just undergo-ing; To set up a standard reference series with defined antigen fractions for an improvedquantitative determination of CAgs with the sandwich ELISAs,purified SEAj reactive frac-tions were isolated by means of a Mono-Q FPLC protocoll; Methodological improvementin quantitative determinations of the resistance-associated immunoglobulin, the specific IgE,and the disease-associated IgG, were investigated. By using the Auto BIO-TECH Instrumentto perform a kinetic ELISA or monitored end-point ELISA protocol and on the basis of achronic patient detection study with 243 cases, high detection specificities of 97. 3% and100% respectively in specific IgE and IgG4 were achieved in normal human samples (n= 100)with no cross reactions to paragonimiasis (n= 16).