霍乱弧菌细胞壁抗原菌苗的研究

霍乱弧菌经过 SephadexG-200凝胶柱层析提纯得到2个细胞壁抗原,称为Ⅰ抗原和Ⅱ抗原,分子量分别为110,000 Dal 和60,000Dal。Ⅰ抗原为脂多糖成份;Ⅱ抗原主要为蛋白成份。二者无论经口服或非肠遭途径免疫家免或小鼠都能产生特异性抗体,即其免疫血清在琼脂双扩散试验中有特异性抗原抗体沉淀线形成,杀弧菌抗体和凝集抗体的水平升高,并可使免疫动物耐受一定量霍乱弧菌或霍乱毒素的攻击。当Ⅰ、Ⅱ两抗原混台(称为Ⅰ+Ⅱ抗原),产生的免疫反应较单一种抗原更强。若将Ⅰ+Ⅱ抗原再加入霍乱毒素 B 亚单位,或加热毒素或灭活的霍乱弧菌菌体,免疫家兔或小鼠后,则三者产生的免疫反应也不相同,即在小鼠肠结扎试验中耐受肠毒素攻击的反应性不同,以Ⅰ+Ⅱ抗原加菌体保护效果最好。本研究还用免疫缺陷型裸鼠证明Ⅰ、Ⅱ抗原在体内主要依赖 B 淋巴细胞引起免疫应答,而霍乱毒素主要依赖 T 淋巴细胞引起免疫应答,这是两种不同免疫反应性抗原。

STUDY OF ANTIGENIC VACCINE EXTRACTED FROM THE VIBRIO CHOLERAE CELL WALL

Two antigenic fractions are extracted from the cell wall of vibrio chole- rae El Tor belonging to serotypes,Inaba and Ogawa.They are present as soluble form in the media after lysis of microorganisms.These antigenic fractions are purified on a sephadex G-200 column.We have called antigenic fraction Ⅰ and Ⅱ,having molecular Wt.around 110,000 daltons and 60,000 daltons.The chemical structure of the fraction I consists of lypopolysaccharides,and the fraction Ⅱ is mainly proteins.Both two fra- ctions are antigens which induce the formation of specific antibody after immunization byeither parenteral or oral routes in rabbit or mice.The specific precipitation reaction of antigen-antibody is visualized in double agar gel diffusion.The vibriocidal and agglu- tination antibody titre is raised.The effective protection against challenge with viru- lent vibrio cholerae or enterotoxin in mice has been shown.Especially,after mixing fra- ction Ⅰ and Ⅱ,the immune response is more evident than single antigen fraction.When the fractions Ⅰ and Ⅱ were associated with the subunit B of cholera toxin,the heated toxin,or bacterial vaccine,these mixtures were respectively administed by oral in mice, their synergistic protection against challenge with the enterotoxin was different.The fraction Ⅰ and Ⅱ associated with whole bacterial vaccine could induce the most signifi- cant protection against challenge with the enterotoxin.By the immunodeficiency type- nude mice for the study of immunity to fraction Ⅰ and Ⅱ.We have found that both Ⅰ Ⅱ antignic fractions from cell wall of cholera vibrio and cholera toxin are two different lymphocyte dependent antigens,one is the B-cell dependent antigen,the other is the T-cell dependent antigen.So it is possible that two antigenic fractions will be developed into a important material of a new candidate vaccine of oral route.