Tabatabai L B, Deyoe B L
Dev Biol Stand. 1984;56:199-211.
Soluble salt-extractable protein antigens (CSP) from Brucella abortus may be of potential value as a vaccine and as a diagnostic reagent for the prevention and diagnosis of bovine brucellosis. These protein antigens, excluding protoplasmic proteins, are those present in the matrix of the outer membrane and in the periplasmic space of gram-negative bacteria. Our research deals mainly with the proteins of the periplasmic space and the nonporin proteins of the outer membrane. We have isolated a group of proteins from intact inactivated cells using mild, nondestructive extraction procedures. The proteins thus obtained range in molecular weight from 10 000 to 51 000 daltons as determined under denaturing conditions and from 10 000 to 124 000 daltons under nondenaturing conditions. The isoelectric pH of these proteins range from 3.5 to 10 with numerous bands in the pH 4.5 to 5.5 region, and a few bands in the pH 6 to 10 region. The low pH region also contains those protein bands which can be labeled with the membrane impermeant reagent, diazotized [125I]-iodosulfanilic acid. The soluble protein preparations are antigenic in guinea pigs, rabbits and cattle, and immunogenic in lemmings, guinea pigs and cattle. Cross-reacting protein antigens are present in protein preparations from B. abortus strains 19 and 2308 when tested with heterologous rabbit sera and with sera from vaccinated and experimentally infected cattle. The soluble protein antigens can be rendered more immunogenic by chemical modification of the primary amino groups with acyl anhydrides, especially with dodecanoyl anhydride. Immunization with dodecanoyl--modified proteins resulted in decreased humoral antibody levels (as measured in guinea pigs and cattle) without loss of protective activity, as measured in lemmings. Furthermore, the soluble proteins have proven to be a sensitive, stable and reliable reagent in the enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Brucella abortus in serum of vaccinated and experimentally infected cattle. Other soluble protein antigen preparations have also been evaluated and compared with strain 19 proteins for immunogenic properties and for use as an ELISA reagent.
流产布鲁氏菌的可溶性盐提取物蛋白抗原（CSP）作为预防和诊断牛布鲁氏菌病的疫苗及诊断试剂可能具有潜在价值。这些蛋白抗原不包括原生质蛋白，是革兰氏阴性菌外膜基质和周质空间中的蛋白。我们的研究主要涉及周质空间蛋白和外膜非孔蛋白。我们采用温和、无损的提取方法从完整的灭活细胞中分离出了一组蛋白。在变性条件下测定，这些蛋白的分子量范围为10000至51000道尔顿，在非变性条件下为10000至124000道尔顿。这些蛋白的等电点pH值范围为3.5至10，在pH 4.5至5.5区域有许多条带，在pH 6至10区域有几条带。低pH区域还包含那些可用膜不通透试剂重氮化[125I] - 碘磺胺酸标记的蛋白条带。可溶性蛋白制剂在豚鼠、兔子和牛中具有抗原性，在旅鼠、豚鼠和牛中具有免疫原性。用异源兔血清以及接种疫苗和实验感染牛的血清检测时，流产布鲁氏菌19株和2308株的蛋白制剂中存在交叉反应蛋白抗原。通过用酸酐，特别是十二烷酸酐对伯氨基进行化学修饰，可使可溶性蛋白抗原的免疫原性增强。用十二烷酰修饰的蛋白进行免疫导致体液抗体水平降低（在豚鼠和牛中测定），但在旅鼠中测定时保护活性未丧失。此外，可溶性蛋白已被证明是酶联免疫吸附测定（ELISA）中用于检测接种疫苗和实验感染牛血清中抗流产布鲁氏菌抗体的灵敏、稳定且可靠的试剂。还对其他可溶性蛋白抗原制剂进行了评估，并与19株蛋白的免疫原性特性以及用作ELISA试剂的情况进行了比较。
