Stiles B G, Krakauer T, Bonventre P F
Division of Toxinology, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, Maryland 21702-5011.
Infect Immun. 1995 Apr;63(4):1229-34. doi: 10.1128/iai.63.4.1229-1234.1995.
A recombinant of toxic shock syndrome toxin 1 (TSST-1) which contains a single histidine-to-alanine mutation at residue 135 (H135A) was analyzed for toxicity and vaccine potential in a lipopolysaccharide (LPS)-potentiated mouse lethality model. The 50% lethal dose (LD50) of TSST-1 in BALB/c mice was 47.2 micrograms/kg, but H135A was not lethal when tested at a dose equivalent to 10 LD50s of TSST-1. Levels of tumor necrosis factor (TNF) and gamma interferon (IFN-gamma) in serum were, respectively, 10- and 50-fold higher in LPS-potentiated mice injected with 15 LD50s of TSST-1 than in mice given H135A. Mice injected with only TSST-1 did not have elevated levels of TNF or IFN-gamma in serum, while H135A plus LPS or LPS alone elicited identical, yet very low, levels of TNF and IFN-gamma. An enzyme-linked immunosorbent assay of H135A and TSST-1 with anti-TSST-1 serum yielded very similar dose-response curves, which strongly suggests that H135A serologically and conformationally resembles the native toxin. Mice immunized with H135A developed antibodies that recognized TSST-1 in an enzyme-linked immunosorbent assay and afforded protection against a 15-LD50 challenge of TSST-1 plus LPS. The pooled sera of mice immunized with either TSST-1 or H135A also prevented lymphocyte proliferation due to TSST-1.
对一种在135位残基处含有单个组氨酸到丙氨酸突变（H135A）的中毒性休克综合征毒素1（TSST-1）重组体，在脂多糖（LPS）增强的小鼠致死模型中分析其毒性和疫苗潜力。TSST-1在BALB/c小鼠中的50%致死剂量（LD50）为47.2微克/千克，但当以相当于TSST-1的10倍LD50剂量进行测试时，H135A并无致死性。在注射了15倍LD50的TSST-1的LPS增强小鼠中，血清中的肿瘤坏死因子（TNF）和γ干扰素（IFN-γ）水平分别比给予H135A的小鼠高10倍和50倍。仅注射TSST-1的小鼠血清中TNF或IFN-γ水平并未升高，而H135A加LPS或单独的LPS引发相同但非常低水平的TNF和IFN-γ。用抗TSST-1血清对H135A和TSST-1进行酶联免疫吸附测定产生了非常相似的剂量反应曲线，这强烈表明H135A在血清学和构象上类似于天然毒素。用H135A免疫的小鼠产生了在酶联免疫吸附测定中能识别TSST-1的抗体，并对15倍LD50的TSST-1加LPS攻击提供了保护。用TSST-1或H135A免疫的小鼠的合并血清也阻止了因TSST-1导致的淋巴细胞增殖。
