McCabe W R, DeMaria A, Berberich H, Johns M A
Maxwell Finland Laboratory for Infectious Diseases, Boston City Hospital, Massachusetts 02118.
J Infect Dis. 1988 Aug;158(2):291-300. doi: 10.1093/infdis/158.2.291.
We evaluated the immunoglobulin class responsible for the protective activity in serum obtained from humans and rabbits after immunization with the R595 (Re chemotype) mutant of Salmonella minnesota. Whole serum obtained before immunization and the IgG and IgM fractions failed to protect mice against lethal challenge with viable Klebsiella pneumoniae or Morganella morganii or with Salmonella typhi lipopolysaccharide (LPS). The protective activity of postimmunization serum resided solely in IgM antibody, whereas IgG antibody exhibited no protective activity. IgM antibody to the Re mutant was protective against bacterial challenge with both test strains of bacteria and S. typhi LPS. IgM antibody, at approximately the same concentration present in postimmunization serum, increased the LD50 of K. pneumoniae from less than 8.0 x 10(2) to greater than 2.0 x 10(4). These findings indicate that commercially prepared human IgG with high titers of antibody to antigens of the core portion of LPS would have little clinical utility.
我们评估了用明尼苏达沙门氏菌的R595（Re化学型）突变株免疫后，人及兔血清中具有保护活性的免疫球蛋白类别。免疫前获得的全血清以及IgG和IgM组分均无法保护小鼠免受活的肺炎克雷伯菌、摩根氏摩根菌或伤寒沙门氏菌脂多糖（LPS）的致死性攻击。免疫后血清的保护活性仅存在于IgM抗体中，而IgG抗体则无保护活性。针对Re突变株的IgM抗体对两种测试菌株及伤寒沙门氏菌LPS的细菌攻击均具有保护作用。浓度与免疫后血清中大致相同的IgM抗体，将肺炎克雷伯菌的半数致死剂量（LD50）从小于8.0×10²提高到大于2.0×10⁴。这些发现表明，市售的高滴度针对LPS核心部分抗原的人IgG临床效用不大。
