Bronze M S, Courtney H S, Dale J B
Department of Veterans Affairs Medical Center, Memphis, TN 38104.
J Immunol. 1992 Feb 1;148(3):888-93.
The present studies were undertaken to identify conserved epitopes of group A streptococcal M proteins that evoke cross-protective mucosal immune responses. Two synthetic peptides copying conserved regions of type 5 M protein, designated SM5(235-264)C and SM5(265-291)C, were covalently linked to carrier molecules and their immunogenicity was tested in laboratory animals. Rabbit antisera against both peptides cross-reacted with multiple serotypes of group A streptococci, indicating that the peptides contained broadly cross-reactive, surface exposed M protein epitopes. Serum antipeptide antibodies adsorbed to the surface of heterologous type 24 streptococci passively protected mice against intranasal challenge infections. Mice that were actively immunized intranasally with each synthetic peptide covalently linked to the B subunit of cholera toxin were protected against colonization and death after intranasal challenge infections with type 24 streptococci in the absence of serum opsonic antibodies. These data confirm and extend previous observations that conserved M protein epitopes evoke cross-protective local immunity and may serve as the basis for broadly cross-protective M protein vaccines.
开展本研究以鉴定A群链球菌M蛋白的保守表位，这些表位可引发交叉保护性黏膜免疫反应。两条复制5型M蛋白保守区域的合成肽，命名为SM5(235 - 264)C和SM5(265 - 291)C，与载体分子共价连接，并在实验动物中测试其免疫原性。针对这两种肽的兔抗血清与多种A群链球菌血清型发生交叉反应，表明这些肽含有广泛交叉反应的、表面暴露的M蛋白表位。吸附于异源24型链球菌表面的血清抗肽抗体被动保护小鼠免受鼻内攻击感染。在没有血清调理抗体的情况下，用与霍乱毒素B亚基共价连接的每种合成肽经鼻内主动免疫的小鼠，在经鼻内用24型链球菌攻击感染后受到保护，免于定植和死亡。这些数据证实并扩展了先前的观察结果，即保守的M蛋白表位可引发交叉保护性局部免疫，并且可能作为广泛交叉保护性M蛋白疫苗的基础。
