Immunization with recombinant Sao protein confers protection against Streptococcus suis infection
Immunization with recombinant Sao protein confers protection against Streptococcus suis infection
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DOI：
10.1128/cvi.00046-07
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发表时间：
2007-08-01
影响因子：
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通讯作者：
Harel, Josee
中科院分区：
文献类型：
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作者：
Li, Yuanyi;Gottschalk, Marcelo;Harel, Josee
Sao是一种猪链球菌表面蛋白，最近被确定为潜在的候选疫苗。在这项研究中，重组Sao与Quil A联合在小鼠和猪疫苗接种方案中提供了对猪链球菌血清2型疾病的交叉保护。小鼠皮下免疫可引起强烈的免疫球蛋白G （IgG）抗体反应。四种IgG亚类均可诱导，其中IgG2a的滴度最高，其次是IgG1、IgG2b和IgG3。用猪链球菌31533菌株攻毒的小鼠在只接受奎尔a的对照组中死亡率为80%。相比之下，所有接种Sao的小鼠都存活了下来。在猪疫苗接种方案中，Sao肌肉免疫也引起了显着的不道德抗体反应，并且诱导了IgG1和IgG2亚类，以IgG2的产生为主。体外实验表明，sao诱导的抗体显著提高了猪中性粒细胞对猪链球菌的自噬杀伤能力。用猪链球菌166菌株对猪进行气雾剂攻击后，出现猪链球菌感染的典型临床症状。与对照组相比，接种疫苗组的存活率明显提高，临床评分较低，死后组织样本中猪链球菌的恢复率也较低。此外，本研究还发现，尽管猪链球菌的攻毒菌株表达Sao大小变异，但重组Sao具有交叉保护作用。这些数据表明，用Quill A配制的重组Sao可触发强烈的活化抗体反应，从而有效地免疫异源猪链球菌2型的攻击感染。
Sao is a Streptococcus suis surface protein recently identified as a potential vaccine candidate. In this study, recombinant Sao in combination with Quil A provided cross-protection against S. suis serotype 2 disease in mouse and pig vaccination protocols. Subcutaneous immunization of mice elicited strong immunoglobullin G (IgG) antibody responses. All four IgG subclasses were induced, with the IgG2a titer being the highest, followed by those of IgG1, IgG2b, and IgG3. Challenge of the mice with S. suis strain 31533 resulted in a mortality rate of 80% for the control group, which received Quil A only. In contrast, all of the mice immunized with Sao survived. In a pig vaccination protocol, intramuscular immunization with Sao also elicited significant Immoral antibody responses, and both the IgG1 and IgG2 subclasses were induced, with a predominance of IgG2 production. In vitro assay showed that Sao-induced antibodies significantly promoted the ability of porcine neutrophils in opsonophagocytic killing of S. suis. An aerosol challenge of the pigs with S. suis strain 166 resulted in clinical signs characteristic of S. suis infection in diseased pigs. The vaccine group showed significantly better survival, lower clinical scores, and less S. suis recovery from postmortem tissue samples than did the control group. Furthermore, this study also revealed that although challenge S. suis strains express Sao size variants, recombinant Sao conferred cross-protection. These data demonstrate that recombinant Sao formulated with Quill A triggers strong opsonizing antibody responses which confer efficient immunity against challenge infection with heterologous S. suis type 2.