肺炎球菌鼻咽定植的免疫效果;预防未来定植和致命性侵袭性疾病。
The immunising effect of pneumococcal nasopharyngeal colonisation; protection against future colonisation and fatal invasive disease.
机构信息
Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE19HN, United Kingdom.
出版信息
Immunobiology. 2010 Apr;215(4):251-63. doi: 10.1016/j.imbio.2009.12.004. Epub 2009 Dec 28.
The human nasopharynx is an important ecological niche for Streptococcus pneumoniae, and asymptomatic nasopharyngeal carriage is a common precursor to invasive disease. However, knowledge of the immunological events, which occur during carriage, both on a cellular and humoral level, remains limited. Here, we present a long-term stable model of asymptomatic nasopharyngeal carriage using outbred naïve mice, in which we have investigated the effect of previous nasopharyngeal exposure to pneumococci, in the prevention of subsequent carriage and invasive disease. Carriage of D39 wildtype pneumococci restricted to the nasopharynx could be detected for at least 28 days post-infection, whereas nasopharyngeal carriage of a pneumolysin negative isogenic mutant (PLN-A) was cleared in 7-14 days. Both carriage events induced total and capsule specific IgA mucosal antibodies and increased levels of systemic antibodies (IgG against pneumococcal surface protein A (PspA) and IgM capsular polysaccharide), which increased over time and correlated to reduced nasopharyngeal pneumococcal numbers. Prior nasopharyngeal colonisation with PLN-A significantly reduced the duration of subsequent D39 wildtype carriage, and significantly increased survival following invasive pneumococcal challenge. In this case systemic anti-PspA and anti-capsular antibody IgM concentrations showed a strong correlation with reduced bacterial numbers in the lungs and nasopharynx, respectively and also with increased levels of IL17A and CD4+ T cells in lungs of pre-colonised mice. Prior nasopharyngeal colonisation with PLN-A also resulted in significant cross-serotype protection with mice protected from invasive disease with serotype 3 strain (A66) after pre-colonisation with a serotype 2 strain (D39). Our results suggest that both mucosal and systemic antibody as well as cellular host factors have a role in long-term protection against both colonisation and invasive pneumococcal challenge.
人类鼻咽部是肺炎链球菌的重要生态位,无症状鼻咽携带是侵袭性疾病的常见前驱状态。然而,人们对于携带状态下发生的细胞和体液免疫事件的认识仍然有限。在这里,我们使用非近亲繁殖的幼稚小鼠建立了一个无症状鼻咽携带的长期稳定模型,在此模型中我们研究了先前鼻咽暴露于肺炎链球菌对预防随后的携带和侵袭性疾病的影响。感染后至少 28 天可检测到 D39 野生型肺炎链球菌在鼻咽部的单纯携带,而肺炎球菌溶血素阴性的同源突变株(PLN-A)的鼻咽携带可在 7-14 天内清除。这两种携带事件均诱导了总免疫球蛋白 A 和荚膜特异性免疫球蛋白 A 黏膜抗体,并增加了针对肺炎球菌表面蛋白 A(PspA)的系统抗体(IgG)和针对荚膜多糖的 IgM 水平,这些抗体水平随时间增加,与鼻咽部肺炎链球菌数量减少相关。先前鼻咽定植 PLN-A 可显著缩短随后 D39 野生型的携带持续时间,并显著增加侵袭性肺炎球菌感染后的存活率。在这种情况下,系统抗 PspA 和抗荚膜抗体 IgM 浓度与肺部和鼻咽部的细菌数量分别呈强相关,与预先定植小鼠肺部的 IL17A 和 CD4+T 细胞水平也呈正相关。先前鼻咽定植 PLN-A 还导致了显著的交叉血清型保护,在预先用血清型 2 菌株(D39)定植后,用血清型 3 菌株(A66)进行侵袭性疾病攻击时,小鼠得到了保护。我们的结果表明,黏膜和系统抗体以及细胞宿主因素在长期预防定植和侵袭性肺炎球菌挑战方面都发挥了作用。