Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa.
Vaccine. 2013 Sep 13;31(40):4421-7. doi: 10.1016/j.vaccine.2013.06.097. Epub 2013 Jul 8.
Due to the high cost and limited serotype coverage of pneumococcal conjugate vaccines (PCV), pneumococcal common protein antigens (CPAs) are being investigated as potential vaccine candidates. CPAs are likely to be immunogenic in infants and could confer serotype-independent protection. There are limited data on natural antibody kinetics against CPAs in African populations. We aimed to determine the prevalence of naturally acquired antibody titres to 15 CPAs and explore their association to concurrent pneumococcal nasopharyngeal colonization in children aged 4-7 years with and without underlying HIV-infection and/or previous PCV-vaccination. A 15-plex Luminex assay was established to measure serum IgG titres against "cell-wall associated or surface-exposed" proteins (PspA, PspC, LytB, IgA1-proteinase, SP0082, PdB and PcsB), "membrane-associated" proteins (PsaA, SP0609, SP0749, PpmA, SlrA, StkP and SP2194) as well as the hypothetical protein, SP2027. Archived serum samples from HIV-uninfected (n=212) and HIV-infected (n=74) children were analyzed. Concurrent pneumococcal nasopharyngeal colonization was determined with standard microbiological methods. HIV-uninfected children had significantly higher antibody titres against PspA, PspC, PdB, SP0082, LytB, IgA1 proteinase and PcsB compared to HIV-infected children. In contrast, antibody titres against membrane associated proteins (PsaA, SP2027, PpmA and SlrA) were significantly lower in HIV-uninfected compared to HIV-infected children. Higher antibody titres against PdB, and PcsB were associated with the absence of pneumococcal colonization. There was no association between anti-CPA titres and PCV vaccination. In conclusion PdB and PcsB antigens are potential vaccine-candidates which may protect against pneumococcal colonization and consequently pneumococcal disease.
由于肺炎球菌结合疫苗（PCV）的成本高和血清型覆盖有限，肺炎球菌共同蛋白抗原（CPA）正在被研究作为潜在的疫苗候选物。CPA 很可能在婴儿中具有免疫原性，并能提供非血清型依赖的保护。关于非洲人群中针对 CPA 的天然抗体动力学的资料有限。我们的目的是确定 4-7 岁儿童中自然获得针对 15 种 CPA 的抗体滴度的流行率，并探讨它们与同时发生的肺炎球菌鼻咽定植的关系，这些儿童有无 HIV 感染和/或既往 PCV 疫苗接种。建立了 15 聚体 Luminex 测定法来测量针对“细胞壁相关或表面暴露”蛋白（PspA、PspC、LytB、IgA1-蛋白酶、SP0082、PdB 和 PcsB）、“膜相关”蛋白（PsaA、SP0609、SP0749、PpmA、SlrA、StkP 和 SP2194）以及假设蛋白 SP2027 的血清 IgG 滴度。分析了 HIV 未感染（n=212）和 HIV 感染（n=74）儿童的存档血清样本。通过标准微生物学方法确定同时发生的肺炎球菌鼻咽定植。与 HIV 感染的儿童相比，HIV 未感染的儿童针对 PspA、PspC、PdB、SP0082、LytB、IgA1 蛋白酶和 PcsB 的抗体滴度显著更高。相比之下，针对膜相关蛋白（PsaA、SP2027、PpmA 和 SlrA）的抗体滴度在 HIV 未感染的儿童中明显低于 HIV 感染的儿童。针对 PdB 和 PcsB 的更高抗体滴度与无肺炎球菌定植相关。针对 CPA 的抗体滴度与 PCV 疫苗接种之间没有关联。总之，PdB 和 PcsB 抗原是潜在的疫苗候选物，可能对肺炎球菌定植和随后的肺炎球菌病具有保护作用。
