de Silva Thushan I, Gould Victoria, Mohammed Nuredin I, Cope Alethea, Meijer Adam, Zutt Ilse, Reimerink Johan, Kampmann Beate, Hoschler Katja, Zambon Maria, Tregoning John S
Section of Paediatrics, Imperial College London, St Mary's Campus, London, W2 1PG, UK; Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF, UK; Vaccines and Immunity Theme, Medical Research Council Unit The Gambia, PO Box 273, Banjul, Gambia.
Mucosal infection and Immunity, Section of Virology, Imperial College London, St Mary's Campus, London, W2 1PG, UK.
J Immunol Methods. 2017 Oct;449:1-6. doi: 10.1016/j.jim.2017.06.008. Epub 2017 Jun 21.
We need greater understanding of the mechanisms underlying protection against influenza virus to develop more effective vaccines. To do this, we need better, more reproducible methods of sampling the nasal mucosa. The aim of the current study was to compare levels of influenza virus A subtype-specific IgA collected using three different methods of nasal sampling. Samples were collected from healthy adult volunteers before and after LAIV immunization by nasal wash, flocked swabs and Synthetic Absorptive Matrix (SAM) strips. Influenza A virus subtype-specific IgA levels were measured by haemagglutinin binding ELISA or haemagglutinin binding microarray and the functional response was assessed by microneutralization. Nasosorption using SAM strips lead to the recovery of a more concentrated sample of material, with a significantly higher level of total and influenza H1-specific IgA. However, an equivalent percentage of specific IgA was observed with all sampling methods when normalized to the total IgA. Responses measured using a recently developed antibody microarray platform, which allows evaluation of binding to multiple influenza strains simultaneously with small sample volumes, were compared to ELISA. There was a good correlation between ELISA and microarray values. Material recovered from SAM strips was weakly neutralizing when used in an in vitro assay, with a modest correlation between the level of IgA measured by ELISA and neutralization, but a greater correlation between microarray-measured IgA and neutralizing activity. In conclusion we have tested three different methods of nasal sampling and show that flocked swabs and novel SAM strips are appropriate alternatives to traditional nasal washes for assessment of mucosal influenza humoral immunity.
为研发更有效的疫苗，我们需要更深入地了解预防流感病毒的潜在机制。为此，我们需要更好、更具可重复性的鼻黏膜采样方法。本研究的目的是比较使用三种不同鼻采样方法收集的甲型流感病毒亚型特异性IgA水平。在接种流感减毒活疫苗（LAIV）前后，通过鼻腔冲洗、植绒拭子和合成吸收性基质（SAM）试纸从健康成年志愿者中采集样本。通过血凝素结合ELISA或血凝素结合微阵列测量甲型流感病毒亚型特异性IgA水平，并通过微量中和试验评估功能反应。使用SAM试纸进行鼻腔吸附可回收更浓缩的样本材料，其总IgA和甲型流感H1特异性IgA水平显著更高。然而，当以总IgA进行标准化时，所有采样方法观察到的特异性IgA百分比相当。将使用最近开发的抗体微阵列平台测量的反应（该平台允许用少量样本同时评估与多种流感毒株的结合）与ELISA进行比较。ELISA和微阵列值之间具有良好的相关性。从SAM试纸回收的材料在体外试验中具有较弱的中和作用，ELISA测量的IgA水平与中和作用之间存在适度相关性，但微阵列测量的IgA与中和活性之间的相关性更强。总之，我们测试了三种不同的鼻采样方法，结果表明，对于评估黏膜流感体液免疫，植绒拭子和新型SAM试纸是传统鼻腔冲洗的合适替代方法。
