Massai Luisa, Carducci Martina, Rovetini Luca, Paterson Aimee, Whitcombe Alana, McGregor Reuben, Lorenz Natalie, Keeley Alexander J, de Silva Thushan I, Bennett Julie, Berlanda Scorza Francesco, Iturriza Miren, Moreland Nicole J, Moriel Danilo G, Rossi Omar
GSK Vaccines Institute for Global Health (GVGH), GSK Global Health Vaccines R&D, Via Fiorentina 1, 53100 Siena, Italy.
School of Medical Sciences and Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand.
J Immunol Methods. 2025 Jan;536:113786. doi: 10.1016/j.jim.2024.113786. Epub 2024 Dec 4.
Exposure to Group A Streptococcus leads to a broad spectrum of disease and sequelae, as the bacterium employs a wide range of virulence factors to facilitate colonization of the host, propagation and onward transmission, disrupting both innate and adaptive immune responses. The protease SpyCEP has a crucial role in contributing to bacterial immune evasion by impairing neutrophil recruitment and killing of bacteria through the cleavage of interleukin-8 (IL-8). Given this critical function, SpyCEP represents a key vaccine antigen and quantifying functional anti-SpyCEP antibodies represents not only an important marker of vaccine efficacy, but also a tool to dissect the natural immune response. Here, we report the development and characterization of an IL-8 cleavage inhibition assay to measure the function of anti-SpyCEP antibodies in human sera. The assay was demonstrated to be sensitive, highly specific, linear and reproducible, and suitable for evaluating the function of anti-SpyCEP antibodies induced in humans in vaccine clinical trials and in observational studies of natural immunity.
感染A组链球菌会导致一系列广泛的疾病和后遗症，因为该细菌利用多种毒力因子促进在宿主体内的定植、繁殖和进一步传播，破坏先天性和适应性免疫反应。蛋白酶SpyCEP通过切割白细胞介素-8（IL-8）来损害中性粒细胞的募集和细菌杀伤，在细菌免疫逃逸中起关键作用。鉴于这一关键功能，SpyCEP是一种关键的疫苗抗原，定量功能性抗SpyCEP抗体不仅是疫苗效力的重要标志物，也是剖析天然免疫反应的工具。在此，我们报告了一种用于测量人血清中抗SpyCEP抗体功能的IL-8切割抑制试验的开发和特性。该试验被证明具有敏感性、高度特异性、线性和可重复性，适用于评估疫苗临床试验和天然免疫观察研究中诱导的人抗SpyCEP抗体的功能。
