Sharma Pragati, Nayak Kaustuv, Reddy Elluri Seetharami, Farooqi Humaira, Murali-Krishna Kaja, Chandele Anmol
ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
Vaccines (Basel). 2021 Nov 17;9(11):1339. doi: 10.3390/vaccines9111339.
Dengue is an important public health problem worldwide, with India contributing nearly a third of global dengue disease burden. The measurement of neutralizing antibody responses is critical for understanding dengue pathophysiology, vaccine development and evaluation. Historically, dengue virus neutralization titers were measured using plaque reduction neutralization tests (PRNTs), which were later adapted to focus reduction neutralization tests (FRNTs). Given the slow and laborious nature of both these assays, there has been interest in adapting a high-throughput flow cytometry based neutralization assay. However, flow cytometry based assays typically underestimate neutralization titers, and in situations where the titers are low they can even fail to detect neutralization activity. In this study, by evaluating graded numbers of input Vero cell numbers and viral inoculum, we optimized the flow cytometry based neutralization assay in such a way that it is sensitive and scores titers that are in concordance with focus reduction neutralization tests for each of the four dengue virus serotypes ( < 0.0001). Given that dengue is a global public health concern, and several research groups are making efforts to understand its pathophysiology and accelerate vaccine development and evaluation both in India and worldwide, our findings have timely significance for facilitating these efforts.
登革热是全球重要的公共卫生问题，印度的登革热疾病负担占全球近三分之一。中和抗体反应的测定对于理解登革热病理生理学、疫苗研发和评估至关重要。历史上，登革热病毒中和滴度是通过蚀斑减少中和试验（PRNTs）来测定的，后来又发展为焦点减少中和试验（FRNTs）。鉴于这两种检测方法都具有缓慢且费力的特点，人们一直对采用基于高通量流式细胞术的中和检测方法感兴趣。然而，基于流式细胞术的检测方法通常会低估中和滴度，在滴度较低的情况下甚至可能无法检测到中和活性。在本研究中，通过评估不同数量的输入Vero细胞和病毒接种物，我们优化了基于流式细胞术的中和检测方法，使其具有敏感性，并且对四种登革热病毒血清型中的每一种所测得的滴度都与焦点减少中和试验结果一致（<0.0001）。鉴于登革热是一个全球公共卫生问题，并且几个研究小组都在努力了解其病理生理学，并在印度和全球范围内加速疫苗研发和评估，我们的研究结果对于推动这些努力具有及时的意义。
