Mahallawi Waleed H, Aljeraisi Talal M
Department of Medical Laboratory Technology, College of Applied Medical Sciences, Taibah University, Madinah 41541, Saudi Arabia.
Otorhinolaryngology, Head& Neck Surgery Department, Faculty of Medicine, Taibah University, Madinah, Saudi Arabia.
Saudi J Biol Sci. 2021 Aug;28(8):4516-4521. doi: 10.1016/j.sjbs.2021.04.051. Epub 2021 Apr 24.
To date, coronavirus disease 2019 (COVID-19) continues to be considered a pandemic worldwide, with a mild to severe disease presentation that is sometimes associated with serious complications that are concerning to global health authorities. Scientists are working hard to understand the pathogenicity of this novel virus, and a great deal of attention and effort has been focused on identifying therapeutics and vaccines to control this pandemic.
This study used tonsils removed from twelve patients who underwent an elective tonsillectomy in the ear, nose, and throat (ENT) department at Saudi Germany Hospital, Madinah, Saudi Arabia. Tonsillar mononuclear cells (MNCs) were separated and co-cultured in RPMI complete medium in the presence and absence of viral spike (S) proteins (the full-length S, S1 subunit, and S2 subunit proteins). Enzyme-linked immunosorbent assay (ELISA) was used to measure secreted antibody concentrations following stimulation.
The human nasal-associated lymphoid tissue (NALT) cell culture model was successfully used to evaluate the humoral immune response against SARS-CoV-2- S protein. Significant (p < 0.0001, n = 12) levels of specific, anti-S IgG, IgM, and IgA antibody responses were detected in cells culture supernatanat folloeing stimulation with the full-length S protein compared with unstimulated cells. In contrast, S1 and S2 subunit proteins alone failed to induce a mucosal humoral immune response following tonsillar MNC stimulation.
We demonstrated a successful human NALT cell culture model that was used to study the mucosal humoral immune response to the SARS-CoV-2 S protein. This model could be advantageous for the in-depth study of cellular immune responses to the S protein and other viral antigens, such as nucleocapsid and matrix antigen. The S protein appears to be the important viral protein that may be able to mimic the natural infection process intranasally and should be studied as a component of a candidate vaccine.
迄今为止，2019冠状病毒病（COVID-19）在全球范围内仍被视为大流行病，其疾病表现从轻症到重症不等，有时还会出现严重并发症，这令全球卫生当局担忧。科学家们正在努力了解这种新型病毒的致病性，并且大量的关注和努力都集中在寻找控制这一疫情的治疗方法和疫苗上。
本研究使用了从沙特阿拉伯麦地那市沙特德国医院耳鼻喉科接受择期扁桃体切除术的12名患者身上切除的扁桃体。分离扁桃体单核细胞（MNCs），并在有和没有病毒刺突（S）蛋白（全长S、S1亚基和S2亚基蛋白）的情况下，于RPMI完全培养基中进行共培养。使用酶联免疫吸附测定（ELISA）来测量刺激后分泌的抗体浓度。
人鼻相关淋巴组织（NALT）细胞培养模型成功用于评估针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）S蛋白的体液免疫反应。与未刺激的细胞相比，用全长S蛋白刺激后，在细胞培养上清液中检测到显著（p < 0.0001，n = 12）水平的特异性抗S IgG、IgM和IgA抗体反应。相比之下，单独的S1和S2亚基蛋白在扁桃体MNC刺激后未能诱导黏膜体液免疫反应。
我们展示了一种成功的人NALT细胞培养模型，该模型用于研究对SARS-CoV-2 S蛋白的黏膜体液免疫反应。该模型可能有利于深入研究对S蛋白和其他病毒抗原（如核衣壳和基质抗原）的细胞免疫反应。S蛋白似乎是重要的病毒蛋白，可能能够模拟鼻腔内的自然感染过程，应作为候选疫苗的一个成分进行研究。
