Arya Ravi Prakash, Lahon Anismrita, Patel Ashok Kumar
Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India.
National Institute of Immunology, New Delhi, India.
Immunol Lett. 2021 Aug;236:31-36. doi: 10.1016/j.imlet.2021.06.001. Epub 2021 Jun 7.
Activation of innate receptors in megakaryocytes (MKs) may affect the ability to produce functional platelets. Low platelet count is one of the clinical manifestations of dengue virus (DENV) infection. In MKs, the effect of innate receptors during DENV-infection is not well studied. Here we used MEG-01 cells to investigate DENV serotype 2 induced innate receptors in these cells. DENV RNA was estimated by qRT-PCR in the culture supernatant. The expression of innate receptors was determined by western blot and qPCR. DENV infection led to increased expression of RIG-I at 24 hrs post-infection (hpi) and MDA-5 at 48 and 72 hpi (p<0.05). However, no change in the expression of TLR3 at protein level was observed. Activation of MDA-5 resulted in increased expression of IFN-β and ISG-15 in DENV infected MEG-01 cells, which was further confirmed by MDA-5 siRNA treatment. Apart from inducing innate receptors, DENV significantly decreases the expression of CD61, an activation marker of megakaryocyteson MEG-01 cells as observed by flow cytometry analysis (p<0.01). Results from this study confirm that DENV infection activates the type-I interferon in megakaryocytes and may play a significant role in maturation and development.
巨核细胞（MKs）中固有受体的激活可能会影响产生功能性血小板的能力。血小板计数低是登革热病毒（DENV）感染的临床表现之一。在巨核细胞中，DENV感染期间固有受体的作用尚未得到充分研究。在此，我们使用MEG-01细胞来研究2型DENV在这些细胞中诱导的固有受体。通过qRT-PCR在培养上清液中估计DENV RNA。通过蛋白质印迹和qPCR确定固有受体的表达。DENV感染导致感染后24小时（hpi）时RIG-I表达增加，48和72 hpi时MDA-5表达增加（p<0.05）。然而，未观察到蛋白质水平的TLR3表达有变化。MDA-5的激活导致DENV感染的MEG-01细胞中IFN-β和ISG-15表达增加，MDA-5 siRNA处理进一步证实了这一点。除了诱导固有受体外，通过流式细胞术分析观察到，DENV显著降低了MEG-01细胞上巨核细胞激活标志物CD61的表达（p<0.01）。本研究结果证实，DENV感染激活了巨核细胞中的I型干扰素，可能在其成熟和发育中起重要作用。
