8月出版的《自然—免疫学》报道了一种免疫机制,利用该机制,小鼠身体可以绕开病毒为躲避免疫系统的攻击以及产生慢性感染而实施的策略。
Zhenghong Yuan等人研究了外显子组(一种从细胞获得的小泡)在控制小鼠体内肝炎病毒方面所起到的作用。外显子组一旦从细胞中释放出来,便会在细胞间通讯中发挥重要作用,但有关外显子组在免疫方面的研究还是寥寥无几。研究人员发现肝脏中肝炎病毒的存在会刺激外显子组从抗感染肝脏固有细胞比如库普弗细胞中释放出来,并将其输送到病毒易感肝细胞处。这些外显子组含有高浓度的各种抗病毒分子,干细胞可利用这些分子来抵抗病毒感染。
研究人员相信外显子组中如此多种的抗病毒分子使得病毒很难进化出针对其中一种或多种的躲避机制,因此,利用外显子组实现的这一大团抗病毒分子的输送算得上是一种有效的免疫武器。此外,他们发现阻断外显子组会增加小鼠的肝炎发生,所以引发外显子组的释放能在特定治疗某些病毒感染时发挥有利作用。(生物谷 Bioon.com)
生物谷推荐的英文摘要
Nature Immunology doi:10.1038/ni.2647
Exosomes mediate the cell-to-cell transmission of IFN-α-induced antiviral activity
Jianhua Li,1 Kuancheng Liu,1 Yang Liu,1 Yan Xu,1 Fei Zhang,1 Huijuan Yang,1 Jiangxia Liu,1 Tingting Pan,1 Jieliang Chen,1 Min Wu,2 Xiaohui Zhou3 & Zhenghong Yuan1, 2
The cell-to-cell transmission of viral resistance is a potential mechanism for amplifying the interferon-induced antiviral response. In this study, we report that interferon-α (IFN-α) induced the transfer of resistance to hepatitis B virus (HBV) from nonpermissive liver nonparenchymal cells (LNPCs) to permissive hepatocytes via exosomes. Exosomes from IFN-α-treated LNPCs were rich in molecules with antiviral activity. Moreover, exosomes from LNPCs were internalized by hepatocytes, which mediated the intercellular transfer of antiviral molecules. Finally, we found that exosomes also contributed to the antiviral response of IFN-α to mouse hepatitis virus A59 and adenovirus in mice. Thus, we propose an antiviral mechanism of IFN-α activity that involves the induction and intercellular transfer of antiviral molecules via exosomes.