Interferon γ expressed by a recombinant respiratory syncytial virus attenuates virus replication in mice without compromising immunogenicity
Interferon γ expressed by a recombinant respiratory syncytial virus attenuates virus replication in mice without compromising immunogenicity
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DOI：
10.1073/pnas.96.5.2367
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发表时间：
1999-03-02
影响因子：
11.1
通讯作者：
Collins, PL
中科院分区：
文献类型：
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作者：
Bukreyev, A;Whitehead, SS;Collins, PL
干扰素γ（IFN-γ）具有多效性生物学效应，包括内在抗病毒活性以及刺激和调节免疫应答。构建了感染性重组人呼吸道合胞病毒（rRSV/mIFN-γ），其编码鼠（m）IFN-γ，作为插入G-F基因间区的单独基因。用rRSV/mIFN-γ感染的培养细胞每10（6）个细胞分泌22 μ g mIFN-γ。rRSV/mIFN-γ的复制，但不是对照嵌合rRSV含有氯霉素乙酰转移酶（CAT）基因作为一个额外的基因，是63-和20-倍，分别低于野生型（wt）RSV在上和下呼吸道，小鼠。因此，rRSV/mIFN-γ在体内的减毒可归因于mIFN-γ的活性，而不是额外基因本身的存在。小鼠对随后用wt RSV的攻击完全耐受。尽管其生长受限，但用rRSV/mIFN-γ感染小鼠诱导的RSV特异性抗体水平在第56天与用wt RSV感染诱导的RSV特异性抗体水平相当或更高。感染rRSV/mIFN-γ的小鼠在其肺中产生高水平的IFN-γ mRNA和增加量的白细胞介素12 p40 mRNA，而测试的其他细胞因子mRNA与野生型RSV诱导的那些相比没有变化。因为RSV的减毒通常伴随着免疫原性的降低，所以通过rRSV表达IFN-γ代表了一种减毒方法，其中免疫原性可以维持而不是降低。
Interferon gamma (IFN-gamma) has pleiotropic biological effects, including intrinsic antiviral activity as well as stimulation and regulation of immune responses. An infectious recombinant human respiratory syncytial virus (rRSV/mIFN-gamma) was constructed that encodes murine (m) IFN-gamma as a separate gene inserted into the G-F intergenic region. Cultured cells infected with rRSV/mIFN-gamma secreted 22 mu g mIFN-gamma per 10(6) cells. The replication of rRSV/mIFN-gamma, but not that of a control chimeric rRSV containing the chloramphenicol acetyl transferase (CAT) gene as an additional gene, was 63- and 20-fold lower than that of wild-type (wt) RSV in the upper and lower respiratory tract, respectively, of mice. Thus, the attenuation of rRSV/mIFN-gamma in vivo could be attributed to the activity of mIFN-gamma and not to the presence of the additional gene per se. The mice mere completely resistant to subsequent challenge with wt RSV. Despite its growth restriction, infection of mice with rRSV/mIFN-gamma induced a level of RSV-specific antibodies that, on day 56, was comparable to or greater than that induced by infection with wt RSV. Mice infected with rRSV/mIFN-gamma developed a high level of IFN-gamma mRNA and an increased amount of interleukin 12 p40 mRNA in their lungs, whereas other cytokine mRNAs tested were unchanged compared with those induced by wt RSV. Because attenuation of RSV typically is accompanied by a reduction in immunogenicity, expression of IFN-gamma by an rRSV represents a method of attenuation in which immunogenicity can be maintained rather than be reduced.