The Ebola Interferon Inhibiting Domains Attenuate and Dysregulate Cell-Mediated Immune Responses.
The Ebola Interferon Inhibiting Domains Attenuate and Dysregulate Cell-Mediated Immune Responses.
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DOI：
10.1371/journal.ppat.1006031
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发表时间：
2016-12
期刊：
影响因子：
6.7
通讯作者：
Bukreyev A
中科院分区：
文献类型：
--
作者：
Lubaki NM;Younan P;Santos RI;Meyer M;Iampietro M;Koup RA;Bukreyev A
埃博拉病毒(Ebola Virus，EBOV)感染的特点是T淋巴细胞反应不足、T淋巴细胞凋亡和淋巴细胞减少。我们之前的研究表明，VP24和VP35蛋白中的干扰素抑制域(IID)的失效有效地解除了树突状细胞(DC)的成熟，并增加了细胞因子和趋化因子的分泌。在这里，我们使用携带点突变的重组病毒来研究IID在适应性和先天细胞介导的反应中的作用，这些重组病毒使VP24(EBOV/VP24m)、VP35(EBOV/VP35m)或两者(EBOV/VP35m/VP24m)中的IID失效。将巨细胞病毒(CMV)阳性献血者的外周血单个核细胞(PBMC)接种该组病毒，并用CMV pp65多肽刺激。禁用VP35IID可促进增殖，增加分泌干扰素γ和/或肿瘤坏死因子α的T细胞百分率。为了阐明异常DC成熟在IID介导的抑制T细胞反应中的作用，将CMV刺激的DC感染病毒组，并与自体T淋巴细胞共同培养。与野生型EBOV相比，感染EBOV/VP35m能显著增加CD_4+细胞分泌干扰素γ、肿瘤坏死因子α和IL-2的能力。用扩增的CMV特异性T细胞与预先感染EBOV/VP24m、EBOV/VP35m和EBOV/VP35m/VP24m的CMV冲击的DC共培养后，与wt EBOV相比，它们的激活增加。研究发现，这两种IID都能阻断TCR复合体相关接头和下游信号分子的磷酸化。接下来，我们研究了IIDs对感染PBMC中B细胞功能的影响。与野生型EBOV相比，感染EBOV/VP35m和EBOV/VP35m/VP24m的B细胞亚群和浆细胞比例显著增加，提示VP35 IID抑制了B细胞的功能和分化。最后，与野生型EBOV相比，感染EBOV/VP35m可增加NK细胞的活性。这些结果证明了EBOV IID对细胞介导的反应的全局抑制，并确定了DC在抑制T细胞反应中的作用。在过去的16年里，对埃博拉病毒(EBOV)介导的干扰素拮抗作用的广泛研究导致了位于病毒VP24和VP35蛋白上的两个干扰素抑制结构域(IID)的鉴定，以及这些结构域禁用天然免疫系统和促进病毒复制的多种机制。然而，这些结构域对细胞免疫应答的影响还没有被研究过。为了确定IID对细胞介导的反应的影响，我们使用了一组点突变使VP24和/或VP35 IID失效的EBOV重组菌株。病毒被用来感染外周血单个核细胞(PBMC)或树突状细胞(DC)，然后与T细胞共同培养。我们发现IIDs通过抑制树突状细胞的成熟和限制免疫突触的形成而阻断T细胞的激活和增殖。类似地，IID可以抑制B细胞的激活和分化，以及感染PBMC中存在的NK细胞的偏向激活。这些数据提供了以前未知的IID对适应性和先天细胞介导的免疫反应的影响的证据，并确定了在EBOV感染过程中“免疫瘫痪”的新机制。
Ebola virus (EBOV) infections are characterized by deficient T-lymphocyte responses, T-lymphocyte apoptosis and lymphopenia. We previously showed that disabling of interferon-inhibiting domains (IIDs) in the VP24 and VP35 proteins effectively unblocks maturation of dendritic cells (DCs) and increases the secretion of cytokines and chemokines. Here, we investigated the role of IIDs in adaptive and innate cell-mediated responses using recombinant viruses carrying point mutations, which disabled IIDs in VP24 (EBOV/VP24m), VP35 (EBOV/VP35m) or both (EBOV/VP35m/VP24m). Peripheral blood mononuclear cells (PBMCs) from cytomegalovirus (CMV)-seropositive donors were inoculated with the panel of viruses and stimulated with CMV pp65 peptides. Disabling of the VP35 IID resulted in increased proliferation and higher percentages of CD4+ T cells secreting IFNγ and/or TNFα. To address the role of aberrant DC maturation in the IID-mediated suppression of T cell responses, CMV-stimulated DCs were infected with the panel of viruses and co-cultured with autologous T-lymphocytes. Infection with EBOV/VP35m infection resulted in a significant increase, as compared to wt EBOV, in proliferating CD4+ cells secreting IFNγ, TNFα and IL-2. Experiments with expanded CMV-specific T cells demonstrated their increased activation following co-cultivation with CMV-pulsed DCs pre-infected with EBOV/VP24m, EBOV/VP35m and EBOV/VP35m/VP24m, as compared to wt EBOV. Both IIDs were found to block phosphorylation of TCR complex-associated adaptors and downstream signaling molecules. Next, we examined the effects of IIDs on the function of B cells in infected PBMC. Infection with EBOV/VP35m and EBOV/VP35m/VP24m resulted in significant increases in the percentages of phenotypically distinct B-cell subsets and plasma cells, as compared to wt EBOV, suggesting inhibition of B cell function and differentiation by VP35 IID. Finally, infection with EBOV/VP35m increased activation of NK cells, as compared to wt EBOV. These results demonstrate a global suppression of cell-mediated responses by EBOV IIDs and identify the role of DCs in suppression of T-cell responses. The extensive investigation of interferon antagonism mediated by Ebola virus (EBOV) over the last 16 years resulted in identification of two interferon inhibiting domains (IIDs) located in the VP24 and VP35 proteins of the virus and of multiple mechanisms by which the domains disable the innate immune system and promote replication of the virus. However, the effects of these domains on cell-mediated immune response had not been investigated. To determine the effects of IIDs on cell-mediated responses, we used a panel of recombinant strains of EBOVs with point mutations disabling the VP24 and/or VP35 IIDs. The viruses were used for infection of peripheral blood mononuclear cells (PBMCs) or dendritic cells (DCs), which were subsequently co-cultured with T cells. We found that IIDs block activation and proliferation of T cells as a result of their functional role in suppressing maturation of DCs and limiting the formation of immunological synapses. Similarly, IIDs were demonstrated to suppress activation and differentiation of B cells, and skew activation of NK cells present in infected PBMCs. These data provide evidence of previously unknown effects of IIDs on the adaptive and innate cell-mediated immune responses and identify a novel mechanism of “immune paralysis” during EBOV infections.
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影响因子：
3.2
作者：
CAMBIAGGI, C;SCUPOLI, MT;ACCOLLA, RS
通讯作者：
ACCOLLA, RS
DOI：
10.1084/jem.20070784
发表时间：
2007-10-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Almeida JR;Price DA;Papagno L;Arkoub ZA;Sauce D;Bornstein E;Asher TE;Samri A;Schnuriger A;Theodorou I;Costagliola D;Rouzioux C;Agut H;Marcelin AG;Douek D;Autran B;Appay V
通讯作者：
Appay V
影响因子：
5.4
作者：
Chi, Bo;Dickensheets, Harold L.;Rabin, Ronald L.
通讯作者：
Rabin, Ronald L.
影响因子：
4.4
作者：
Chang, W. L. William;Coro, Elizabeth S.;Baumgarth, Nicole
通讯作者：
Baumgarth, Nicole
影响因子：
6.4
作者：
Bosio, CM;Aman, MJ;Schmaljohn, A
通讯作者：
Schmaljohn, A