Division of Pulmonary and Critical Care, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
VA San Diego Healthcare System, Medical and Research Sections, La Jolla, CA, USA.
Sci Rep. 2022 Mar 30;12(1):5382. doi: 10.1038/s41598-022-09197-7.
Survival from influenza A virus (IAV) infection largely depends on an intricate balance between pathogen clearance and immunomodulation in the lung. We demonstrate that genetic alteration of the glycan heparan sulfate (HS) in CD11c + cells via Ndst1f/f CD11cCre + mutation, which inhibits HS sulfation in a major antigen presenting cell population, reduces lung inflammation by A/Puerto Rico/8/1934(H1N1) influenza in mice. Mutation was also characterized by a reduction in lung infiltration by CD4 regulatory T (T) cells in the late infection/effector phase, 9 days post inoculation (p.i.), without significant differences in lung CD8 + T cells, or T cells at an earlier point (day 5) following infection. Induction of under-sulfated HS via Ndst1 silencing in a model dendritic cell line (DC2.4) resulted in up-regulated basal expression of the antiviral cytokine interferon β (IFN-β) relative to control. Stimulating cells with the TLR9 ligand CpG resulted in greater nuclear factor-κB (NFκB) phosphorylation in Ndst1 silenced DC2.4 cells. While stimulating cells with CpG also modestly increased IFN-β expression, this did not lead to significant increases in IFN-β protein production. In further IFN-β protein response studies using primary bone marrow DCs from Ndst1f/f CD11cCre + mutant and Cre- control mice, while trace IFN-β protein was detected in response to CpG, stimulation with the TLR7 ligand R848 resulted in robust IFN-β production, with significantly higher levels associated with DC Ndst1 mutation. In vivo, improved pathogen clearance in Ndst1f/f CD11cCre + mutant mice was suggested by reduced IAV AA5H nucleoprotein in lung examined in the late/effector phase. Earlier in the course of infection (day 5 p.i.), mean viral load, as measured by viral RNA, was not significantly different among genotypes. These findings point to novel regulatory roles for DC HS in innate and adaptive immunity during viral infection. This may have therapeutic potential and guide DC targeted HS engineering platforms in the setting of IAV or other respiratory viruses.
流感病毒 (IAV) 感染的存活在很大程度上取决于肺部病原体清除和免疫调节之间的复杂平衡。我们证明，通过 Ndst1f/f CD11cCre+ 突变对 CD11c+ 细胞中的糖肝素硫酸 (HS) 进行遗传改变，该突变抑制主要抗原呈递细胞群体中的 HS 磺化，可减少小鼠中 A/Puerto Rico/8/1934(H1N1) 流感引起的肺部炎症。突变还表现为在感染后 9 天（接种后）的晚期感染/效应阶段，肺中 CD4 调节性 T (T) 细胞的浸润减少，而肺 CD8+T 细胞或更早（第 5 天）感染后的 T 细胞没有差异。在模型树突状细胞系 (DC2.4) 中通过 Ndst1 沉默诱导低硫酸化 HS，导致抗病毒细胞因子干扰素 β (IFN-β) 的基础表达相对于对照上调。用 TLR9 配体 CpG 刺激细胞会导致 Ndst1 沉默的 DC2.4 细胞中核因子-κB (NFκB) 磷酸化增加。虽然用 CpG 刺激细胞也适度增加 IFN-β 的表达，但这并没有导致 IFN-β 蛋白产生的显著增加。在使用 Ndst1f/f CD11cCre+ 突变和 Cre-对照小鼠的原代骨髓 DC 进行进一步的 IFN-β 蛋白反应研究中，虽然在 TLR7 配体 R848 刺激下检测到痕量 IFN-β 蛋白，但刺激 TLR7 配体 R848 可导致强烈的 IFN-β 产生，与 DC Ndst1 突变相关的水平明显更高。在体内，通过在晚期/效应阶段检查肺中的 IAV AA5H 核蛋白，表明 Ndst1f/f CD11cCre+ 突变小鼠中的病原体清除得到改善。在感染早期（接种后第 5 天），通过病毒 RNA 测量的平均病毒载量在基因型之间没有显著差异。这些发现指出了 DC HS 在病毒感染期间固有和适应性免疫中的新的调节作用。这可能具有治疗潜力，并指导 IAV 或其他呼吸道病毒感染时针对 DC 的 HS 工程平台。
