SUMMARY Zika virus (ZIKV) infection during pregnancy in humans results in intrauterine growth restriction, spontaneous abortion and microcephaly. Here, we found that fetus-derived type I interferon (IFN-I) signaling can enhance anti-ZIKV responses and provide clinical benefits to the fetus. Since IFN-λ shares signaling cascades and antiviral functions with IFN-I, we investigated the in vivo effects of IFN-λ in ZIKV-infected pregnant mice. IFN-λ administration during mid-pregnancy reduced ZIKV burden in maternal and fetal organs and alleviated placental injuries and fetal demise. In addition, prophylactic and therapeutic treatment of IFN-λ1 in a human trophoblast line, as well as in primary human amniotic epithelial cells, greatly reduced the ZIKV burden. Our data highlight IFN-λ1 as a potential therapeutic useful for women at risk for congenital Zika disease.

Chronic hepatitis B virus (HBV) infection due to mother-to-child transmission (MTCT) during perinatal period remains an important global health problem. Despite standard passive-active immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine in neonates, up to 9% of newborns still acquire HBV infection, especially these from hepatitis B e antigen (HBeAg) positive mothers. Management of HBV infection in pregnancy still need to draw careful attention because of some controversial aspects, including the failure of passive-active immunoprophylaxis in a fraction of newborns, the effect and necessity of periodical hepatitis B immunoglobulin (HBIG) injection to the mothers, the safety of antiviral prophylaxis with nucleoside/nucleotide analogs, the benefit of different delivery ways, and the safety of breastfeeding. In this review, we highlight these unsettled issues of preventive strategies in perinatal period, and we further aim to provide an optimal approach to the management of preventing MTCT of HBV infection.

Hepatocellular carcinoma (HCC), one of the most common type of cancers, is highly refractory to most systemic therapies. Understanding the genomic dysregulations, in particularly non-coding RNA (ncRNA) dysregulations, in HCC may provide novel strategies to HCC treatment. In our previous study, we demonstrated the key role of miR-200a-mediated HMGB1/RAGE signaling in HCC carcinogenesis. In the present study, we identified circular RNA (circRNA)-miRNA pair that might modulate the migration of HCC cell lines based on previously reported GEO database (GSE78520 and GSE43445) and investigated the function and molecular mechanism. circRNA-101368 was predicted by lncTar to target miR-200a, and the expression of circRNA-101368 was significantly upregulated in HCC tissue samples; the overexpression of circRNA-101368 was correlated with poorer prognosis in patients with HCC. Moreover, circRNA-101368 knockdown suppressed the migration and the protein levels of HMGB1, RAGE and NF-κB, while increased the E-Cadherin expression in HCC cell lines. As confirmed by luciferase reporter and RNA immunoprecipitation assays, circRNA-101368 directly bound to miR-200a to negatively regulate each other. The effect of circRNA-101368 knockdown on cell migration and HMGB1/RAGE signaling could be partially attenuated by miR-200a inhibition. In tissue samples, miR-200a was negatively correlated with circRNA-101368 and HMGB1, respectively, whereas circRNA-101368 and HMGB1 was positively correlated. Taken together, we demonstrated a network of circRNAs-miRNA-mRNA in HCC and provided a novel mechanism of HCC cell migration regulation.

Hepatocellular carcinoma (HCC) is one of the most common malignancies and has an unfavorable prognosis. The hepatitis B virus X (HBx) protein has been reported to be closely associated with hepatocarcinogenesis. Meanwhile, emerging evidence has indicated that long noncoding RNAs (lncRNAs) are involved in the pathogenesis and progression of cancers. Our previous investigation has demonstrated that HBx could promote HCC by regulating the expression levels of various lncRNAs. In this study, we identified an lncRNA, lncRNA-TCONS_00006195 (termed lncRNA-6195), which was downregulated in HBV-related HCC tissues compared with its expression in adjacent noncancerous hepatic tissues. Clinical data showed that a low level of lncRNA-6195 was correlated with a high Edmondson–Steiner grade of the tumor and a poor prognosis in HCC patients. Furthermore, lncRNA-6195 acted as a tumor repressor in the development of hepatitis B-related HCC, inhibiting HCC cell proliferation in vitro and in vivo. Moreover, lncRNA-6195 could combine with α-enolase (ENO1) and repress its enzymatic activity, thus further inhibiting the energy metabolism in HCC cells. Our results suggest that lncRNA-6195 represses the growth of HCC by inhibiting the enzymatic activity of ENO1. These findings provide new insights into the mechanisms underlying the lncRNA involvement in hepatocarcinogenesis and can serve as a basis for the development of novel strategies to hinder HCC.

Traumatic optic neuropathy (TON) is an acute injury of the optic nerve secondary to trauma. Loss of retinal ganglion cells (RGCs) is a key pathological process in TON, yet mechanisms responsible for RGC death remain unclear. In a mouse model of TON, real-time noninvasive imaging revealed a dramatic increase in leukocyte rolling and adhesion in veins near the optic nerve (ON) head at 9 hours after ON injury. Although RGC dysfunction and loss were not detected at 24 hours after injury, massive leukocyte infiltration was observed in the superficial retina. These cells were identified as T cells, microglia/monocytes, and neutrophils but not B cells. CXCL10 is a chemokine that recruits leukocytes after binding to its receptor C-X-C chemokine receptor (CXCR) 3. The levels of CXCL10 and CXCR3 were markedly elevated in TON, and up-regulation of CXCL10 was mediated by STAT1/3. Deleting CXCR3 in leukocytes significantly reduced leukocyte recruitment, and prevented RGC death at 7 days after ON injury. Treatment with CXCR3 antagonist attenuated TON-induced RGC dysfunction and cell loss. In vitro co-culture of primary RGCs with leukocytes resulted in increased RGC apoptosis, which was exaggerated in the presence of CXCL10. These results indicate that leukocyte recruitment in retinal vessels near the ON head is an early event in TON and the CXCL10/CXCR3 axis has a critical role in recruiting leukocytes and inducing RGC death. (Am J Pathol 2017, 187: 352e365; http://dx

Viral hepatitis is still a public health problem affecting several million people around the world. Neutrophils are polymorphonuclear cells that have a critical role in antibacterial infection. However, the role of neutrophils in viral infection is not fully understood. By using a mouse model of lymphocytic choriomeningitis virus infection-induced viral hepatitis, we observed increased neutrophil recruitment in the liver accompanied by enhanced CD8 T-cell responses. Liver neutrophils expressed high levels of immunomodulatory cytokines, such as C-X-C chemokine ligand 2, arginase-1, inducible nitric oxide synthase and interleukin (IL)-10, demonstrating immunosuppressive properties. Depletion of neutrophils in vivo by a neutralizing antibody resulted in the exacerbation of liver injury and the promotion of T-cell responses at the immune contraction stage. IL-33 significantly induced neutrophil recruitment in the liver and attenuated liver injury by limiting effector T-cell accumulation. Mechanistically, we found that IL-33 promoted the expression of arginase-1 in neutrophils through the type 2 innate lymphoid cell (ILC2)-derived IL-13. Additionally, IL-13 increased the inhibitory effect of neutrophils on CD8 T-cell proliferation in vitro, partially through arginase-1. Finally, we found that IL-13 induced arginase-1 expression, depending on signal transducer and activator of transcription factor 6 (STAT6) signaling. Therefore, IL-33 induced immunosuppressive neutrophils via an ILC2/IL-13/STAT6 axis. Collectively, our findings shed new light on the mechanisms associated with IL-33-triggered neutrophils in the liver and suggest potential targets for therapeutic investigation in viral hepatitis.Cellular and Molecular Immunology advance online publication, 5 February 2018; doi:10.1038/cmi.2017.147.

Recent studies have revealed IL-33 as a key factor in promoting antiviral T-cell responses. However, it is less clear as to how IL-33 regulates innate immunity. In this study, we infected wild-type (WT) and IL-33−/− mice with lymphocytic choriomeningitis virus (LCMV) and demonstrated an essential role of infection-induced IL-33 expression for robust innate IFN-γ production in the liver. We first shown that IL-33 deficiency resulted in a marked reduction in the number of IFN-γ+ γδ T and NK cells, but an increase in that of IL-17+ γδ T cells at 16 hours post-infection. Recombinant IL-33 (rIL-33) treatment could reverse such deficiency via increasing IFN-γ-producing γδ T and NK cells, and inhibiting IL-17+ γδ T cells. We also found that rIL-33-induced type 2 innate lymphoid cells (ILC2) were not involved in T-cell responses and liver injury, since the adoptive transfer of ILC2s neither affected the IFN-γ and TNF-α production in T cells, nor liver transferase levels in LCMV-infected mice. Interestingly, we found that while IL-33 was not required for costimulatory molecule expression, it was critical for DC proliferation and cytokine production. Together, this study highlights an essential role of IL-33 in regulating innate IFN-γ-production and DC function during viral hepatitis.

Although large amounts of vitamin A and its metabolite all-trans retinoic acid (RA) are stored in the liver, how RA regulates liver immune responses during viral infection remains unclear. In this study, we demonstrated that IL-22, mainly produced by hepatic γδ T cells, attenuated liver injury in adenovirus-infected mice. RA can promote γδ T cells to produce mTORC1-dependent IL-22 in the liver, but inhibits IFN-γ and IL-17. RA also affected the aptitude of T cell responses by modulating dendritic cell (DC) migration and co-stimulatory molecule expression. These results suggested that RA plays an immunomodulatory role in viral infection. Proteomics data revealed that RA down-regulated S100 family protein expression in DCs, as well as NF-κB/ERK pathway activation in these cells. Furthermore, adoptive transfer of S100A4-repressed, virus-pulsed DCs into the hind foot of naïve mice failed to prime T cell responses in draining lymph nodes. Our study has demonstrated a crucial role for RA in promoting IL-22 production and tempering DC function through down-regulating S100 family proteins during viral hepatitis.