scholarly journals Natural Killer T Cell Activation Inhibits Hepatitis B Virus Replication in Vivo

2000 ◽  
Vol 192 (7) ◽  
pp. 921-930 ◽  
Author(s):  
Kazuhiro Kakimi ◽  
Luca G. Guidotti ◽  
Yasuhiko Koezuka ◽  
Francis V. Chisari

We have previously reported that hepatitis B virus (HBV)–specific CD8+ cytotoxic T lymphocytes and CD4+ helper T lymphocytes can inhibit HBV replication in the liver of HBV transgenic mice by secreting interferon (IFN)-γ when they recognize viral antigen. To determine whether an activated innate immune system can also inhibit HBV replication, in this study we activated natural killer T (NKT) cells in the liver of HBV transgenic mice by a single injection of α-galactosylceramide (α-GalCer), a glycolipid antigen presented to Vα14+NK1.1+ T cells by the nonclassical major histocompatibility complex class I–like molecule CD1d. Within 24 h of α-GalCer injection, IFN-γ and IFN-α/β were detected in the liver of HBV transgenic mice and HBV replication was abolished. Both of these events were temporally associated with the rapid disappearance of NKT cells from the liver, presumably reflecting activation-induced cell death, and by the recruitment of activated NK cells into the organ. In addition, prior antibody-mediated depletion of CD4+ and CD8+ T cells from the mice did not diminish the ability of α-GalCer to trigger the disappearance of HBV from the liver, indicating that conventional T cells were not downstream mediators of this effect. Finally, the antiviral effect of α-GalCer was inhibited in mice that are genetically deficient for either IFN-γ or the IFN-α/β receptor, indicating that most of the antiviral activity of α-GalCer is mediated by these cytokines. Based on these results, we conclude that α-GalCer inhibits HBV replication by directly activating NKT cells and by secondarily activating NK cells to secrete antiviral cytokines in the liver. In view of these findings, we suggest that, if activated, the innate immune response, like the adaptive immune response, has the potential to control viral replication during natural HBV infection. In addition, the data suggest that therapeutic activation of NKT cells may represent a new strategy for the treatment of chronic HBV infection.

2002 ◽  
Vol 76 (21) ◽  
pp. 10702-10707 ◽  
Author(s):  
Kiminori Kimura ◽  
Kazuhiro Kakimi ◽  
Stefan Wieland ◽  
Luca G. Guidotti ◽  
Francis V. Chisari

ABSTRACT Interleukin-18 (IL-18) produced by activated antigen-presenting cells stimulates natural killer (NK) cells, natural killer T (NKT) cells, and T cells to secrete gamma interferon (IFN-γ). In this study, injection of a single 10-μg dose of recombinant murine IL-18 rapidly, reversibly, and noncytopathically inhibited hepatitis B virus (HBV) replication in the livers of HBV transgenic mice. Furthermore, HBV replication was inhibited by as little as 1 μg of IL-18 injected repetitively, and also by a single 0.1-μg dose of IL-18 injected together with 1 ng of IL-12, neither of which inhibited HBV replication individually, demonstrating synergy between these cytokines in this system. The antiviral effect of IL-18 was mediated by its ability to activate resident intrahepatic NK cells and NKT cells to produce IFN-γ and by its ability to induce IFN-α/β production in the liver. These results suggest that IL-18 has the potential to contribute to the control of HBV replication during self-limited infection and that it may have therapeutic value for the treatment of patients with chronic hepatitis.


2000 ◽  
Vol 191 (7) ◽  
pp. 1247-1252 ◽  
Author(s):  
Luca G. Guidotti ◽  
Heike McClary ◽  
Jacquelyn Moorhead Loudis ◽  
Francis V. Chisari

We have previously identified two antiviral cytokines (interferon [IFN]-γ and IFN-α/β) that downregulate hepatitis B virus (HBV) replication in the liver of transgenic mice. The cytokine-inducible downstream events that inhibit HBV replication have not been identified. One possible factor is nitric oxide (NO), a pleiotropic free radical with antiviral activity that is produced in the liver by the inducible NO synthase (iNOS). To examine the role of NO in our model, we crossed transgenic mice that replicate HBV with mice that lack a functional iNOS. Importantly, iNOS-deficient mice were almost completely resistant to the noncytopathic inhibitory effect of HBV-specific cytotoxic T lymphocytes on viral replication, an effect that we have shown previously to depend on the intrahepatic induction of IFN-γ. Conversely, iNOS-deficient mice were not resistant to the antiviral effect of IFN-α/β induced by either polyinosinic-polycytidylic acid complex or by lymphocytic choriomeningitis virus (LCMV) infection. These results indicate that NO mediates the antiviral activity of IFN-γ, whereas the antiviral activity of IFN-α/β is NO independent. We also compared the relative sensitivity of LCMV to control by NO in these animals. Interestingly, LCMV replicated to higher levels in the liver of iNOS-deficient mice than control mice, indicating that NO controls LCMV replication in the liver, as well as HBV.


2002 ◽  
Vol 76 (6) ◽  
pp. 2617-2621 ◽  
Author(s):  
Luca G. Guidotti ◽  
Amber Morris ◽  
Heike Mendez ◽  
Rick Koch ◽  
Robert H. Silverman ◽  
...  

ABSTRACT We previously showed that the intrahepatic induction of cytokines such as alpha/beta interferon (IFN-α/β) and gamma interferon (IFN-γ) inhibits hepatitis B virus (HBV) replication noncytopathically in the livers of transgenic mice. The intracellular pathway(s) responsible for this effect is still poorly understood. To identify interferon (IFN)-inducible intracellular genes that could play a role in our system, we crossed HBV transgenic mice with mice deficient in IFN regulatory factor 1 (IRF-1), the double-stranded RNA-activated protein kinase (PKR), or RNase L (RNase L) (IRF-1−/−, PKR−/−, or RNase L−/− mice, respectively), three well-characterized IFN-inducible genes that mediate antiviral activity. We showed that unmanipulated IRF-1−/− or PKR−/− transgenic mice replicate HBV in the liver at slightly higher levels than the respective controls, suggesting that both IRF-1 and PKR individually appear to mediate signals that modulate HBV replication under basal conditions. These same animals were responsive to the antiviral effects of the IFN-α/β inducer poly(I-C) or recombinant murine IFN-γ, suggesting that under these conditions, either the IRF-1 or the PKR genes can mediate the antiviral activity of the IFNs or other IFN-inducible genes mediate the antiviral effects. Finally, RNase L−/− transgenic mice were undistinguishable from controls under basal conditions and after poly(I-C) or IFN-γ administration, suggesting that RNase L does not modulate HBV replication in this model.


2000 ◽  
Vol 192 (4) ◽  
pp. 529-536 ◽  
Author(s):  
Valerie Pasquetto ◽  
Luca G. Guidotti ◽  
Kazuhiro Kakimi ◽  
Moriya Tsuji ◽  
Francis V. Chisari

We have previously shown that hepatitis B virus (HBV) replication is abolished in the liver of HBV transgenic mice by inflammatory cytokines induced by HBV-specific cytotoxic T cells and during unrelated viral infections of the liver. We now report that intrahepatic HBV replication is also inhibited in mice infected by the malaria species Plasmodium yoelii 17X NL. P. yoelii infection triggers an intrahepatic inflammatory response characterized by the influx of natural killer cells, macrophages, and T cells. During this process, interferon (IFN)-γ and IFN-α/β suppress HBV gene expression and replication in the liver. Collectively, the data suggest that malaria infection might influence the course and pathogenesis of HBV infection in coinfected humans.


2005 ◽  
Vol 79 (9) ◽  
pp. 5568-5576 ◽  
Author(s):  
An Chen ◽  
Li Wang ◽  
Jingbo Zhang ◽  
Liyun Zou ◽  
Zhengcai Jia ◽  
...  

ABSTRACT It is necessary to evaluate the cytokine secretion status of CD8+ T lymphocytes and elucidate the factors influencing cytokine secretion, because the secretion of cytokines is also an important feature of CD8+ T lymphocytes, and the cytokines usually play critical roles in the outcome of diseases. We showed here that peptide AYRPPNAPI, derived from the core antigen of hepatitis B virus (HBV), could bind to H-2 Kd and induce primed splenocytes from HBcAg expression plasmid-immunized mice to produce gamma interferon (IFN-γ) in H-2 Kd- and CD8-dependent manners instead of in a CD4-dependent manner. The induced cells were mainly CD3 and CD8 positive but had no cytotoxic effect on the corresponding target cells. When administered into HBV transgenic mice, these cells can decrease the serum HBV load without causing liver damage. These results suggest that this peptide is a special kind of CD8+ T-cell epitope, for which specific CD8+ T cells can produce IFN-γ when antigenic stimulation is encountered but which have no cytotoxic effect on the corresponding target cells both in vitro and in HBV transgenic mice. This phenomenon indicates initially that the functional mechanisms of CD8+ T cells can be determined by their epitope specificity, which may be associated with the development of epitope-based immunotherapeutic approaches for infectious diseases and tumors.


2000 ◽  
Vol 192 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Heike McClary ◽  
Rick Koch ◽  
Francis V. Chisari ◽  
Luca G. Guidotti

Although coinfection of hepatitis B virus (HBV) and Schistosoma mansoni is a frequent event in humans, little is known about the interactions between these two pathogens. S. mansoni infection induces T helper cell type 2 (Th2)–type cytokines in the liver of humans and mice. The intrahepatic induction of nitric oxide (NO) and Th1-type cytokines, such as interferon (IFN)-γ and IFN-α/β, inhibits HBV replication noncytopathically in the liver of transgenic mice. To examine whether S. mansoni infection and the accompanying induction of Th2-type cytokines could interfere with HBV replication in the liver, HBV transgenic mice were infected with S. mansoni. By 5 wk after infection, HBV replication disappeared concomitant with the intrahepatic induction of NO and Th1-type cytokines, and in the absence of Th2-type cytokines. By 6–8 wk after infection, HBV replication remained undetectable and this was associated with further induction of NO and Th1-type cytokines together with the appearance of Th2-type cytokines. The S. mansoni–dependent antiviral effect was partially blocked by genetically deleting IFN-γ, although it was unaffected by deletion of IFN-α/β. These results indicate that IFN-γ (probably via NO) mediates most of this antiviral activity and that Th2-type cytokines do not counteract the antiviral effect of IFN-γ. Similar events may suppress HBV replication during human S. mansoni infection.


Hepatology ◽  
2010 ◽  
Vol 53 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Zixue Jin ◽  
Rui Sun ◽  
Haiming Wei ◽  
Xiang Gao ◽  
Yongyan Chen ◽  
...  

1999 ◽  
Vol 73 (1) ◽  
pp. 474-481 ◽  
Author(s):  
Tilman Heise ◽  
Luca G. Guidotti ◽  
Victoria J. Cavanaugh ◽  
Francis V. Chisari

ABSTRACT Hepatitis B virus (HBV) gene expression is downregulated in the liver of HBV transgenic mice by a posttranscriptional mechanism that is triggered by the local production of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) during intrahepatic inflammation (hepatitis). The molecular basis for this antiviral effect is unknown. In this study, we identified three HBV RNA-binding liver nuclear proteins (p45, p39, and p26) the relative abundance of which correlates with the abundance of HBV RNA in response to the induction of IFN-γ and TNF-α. All three proteins bind to a 91-bp element located at the 5′ end of a previously defined posttranscriptional regulatory element that is thought to mediate the nuclear export of HBV RNA. The presence of p45 correlates directly with the presence of HBV RNA, being detectable under baseline conditions when the viral RNA is abundant and undetectable when the viral RNA disappears in response to IFN-γ and TNF-α. In contrast, p26 is inversely related to HBV RNA, being detectable only when the viral RNA disappears following cytokine activation. Finally, p39 is constitutively expressed, and its abundance and mobility appear to be slightly increased by cytokine activation. These results suggest a model in which hepatocellular HBV RNA content might be controlled by the stabilizing and/or destabilizing influences of these RNA-binding proteins whose activity is regulated by cytokine-induced signaling pathways.


Hepatology ◽  
2005 ◽  
Vol 41 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Jeroen N. Stoop ◽  
Renate G. van der Molen ◽  
Carla C. Baan ◽  
Luc J. W. van der Laan ◽  
Ernst J. Kuipers ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document