scholarly journals Hepatitis C Virus as a Unique Human Model Disease to Define Differences in the Transcriptional Landscape of T Cells in Acute versus Chronic Infection

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 683 ◽  
Author(s):  
David Wolski ◽  
Georg M. Lauer

The hepatitis C virus is unique among chronic viral infections in that an acute outcome with complete viral elimination is observed in a minority of infected patients. This unique feature allows direct comparison of successful immune responses with those that fail in the setting of the same human infection. Here we review how this scenario can be used to achieve better understanding of transcriptional regulation of T-cell differentiation. Specifically, we discuss results from a study comparing transcriptional profiles of hepatitis C virus (HCV)-specific CD8 T-cells during early HCV infection between patients that do and do not control and eliminate HCV. Identification of early gene expression differences in key T-cell differentiation molecules as well as clearly distinct transcriptional networks related to cell metabolism and nucleosomal regulation reveal novel insights into the development of exhausted and memory T-cells. With additional transcriptional studies of HCV-specific CD4 and CD8 T-cells in different stages of infection currently underway, we expect HCV infection to become a valuable model disease to study human immunity to viruses.

Hepatology ◽  
2008 ◽  
Vol 47 (2) ◽  
pp. 396-406 ◽  
Author(s):  
John W. Northfield ◽  
Victoria Kasprowicz ◽  
Michaela Lucas ◽  
Nadine Kersting ◽  
Bertram Bengsh ◽  
...  

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A696-A696
Author(s):  
Teresa Manzo ◽  
Carina Nava Lauveson ◽  
Teresa Maria Frasconi ◽  
Silvia Tiberti ◽  
Ignazio Caruana ◽  
...  

BackgroundAdoptive cell therapy (ACT) harnesses the immune system to recognise tumor cells and carry out an anti-tumor function. However, metabolic constraints imposed by the tumour microenvironment (TME) suppress anti-tumor responses of CTL by reshaping their metabolism and epigenetic landscape. We have recently demonstrated that progressive accumulation of specific long-chain fatty acids (LCFAs) impair mitochondrial function and drives CD8+ T cell dysfunction. In this scenario, maintaining T cells in a less-differentiated state and with high metabolic plasticity during ex vivo T cell production and after infusion may have a strong therapeutic impact. Here, we propose a novel strategy to boost ACT efficacy by implementing T cell long-term functionality, metabolic fitness and preventing exhaustion through lipid-induced mitochondrial rewiring.MethodsWe screen different LCFAs and assess their ability to shape CD8+ T cell differentiation using multi-parametric flow cytometry, proliferation and cytotoxic assays, together with a complete transcriptomic and epigenomic profiling. Metabolic reprogramming of lipid-treated CD8+ T cell was examined by bioenergetic flux measurements paired with metabolomic and lipidomic analysis. Finally, the anti-tumor responses of lipid-instructed CD8 T cells was evaluated in a melanoma mouse model, known to poorly respond to immunotherapy.ResultsLCFAs-treated CD8+ T cells are endowed with highly effector and cytotoxic features but still retaining a memory-like phenotype with decreased PD1 protein levels. Consistently, analysis of the bioenergetic profile and mitochondrial activity has shown that LCFA-instructed CD8+ T cells display a greater mitochondrial fitness. Thus, in vitro LCFA-instructed CD8+ T cells are characterized by higher mitochondrial fitness, potent functionality, memory-like phenotype and PD-1 down-regulation, overall evoking the ideal T cell population associated with a productive anti-tumor response. The therapeutic potential of CD8 T cells lipid-induced metabolic rewiring was further confirmed in vivo. ACT performed with LCFA-reprogrammed CD8 T cells induces higher frequency of memory T cells, which show high polyfunctionality and mitochondrial function, decreased PD1 expression, ultimately resulting in improved tumor control. In addition, LCFA-induced metabolic rewiring during manufacturing of human CAR-redirected T cells, generated a CD8+ T cell memory-like population with higher mitochondrial fitness coupled with a much potent cytotoxic activity.ConclusionsThese results suggest that LCFAs dictate the fate of CD8+ T cell differentiation and could be considered as a molecular switch to fine-tune memory T cell formation and metabolic fitness maintenance, linking lipid metabolism to anti-tumor surveillance. This will be of fundamental importance for a new generation of adoptive T cell-based therapies.Ethics ApprovalThe experiments described were performed in accordance with the European Union Guideline on Animal Experiments and mouse protocols were approved by Italian Ministry of Health and the IEO Committee.


2017 ◽  
Vol 199 (12) ◽  
pp. 4091-4102 ◽  
Author(s):  
Nina Chi Sabins ◽  
Olesya Chornoguz ◽  
Karen Leander ◽  
Fred Kaplan ◽  
Richard Carter ◽  
...  

2018 ◽  
Vol 115 (18) ◽  
pp. 4749-4754 ◽  
Author(s):  
Eunseon Ahn ◽  
Koichi Araki ◽  
Masao Hashimoto ◽  
Weiyan Li ◽  
James L. Riley ◽  
...  

PD-1 (programmed cell death-1) is the central inhibitory receptor regulating CD8 T cell exhaustion during chronic viral infection and cancer. Interestingly, PD-1 is also expressed transiently by activated CD8 T cells during acute viral infection, but the role of PD-1 in modulating T cell effector differentiation and function is not well defined. To address this question, we examined the expression kinetics and role of PD-1 during acute lymphocytic choriomeningitis virus (LCMV) infection of mice. PD-1 was rapidly up-regulated in vivo upon activation of naive virus-specific CD8 T cells within 24 h after LCMV infection and in less than 4 h after peptide injection, well before any cell division had occurred. This rapid PD-1 expression by CD8 T cells was driven predominantly by antigen receptor signaling since infection with a LCMV strain with a mutation in the CD8 T cell epitope did not result in the increase of PD-1 on antigen-specific CD8 T cells. Blockade of the PD-1 pathway using anti–PD-L1 or anti–PD-1 antibodies during the early phase of acute LCMV infection increased mTOR signaling and granzyme B expression in virus-specific CD8 T cells and resulted in faster clearance of the infection. These results show that PD-1 plays an inhibitory role during the naive-to-effector CD8 T cell transition and that the PD-1 pathway can also be modulated at this stage of T cell differentiation. These findings have implications for developing therapeutic vaccination strategies in combination with PD-1 blockade.


2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Alex S. Hartlage ◽  
Christopher M. Walker ◽  
Amit Kapoor

ABSTRACT Immune-competent animal models for the hepatitis C virus (HCV) are nonexistent, impeding studies of host-virus interactions and vaccine development. Experimental infection of laboratory rats with a rodent hepacivirus isolated from Rattus norvegicus (RHV) is a promising surrogate model due to its recapitulation of HCV-like chronicity. However, several aspects of rat RHV infection remain unclear, for instance, how RHV evades host adaptive immunity to establish persistent infection. Here, we analyzed the induction, differentiation, and functionality of RHV-specific CD8 T cell responses that are essential for protection against viral persistence. Virus-specific CD8 T cells targeting dominant and subdominant major histocompatibility complex class I epitopes proliferated considerably in liver after RHV infection. These populations endured long term yet never acquired antiviral effector functions or selected for viral escape mutations. This was accompanied by the persistent upregulation of programmed cell death-1 and absent memory cell formation, consistent with a dysfunctional phenotype. Remarkably, transient suppression of RHV viremia with a direct-acting antiviral led to the priming of CD8 T cells with partial effector function, driving the selection of a viral escape variant. These data demonstrate an intrinsic abnormality within CD8 T cells primed by rat RHV infection, an effect that is governed at least partially by the magnitude of early virus replication. Thus, this model could be useful in investigating mechanisms of CD8 T cell subversion, leading to the persistence of hepatotropic pathogens such as HCV. IMPORTANCE Development of vaccines against hepatitis C virus (HCV), a major cause of cirrhosis and cancer, has been stymied by a lack of animal models. The recent discovery of an HCV-like rodent hepacivirus (RHV) enabled the development of such a model in rats. This platform recapitulates HCV hepatotropism and viral chronicity necessary for vaccine testing. Currently, there are few descriptions of RHV-specific responses and why they fail to prevent persistent infection in this model. Here, we show that RHV-specific CD8 T cells, while induced early at high magnitude, do not develop into functional effectors capable of controlling virus. This defect was partially alleviated by short-term treatment with an HCV antiviral. Thus, like HCV, RHV triggers dysfunction of virus-specific CD8 T cells that are vital for infection resolution. Additional study of this evasion strategy and how to mitigate it could enhance our understanding of hepatotropic viral infections and lead to improved vaccines and therapeutics.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S163-S163
Author(s):  
Alex S Hartlage ◽  
Amit Kapoor

Abstract Background Virus-specific CD8 T cells are essential for control of acute hepatitis C virus (HCV) infections, yet spontaneously fail in most patients leading to lifelong chronicity and increased risk for severe liver diseases. Efforts to study HCV-specific CD8 T-cell impairment have been hampered by a lack of small animal models. Recently, we established a rat model of chronic HCV-like infection using a hepacivirus homolog identified in Rattus norvegicus. The nature of virus-specific CD8 T-cell immunity in this model has yet to be determined. Methods Using two MHC class I tetramers against epitopes located in the E1 and NS5B proteins, we tracked the induction and phenotype of virus-specific CD8 T cells during chronic infection. Responses to infection were similarly analyzed in immune rats that had been vaccinated against the NS3-5B proteins, a strategy that is effective in this experimental setting. Results Virus-specific CD8 T cells expanded vigorously in liver shortly after infection but did not develop into functional effectors based upon failure to produce cytokines (IFNγ, TNFα, IL-2, IL-4, IL-10, IL-17A) following peptide stimulation. Notably, subversion of responses was not due to viral escape from T-cell recognition, but rather an intrinsic defect in the antiviral response. Indeed, these populations expressed the inhibitory receptor programed cell death-1 and other markers consistent with an arrested effector-like state precluded from long-term memory formation (CD127-CD27+CD28+CD62L-GranzymeB+). In contrast, adenoviral immunization of naïve rats protected virus-specific T cells from functional impairment after infection and supported memory response development, including against the E1 epitope not encoded by vaccine. Conclusion Together, our findings reveal a spontaneous failure of virus-specific CD8 T cells following rat hepacivirus challenge that is highly reminiscent of human HCV infections. Furthermore, these results highlight the utility and significance of this model for understanding mechanisms of HCV persistence and protective immunity necessary for the development of effective vaccines and immune interventions. Disclosures All authors: No reported disclosures.


2008 ◽  
Vol 82 (15) ◽  
pp. 7567-7577 ◽  
Author(s):  
Joana Caetano ◽  
António Martinho ◽  
Artur Paiva ◽  
Beatriz Pais ◽  
Cristina Valente ◽  
...  

ABSTRACT CD8 T cells play a major role in antiviral immune responses. Their importance for progression to chronic hepatitis C and response to treatment are still unclear. To address these issues, hepatitis C virus (HCV)-specific CD8 T-cell responses were monitored, at the single-cell level, using HLA class I pentamers specific for HCV core and HCV NS3 epitopes, in 23 chronically infected patients during treatment with pegylated alpha interferon and ribavirin. Patients who presented a sustained-response to therapy had stronger HCV-specific CD8 T-cell responses at all time points studied. Moreover, there were clear differences in the phenotypes of these cells during therapy: in responder patients, terminally differentiated effector cells increased more rapidly, and their frequency was always higher than in nonresponder patients. Sustained-responder patients also showed a higher frequency of HCV-specific CD8 T cells producing cytotoxic factors. Overall, a late and inefficient differentiation process of HCV-specific CD8 T cells might be associated with lack of response to treatment. A better knowledge of the mechanisms underlying this impairment may be important for the development of new therapeutic strategies to maintain, restore, or increase CD8 T-cell effectiveness in chronic HCV infection.


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