scholarly journals Hepatitis-D Virus Infection Is Not Impaired by Innate Immunity but Increases Cytotoxic T-Cell Activity

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3253
Author(s):  
Sebastian Maximilian Altstetter ◽  
Oliver Quitt ◽  
Francesca Pinci ◽  
Veit Hornung ◽  
Aaron Michael Lucko ◽  
...  

Approximately 70 million humans worldwide are affected by chronic hepatitis D, which rapidly leads to liver cirrhosis and hepatocellular carcinoma due to chronic inflammation. The triggers and consequences of this chronic inflammation, induced by co-infection with the hepatitis D virus (HDV) and the hepatitis B virus (HBV), are poorly understood. Using CRISPR technology, we characterized the recognition of HDV mono- and co-infection by intracellular innate immunity and determined its influence on the viral life cycle and effector T-cell responses using different HBV and HDV permissive hepatoma cell lines. We showed that HDV infection is detected by MDA5 and -after a lag phase -induces a profound type I interferon response in the infected cells. The type I interferon response, however, was not able to suppress HDV replication or spread, thus providing a persistent trigger. Using engineered T-cells directed against the envelope proteins commonly used by HBV and HDV, we found that HDV immune recognition enhanced T-cell cytotoxicity. Interestingly, the T-cell effector function was enhanced independently of antigen presentation. These findings help to explain immune mediated tissue damage in chronic hepatitis D patients and indicate that combining innate triggers with T-cell activating therapies might allow for a curative approach.

2020 ◽  
Vol 10 (3) ◽  
pp. 382-393 ◽  
Author(s):  
Jun-Bao Fan ◽  
Sayuri Miyauchi ◽  
Hui-Zhong Xu ◽  
Dan Liu ◽  
Leo J.Y. Kim ◽  
...  

2018 ◽  
Author(s):  
Shaylynn Miller ◽  
Patrick Coit ◽  
Elizabeth Gensterblum-Miller ◽  
Paul Renauer ◽  
Nathan C Kilian ◽  
...  

AbstractObjectiveWe examined genome-wide DNA methylation changes in CD8+ T cells from lupus patients and controls, and investigated the functional relevance of some of these changes in lupus.MethodsGenome-wide DNA methylation of lupus and age, sex, and ethnicity-matched control CD8+ T cells was measured using the Infinium MethylationEPIC arrays. Measurement of relevant cell subsets was performed via flow cytometry. Gene expression was quantified by qPCR.ResultsLupus CD8+ T cells had 188 hypomethylated CpG sites compared to healthy matched controls. Among the most hypomethylated were sites associated with HLA-DRB1. Genes involved in the type-I interferon response, including STAT1, were also found to be hypomethylated. IFNα upregulated HLA-DRB1 expression on lupus but not control CD8+ T cells. Lupus and control CD8+ T cells significantly increased STAT1 mRNA levels after treatment with IFNα. The expression of CIITA, a key interferon/STAT1 dependent MHC-class II regulator, is induced by IFNα in lupus CD8+ T cells, but not healthy controls. Co-incubation of naïve CD4+ T cells with IFNα-treated CD8+ T cells led to CD4+ T cell activation, determined by increased expression of CD69, in lupus patients but not in healthy controls. This can be blocked by neutralizing antibodies targeting HLA-DR.ConclusionsLupus CD8+ T cells are epigenetically primed to respond to type-I interferon. We describe an HLA-DRB1+ CD8+ T cell subset that can be induced by IFNα in lupus patients. A possible pathogenic role for CD8+ T cells in lupus that is dependent upon a high type-I interferon environment and epigenetic priming warrants further characterization.


2017 ◽  
Vol 91 (9) ◽  
Author(s):  
Juan García-Arriaza ◽  
Beatriz Perdiguero ◽  
Jonathan L. Heeney ◽  
Michael S. Seaman ◽  
David C. Montefiori ◽  
...  

ABSTRACT The nonreplicating attenuated poxvirus vector NYVAC expressing clade C(CN54) HIV-1 Env(gp120) and Gag-Pol-Nef antigens (NYVAC-C) showed limited immunogenicity in phase I clinical trials. To enhance the capacity of the NYVAC vector to trigger broad humoral responses and a more balanced activation of CD4+ and CD8+ T cells, here we compared the HIV-1-specific immunogenicity elicited in nonhuman primates immunized with two replicating NYVAC vectors that have been modified by the insertion of the K1L and C7L vaccinia virus host range genes and express the clade C(ZM96) trimeric HIV-1 gp140 protein or a Gag(ZM96)-Pol-Nef(CN54) polyprotein as Gag-derived virus-like particles (termed NYVAC-C-KC). Additionally, one NYVAC-C-KC vector was generated by deleting the viral gene B19R, an inhibitor of the type I interferon response (NYVAC-C-KC-ΔB19R). An immunization protocol mimicking that of the RV144 phase III clinical trial was used. Two groups of macaques received two doses of the corresponding NYVAC-C-KC vectors (weeks 0 and 4) and booster doses with NYVAC-C-KC vectors plus the clade C HIV-1 gp120 protein (weeks 12 and 24). The two replicating NYVAC-C-KC vectors induced enhanced and similar HIV-1-specific CD4+ and CD8+ T cell responses, similar levels of binding IgG antibodies, low levels of IgA antibodies, and high levels of antibody-dependent cellular cytotoxicity responses and HIV-1-neutralizing antibodies. Small differences within the NYVAC-C-KC-ΔB19R group were seen in the magnitude of CD4+ and CD8+ T cells, the induction of some cytokines, and the neutralization of some HIV-1 isolates. Thus, replication-competent NYVAC-C-KC vectors acquired relevant immunological properties as vaccine candidates against HIV/AIDS, and the viral B19 molecule exerts some control of immune functions. IMPORTANCE It is of special importance to find a safe and effective HIV/AIDS vaccine that can induce strong and broad T cell and humoral immune responses correlating with HIV-1 protection. Here we developed novel replicating poxvirus NYVAC-based HIV/AIDS vaccine candidates expressing clade C HIV-1 antigens, with one of them lacking the vaccinia virus B19 protein, an inhibitor of the type I interferon response. Immunization of nonhuman primates with these novel NYVAC-C-KC vectors and the protein component gp120 elicited high levels of T cell and humoral immune responses, with the vector containing a deletion in B19R inducing a trend toward a higher magnitude of CD4+ and CD8+ T cell responses and neutralization of some HIV-1 strains. These poxvirus vectors could be considered HIV/AIDS vaccine candidates based on their activation of potential immune correlates of protection.


2009 ◽  
Vol 206 (7) ◽  
pp. 1589-1602 ◽  
Author(s):  
M. Paula Longhi ◽  
Christine Trumpfheller ◽  
Juliana Idoyaga ◽  
Marina Caskey ◽  
Ines Matos ◽  
...  

Relative to several other toll-like receptor (TLR) agonists, we found polyinosinic:polycytidylic acid (poly IC) to be the most effective adjuvant for Th1 CD4+ T cell responses to a dendritic cell (DC)–targeted HIV gag protein vaccine in mice. To identify mechanisms for adjuvant action in the intact animal and the polyclonal T cell repertoire, we found poly IC to be the most effective inducer of type I interferon (IFN), which was produced by DEC-205+ DCs, monocytes, and stromal cells. Antibody blocking or deletion of type I IFN receptor showed that IFN was essential for DC maturation and development of CD4+ immunity. The IFN-AR receptor was directly required for DCs to respond to poly IC. STAT 1 was also essential, in keeping with the type I IFN requirement, but not type II IFN or IL-12 p40. Induction of type I IFN was mda5 dependent, but DCs additionally used TLR3. In bone marrow chimeras, radioresistant and, likely, nonhematopoietic cells were the main source of IFN, but mda5 was required in both marrow–derived and radioresistant host cells for adaptive responses. Therefore, the adjuvant action of poly IC requires a widespread innate type I IFN response that directly links antigen presentation by DCs to adaptive immunity.


2006 ◽  
Vol 80 (12) ◽  
pp. 5958-5967 ◽  
Author(s):  
Alexander Kotelkin ◽  
Igor M. Belyakov ◽  
Lijuan Yang ◽  
Jay A. Berzofsky ◽  
Peter L. Collins ◽  
...  

ABSTRACT The NS1 and NS2 proteins of human respiratory syncytial virus (HRSV) have been shown to antagonize the type I interferon (IFN) response, an effect subject to host range constraints. We have now found that the HRSV NS2 protein strongly controls IFN induction in mouse cells in vitro, validating the use of the mouse model to study the consequences of these gene deletions on host immunity. We evaluated the effects of deleting the NS1 and/or NS2 gene on the induction of HRSV-specific pulmonary cytotoxic T lymphocytes (CTL) in BALB/c and 129S6 mice in response to intranasal infection with HRSV lacking the NS1 and/or NS2 gene and subsequent challenge with wild-type (wt) HRSV. In mice infected with HRSV lacking the NS2 gene (ΔNS2) or lacking the NS2 gene in combination with the NS1 gene (ΔNS1/2 HRSV), the magnitude of the pulmonary CTL response was substantially elevated compared to that of mice infected with wt HRSV or the ΔNS1 mutant, whether measured by binding of CD8+ cells to an HRSV-specific major histocompatibility complex class I tetramer, by measurement of CD8+ cells secreting gamma interferon (IFN-γ) in response to specific in vitro stimulation, or by a standard chromium release cell-killing assay. In contrast, in STAT1 knockout mice, which lack responsiveness to type I IFN, the level of IFN-γ-secreting CD8+ cells was not significantly different for HRSV lacking the NS2 gene, suggesting that the increase in CTL observed in IFN-responsive mice is type I IFN dependent. Thus, the NS2 protein of HRSV suppresses the CTL component of the adaptive immune response, and this appears to be a consequence of its suppression of type I IFN.


2019 ◽  
Vol 78 (4) ◽  
pp. 519-528 ◽  
Author(s):  
Shaylynn Miller ◽  
Pei-Suen Tsou ◽  
Patrick Coit ◽  
Elizabeth Gensterblum-Miller ◽  
Paul Renauer ◽  
...  

ObjectiveWe examined genome-wide DNA methylation changes in CD8+ T cells from patients with lupus and controls and investigated the functional relevance of some of these changes in lupus.MethodsGenome-wide DNA methylation of lupus and age, sex and ethnicity-matched control CD8+ T cells was measured using the Infinium MethylationEPIC arrays. Measurement of relevant cell subsets was performed via flow cytometry. Gene expression was quantified by qPCR. Inhibiting STAT1 and CIITA was performed using fludarabine and CIITA siRNA, respectively.ResultsLupus CD8+ T cells had 188 hypomethylated CpG sites compared with healthy matched controls. Among the most hypomethylated were sites associated with HLA-DRB1. Genes involved in the type-I interferon response, including STAT1, were also found to be hypomethylated. IFNα upregulated HLA-DRB1 expression on lupus but not control CD8+ T cells. Lupus and control CD8+ T cells significantly increased STAT1 mRNA levels after treatment with IFNα. The expression of CIITA, a key interferon/STAT1 dependent MHC-class II regulator, is induced by IFNα in lupus CD8+ T cells, but not healthy controls. CIITA knockdown and STAT1 inhibition experiments revealed that HLA-DRB1 expression in lupus CD8+ T cells is dependent on CIITA and STAT1 signalling. Coincubation of naïve CD4+ T cells with IFNα-treated CD8+ T cells led to CD4+ T cell activation, determined by increased expression of CD69 and cytokine production, in patients with lupus but not in healthy controls. This can be blocked by neutralising antibodies targeting HLA-DR.ConclusionsLupus CD8+ T cells are epigenetically primed to respond to type-I interferon. We describe an HLA-DRB1+ CD8+ T cell subset that can be induced by IFNα in patients with lupus. A possible pathogenic role for CD8+ T cells in lupus that is dependent on a high type-I interferon environment and epigenetic priming warrants further characterisation.


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