scholarly journals Adenovirus Vector Harboring the HBcAg and Tripeptidyl Peptidase II Genes Induces Potent Cellular Immune Responses In Vivo

2017 ◽  
Vol 41 (2) ◽  
pp. 423-438 ◽  
Author(s):  
Quanhui Tan ◽  
Siyuan Ma ◽  
Jianjun Hu ◽  
Xiaohua Chen ◽  
Yongsheng Yu ◽  
...  

Background: Chronic hepatitis B virus (HBV) infection is associated with a weak but specific cellular immune response of the host to HBV. Tripeptidyl peptidaseⅡ (TPPⅡ), an intracellular macromolecule and proteolytic enzyme, plays an important complementary and compensatory role for the proteasome during viral protein degradation and major histocompatibility complex class I antigen presentation by inducing a specific cellular immune response in vivo. Based on a previous study, we aimed to explore the role of MHC class I antigen presentation in vivo and the mechanisms that may be involved. Methods: In this study, recombinant adenoviral vectors harboring the hepatitis B core antigen (HBcAg) and the TPPII gene were constructed (Adv-HBcAg and Adv-HBcAg-TPPII), and H-2Kd HBV-transgenic BALB/c mice and HLA-A2 C57BL/6 mice were immunized with these vectors, respectively. We evaluated the specific immune responses induced by Adv-HBcAg-TPPII in the HBV transgenic BALB/c mice and HLA-A2 C57BL/6 mice as well as the anti-viral ability of HBV transgenic mice, and we explored the underlying mechanisms. Results: We found that immunization with Adv-HBcAg-TPPII induced the secretion of the cytokines interleukin-2 (IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) as well as the activities of IFN-γ-secreting CD8+ T cells and CD4+ T cells. In addition, HBcAg-specific CTL activity in C57/BL mice and HBV transgenic animals was significantly enhanced in the Adv-HBcAg-TPPII group. Furthermore, Adv-HBcAg-TPPII decreased the hepatitis B surface antigen (HBsAg) and HBV DNA levels and the amount of HBsAg and HBcAg in liver tissues. Moreover, Adv-HBcAg-TPPII enhanced the expression of T-box transcription factor (T-bet) and downregulated GATA-binding protein 3 (GATA-3) while increasing the expression levels of JAK2, STAT1, STAT4 and Tyk2. Conclusions: These results suggested that the JAK/STAT signaling pathway participates in the CTL response that is mediated by the adenoviral vector encoding TPPII. Adv-HBcAg-TPPII could therefore break immune tolerance and stimulate HBV-specific cytotoxic T lymphocyte activity and could have a good therapeutic effect in transgenic mice.

2020 ◽  
Author(s):  
Nina Le Bert ◽  
Hannah E Clapham ◽  
Anthony T Tan ◽  
Wan Ni Chia ◽  
Christine YL Tham ◽  
...  

AbstractThe efficacy of virus-specific T cells in clearing pathogens involves a fine balance between their antiviral and inflammatory features. SARS-CoV-2-specific T cells in individuals who clear SARS-CoV-2 infection without symptoms or disease could reveal non-pathological yet protective characteristics. We therefore compared the quantity and function of SARS-CoV-2-specific T cells in a cohort of asymptomatic individuals (n=85) with that of symptomatic COVID-19 patients (n=76), at different time points after antibody seroconversion. We quantified T cells reactive to structural proteins (M, NP and Spike) using ELISpot assays, and measured the magnitude of cytokine secretion (IL-2, IFN-γ, IL-4, IL-6, IL-1β, TNF-α and IL-10) in whole blood following T cell activation with SARS-CoV-2 peptide pools as a functional readout. Frequencies of T cells specific for the different SARS-CoV-2 proteins in the early phases of recovery were similar between asymptomatic and symptomatic individuals. However, we detected an increased IFN-γ and IL-2 production in asymptomatic compared to symptomatic individuals after activation of SARS-CoV-2-specific T cells in blood. This was associated with a proportional secretion of IL-10 and pro-inflammatory cytokines (IL-6, TNF-α and IL-1β) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2-specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2 infected individuals are not characterized by a weak antiviral immunity; on the contrary, they mount a robust and highly functional virus-specific cellular immune response. Their ability to induce a proportionate production of IL-10 might help to reduce inflammatory events during viral clearance.


2015 ◽  
Vol 129 (5) ◽  
pp. 395-404 ◽  
Author(s):  
Xuefen Li ◽  
Li Tian ◽  
Yuejiao Dong ◽  
Qiaoyun Zhu ◽  
Yiyin Wang ◽  
...  

Inhibitory cytokine, interleukin-35 (IL-35), is highly expressed in CD4+ T-cells from CHB patients and plays an important role in the inhibition of the cellular immune response, which contribute to the development and progression of chronic hepatitis B.


2021 ◽  
Vol 218 (5) ◽  
Author(s):  
Nina Le Bert ◽  
Hannah E. Clapham ◽  
Anthony T. Tan ◽  
Wan Ni Chia ◽  
Christine Y.L. Tham ◽  
...  

The efficacy of virus-specific T cells in clearing pathogens involves a fine balance between antiviral and inflammatory features. SARS-CoV-2–specific T cells in individuals who clear SARS-CoV-2 without symptoms could reveal nonpathological yet protective characteristics. We longitudinally studied SARS-CoV-2–specific T cells in a cohort of asymptomatic (n = 85) and symptomatic (n = 75) COVID-19 patients after seroconversion. We quantified T cells reactive to structural proteins (M, NP, and Spike) using ELISpot and cytokine secretion in whole blood. Frequencies of SARS-CoV-2–specific T cells were similar between asymptomatic and symptomatic individuals, but the former showed an increased IFN-γ and IL-2 production. This was associated with a proportional secretion of IL-10 and proinflammatory cytokines (IL-6, TNF-α, and IL-1β) only in asymptomatic infection, while a disproportionate secretion of inflammatory cytokines was triggered by SARS-CoV-2–specific T cell activation in symptomatic individuals. Thus, asymptomatic SARS-CoV-2–infected individuals are not characterized by weak antiviral immunity; on the contrary, they mount a highly functional virus-specific cellular immune response.


2002 ◽  
Vol 76 (12) ◽  
pp. 6093-6103 ◽  
Author(s):  
Eishiro Mizukoshi ◽  
Michelina Nascimbeni ◽  
Joshua B. Blaustein ◽  
Kathleen Mihalik ◽  
Charles M. Rice ◽  
...  

ABSTRACT The chimpanzee is a critical animal model for studying cellular immune responses to infectious pathogens such as hepatitis B and C viruses, human immunodeficiency virus, and malaria. Several candidate vaccines and immunotherapies for these infections aim at the induction or enhancement of cellular immune responses against viral epitopes presented by common human major histocompatibility complex (MHC) alleles. To identify and characterize chimpanzee MHC class I molecules that are functionally related to human alleles, we sequenced 18 different Pan troglodytes (Patr) alleles of 14 chimpanzees, 2 of them previously unknown and 3 with only partially reported sequences. Comparative analysis of Patr binding pockets and binding assays with biotinylated peptides demonstrated a molecular homology between the binding grooves of individual Patr alleles and the common human alleles HLA-A1, -A2, -A3, and -B7. Using cytotoxic T cells isolated from the blood of hepatitis C virus (HCV)-infected chimpanzees, we then mapped the Patr restriction of these HCV peptides and demonstrated functional homology between the Patr-HLA orthologues in cytotoxicity and gamma interferon (IFN-γ) release assays. Based on these results, 21 HCV epitopes were selected to characterize the chimpanzees' cellular immune response to HCV. In each case, IFN-γ-producing T cells were detectable in the blood after but not prior to HCV infection and were specifically targeted against those HCV peptides predicted by Patr-HLA homology. This study demonstrates a close functional homology between individual Patr and HLA alleles and shows that HCV infection generates HCV peptides that are recognized by both chimpanzees and humans with Patr and HLA orthologues. These results are relevant for the design and evaluation of vaccines in chimpanzees that can now be selected according to the most frequent human MHC haplotypes.


2004 ◽  
Vol 189 (7) ◽  
pp. 1199-1208 ◽  
Author(s):  
Annette Oxenius ◽  
David A. Price ◽  
Martin Hersberger ◽  
Erika Schlaepfer ◽  
Rainer Weber ◽  
...  

2000 ◽  
Vol 191 (1) ◽  
pp. 157-170 ◽  
Author(s):  
Hitoshi Nishimura ◽  
Toshiki Yajima ◽  
Yoshikazu Naiki ◽  
Hironaka Tsunobuchi ◽  
Masayuki Umemura ◽  
...  

At least two types of interleukin (IL)-15 mRNA isoforms are generated by alternative splicing at the 5′ upstream of exon 5 in mice. To elucidate the potential roles of IL-15 isoforms in immune responses in vivo, we constructed two groups of transgenic mice using originally described IL-15 cDNA with a normal exon 5 (normal IL-15 transgenic [Tg] mice) and IL-15 cDNA with an alternative exon 5 (alternative IL-15 Tg mice) under the control of an MHC class I promoter. Normal IL-15 Tg mice constitutionally produced a significant level of IL-15 protein and had markedly increased numbers of memory type (CD44high Ly6C+) of CD8+ T cells in the LN. These mice showed resistance to Salmonella infection accompanied by the enhanced interferon (IFN)-γ production, but depletion of CD8+ T cells exaggerated the bacterial growth, suggesting that the IL-15–dependent CD8+ T cells with a memory phenotype may serve to protect against Salmonella infection in normal IL-15 Tg mice. On the other hand, a large amount of intracellular IL-15 protein was detected but hardly secreted extracellularly in alternative IL-15 Tg mice. Although most of the T cells developed normally in the alternative IL-15 Tg mice, they showed impaired IFN-γ production upon TCR engagement. The alternative IL-15 transgenic mice were susceptible to Salmonella accompanied by impaired production of endogenous IL-15 and IFN-γ. Thus, two groups of IL-15 Tg mice may provide information concerning the different roles of IL-15 isoforms in the immune system in vivo.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1384
Author(s):  
Haibo Feng ◽  
Jie Yang ◽  
Hui Zhi ◽  
Xin Hu ◽  
Yan Yang ◽  
...  

In this investigation, to maximize the desired immunoenhancement effects of PsEUL and stimulate an efficient humoral and cellular immune response against an antigen, PsEUL and the model antigen ovalbumin (OVA) were coupled using the N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) reaction to yield a novel delivery system (PsEUL-OVA). The physicochemical characteristics and immune regulation effects of this new system were investigated. We found the yield of this EDC method to be 46.25%. In vitro, PsEUL-OVA (200 μg mL−1) could enhance macrophage proliferation and increase their phagocytic efficiency. In vivo, PsEUL-OVA could significantly increase the levels of OVA-specific antibody (IgG, IgG1, IgG2a, and IgG2b) titers and cytokine (IL-2, IL-4, IL-6, IFN-γ) levels. Additionally, it could activate T lymphocytes and facilitate the maturation of dendritic cells (DCs). These findings collectively suggested that PsEUL-OVA induced humoral and cellular immune responses by promoting the phagocytic activity of macrophages and DCs. Taken together, these results revealed that PsEUL-OVA had the potential to improve immune responses and provide a promising theoretical basis for the design of a novel delivery system.


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