scholarly journals Mechanisms of Hepatocellular Injury in Hepatitis A

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 861
Author(s):  
Minghang Wang ◽  
Zongdi Feng
Keyword(s):  
T Cells ◽  
Liver Injury ◽  
Hepatitis A ◽  
Acute Viral Hepatitis ◽  
Hepatitis A Virus ◽  
Current Knowledge ◽  
Cytotoxic T Cells ◽  
Host Factors ◽  
Hepatocellular Injury

Hepatitis A virus (HAV) infection is a common cause of acute viral hepatitis worldwide. Despite decades of research, the pathogenic mechanisms of hepatitis A remain incompletely understood. As the replication of HAV is noncytopathic in vitro, a widely accepted concept has been that virus-specific cytotoxic T cells are responsible for liver injury. However, accumulating evidence suggests that natural killer (NK) cells, NKT cells, and even non-HAV-specific CD8+ T cells contribute to liver damage during HAV infection. In addition, intrinsic death of virus-infected hepatocytes has been implicated as a cause of liver injury in a murine model of hepatitis A. Furthermore, genetic variations in host factors such as T cell immunoglobulin-1 (TIM1) and IL-18 binding protein (IL-18BP) have been linked to hepatitis A severity. This review summarizes the current knowledge of the mechanisms of hepatocellular injury in hepatitis A. Different mechanisms may be involved under different conditions and they are not necessarily mutually exclusive. A better understanding of these mechanisms would aid in diagnosis and treatment of diseases associated with HAV infection.

Liver-Derived Cytotoxic T Cells in Hepatitis A Virus Infection

1989 ◽  
Vol 160 (2) ◽  
pp. 209-217 ◽  
Author(s):  
A. Vallbracht ◽  
K. Maier ◽  
Y.-D. Stierhof ◽  
K. H. Wiedmann ◽  
B. Flehmig ◽  
...  
Keyword(s):  
T Cells ◽  
Virus Infection ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Cytotoxic T Cells

scholarly journals T cells protect against hepatitis A virus infection and limit infection-induced liver injury

2021 ◽  
Author(s):  
Ichiro Misumi ◽  
Joseph E. Mitchell ◽  
Makayla M. Lund ◽  
John M. Cullen ◽  
Stanley M. Lemon ◽  
...  
Keyword(s):  
T Cells ◽  
Liver Injury ◽  
Virus Infection ◽  
Hepatitis A ◽  
Hepatitis A Virus

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

scholarly journals Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro

2021 ◽  
Vol 22 (15) ◽  
pp. 7906
Author(s):  
Alexey A. Komissarov ◽  
Maria A. Karaseva ◽  
Marina P. Roschina ◽  
Andrey V. Shubin ◽  
Nataliya A. Lunina ◽  
...  
Keyword(s):  
Cell Death ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Proteolytic Enzymes ◽  
Morphological Changes ◽  
Human Cells ◽  
Mitochondrial Potential ◽  
3C Protease ◽  
Wide Range

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.

scholarly journals Human fetal liver MSCs are more effective than adult bone marrow MSCs for their immunosuppressive, immunomodulatory, and Foxp3+ T reg induction capacity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Fetal Liver ◽  
Cytotoxic T Cells ◽  
Cell Contact ◽  
Adult Bone Marrow ◽  
Adult Bone

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.

scholarly journals A genome-wide CRISPR screen identifies UFMylation and TRAMP-like complexes as host factors required for hepatitis A virus infection

Cell Reports ◽  
2021 ◽  
Vol 34 (11) ◽  
pp. 108859
Author(s):  
Jessie Kulsuptrakul ◽  
Ruofan Wang ◽  
Nathan L. Meyers ◽  
Melanie Ott ◽  
Andreas S. Puschnik
Keyword(s):  
Virus Infection ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Host Factors ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen

Influence of twenty potentially antiviral substances on in vitro multiplication of hepatitis a virus

1986 ◽  
Vol 6 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Anders Widell ◽  
Bengt Göran Hansson ◽  
Bo Öberg ◽  
Erik Nordenfelt
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
In Vitro Multiplication

scholarly journals Participation of the H-2 antigens of tumor cells in their lysis by syngeneic T cells.

1976 ◽  
Vol 143 (3) ◽  
pp. 601-614 ◽  
Author(s):  
J W Schrader ◽  
G M Edelman
Keyword(s):  
T Cells ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Target Cell ◽  
Cytotoxic T Cells ◽  
Hybrid Origin ◽  
Target Cells ◽  
Cytotoxic Lymphocytes ◽  
Effector Cells

Cytotoxic T lymphocytes were generated in vitro against H-2 compatible or syngeneic tumor cells. In vitro cytotoxic activity was inhibited by specific anti-H2 sera, suggesting that H-2 antigens are involved in cell lysis. Two observations directly demonstrated the participation of the H-2 antigens on the tumor cells in their lysis by H-2-compatible T cells. First, coating of the H-2 antigens on the target tumor cell reduced the number of cells lysed on subsequent exposure to cytotoxic T cells. Second, when cytotoxic T cells were activated against an H-2 compatible tumor and assayed against an H-2-incompatible tumor, anti-H-2 serum that could bind to the target cell, but not to the cytotoxic lymphocyte, inhibited lysis. H-2 antigens were also shown to be present on the cytotoxic lymphocytes. Specific antisera reacting with these H-2 antigens, but not those of the target cell, failed to inhibit lysis when small numbers of effector cells were assayed against H-2-incompatible target cells or when effector cells of F1-hybrid origin and bearing two H-2 haplotypes were assayed against a tumor cell of one of the parental strains. These findings suggest that it is the H-2 antigens on the tumor cell and not those on the cytotoxic lymphocytes that are important in cell-mediated lysis of H-2-compatible tumor cells.

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