scholarly journals Immune Checkpoints in Viral Infections

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1051
Author(s):  
Huiming Cai ◽  
Ge Liu ◽  
Jianfeng Zhong ◽  
Kai Zheng ◽  
Haitao Xiao ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Cancer Cells ◽  
Antiviral Therapy ◽  
Immune Checkpoint ◽  
Viral Infections ◽  
Immune Checkpoints ◽  
Chronic Viral Infections ◽  
Infected Cells

As evidence has mounted that virus-infected cells, such as cancer cells, negatively regulate the function of T-cells via immune checkpoints, it has become increasingly clear that viral infections similarly exploit immune checkpoints as an immune system escape mechanism. Although immune checkpoint therapy has been successfully used in cancer treatment, numerous studies have suggested that such therapy may also be highly relevant for treating viral infection, especially chronic viral infections. However, it has not yet been applied in this manner. Here, we reviewed recent findings regarding immune checkpoints in viral infections, including COVID-19, and discussed the role of immune checkpoints in different viral infections, as well as the potential for applying immune checkpoint blockades as antiviral therapy.

scholarly journals SARS-CoV-2-specific T cells in infection and vaccination

2021 ◽  
Vol 18 (10) ◽  
pp. 2307-2312 ◽  
Author(s):  
Antonio Bertoletti ◽  
Nina Le Bert ◽  
Martin Qui ◽  
Anthony T. Tan
Keyword(s):  
T Cells ◽  
Adaptive Immunity ◽  
Viral Infections ◽  
Infected Cells

AbstractDuring viral infections, antibodies and T cells act together to prevent pathogen spread and remove virus-infected cells. Virus-specific adaptive immunity can, however, also trigger pathological processes characterized by localized or systemic inflammatory events. The protective and/or pathological role of virus-specific T cells in SARS-CoV-2 infection has been the focus of many studies in COVID-19 patients and in vaccinated individuals. Here, we review the works that have elucidated the function of SARS-CoV-2-specific T cells in patients and in vaccinated individuals. Understanding whether SARS-CoV-2-specific T cells are more linked to protection or pathogenesis is pivotal to define future therapeutic and prophylactic strategies to manage the current pandemic.

scholarly journals The proposed promiscuity value of an HLA can vary significantly depending on the source data used

2021 ◽  
Author(s):  
Jordan Anaya ◽  
Alexander S. Baras
Keyword(s):  
T Cells ◽  
Immune System ◽  
Cancer Cells ◽  
Immune Checkpoint ◽  
Peptide Binding ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Data Types ◽  
Patient Response ◽  
Source Data

ABSTRACTImmune checkpoint blockade, a form of immunotherapy, mobilizes a patient’s own immune system against cancer cells by releasing some of the natural brakes on T cells. Although our understanding of this process is evolving, it is thought that a patient response to immunotherapy requires tumor presentation of neoantigens to T cells and patients whose tumors present a wider array of neoantigens are more likely to derive benefit from immune checkpoint blockade1–4. Manczinger et al.5 recently reported findings that would appear contrarian to this notion in that they suggested patients with HLA alleles which bind more diverse peptides (higher promiscuity) are less likely to respond to immunotherapy. To estimate HLA promiscuity they looked at the HLA-peptide binding repertoires for class I alleles contained in the IEDB6, and obtained consistent results when performing robustness checks and subsequent analyses. Here we show that the proposed HLA promiscuity values can vary significantly across source data types and individual experiments.

scholarly journals Gamma Delta T Cells and Their Involvement in COVID-19 Virus Infections

2021 ◽  
Vol 12 ◽  
Author(s):  
Georg von Massow ◽  
Steve Oh ◽  
Alan Lam ◽  
Kenth Gustafsson
Keyword(s):  
T Cells ◽  
Viral Infections ◽  
Cell Subset ◽  
Γδ T Cells ◽  
Common Symptom ◽  
Virus Infections ◽  
Infected Cells ◽  
The Relationship

The global outbreak of the SARS-Cov-2 virus in 2020 has killed millions of people worldwide and forced large parts of the world into lockdowns. While multiple vaccine programs are starting to immunize the global population, there is no direct cure for COVID-19, the disease caused by the SARS-Cov-2 infection. A common symptom in patients is a decrease in T cells, called lymphopenia. It is as of yet unclear what the exact role of T cells are in the immune response to COVID-19. The research so far has mainly focused on the involvement of classical αβ T cells. However, another subset of T cells called γδ T cells could have an important role to play. As part of the innate immune system, γδ T cells respond to inflammation and stressed or infected cells. The γδ T cell subset appears to be particularly affected by lymphopenia in COVID-19 patients and commonly express activation and exhaustion markers. Particularly in children, this subset of T cells seems to be most affected. This is interesting and relevant because γδ T cells are more prominent and active in early life. Their specific involvement in this group of patients could indicate a significant role for γδ T cells in this disease. Furthermore, they seem to be involved in other viral infections and were able to kill SARS infected cells in vitro. γδ T cells can take up, process and present antigens from microbes and human cells. As e.g. tumour-associated antigens are presented by MHC on γδ T cells to classical T-cells, we argue here that it stands to reason that also viral antigens, such as SARS-Cov-2-derived peptides, can be presented in the same way. γδ T cells are already used for medical purposes in oncology and have potential in cancer therapy. As γδ T cells are not necessarily able to distinguish between a transformed and a virally infected cell it could therefore be of great interest to investigate further the relationship between COVID-19 and γδ T cells.

scholarly journals Current Progress and Future Perspectives of Immune Checkpoint in Cancer and Infectious Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Cai ◽  
Huajie Zhan ◽  
Yuguang Ye ◽  
Jinjin Yang ◽  
Minghui Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Immune Checkpoint ◽  
Current Knowledge ◽  
Checkpoint Inhibitors ◽  
Single Agent ◽  
Immune Checkpoint Blockade ◽  
Immune Checkpoints ◽  
Microbial Infection ◽  
Antiviral Immune Response

The inhibitory regulators, known as immune checkpoints, prevent overreaction of the immune system, avoid normal tissue damage, and maintain immune homeostasis during the antimicrobial or antiviral immune response. Unfortunately, cancer cells can mimic the ligands of immune checkpoints to evade immune surveillance. Application of immune checkpoint blockade can help dampen the ligands expressed on cancer cells, reverse the exhaustion status of effector T cells, and reinvigorate the antitumor function. Here, we briefly introduce the structure, expression, signaling pathway, and targeted drugs of several inhibitory immune checkpoints (PD-1/PD-L1, CTLA-4, TIM-3, LAG-3, VISTA, and IDO1). And we summarize the application of immune checkpoint inhibitors in tumors, such as single agent and combination therapy and adverse reactions. At the same time, we further discussed the correlation between immune checkpoints and microorganisms and the role of immune checkpoints in microbial-infection diseases. This review focused on the current knowledge about the role of the immune checkpoints will help in applying immune checkpoints for clinical therapy of cancer and other diseases.

scholarly journals Hepadnaviral Lymphotropism and Its Relevance to HBV Persistence and Pathogenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Carla S. Coffin ◽  
Patricia M. Mulrooney-Cousins ◽  
Tomasz I. Michalak
Keyword(s):  
Immune System ◽  
Hepatitis B ◽  
Antiviral Therapy ◽  
Immune Cells ◽  
Viral Infections ◽  
Hepatitis Virus ◽  
Viral Persistence ◽  
Lymphoid Cells ◽  
Pathogenic Variants

Since the discovery of hepatitis B virus (HBV) over five decades ago, there have been many independent studies showing presence of HBV genomes in cells of the immune system. However, the nature of HBV lymphotropism and its significance with respect to HBV biology, persistence and the pathogenesis of liver and extrahepatic disorders remains underappreciated. This is in contrast to studies of other viral pathogens in which the capability to infect immune cells is an area of active investigation. Indeed, in some viral infections, lymphotropism may be essential, and even a primary mechanism of viral persistence, and a major contributor to disease pathogenesis. Nevertheless, there are advances in understanding of HBV lymphotropism in recent years due to cumulative evidence showing that: (i) lymphoid cells are a reservoir of replicating HBV, (ii) are a site of HBV-host DNA integration and (iii) virus genomic diversification leading to pathogenic variants, and (iv) they play a role in HBV resistance to antiviral therapy and (v) likely contribute to reactivation of hepatitis B. Further support for HBV lymphotropic nature is provided by studies in a model infection with the closely related woodchuck hepatitis virus (WHV) naturally infecting susceptible marmots. This animal model faithfully reproduces many aspects of HBV biology, including its replication scheme, tissue tropism, and induction of both symptomatic and silent infections, immunological processes accompanying infection, and progressing liver disease culminating in hepatocellular carcinoma. The most robust evidence came from the ability of WHV to establish persistent infection of the immune system that may not engage the liver when small quantities of virus are experimentally administered or naturally transmitted into virus-naïve animals. Although the concept of HBV lymphotropism is not new, it remains controversial and not accepted by conventional HBV researchers. This review summarizes research advances on HBV and hepadnaviral lymphotropism including the role of immune cells infection in viral persistence and the pathogenesis of HBV-induced liver and extrahepatic diseases. Finally, we discuss the role of immune cells in HBV diagnosis and assessment of antiviral therapy efficacy.

Role of Tim-3 in regulating tumorigenesis, inflammation, and antitumor immunity therapy

2021 ◽  
pp. 1-12
Author(s):  
Yuting Cao ◽  
Qiang Li ◽  
Huihui Liu ◽  
Xianglei He ◽  
Fang Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Viral Infections ◽  
Checkpoint Inhibitors ◽  
Innate Immune ◽  
The Past ◽  
Chronic Viral Infections ◽  
Antitumor Potential ◽  
Programmed Cell Death 1 ◽  
Ifn Γ

Over the past decade, cancer immunotherapy, such as immune checkpoint inhibitors (ICRs), has attained considerable progresses in clinical practice. T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) act as next ICRs, and originally function as a co-inhibitory receptor expressed on interferon (IFN)-γ producing CD4+ and CD8+ T-cells. Furthermore, Tim-3 has also been found to express on innate immune cells and several types of tumors, signifying the pivotal role that Tim-3 plays in chronic viral infections and cancer. In addition, Tim-3 and multiple ICRs are concurrently expressed and regulated on dysfunctional or exhausted T-cells, leading to improved antitumor immune responses in preclinical or clinical cancer therapy through co-blockade of Tim-3 and other ICRs such as programmed cell death-1 (PD-1). In this review, the biological characteristics of Tim-3 and the function of Tim-3 in regulating tumorigenesis and inflammation have been summarized. The usage of a single blockade of Tim-3 or in combination with multiple immunotherapy regimens have drawn attention to antitumor potential as a target for immunotherapy.

scholarly journals A review on immune checkpoint blockage therapy

2020 ◽  
Vol 2 (1) ◽  
pp. 12-17
Author(s):  
Thamrook s Shajahan ◽  
Shaiju S Dharan ◽  
Merlin Nj
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Cancer Cells ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Immune Cell ◽  
Checkpoint Inhibitor ◽  
Checkpoint Inhibitors ◽  
The Body

Activating the immune system to eliminate cancer cells and produce clinically relevant response has been a long standing goal of cancer research. Most promising therapeutic approaches of activating antitumor immunity include immune checkpoint inhibitors. Our immune system protect us from disease, killing bacteria and virus. One main type of immune cell called T-cells. T-cells have protein that turn it off. These are called checkpoint. Immune checkpoint are accessory molecules that either promote or inhibit T-cell activation. Checkpoint inhibitor are a type of immunotherapy. They block protein that stops the immune system from attacking the cancer cells. Checkpoint inhibitor are a type of monoclonal antibody or targeted treatment. Immune system cells, such as T-cells and Antigen presenting cells (APCs), defend and protect the body. Immune system play an important role in controlling and eradicating cancer. Cytotoxic T lymphocytes associated protein 4(CTLA-4) and Programmed cell dealth protein (PD-1) are checkpoint protein which is the negative regulation of T-cell immune function. Inhibition of the target, results in increased activation of immune system.

scholarly journals Telomerase activity of HIV-1–specific CD8+ T cells: constitutive up-regulation in controllers and selective increase by blockade of PD ligand 1 in progressors

Blood ◽  
2008 ◽  
Vol 112 (9) ◽  
pp. 3679-3687 ◽  
Author(s):  
Mathias Lichterfeld ◽  
Danlei Mou ◽  
Thai Duong Hong Cung ◽  
Katie L. Williams ◽  
Michael T. Waring ◽  
...  
Keyword(s):  
T Cells ◽  
Telomere Length ◽  
Cd8 T Cells ◽  
Viral Infections ◽  
Telomerase Activity ◽  
Barr Virus ◽  
Chronic Viral Infections ◽  
Epstein Barr ◽  
Hiv 1

Abstract Exhaustion of virus-specific T cells may play an important role in the pathophysiology of chronic viral infections. Here, we analyzed telomere length and telomerase activity in HIV-1–specific CD8+ T cells from progressors or controllers to determine underlying molecular pathways of T-cell exhaustion and senescence. Telomere lengths of HIV-1–specific CD8+ T cells from progressors were significantly shorter compared with autologous cytomegalovirus (CMV)/Epstein-Barr virus (EBV)–specific CD8+ T cells or bulk CD8+ T cells, while telomere lengths from controllers significantly exceeded those of autologous bulk CD8+ T cells and reached a similar level as HIV-1–specific CD8+ T cells collected during primary HIV-1 infection. Telomere length stabilization in controllers corresponded to high levels of constitutive telomerase activity, which was associated with preservation of cytotoxic and proliferative properties. Conversely, limited constitutive telomerase activity was observed in HIV-1–specific CD8+ T cells from progressors, although an increase in both telomere length and telomerase activity was achieved in antigenic-peptide–stimulated cells from progressors after blocking the PD-1/PD ligand 1 (PD-L1) pathway. Collectively, these data suggest a causal role of telomere shortening for the functional deficiencies of HIV-1–specific CD8+ T cells in chronic progressive infection, while high constitutive telomerase activities appears to contribute to maintenance of polyfunctional HIV-1–specific CD8+ T cells from HIV-1 controllers.

scholarly journals Implications for Treatment Strategies in Cancer and Infectious Diseases

2021 ◽  
pp. 121-159
Author(s):  
Elena Locci ◽  
Silvia Raymond
Keyword(s):  
T Cells ◽  
Immune System ◽  
Infectious Diseases ◽  
Cancer Cells ◽  
Viral Infections ◽  
Treatment Strategies ◽  
Treatment Management ◽  
New Therapies ◽  
Long Time ◽  
Keywords Cancer

It is widely known that severe viral infections and cancer disrupt the immune system, including T cells, a process called "immune fatigue." Overcoming immune depletion is the main goal of developing new therapies for cancer or severe viral infections. Called Tpex cells, they can maintain their function for a long time. Keywords: Cancer; Cells; Tissues, Tumors; Prevention, Prognosis; Diagnosis; Imaging; Screening; Treatment; Management

scholarly journals Overcoming Immune Depletion is the Main Goal of Developing New Therapies for Cancer or Severe Viral Infections

2021 ◽  
pp. 100-140
Author(s):  
Ricardo Gobato ◽  
Abhijit Mitra
Keyword(s):  
T Cells ◽  
Immune System ◽  
Cancer Cells ◽  
Viral Infections ◽  
Treatment Management ◽  
New Therapies ◽  
Long Time ◽  
Keywords Cancer

It is widely known that severe viral infections and cancer disrupt the immune system, including T cells, a process called "immune fatigue." Overcoming immune depletion is the main goal of developing new therapies for cancer or severe viral infections. Called Apex cells, they can maintain their function for a long time. Keywords: Cancer; Cells; Tissues; Tumors; Prevention; Prognosis; Diagnosis; Imaging; Screening, Treatment; Management

Sign in / Sign up

Export Citation Format

Share Document