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1.
Front Cell Infect Microbiol ; 10: 596166, 2020.
Article in English | MEDLINE | ID: covidwho-1574497

ABSTRACT

Viral infections continue to cause considerable morbidity and mortality around the world. Recent rises in these infections are likely due to complex and multifactorial external drivers, including climate change, the increased mobility of people and goods and rapid demographic change to name but a few. In parallel with these external factors, we are gaining a better understanding of the internal factors associated with viral immunity. Increasingly the gastrointestinal (GI) microbiome has been shown to be a significant player in the host immune system, acting as a key regulator of immunity and host defense mechanisms. An increasing body of evidence indicates that disruption of the homeostasis between the GI microbiome and the host immune system can adversely impact viral immunity. This review aims to shed light on our understanding of how host-microbiota interactions shape the immune system, including early life factors, antibiotic exposure, immunosenescence, diet and inflammatory diseases. We also discuss the evidence base for how host commensal organisms and microbiome therapeutics can impact the prevention and/or treatment of viral infections, such as viral gastroenteritis, viral hepatitis, human immunodeficiency virus (HIV), human papilloma virus (HPV), viral upper respiratory tract infections (URTI), influenza and SARS CoV-2. The interplay between the gastrointestinal microbiome, invasive viruses and host physiology is complex and yet to be fully characterized, but increasingly the evidence shows that the microbiome can have an impact on viral disease outcomes. While the current evidence base is informative, further well designed human clinical trials will be needed to fully understand the array of immunological mechanisms underlying this intricate relationship.


Subject(s)
Dysbiosis/virology , Microbiota/immunology , Probiotics/therapeutic use , Virus Diseases/immunology , Virus Diseases/microbiology , Animals , COVID-19/immunology , Dysbiosis/immunology , Gastrointestinal Microbiome/immunology , Host Microbial Interactions , Humans , SARS-CoV-2/isolation & purification , Viral Vaccines/administration & dosage , Viral Vaccines/immunology
2.
Viruses ; 13(12)2021 11 27.
Article in English | MEDLINE | ID: covidwho-1574265

ABSTRACT

Modulation of the antiviral innate immune response has been proposed as a putative cellular target for the development of novel pan-viral therapeutic strategies. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is especially relevant due to its essential role in the regulation of local and systemic inflammation in response to viral infections, being, therefore, a putative therapeutic target. Here, we review the extraordinary diversity of strategies that viruses have evolved to interfere with JAK-STAT signaling, stressing the relevance of this pathway as a putative antiviral target. Moreover, due to the recent remarkable progress on the development of novel JAK inhibitors (JAKi), the current knowledge on its efficacy against distinct viral infections is also discussed. JAKi have a proven efficacy against a broad spectrum of disorders and exhibit safety profiles comparable to biologics, therefore representing good candidates for drug repurposing strategies, including viral infections.


Subject(s)
Janus Kinases/metabolism , STAT Transcription Factors/metabolism , Signal Transduction/drug effects , Virus Diseases/metabolism , Viruses/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Humans , Immunity, Innate , Inflammation , Janus Kinase Inhibitors/pharmacology , Janus Kinase Inhibitors/therapeutic use , Janus Kinases/antagonists & inhibitors , Virus Diseases/drug therapy , Virus Diseases/immunology , Viruses/classification , Viruses/drug effects
3.
J Med Virol ; 93(12): 6798-6802, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1530182

ABSTRACT

Viral infections have been on the rise for the past decades. The impact of the viruses worsened amidst the pandemic burdening the already overwhelmed health care system in African countries. This article sheds light on how the coronavirus together with the already existing viral infections, some of which re-emerged, impacted the continent. The strategies in place such as immunization, education, will have to be strengthened in all African countries to reduce the burden. Furthermore, governments can further collaborate with other countries in creating guidelines to reduce co-infection of the diseases.


Subject(s)
COVID-19/enzymology , COVID-19/virology , Coinfection/epidemiology , Coinfection/virology , Virus Diseases/epidemiology , Africa/epidemiology , COVID-19/immunology , Coinfection/immunology , Humans , Pandemics/prevention & control , SARS-CoV-2/immunology , Vaccination/methods , Virus Diseases/immunology , Virus Diseases/virology
4.
PLoS Pathog ; 17(9): e1009811, 2021 09.
Article in English | MEDLINE | ID: covidwho-1526706
5.
Antioxid Redox Signal ; 35(16): 1376-1392, 2021 12.
Article in English | MEDLINE | ID: covidwho-1510864

ABSTRACT

Significance: It is estimated that close to 50 million cases of sepsis result in over 11 million annual fatalities worldwide. The pathognomonic feature of sepsis is a dysregulated inflammatory response arising from viral, bacterial, or fungal infections. Immune recognition of pathogen-associated molecular patterns is a hallmark of the host immune defense to combat microbes and to prevent the progression to sepsis. Mitochondrial antiviral signaling protein (MAVS) is a ubiquitous adaptor protein located at the outer mitochondrial membrane, which is activated by the cytosolic pattern recognition receptors, retinoic acid-inducible gene I (RIG-I) and melanoma differentiation associated gene 5 (MDA5), following binding of viral RNA agonists. Recent Advances: Substantial progress has been made in deciphering the activation of the MAVS pathway with its interacting proteins, downstream signaling events (interferon [IFN] regulatory factors, nuclear factor kappa B), and context-dependent type I/III IFN response. Critical Issues: In the evolutionary race between pathogens and the host, viruses have developed immune evasion strategies for cleavage, degradation, or blockade of proteins in the MAVS pathway. For example, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) M protein and ORF9b protein antagonize MAVS signaling and a protective type I IFN response. Future Directions: The role of MAVS as a sensor for nonviral pathogens, host cell injury, and metabolic perturbations awaits better characterization in the future. New technical advances in multidimensional single-cell analysis and single-molecule methods will accelerate the rate of new discoveries. The ultimate goal is to manipulate MAVS activities in the form of immune-modulatory therapies to combat infections and sepsis. Antioxid. Redox Signal. 35, 1376-1392.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Sepsis/immunology , Signal Transduction/immunology , Virus Diseases/immunology , Animals , Host-Pathogen Interactions/immunology , Humans , Immune Evasion/immunology , Sepsis/virology
6.
J Virol ; 95(12)2021 05 24.
Article in English | MEDLINE | ID: covidwho-1501541

ABSTRACT

Long disregarded as junk DNA or genomic dark matter, endogenous retroviruses (ERVs) have turned out to represent important components of the antiviral immune response. These remnants of once-infectious retroviruses not only regulate cellular immune activation, but may even directly target invading viral pathogens. In this Gem, we summarize mechanisms by which retroviral fossils protect us from viral infections. One focus will be on recent advances in the role of ERVs as regulators of antiviral gene expression.


Subject(s)
Endogenous Retroviruses/physiology , Retroelements , Virus Diseases/immunology , Animals , Endogenous Retroviruses/genetics , Enhancer Elements, Genetic , Gene Expression Regulation , Humans , Immunity, Cellular , Promoter Regions, Genetic , RNA, Double-Stranded/genetics , RNA, Double-Stranded/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , Receptors, Pattern Recognition/metabolism , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/metabolism , Viral Proteins/metabolism , Virion/metabolism , Virus Diseases/genetics , Virus Diseases/virology
7.
Int J Mol Sci ; 22(20)2021 Oct 19.
Article in English | MEDLINE | ID: covidwho-1477961

ABSTRACT

Chronic diseases and viral infections have threatened human life over the ages and constitute the main reason for increasing death globally. The rising burden of these diseases extends to negatively affecting the economy and trading globally, as well as daily life, which requires inexpensive, novel, and safe therapeutics. Therefore, scientists have paid close attention to probiotics as safe remedies to combat these morbidities owing to their health benefits and biotherapeutic effects. Probiotics have been broadly adopted as functional foods, nutraceuticals, and food supplements to improve human health and prevent some morbidity. Intriguingly, recent research indicates that probiotics are a promising solution for treating and prophylactic against certain dangerous diseases. Probiotics could also be associated with their essential role in animating the immune system to fight COVID-19 infection. This comprehensive review concentrates on the newest literature on probiotics and their metabolism in treating life-threatening diseases, including immune disorders, pathogens, inflammatory and allergic diseases, cancer, cardiovascular disease, gastrointestinal dysfunctions, and COVID-19 infection. The recent information in this report will particularly furnish a platform for emerging novel probiotics-based therapeutics as cheap and safe, encouraging researchers and stakeholders to develop innovative treatments based on probiotics to prevent and treat chronic and viral diseases.


Subject(s)
Chronic Disease/therapy , Probiotics/administration & dosage , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/therapy , Fatty Acids, Volatile/metabolism , Gastrointestinal Microbiome , Humans , Immune System/metabolism , Inflammation/metabolism , Inflammation/pathology , Neoplasms/metabolism , Neoplasms/therapy , Virus Diseases/immunology , Virus Diseases/metabolism , Virus Diseases/therapy
8.
Clin Sci (Lond) ; 135(19): 2217-2242, 2021 10 14.
Article in English | MEDLINE | ID: covidwho-1462047

ABSTRACT

The ability of dendritic cells (DCs) to sense viral pathogens and orchestrate a proper immune response makes them one of the key players in antiviral immunity. Different DC subsets have complementing functions during viral infections, some specialize in antigen presentation and cross-presentation and others in the production of cytokines with antiviral activity, such as type I interferons. In this review, we summarize the latest updates concerning the role of DCs in viral infections, with particular focus on the complex interplay between DC subsets and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Despite being initiated by a vast array of immune receptors, DC-mediated antiviral responses often converge towards the same endpoint, that is the production of proinflammatory cytokines and the activation of an adaptive immune response. Nonetheless, the inherent migratory properties of DCs make them a double-edged sword and often viral recognition by DCs results in further viral dissemination. Here we illustrate these various aspects of the antiviral functions of DCs and also provide a brief overview of novel antiviral vaccination strategies based on DCs targeting.


Subject(s)
COVID-19/virology , Dendritic Cells/virology , Receptors, Pattern Recognition/immunology , SARS-CoV-2/pathogenicity , Virus Diseases/virology , Cytokines/immunology , Dendritic Cells/immunology , Humans , Virus Diseases/immunology
9.
Acta Med Acad ; 49(2): 130-143, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-1414828

ABSTRACT

In this review, we discuss the latest developments in research pertaining to virus-induced asthma exacerbations and consider recent advances in treatment options. Asthma is a chronic disease of the airways that continues to impose a substantial clinical burden worldwide. Asthma exacerbations, characterised by an acute deterioration in respiratory symptoms and airflow obstruction, are associated with significant morbidity and mortality. These episodes are most commonly triggered by respiratory virus infections. The mechanisms underlying the pathogenesis of virus-induced exacerbations have been the focus of extensive biomedical research. Developing a robust understanding of the interplay between respiratory viruses and the host immune response will be critical for developing more efficacious, targeted therapies for exacerbations. CONCLUSION: There has been significant recent progress in our understanding of the mechanisms underlying virus-induced airway inflammation in asthma and these advances will underpin the development of future clinical therapies.


Subject(s)
Anti-Asthmatic Agents/therapeutic use , Antiviral Agents/therapeutic use , Asthma/drug therapy , Respiratory Tract Infections/drug therapy , Virus Diseases/drug therapy , Adenovirus Infections, Human/drug therapy , Adenovirus Infections, Human/immunology , Adenovirus Infections, Human/physiopathology , Administration, Inhalation , Asthma/immunology , Asthma/physiopathology , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Coronavirus Infections/physiopathology , Disease Progression , Humans , Influenza, Human/drug therapy , Influenza, Human/immunology , Influenza, Human/physiopathology , Interferon-beta/therapeutic use , Macrolides/therapeutic use , Omalizumab/therapeutic use , Paramyxoviridae Infections/drug therapy , Paramyxoviridae Infections/immunology , Paramyxoviridae Infections/physiopathology , Picornaviridae Infections/drug therapy , Picornaviridae Infections/immunology , Picornaviridae Infections/physiopathology , Respiratory Syncytial Virus Infections/drug therapy , Respiratory Syncytial Virus Infections/immunology , Respiratory Syncytial Virus Infections/physiopathology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/physiopathology , Virus Diseases/immunology , Virus Diseases/physiopathology
10.
J Clin Invest ; 131(11)2021 06 01.
Article in English | MEDLINE | ID: covidwho-1448082

ABSTRACT

First administered to a human subject as a tuberculosis (TB) vaccine on July 18, 1921, Bacillus Calmette-Guérin (BCG) has a long history of use for the prevention of TB and later the immunotherapy of bladder cancer. For TB prevention, BCG is given to infants born globally across over 180 countries and has been in use since the late 1920s. With about 352 million BCG doses procured annually and tens of billions of doses having been administered over the past century, it is estimated to be the most widely used vaccine in human history. While its roles for TB prevention and bladder cancer immunotherapy are widely appreciated, over the past century, BCG has been also studied for nontraditional purposes, which include (a) prevention of viral infections and nontuberculous mycobacterial infections, (b) cancer immunotherapy aside from bladder cancer, and (c) immunologic diseases, including multiple sclerosis, type 1 diabetes, and atopic diseases. The basis for these heterologous effects lies in the ability of BCG to alter immunologic set points via heterologous T cell immunity, as well as epigenetic and metabolomic changes in innate immune cells, a process called "trained immunity." In this Review, we provide an overview of what is known regarding the trained immunity mechanism of heterologous protection, and we describe the current knowledge base for these nontraditional uses of BCG.


Subject(s)
Diabetes Mellitus, Type 1/therapy , Immunity, Cellular , Multiple Sclerosis/therapy , Mycobacterium bovis/immunology , T-Lymphocytes/immunology , Urinary Bladder Neoplasms/therapy , Virus Diseases/therapy , Animals , Diabetes Mellitus, Type 1/history , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 1/pathology , History, 20th Century , History, 21st Century , Humans , Multiple Sclerosis/history , Multiple Sclerosis/immunology , Multiple Sclerosis/pathology , Mycobacterium Infections, Nontuberculous/history , Mycobacterium Infections, Nontuberculous/immunology , Mycobacterium Infections, Nontuberculous/pathology , Mycobacterium Infections, Nontuberculous/prevention & control , Tuberculosis/history , Tuberculosis/immunology , Tuberculosis/prevention & control , Urinary Bladder Neoplasms/history , Urinary Bladder Neoplasms/immunology , Urinary Bladder Neoplasms/pathology , Virus Diseases/history , Virus Diseases/immunology , Virus Diseases/pathology
11.
Front Immunol ; 12: 624293, 2021.
Article in English | MEDLINE | ID: covidwho-1394756

ABSTRACT

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, which interacts with a wide range of organic molecules of endogenous and exogenous origin, including environmental pollutants, tryptophan metabolites, and microbial metabolites. The activation of AHR by these agonists drives its translocation into the nucleus where it controls the expression of a large number of target genes that include the AHR repressor (AHRR), detoxifying monooxygenases (CYP1A1 and CYP1B1), and cytokines. Recent advances reveal that AHR signaling modulates aspects of the intrinsic, innate and adaptive immune response to diverse microorganisms. This review will focus on the increasing evidence supporting a role for AHR as a modulator of the host response to viral infection.


Subject(s)
Adaptive Immunity , Immunity, Innate , Receptors, Aryl Hydrocarbon/metabolism , Virus Diseases/virology , Viruses/immunology , Active Transport, Cell Nucleus , Animals , Gene Expression Regulation , Host-Pathogen Interactions , Humans , Ligands , Signal Transduction , Virus Diseases/genetics , Virus Diseases/immunology , Virus Diseases/metabolism , Viruses/genetics , Viruses/pathogenicity
12.
Int J Mol Sci ; 22(6)2021 Mar 13.
Article in English | MEDLINE | ID: covidwho-1389393

ABSTRACT

As most recently demonstrated by the SARS-CoV-2 pandemic, congenital and perinatal infections are of significant concern to the pregnant population as compared to the general population. These outcomes can range from no apparent impact all the way to spontaneous abortion or fetal infection with long term developmental consequences. While some pathogens have developed mechanisms to cross the placenta and directly infect the fetus, other pathogens lead to an upregulation in maternal or placental inflammation that can indirectly cause harm. The placenta is a temporary, yet critical organ that serves multiple important functions during gestation including facilitation of fetal nutrition, oxygenation, and prevention of fetal infection in utero. Here, we review trophoblast cell immunology and the molecular mechanisms utilized to protect the fetus from infection. Lastly, we discuss consequences in the placenta when these protections fail and the histopathologic result following infection.


Subject(s)
Immunity , Placenta/immunology , Placenta/virology , Pregnancy Complications, Infectious/immunology , Pregnancy Complications, Infectious/virology , Virus Diseases/immunology , Viruses/immunology , Female , Fetus/immunology , Fetus/virology , Humans , Placenta/pathology , Pregnancy , Trophoblasts/immunology , Trophoblasts/virology
13.
Immunity ; 54(4): 753-768.e5, 2021 04 13.
Article in English | MEDLINE | ID: covidwho-1385739

ABSTRACT

Viral infections induce a conserved host response distinct from bacterial infections. We hypothesized that the conserved response is associated with disease severity and is distinct between patients with different outcomes. To test this, we integrated 4,780 blood transcriptome profiles from patients aged 0 to 90 years infected with one of 16 viruses, including SARS-CoV-2, Ebola, chikungunya, and influenza, across 34 cohorts from 18 countries, and single-cell RNA sequencing profiles of 702,970 immune cells from 289 samples across three cohorts. Severe viral infection was associated with increased hematopoiesis, myelopoiesis, and myeloid-derived suppressor cells. We identified protective and detrimental gene modules that defined distinct trajectories associated with mild versus severe outcomes. The interferon response was decoupled from the protective host response in patients with severe outcomes. These findings were consistent, irrespective of age and virus, and provide insights to accelerate the development of diagnostics and host-directed therapies to improve global pandemic preparedness.


Subject(s)
Immunity/genetics , Virus Diseases/immunology , Antigen Presentation/genetics , Cohort Studies , Hematopoiesis/genetics , Humans , Interferons/blood , Killer Cells, Natural/immunology , Killer Cells, Natural/pathology , Myeloid Cells/immunology , Myeloid Cells/pathology , Prognosis , Severity of Illness Index , Systems Biology , Transcriptome , Virus Diseases/blood , Virus Diseases/classification , Virus Diseases/genetics , Viruses/classification , Viruses/pathogenicity
14.
Cells ; 10(7)2021 07 20.
Article in English | MEDLINE | ID: covidwho-1389305

ABSTRACT

Microglia are the resident immune cells of the central nervous system contributing substantially to health and disease. There is increasing evidence that inflammatory microglia may induce or accelerate brain aging, by interfering with physiological repair and remodeling processes. Many viral infections affect the brain and interfere with microglia functions, including human immune deficiency virus, flaviviruses, SARS-CoV-2, influenza, and human herpes viruses. Especially chronic viral infections causing low-grade neuroinflammation may contribute to brain aging. This review elucidates the potential role of various neurotropic viruses in microglia-driven neurocognitive deficiencies and possibly accelerated brain aging.


Subject(s)
Aging , Brain/physiopathology , Inflammation/physiopathology , Microglia/virology , Virus Diseases/physiopathology , Animals , Brain/immunology , Brain/virology , COVID-19/immunology , COVID-19/physiopathology , COVID-19/virology , Humans , Inflammation/immunology , Inflammation/virology , Microglia/immunology , Microglia/pathology , SARS-CoV-2/physiology , Virus Diseases/immunology , Virus Diseases/virology
15.
Front Immunol ; 12: 659419, 2021.
Article in English | MEDLINE | ID: covidwho-1389180

ABSTRACT

Highly pathogenic virus infections usually trigger cytokine storms, which may have adverse effects on vital organs and result in high mortalities. The two cytokines interleukin (IL)-4 and interferon (IFN)-γ play key roles in the generation and regulation of cytokine storms. However, it is still unclear whether the cytokine with the largest induction amplitude is the same under different virus infections. It is unknown which is the most critical and whether there are any mathematical formulas that can fit the changing rules of cytokines. Three coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2), three influenza viruses (2009H1N1, H5N1 and H7N9), Ebola virus, human immunodeficiency virus, dengue virus, Zika virus, West Nile virus, hepatitis B virus, hepatitis C virus, and enterovirus 71 were included in this analysis. We retrieved the cytokine fold change (FC), viral load, and clearance rate data from these highly pathogenic virus infections in humans and analyzed the correlations among them. Our analysis showed that interferon-inducible protein (IP)-10, IL-6, IL-8 and IL-17 are the most common cytokines with the largest induction amplitudes. Equations were obtained: the maximum induced cytokine (max) FC = IFN-γ FC × (IFN-γ FC/IL-4 FC) (if IFN-γ FC/IL-4 FC > 1); max FC = IL-4 FC (if IFN-γ FC/IL-4 FC < 1). For IFN-γ-inducible infections, 1.30 × log2 (IFN-γ FC) = log10 (viral load) - 2.48 - 2.83 × (clearance rate). The clinical relevance of cytokines and their antagonists is also discussed.


Subject(s)
Cytokine Release Syndrome/immunology , Cytokines/blood , Models, Immunological , Virus Diseases/complications , Biomarkers/blood , Biomarkers/metabolism , Cytokine Release Syndrome/blood , Cytokine Release Syndrome/diagnosis , Cytokine Release Syndrome/virology , Cytokines/immunology , Cytokines/metabolism , Humans , Viral Load/immunology , Virus Diseases/blood , Virus Diseases/immunology , Virus Diseases/virology
16.
EMBO Rep ; 22(11): e52948, 2021 11 04.
Article in English | MEDLINE | ID: covidwho-1381494

ABSTRACT

The type I interferon (IFN) response is the major host arsenal against invading viruses. IRGM is a negative regulator of IFN responses under basal conditions. However, the role of human IRGM during viral infection has remained unclear. In this study, we show that IRGM expression is increased upon viral infection. IFN responses induced by viral PAMPs are negatively regulated by IRGM. Conversely, IRGM depletion results in a robust induction of key viral restriction factors including IFITMs, APOBECs, SAMHD1, tetherin, viperin, and HERC5/6. Additionally, antiviral processes such as MHC-I antigen presentation and stress granule signaling are enhanced in IRGM-deficient cells, indicating a robust cell-intrinsic antiviral immune state. Consistently, IRGM-depleted cells are resistant to the infection with seven viruses from five different families, including Togaviridae, Herpesviridae, Flaviviverdae, Rhabdoviridae, and Coronaviridae. Moreover, we show that Irgm1 knockout mice are highly resistant to chikungunya virus (CHIKV) infection. Altogether, our work highlights IRGM as a broad therapeutic target to promote defense against a large number of human viruses, including SARS-CoV-2, CHIKV, and Zika virus.


Subject(s)
GTP-Binding Proteins/antagonists & inhibitors , Virus Diseases/immunology , Animals , Antiviral Agents/pharmacology , Humans , Mice , Virus Replication
17.
PLoS One ; 16(8): e0249484, 2021.
Article in English | MEDLINE | ID: covidwho-1379827

ABSTRACT

The human adaptive immune system must generate extraordinary diversity to be able to respond to all possible pathogens. The T-cell repertoire derives this high diversity through somatic recombination of the T-cell receptor (TCR) locus, a random process that results in repertoires that are largely private to each individual. However, factors such as thymic selection and T-cell proliferation upon antigen exposure can affect TCR sharing among individuals. By immunosequencing the TCRß variable region of 426 healthy individuals, we find that, on average, fewer than 1% of TCRß clones are shared between individuals, consistent with largely private TCRß repertoires. However, we detect a significant correlation between increased HLA allele sharing and increased number of shared TCRß clones, with each additional shared HLA allele contributing to an increase in ~0.01% of the total shared TCRß clones, supporting a key role for HLA type in shaping the immune repertoire. Surprisingly, we find that shared antigen exposure to CMV leads to fewer shared TCRß clones, even after controlling for HLA, indicative of a largely private response to major viral antigenic exposure. Consistent with this hypothesis, we find that increased age is correlated with decreased overall TCRß clone sharing, indicating that the pattern of private TCRß clonal expansion is a general feature of the T-cell response to other infectious antigens as well. However, increased age also correlates with increased sharing among the lowest frequency clones, consistent with decreased repertoire diversity in older individuals. Together, all of these factors contribute to shaping the TCRß repertoire, and understanding their interplay has important implications for the use of T cells for therapeutics and diagnostics.


Subject(s)
HLA Antigens/immunology , Histocompatibility Testing , Receptors, Antigen, T-Cell/immunology , Virus Diseases/immunology , Adult , Age Factors , Chronic Disease , Cytomegalovirus Infections/immunology , Histocompatibility Testing/methods , Humans
18.
Viruses ; 13(8)2021 08 16.
Article in English | MEDLINE | ID: covidwho-1376993

ABSTRACT

Given the impact of pandemics due to viruses of bat origin, there is increasing interest in comparative investigation into the differences between bat and human immune responses. The practice of comparative biology can be enhanced by computational methods used for dynamic knowledge representation to visualize and interrogate the putative differences between the two systems. We present an agent based model that encompasses and bridges differences between bat and human responses to viral infection: the comparative biology immune agent based model, or CBIABM. The CBIABM examines differences in innate immune mechanisms between bats and humans, specifically regarding inflammasome activity and type 1 interferon dynamics, in terms of tolerance to viral infection. Simulation experiments with the CBIABM demonstrate the efficacy of bat-related features in conferring viral tolerance and also suggest a crucial role for endothelial inflammasome activity as a mechanism for bat systemic viral tolerance and affecting the severity of disease in human viral infections. We hope that this initial study will inspire additional comparative modeling projects to link, compare, and contrast immunological functions shared across different species, and in so doing, provide insight and aid in preparation for future viral pandemics of zoonotic origin.


Subject(s)
Chiroptera/immunology , Immunity, Innate , Virus Diseases/immunology , Virus Diseases/veterinary , Animals , Chiroptera/virology , Computer Simulation , Endothelium/physiology , Humans , Inflammasomes/immunology , Inflammasomes/metabolism , Interferon Type I/immunology , Interferon Type I/metabolism , Severity of Illness Index , Stress, Physiological , Viral Zoonoses , Virus Diseases/virology , Virus Physiological Phenomena , Virus Shedding
19.
PLoS Pathog ; 17(7): e1009708, 2021 07.
Article in English | MEDLINE | ID: covidwho-1360654

ABSTRACT

The humoral immune response and antibody-mediated functions of B cells during viral infections are well described. However, we have limited understanding of antibody-independent B cell functions, such as cytokine production and antigen presentation, in acute and chronic viral infections and their role in protection and/or immunopathogenesis. Here, we summarize the current literature on these antibody-independent B cell functions and identify remaining knowledge gaps. B cell subsets produce anti- and pro-inflammatory cytokines, which can have both beneficial and detrimental effects during viral clearance. As professional antigen presenting cells, B cells also play an important role in immune regulation/shaping of the developing adaptive immune responses. Since B cells primarily express TLR7 and TLR9, we specifically discuss the role of Toll-like receptor (TLR)-mediated B cell responses to viral infections and their role in augmenting adaptive immunity through enhanced cytokine production and antigen presentation. However, viruses have evolved strategies to subvert TLR signaling and additional stimulation via B cell receptor (BCR) may be required to overcome the defective TLR response in B cells. To conclude, antibody-independent B cell functions seem to have an important role in regulating both acute and chronic viral infections and may form the basis for novel therapeutic approaches in treatment of viral infections in the future.


Subject(s)
B-Lymphocytes/immunology , Virus Diseases/immunology , Animals , Humans
20.
Int J Mol Sci ; 22(9)2021 Apr 28.
Article in English | MEDLINE | ID: covidwho-1359279

ABSTRACT

Deeply understanding the virus-host interaction is a prerequisite for developing effective anti-viral strategies. Traditionally, the transporter associated with antigen processing type 1 (TAP1) is critical for antigen presentation to regulate adaptive immunity. However, its role in controlling viral infections through modulating innate immune signaling is not yet fully understood. In the present study, we reported that TAP1, as a product of interferon-stimulated genes (ISGs), had broadly antiviral activity against various viruses such as herpes simplex virus 1 (HSV-1), adenoviruses (AdV), vesicular stomatitis virus (VSV), dengue virus (DENV), Zika virus (ZIKV), and influenza virus (PR8) etc. This antiviral activity by TAP1 was further confirmed by series of loss-of-function and gain-of-function experiments. Our further investigation revealed that TAP1 significantly promoted the interferon (IFN)-ß production through activating the TANK binding kinase-1 (TBK1) and the interferon regulatory factor 3 (IRF3) signaling transduction. Our work highlighted the broadly anti-viral function of TAP1 by modulating innate immunity, which is independent of its well-known function of antigen presentation. This study will provide insights into developing novel vaccination and immunotherapy strategies against emerging infectious diseases.


Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 2/immunology , Antiviral Agents/immunology , Host Microbial Interactions/immunology , Interferon Type I/biosynthesis , ATP Binding Cassette Transporter, Subfamily B, Member 2/antagonists & inhibitors , ATP Binding Cassette Transporter, Subfamily B, Member 2/deficiency , ATP Binding Cassette Transporter, Subfamily B, Member 2/genetics , Animals , Gene Knockout Techniques , HEK293 Cells , Humans , Immunity, Innate , Interferon Regulatory Factor-3/immunology , Mice , Models, Immunological , RAW 264.7 Cells , Toll-Like Receptors/agonists , Virus Diseases/immunology
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