scholarly journals Exogenous Activation of Invariant Natural Killer T Cells by α-Galactosylceramide Reduces Pneumococcal Outgrowth and Dissemination Postinfluenza

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Adeline Barthelemy ◽  
Stoyan Ivanov ◽  
Maya Hassane ◽  
Josette Fontaine ◽  
Béatrice Heurtault ◽  
...  
Keyword(s):  
Mouse Model ◽  
Influenza A Virus ◽  
Bacterial Pneumonia ◽  
Influenza A ◽  
Bacterial Infections ◽  
Pneumococcal Infection ◽  
Clinical Development ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Invariant Natural Killer

ABSTRACT Influenza A virus infection can predispose to potentially devastating secondary bacterial infections. Invariant natural killer T (iNKT) cells are unconventional, lipid-reactive T lymphocytes that exert potent immunostimulatory functions. Using a mouse model of postinfluenza invasive secondary pneumococcal infection, we sought to establish whether α-galactosylceramide (α-GalCer [a potent iNKT cell agonist that is currently in clinical development]) could limit bacterial superinfection. Our results highlighted the presence of a critical time window during which α-GalCer treatment can trigger iNKT cell activation and influence resistance to postinfluenza secondary pneumococcal infection. Intranasal treatment with α-GalCer during the acute phase (on day 7) of influenza virus H3N2 and H1N1 infection failed to activate (gamma interferon [IFN-γ] and interleukin-17A [IL-17A]) iNKT cells; this effect was associated with a strongly reduced number of conventional CD103 + dendritic cells in the respiratory tract. In contrast, α-GalCer treatment during the early phase (on day 4) or during the resolution phase (day 14) of influenza was associated with lower pneumococcal outgrowth and dissemination. Less intense viral-bacterial pneumonia and a lower morbidity rate were observed in superinfected mice treated with both α-GalCer (day 14) and the corticosteroid dexamethasone. Our results open the way to alternative (nonantiviral/nonantibiotic) iNKT-cell-based approaches for limiting postinfluenza secondary bacterial infections. IMPORTANCE Despite the application of vaccination programs and antiviral drugs, influenza A virus (IAV) infection is responsible for widespread morbidity and mortality (500,000 deaths/year). Influenza infections can also result in sporadic pandemics that can be devastating: the 1918 pandemic led to the death of 50 million people. Severe bacterial infections are commonly associated with influenza and are significant contributors to the excess morbidity and mortality of influenza. Today’s treatments of secondary bacterial (pneumococcal) infections are still not effective enough, and antibiotic resistance is a major issue. Hence, there is an urgent need for novel therapies. In the present study, we set out to evaluate the efficacy of α-galactosylceramide (α-GalCer)—a potent agonist of invariant NKT cells that is currently in clinical development—in a mouse model of postinfluenza, highly invasive pneumococcal pneumonia. Our data indicate that treatment with α-GalCer reduces susceptibility to superinfections and, when combined with the corticosteroid dexamethasone, reduces viral-bacterial pneumonia.

scholarly journals Role of Autophagy and Apoptosis in the Postinfluenza Bacterial Pneumonia

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Zhen Qin ◽  
Yuan Yang ◽  
Hongren Wang ◽  
Jun Luo ◽  
Xiaojun Huang ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Influenza A Virus ◽  
Bacterial Pneumonia ◽  
Influenza A ◽  
Bacterial Infections ◽  
Research Progress ◽  
The Past ◽  
Recent Research Progress ◽  
Increased Susceptibility

The risk of influenza A virus (IAV) is more likely caused by secondary bacterial infections. During the past decades, a great amount of studies have been conducted on increased morbidity from secondary bacterial infections following influenza and provide an increasing number of explanations for the mechanisms underlying the infections. In this paper, we first review the recent research progress that IAV infection increased susceptibility to bacterial infection. We then propose an assumption that autophagy and apoptosis manipulation are beneficial to antagonize post-IAV bacterial infection and discuss the clinical significance.

Invariant natural killer T cells promote immunogenic maturation of lung dendritic cells in mouse models of asthma

2017 ◽  
Vol 313 (6) ◽  
pp. L973-L990 ◽  
Author(s):  
Qing He ◽  
Linlin Liu ◽  
Qiaoyu Yang ◽  
Ailing Wang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Mouse Model ◽  
Mouse Models ◽  
Adoptive Transfer ◽  
Proinflammatory Cytokine ◽  
Inflammatory Responses ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Th2 Responses ◽  
Invariant Natural Killer

Our previous study showed that invariant natural killer T (iNKT) cells might act as an adjuvant to promote Th2 inflammatory responses in an OVA-induced mouse model of allergic asthma, but the mechanism remains unknown. To clarify the underlying mechanism through which iNKT cells promote Th2 inflammatory responses, we investigated the modulatory influence of iNKT cells on phenotypic and functional maturation of lung dendritic cells (LDCs) using iNKT cell-knockout mice, specific iNKT cell activation, coculture experiments, and adoptive transfer of iNKT cells in mouse models of asthma. Our data showed that iNKT cell deficiency could downregulate surface maturation markers and proinflammatory cytokine secretion of LDCs from a mouse model of asthma. However, elevated activation of iNKT cells by α-galactosylceramide and adoptive transfer of iNKT cells could upregulate surface maturation markers and proinflammatory cytokine secretion of LDCs from mouse models of asthma. Meanwhile, iNKT cells significantly influenced the function of LDCs, markedly enhancing Th2 responses in vivo and in vitro. In addition, iNKT cell can induce LDCs expression of CD206 and RELM-α, reflecting alternative activation of LDCs in a mouse model of asthma. α-Galactosylceramide treatment significantly enhanced expression of CD40L of lung iNKT cells from a mouse model of asthma, and the coculture experiment of LDCs with iNKT cells showed that the blockade of CD40L strongly suppressed surface maturation markers and proinflammatory cytokine production by LDCs. Our data suggest that iNKT cells can promote immunogenic maturation of LDCs to enhance Th2 responses in mouse models of asthma.

scholarly journals GP96 drives exacerbation of secondary bacterial pneumonia following influenza A virus infection

2020 ◽  
Author(s):  
Tomoko Sumitomo ◽  
Masanobu Nakata ◽  
Satoshi Nagase ◽  
Yuki Takahara ◽  
Mariko Honda-Ogawa ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Influenza A Virus ◽  
Transcriptional Repression ◽  
Bacterial Pneumonia ◽  
Influenza A ◽  
Surface Expression ◽  
Lung Pathology ◽  
Direct Binding ◽  
Novel Therapeutic Strategies ◽  
Secondary Bacterial Pneumonia

AbstractInfluenza A virus (IAV) infection predisposes the host to secondary bacterial pneumonia, known as a major cause of morbidity and mortality during influenza epidemics. Analysis of interactions between IAV-infected human epithelial cells and Streptococcus pneumoniae revealed that infected cells ectopically exhibited the endoplasmic reticulum chaperon GP96 on the surface. Importantly, efficient pneumococcal adherence to epithelial cells was imparted by interactions with extracellular GP96 and integrin αV, with the surface expression mediated by GP96 chaperone activity. Furthermore, abrogation of adherence was gained by chemical inhibition or genetic knockout of GP96, as well as addition of RGD peptide. Direct binding of extracellular GP96 and pneumococci was shown to be mediated by pneumococcal oligopeptide permease components. Additionally, IAV infection induced activation of calpains and Snail1, which are responsible for degradation and transcriptional repression of junctional proteins in the host, respectively, indicating increased bacterial translocation across the epithelial barrier. Notably, treatment of IAV-infected mice with the GP96 inhibitor enhanced pneumococcal clearance from lung tissues and ameliorated lung pathology. Taken together, the present findings indicate a viral-bacterial synergy in relation to disease progression and suggest a paradigm for developing novel therapeutic strategies tailored to inhibit pneumococcal colonization in an IAV-infected respiratory tract.

scholarly journals 3502 Stimulating iNKT Cell-Mediated Neuroblastoma Cytotoxicity in a Mouse Model

2019 ◽  
Vol 3 (s1) ◽  
pp. 21-21
Author(s):  
Kevin Owen McNerney ◽  
Hamid Bassiri ◽  
Spyridon Karageorgos ◽  
Priya Khurana
Keyword(s):  
Tumor Microenvironment ◽  
Mouse Model ◽  
Neuroblastoma Cells ◽  
Prolonged Survival ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Glycolipid Antigen ◽  
High Affinity

OBJECTIVES/SPECIFIC AIMS: Overall Research Aim: To develop an iNKT-cell engaging reagent (“CAb”)to induce neuroblastoma-directed cytotoxicity in vitro and in a mouse model of neuroblastoma. Objective 1: Explore the contribution of different GD2 affinities to the cytotoxicity against neuroblastoma cells in vitro. Objective 2: Deteremine whether use of different stimulatory glycolipids (alpha-GalCer vs. C34) alter the activation and cytotoxicity of iNKT cells against neuroblastoma in vitro. Objective 3: To analyze survival of an immunocompetent mouse model of neuroblastoma treated with C34-loaded vs alpha-GalCer-loaded CAb molecule, and to analyze the tumor microenvironment in each treatment condition. METHODS/STUDY POPULATION: CAb molecule will be generated by fusing a CD1d protein to an scFv domain for GD2 using cloning techniques. Previous work by our group has used a streptavidin-biotin system to link CD1d to an antibody against GD2, which is large and immunogenic. Protein expression of this novel fusion protein will occur in HEK293 cells. This new CAb molecule will then be loaded with alpha-GalCer or C34 for use in cytotoxicity and in vivo experiments. Cytotoxicity Assessment: Chromium assays will be used to assess the specific cytotoxicity generated by iNKT cells against neuroblastoma cells in vitro. iNKT cells will be activated by “CAb’s” with relatively high and low affinity for GD2, and also with Alpha-GalCer and C34 glycolipid antigen. flow cytometry will be used to assess for CD107a and Interferon Gamma. Mouse Model of Neuroblastoma: TH-MYCN +/+ mice will be used as an immunocompetent model of neuroblastoma. These mice have the MYCN gene under the control of a tyrosine hydroxylase promoter, and spontaneously develop neuroblastomas by 2 weeks of life which are uniformly fatal by 8 weeks of life. In vivo survival studies will be conducted by injecting CAb of relatively high and low affinity, loaded with glycolipid antigen intraperitonealy into TH-MYCN+/+ mice starting at 2 weeks of age, twice weekly. There will also be a matched negative control. Treatment groups are listed below: 1. alpha-GalCer loaded high-affinity Cab 2. alpha-GalCer loaded low-affinity Cab 3. C34-loaded high-affinity Cab 4. C34-loaded low-affinity Cab 5. Unloaded high-affinity Cab 6. Unloaded low-affinity Cab Enrollment will be 6 mice per group for the survival curves. Tumor Microenvironment analysis: 2 additional mice will be included in each group listed above to be sacrificed 2 weeks into treatment for tumor assessment with flow cytomtetry for iNKT cell, NK cell, T-Lymphocyte frequencies as well as interferon-Gamma expression. RESULTS/ANTICIPATED RESULTS: Objective 1: We expect to find that the highest affinity scFv domains for GD2 result in the greatest amount of cytotoxicity against neuroblastoma cells via iNKT cells. Objective 2: We expect that the C34 molecule will induce the greatest amounts of iNKT cell activation against neuroblastoma cells and higher cytotoxicity against neuroblastoma, which has not been shown previously. Objective 3: We expect to see prolonged survival of mice treated with the high affinity GD2 CAb loaded with C34 or alpha GalCer compared with the low affinity CAb loaded with C34 or alpha GalCer. We also expect that the C34 loaded CAb in both groups will have prolonged survival when compared with the alpha-GalCer loaded CAbs of either affinity. DISCUSSION/SIGNIFICANCE OF IMPACT: iNKT cells have been shown previously to confer an improved prognosis in neuroblastoma and other malignancies. Furthermore, high risk neuroblastomas tend to downregulate expression of a chemokine that attracts iNKT’s to the site of the neuroblastoma. Directing iNKT to the site of neuroblastoma holds promise as an effective immunotherapy option. Our preliminary data demonstrate that CAbs directed against GD2 are capable of exerting cytotoxicity of neuroblastoma in vitro. Furthermore a trend towards prolonged survival has been shown in TH-MYCN mice in early experiments. The development of a novel antibody that has reduced immunogenicity, incorporates a glycolipid antigen that does not induce iNKT cell anergy, and is specific for the GD2 tumor specific antigen has potential to result in increased iNKT-mediate neuroblastoma cytotoxicity and prolonged survival in TH-MYCN+/+ mice.

Chios mastic gum inhibits influenza A virus replication and viral pathogenicity

2021 ◽  
Author(s):  
Dong-In Kim ◽  
Yong-Bin Cho ◽  
Younghyun Lim ◽  
So-Hee Hong ◽  
Bumsuk Hahm ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Bacterial Infections ◽  
Early Stage ◽  
Antiviral Drug ◽  
Virus Infectivity ◽  
Viral Attachment ◽  
Cellular Processes ◽  
Chios Mastic Gum

Chios mastic gum (CMG), a resin of the mastic tree (Pistacia lentiscus var. chia), has been used to treat multiple disorders caused by gastrointestinal malfunctions and bacterial infections for more than 2500 years. However, little is known about CMG’s antiviral activity. CMG is known to influence multiple cellular processes such as cell proliferation, differentiation and apoptosis. As virus replication is largely dependent on the host cellular metabolism, it is conceivable that CMG regulates virus infectivity. Therefore, in this study, we evaluated CMG’s potential as an antiviral drug to treat influenza A virus (IAV) infection. CMG treatment dramatically reduced the cytopathogenic effect and production of RNAs, proteins and infectious particles of IAV. Interestingly, CMG interfered with the early stage of the virus life cycle after viral attachment. Importantly, the administration of CMG greatly ameliorated morbidity and mortality in IAV-infected mice. The results suggest that CMG displays a potent anti-IAV activity by blocking the early stage of viral replication. Thus, mastic gum could be exploited as a novel therapeutic agent against IAV infection.

scholarly journals Potential of H1N1 influenza A virus as an air borne pathogen to induce infectivity in pancreas: a mouse model study

2020 ◽  
Vol 18 (1) ◽  
pp. 303-310
Author(s):  
Kaveh Sadeghi ◽  
Vahid Salimi ◽  
Farhad Rezaei ◽  
Farid azizi Jalilian ◽  
Nastaran Ghavami ◽  
...  
Keyword(s):  
Mouse Model ◽  
Influenza A Virus ◽  
Influenza A ◽  
H1n1 Influenza ◽  
Model Study

scholarly journals License to Kill: When iNKT Cells Are Granted the Use of Lethal Cytotoxicity

2020 ◽  
Vol 21 (11) ◽  
pp. 3909
Author(s):  
Angélica Díaz-Basabe ◽  
Francesco Strati ◽  
Federica Facciotti
Keyword(s):  
Immune Responses ◽  
Inkt Cell ◽  
Cell Cytotoxicity ◽  
Future Perspectives ◽  
Inkt Cells ◽  
Cytotoxic Potential ◽  
Lipid Antigens ◽  
Cancer Immunotherapies ◽  
Cluster Of Differentiation ◽  
Invariant Natural Killer

Invariant Natural Killer T (iNKT) cells are a non-conventional, innate-like, T cell population that recognize lipid antigens presented by the cluster of differentiation (CD)1d molecule. Although iNKT cells are mostly known for mediating several immune responses due to their massive and diverse cytokine release, these cells also work as effectors in various contexts thanks to their cytotoxic potential. In this Review, we focused on iNKT cell cytotoxicity; we provide an overview of iNKT cell subsets, their activation cues, the mechanisms of iNKT cell cytotoxicity, the specific roles and outcomes of this activity in various contexts, and how iNKT killing functions are currently activated in cancer immunotherapies. Finally, we discuss the future perspectives for the better understanding and potential uses of iNKT cell killing functions in tumor immunosurveillance.

scholarly journals Distinct bioenergetic features of human invariant natural killer T (iNKT) cells enable retained functions in nutrient-deprived states

2021 ◽  
Author(s):  
Priya Khurana ◽  
Chakkapong Burudpakdee ◽  
Stephan A. Grupp ◽  
Ulf H. Beier ◽  
David M. Barrett ◽  
...  
Keyword(s):  
Natural Killer ◽  
Metabolic Flux ◽  
Cytokine Production ◽  
Inkt Cell ◽  
Flux Analysis ◽  
Inkt Cells ◽  
Effector Functions ◽  
Functional Features ◽  
Invariant Natural Killer ◽  
Natural Killer T

ABSTRACTInvariant natural killer T (iNKT) cells comprise a unique subset of lymphocytes that are primed for activation and possess innate NK-like functional features. Currently, iNKT cell-based immunotherapies remain in early clinical stages, and little is known about the ability of these cells to survive and retain effector functions within the solid tumor microenvironment (TME) long-term. In conventional T cells (TCONV), cellular metabolism is linked to effector functions and their ability to adapt to the nutrient-poor TME. In contrast, the bioenergetic requirements of iNKT cells – particularly those of human iNKT cells – at baseline and upon stimulation are not well understood; neither is how these requirements affect cytokine production or anti-tumor effector functions. We find that unlike TCONV, human iNKT cells are not dependent upon glucose or glutamine for cytokine production and cytotoxicity upon stimulation with anti-CD3 and anti-CD28. Additionally, transcriptional profiling revealed that stimulated human iNKT cells are less glycolytic than TCONV and display higher expression of fatty acid oxidation (FAO) and adenosine monophosphate-activated protein kinase (AMPK) pathway genes. Furthermore, stimulated iNKT cells displayed higher mitochondrial mass and membrane potential relative to TCONV. Real-time Seahorse metabolic flux analysis revealed that stimulated human iNKT cells utilize fatty acids as substrates for oxidation more than stimulated TCONV. Together, our data suggest that human iNKT cells possess different bioenergetic requirements from TCONV and display a more memory-like metabolic program relative to effector TCONV. Importantly, iNKT cell-based immunotherapeutic strategies could co-opt such unique features of iNKT cells to improve their efficacy and longevity of anti-tumor responses.

scholarly journals Enhancing the antitumor functions of invariant natural killer T cells using a soluble CD1d-CD19 fusion protein

2019 ◽  
Vol 3 (5) ◽  
pp. 813-824 ◽  
Author(s):  
Rupali Das ◽  
Peng Guan ◽  
Susan J. Wiener ◽  
Nishant P. Patel ◽  
Trevor G. Gohl ◽  
...  
Keyword(s):  
Fusion Protein ◽  
B Cell ◽  
Natural Killer ◽  
Tumor Cells ◽  
Inkt Cell ◽  
Inkt Cells ◽  
Cell Responses ◽  
Invariant Natural Killer

Abstract Invariant natural killer T (iNKT) cells comprise a unique lineage of CD1d-restricted lipid-reactive T lymphocytes that potently kill tumor cells and exhibit robust immunostimulatory functions. Optimal tumor-directed iNKT cell responses often require expression of the antigen-presenting molecule CD1d on tumors; however, many tumor cells downregulate CD1d and thus evade iNKT cell recognition. We generated a soluble bispecific fusion protein designed to direct iNKT cells to the site of B-cell cancers in a tumor antigen-specific but CD1d-independent manner. This fusion protein is composed of a human CD1d molecule joined to a single chain antibody FV fragment specific for CD19, an antigen widely expressed on B-cell cancers. The CD1d-CD19 fusion protein binds specifically to CD19-expressing, but not CD19-negative cells. Once loaded with the iNKT cell lipid agonist α-galactosyl ceramide (αGC), the CD1d-CD19 fusion induces robust in vitro activation of and cytokine production by human iNKT cells. iNKT cells stimulated by the αGC-loaded CD1d-CD19 fusion also strongly transactivate T-, B-, and NK-cell responses and promote dendritic cell maturation. Importantly, the αGC-loaded fusion induces robust lysis of CD19+CD1d− Epstein-Barr virus immortalized human B-lymphoblastoid cell lines that are otherwise resistant to iNKT cell killing. Consistent with these findings; administration of the αGC-loaded fusion protein controlled the growth of CD19+CD1d− tumors in vivo, suggesting that it can “link” iNKT cells and CD19+CD1d− targets in a therapeutically beneficial manner. Taken together, these preclinical studies demonstrate that this B cell–directed fusion protein can be used to effectively induce iNKT cell antitumor responses in vitro and in vivo.

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