Abstract 039: Natural Killer T Cells Play Protective Roles in Cardiovirus-Induced Myocarditis by Inducing Anti-Viral and Regulatory Cytokines

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Fumitaka Sato ◽  
Seiichi Omura ◽  
Nicholas E Martinez ◽  
Eiichiro Kawai ◽  
Sadie F Pearson ◽  
...  
Keyword(s):  
Natural Killer ◽  
Acute Phase ◽  
Viral Myocarditis ◽  
Chronic Phase ◽  
Nkt Cells ◽  
Viral Clearance ◽  
Left Ventricular Ejection ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Natural Killer T

Picornavirus infections have been known as a leading cause of viral myocarditis in humans. Theiler’s murine encephalomyelitis virus (TMEV) belongs to the genus Cardiovirus, the family Picornaviridae, and can cause myocarditis in susceptible mice. In viral myocarditis, viral replication in the heart and/or immune responses against virus as well as cardiac antigens (autoimmunity) can contribute to the pathogenesis. Natural killer T (NKT) cells can play a regulatory role in viral infections by producing anti-viral and anti-inflammatory cytokines; interferon (IFN)-γ can contribute to either viral clearance or tissue damage (immunopathology), while anti-inflammatory interleukin (IL)-10 has been suggested to regulate viral clearance or immunopathology. To determine the role of NKT cells in TMEV-induced myocarditis, we infected wild-type (WT) and NKT knockout (NKT KO, Jα18 KO) mice with TMEV. Myocarditis was monitored by echocardiography using the Vevo 770 system. During the acute (day 7) or chronic phase (day 60) of TMEV infection, cardiac pathology was evaluated by hematoxylin and eosin staining, and production of cytokines, including IFN-γ and IL-10, from spleen cells was measured by enzyme-linked immunosorbent assays. During the acute phase, the levels of left ventricular ejection fraction were significantly lower in NKT KO mice than in WT mice. Immunologically, NKT KO mice had lower levels of IFN-γ production than WT mice [IFN-γ (pg/ml): WT, 768 ± 533; NKT KO, 293 ± 190]. During the chronic phase, high intensity cardiac lesions were observed by echocardiography in NKT KO mice, but not in WT mice. Histologically, NKT KO mice developed moderate inflammation with basophilic degeneration and calcification in the heart, while WT mice had only mild inflammation in the heart. Immunologically, NKT KO mice had lower levels of IL-10 production compared with WT mice [IL-10 (pg/ml): WT, 1771 ± 381; NKT KO, 1199 ± 160]. These results suggest that NKT cells play a protective role in viral myocarditis by producing IFN-γ and IL-10, which contribute to viral clearance during the acute phase and the suppression of immunopathology during the chronic phase of disease, respectively.

Abstract 116: Detrimental Role of Toll-Like Receptor 4 in Cardiovirus-Induced Myocarditis

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Fumitaka Sato ◽  
Seiichi Omura ◽  
Nicholas E Martinez ◽  
Eiichiro Kawai ◽  
Ganta V Chaitanya ◽  
...  
Keyword(s):  
Immune Responses ◽  
Acute Phase ◽  
Viral Entry ◽  
Viral Myocarditis ◽  
Chronic Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tlr4 Ligand ◽  
Ifn Γ ◽  
Deficient Mice

Picornavirus infections have been known as a leading cause of viral myocarditis in humans. Theiler’s murine encephalomyelitis virus (TMEV) belongs to the genus Cardiovirus, the family Picornaviridae and was reported to cause inflammation in the heart in one manuscript, while its pathomechanism is unclear. In viral myocarditis, viral replication in the heart and/or immune responses against virus as well as heart-antigen (autoimmunity) can contribute to the pathogenesis. Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that are important for recognizing pathogens as well as triggering innate immunity. Among TLRs, TLR4 has been demonstrated to play important roles in virus-mediated pathology: 1) TLR4 can contribute to viral entry in some viruses, 2) TLR4 may mediate tissue damage by anti-virus immune responses (immunopathology), 3) high levels of TLR4 expression were observed in the heart of patients with dilated cardiomyopathy following acute viral myocarditis, and 4) some viruses can bind to lipopolysaccharide (LPS), which is a TLR4 ligand. To determine the role of TLR4 in TMEV-induced myocarditis, we infected male C3H/HeJ (TLR4-deficient) and C3H/HeNtac (control TLR4+) mice with the DA strain of TMEV. We harvested the hearts and spleens on days 6 and 7 (acute phase) or days 63 and 64 (chronic phase) post-infection. Cardiac pathology was evaluated by hematoxylin and eosin staining and production of pro-inflammatory cytokines, interleukin (IL)-17A and interferon (IFN)-γ, from spleen cells was measured by an enzyme-linked immunosorbent assay (ELISA). In both mice, mild myocarditis was observed during the acute phase of TMEV infection. During the chronic phase, both mice developed severe pathology in the heart, including basophilic degeneration and calcification. However, the incidence of myocarditis was higher in control mice than TLR4-deficient mice. IL-17A and IFN-γ production was higher in control mice than in TLR4-deficient mice (control vs. TLR4-deficient mice, acute phase: IL-17A, 196 vs. 146 pg/ml; IFN-γ, 72 vs. 39 ng/ml; chronic phase: IL-17A, 290 vs. 229 pg/ml; IFN- γ, 142 vs. 88 ng/ml). These results suggest that TLR4 may be detrimental in TMEV-induced myocarditis by increasing pro-inflammatory cytokine production.

scholarly journals Natural killer T-cell autoreactivity leads to a specialized activation state

Blood ◽  
2008 ◽  
Vol 112 (10) ◽  
pp. 4128-4138 ◽  
Author(s):  
Xiaohua Wang ◽  
Xiuxu Chen ◽  
Lance Rodenkirch ◽  
William Simonson ◽  
Sarah Wernimont ◽  
...  
Keyword(s):  
Natural Killer ◽  
Mapk Pathway ◽  
Nkt Cells ◽  
Interferon Γ ◽  
Janus Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Flux ◽  
Nkt Cell ◽  
Ifn Γ ◽  
Natural Killer T

Abstract Natural killer T (NKT) cells are innate-like T cells that recognize specific microbial antigens and also display autoreactivity to self-antigens. The nature of NKT-cell autoreactive activation remains poorly understood. We show here that the mitogen-activated protein kinase (MAPK) pathway is operative during human NKT-cell autoreactive activation, but calcium signaling is severely impaired. This results in a response that is biased toward granulocyte macrophage colony-stimulating factor (GM-CSF) secretion because this cytokine requires extracellular signal-regulated kinase (ERK) signaling but is not highly calcium dependent, whereas interferon-γ (IFN-γ), interleukin (IL)–4, and IL-2 production are minimal. Autoreactive activation was associated with reduced migration velocity but did not induce arrest; thus, NKT cells retained the ability to survey antigen presenting cells (APCs). IL-12 and IL-18 stimulated autoreactively activated NKT cells to secrete IFN-γ, and this was mediated by Janus kinase-signal transducers and activators of transcription (JAK-STAT)–dependent signaling without induction of calcium flux. This pathway did not require concurrent contact with CD1d+ APCs but was strictly dependent on preceding autoreactive stimulation that induced ERK activation. In contrast, NKT-cell responses to the glycolipid antigen α-galactosyl ceramide (α-GalCer) were dampened by prior autoreactive activation. These results show that NKT-cell autoreactivity induces restricted cytokine secretion and leads to altered basal activation that potentiates innate responsiveness to costimulatory cytokines while modulating sensitivity to foreign antigens.

scholarly journals The Natural Killer T (NKT) Cell Ligand α-Galactosylceramide Demonstrates Its Immunopotentiating Effect by Inducing Interleukin (IL)-12 Production by Dendritic Cells and IL-12 Receptor Expression on NKT Cells

1999 ◽  
Vol 189 (7) ◽  
pp. 1121-1128 ◽  
Author(s):  
Hidemitsu Kitamura ◽  
Kenji Iwakabe ◽  
Takashi Yahata ◽  
Shin-ichiro Nishimura ◽  
Akio Ohta ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Natural Killer ◽  
Cd40 Ligand ◽  
Nkt Cells ◽  
Receptor Expression ◽  
Antitumor Activities ◽  
Nkt Cell ◽  
Ifn Γ ◽  
Natural Killer T

The natural killer T (NKT) cell ligand α-galactosylceramide (α-GalCer) exhibits profound antitumor activities in vivo that resemble interleukin (IL)-12–mediated antitumor activities. Because of these similarities between the activities of α-GalCer and IL-12, we investigated the involvement of IL-12 in the activation of NKT cells by α-GalCer. We first established, using purified subsets of various lymphocyte populations, that α-GalCer selectively activates NKT cells for production of interferon (IFN)-γ. Production of IFN-γ by NKT cells in response to α-GalCer required IL-12 produced by dendritic cells (DCs) and direct contact between NKT cells and DCs through CD40/CD40 ligand interactions. Moreover, α-GalCer strongly induced the expression of IL-12 receptor on NKT cells from wild-type but not CD1−/− or Vα14−/− mice. This effect of α-GalCer required the production of IFN-γ by NKT cells and production of IL-12 by DCs. Finally, we showed that treatment of mice with suboptimal doses of α-GalCer together with suboptimal doses of IL-12 resulted in strongly enhanced natural killing activity and IFN-γ production. Collectively, these findings indicate an important role for DC-produced IL-12 in the activation of NKT cells by α-GalCer and suggest that NKT cells may be able to condition DCs for subsequent immune responses. Our results also suggest a novel approach for immunotherapy of cancer.

scholarly journals Resistance of Natural Killer T Cell–Deficient Mice to Systemic Shwartzman Reaction

2000 ◽  
Vol 192 (11) ◽  
pp. 1645-1652 ◽  
Author(s):  
Francesco Dieli ◽  
Guido Sireci ◽  
Domenica Russo ◽  
Masaru Taniguchi ◽  
Juraj Ivanyi ◽  
...  
Keyword(s):  
Natural Killer ◽  
Severe Combined Immunodeficiency ◽  
Nkt Cells ◽  
Nkt Cell ◽  
Natural Killer T Cell ◽  
Shwartzman Reaction ◽  
Ifn Γ ◽  
High Doses ◽  
Deficient Mice ◽  
Natural Killer T

The generalized Shwartzman reaction in mice which had been primed and challenged with lipopolysaccharide (LPS) depends on interleukin (IL)-12–induced interferon (IFN)-γ production at the priming stage. We examined the involvement in the priming mechanism of the unique population of Vα14 natural killer T (NKT) cells because they promptly produce IFN-γ after IL-12 stimulation. We report here that LPS- or IL-12–primed NKT cell genetically deficient mice were found to be resistant to LPS-elicited mortality. This outcome can be attributed to the reduction of IFN-γ production, because injection of recombinant mouse IFN-γ, but not injection of IL-12, effectively primed the NKT cell–deficient mice. However, priming with high doses of LPS caused mortality of severe combined immunodeficiency, NKT cell–deficient, and CD1-deficient mice, indicating a major contribution of NKT cells to the Shwartzman reaction elicited by low doses of LPS, whereas at higher doses of LPS NK cells play a prominent role. These results suggest that the numerically small NKT cell population of normal mice apparently plays a mandatory role in the priming stage of the generalized Shwartzman reaction.

scholarly journals Preclinical Evaluation of Invariant Natural Killer T-Cells in the 5T33 Multiple Myeloma Model

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 938-938
Author(s):  
Haneen Nur ◽  
Sandrine Aspeslagh ◽  
Els Van Valckenborgh ◽  
Elke De Bruyne ◽  
Dirk Elewaut ◽  
...  
Keyword(s):  
Natural Killer ◽  
Murine Model ◽  
Conflicts Of Interest ◽  
Nkt Cells ◽  
Spleen Cells ◽  
Ifn Γ ◽  
End Stage ◽  
Natural Killer T

Abstract Abstract 938 Natural killer T (NKT) cells are T-lymphocytes that co-express conventional T-cell (CD3) and NK cell (NK1.1) surface receptors, while invariant NKT cells (iNKTs) also express a unique semi-invariant TCR α-chain encoded by Vα14.Jα18 in mice and Vα24.Jα18 in human. These iNKTs can recognize glycolipid antigens such as α-Galactosylceramide (α-GalCer) presented by the class I-like major histocompatibility complex (MHC) molecule CD1d. Activation of iNKTs can lead to an anti-tumor Th1 (IFN-γ) response or an immunosuppressive Th2 (IL-4) response. Clinical studies in MM patients (1, 2) showed a low frequency and dysfunction of iNKTs which resulted in a low IFN-γ secretion. This defect could be overcome in vitro by stimulating the iNKTs with α-GalCer loaded DCs. Furthermore, when MM patients were injected with loaded DCs their iNKT pool expanded 100 fold. This make MM cells an interesting target for iNKT therapy. However, the data on NKT activity in MM patients is limited and the use of α-GalCer as a drug has not been preclinically evaluated yet. Therefore, in this study, we investigated the characteristics of iNKTs in the syngeneic 5T33MM murine model, which is an immunocompetent model of myeloma which mimics the human disease closely. We first investigated the frequency of iNKTs in the blood, BM, spleen and liver of both healthy and terminally diseased 5T33MM mice. The highest percentage of iNKTs was found in the liver (naive 7%) with a significant decrease in 5T33MM mice (2.6%). The percentage was also slightly decreased in spleen (from 1.5% in naive to 0.7% in 5T33MM mice) while no significant differences were observed in the other tissues. Next, we followed the frequency of iNKTs in the liver and spleen of MM mice during the development of the disease. We analyzed the number of iNKTs in the first, second, third and terminal week. We found that the percentage of iNKTs declined at the end stage of MM disease. To analyze the activity of iNKTs in vitro, liver iNKTs were cocultured with naive matured BM derived DCs in the presence or absence of 100 ng/ml α-GalCer. Naive iNKTs could secrete up to 2.3 ng/ml IFN-γ when stimulated with α-GalCer, and this level increased with the progression of MM to reach 3.3 ng/ml at week 2. However, the activity of the iNKTs dropped to undetectable levels upon further progression of the disease (week 4). In contrast, very slight IL-4 production was observed indicating that liver iNKTs are skewed to a Th1 profile and can therefore be used as an immunotherapeutic tool in MM. The activity of the NKTs was also followed in vivo. The serum level of IFN-γ peaked at 18h after α-GalCer injection in naive and non-terminal diseased mice and returned to baseline by 48h, however, the response of IFN-γ in diseased mice was twice (6 ng/ml) that measured in naive mice, confirming the possibility of inducing Th1 responses with α-GalCer in vivo in healthy and diseased mice. No response could be detected from terminally diseased mice. It has been described previously that CD1d is significantly downregulated in patients with advanced stages of MM (3). To investigate if this is similar in the 5T33MM model, we followed the expression of CD1d on spleen and BM cells during the course of the disease. Results showed a significant downregulation of CD1d expression on spleen cells from 93% CD1d (naive) to 68% at end stage. On BM cells, CD1d was less expressed compared to spleen cells, 52% in naive mice and expression declined significantly to 35%. CD1d expression on the MM cells themselves was high (79%) and did not alter during the course of the disease. We finally evaluated the effect of α-GalCer on the survival of MM mice. Survival was significantly increased when mice were injected with α-GalCer loaded DCs on the same day of 5T33MM inoculation (29 days survival) compared to mice injected with unloaded DCs (22 days survival). Taken together, our data demonstrate for the first time the possibility of using a murine model as a preclinical MM model to study the effects of α-GalCer on iNKTs and shows promising results of treating MM patients with a low tumorload. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Distinct Cytokine Profiles of Neonatal Natural Killer T Cells after Expansion with Subsets of Dendritic Cells

2001 ◽  
Vol 193 (10) ◽  
pp. 1221-1226 ◽  
Author(s):  
Norimitsu Kadowaki ◽  
Svetlana Antonenko ◽  
Stephen Ho ◽  
Marie-Clotilde Rissoan ◽  
Vassili Soumelis ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Natural Killer ◽  
Critical Role ◽  
Nkt Cells ◽  
Dependent Manner ◽  
Helper Cell Type ◽  
Ifn Γ ◽  
Natural Killer T

Natural killer T (NKT) cells are a highly conserved subset of T cells that have been shown to play a critical role in suppressing T helper cell type 1–mediated autoimmune diseases and graft versus host disease in an interleukin (IL)-4–dependent manner. Thus, it is important to understand how the development of IL-4– versus interferon (IFN)-γ–producing NKT cells is regulated. Here, we show that NKT cells from adult blood and those from cord blood undergo massive expansion in cell numbers (500–70,000-fold) during a 4-wk culture with IL-2, IL-7, phytohemagglutinin, anti-CD3, and anti-CD28 mAbs. Unlike adult NKT cells that preferentially produce both IL-4 and IFN-γ, neonatal NKT cells preferentially produce IL-4 after polyclonal activation. Addition of type 2 dendritic cells (DC2) enhances the development of neonatal NKT cells into IL-4+IFN-γ− NKT2 cells, whereas addition of type 1 dendritic cells (DC1) induces polarization towards IL-4−IFN-γ+ NKT1 cells. Adult NKT cells display limited plasticity for polarization induced by DC1 or DC2. Thus, newly generated NKT cells may possess the potent ability to develop into IL-4+IFN-γ− NKT2 cells in response to appropriate stimuli and may thereafter acquire the tendency to produce both IL-4 and IFN-γ.

scholarly journals Enhanced Gamma Interferon Production through Activation of Vα14+ Natural Killer T Cells by α-Galactosylceramide in Interleukin-18-Deficient Mice with Systemic Cryptococcosis

2001 ◽  
Vol 69 (11) ◽  
pp. 6643-6650 ◽  
Author(s):  
Kazuyoshi Kawakami ◽  
Yuki Kinjo ◽  
Satomi Yara ◽  
Kaori Uezu ◽  
Yoshinobu Koguchi ◽  
...  
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Natural Killer T Cells ◽  
Nkt Cells ◽  
Gamma Interferon ◽  
Interleukin 18 ◽  
Enhanced Production ◽  
Ifn Γ ◽  
Killer T Cells ◽  
Natural Killer T

ABSTRACT We showed recently that activation of Vα14+ natural killer T cells (NKT cells) by α-galactosylceramide (α-GalCer) resulted in increased gamma interferon (IFN-γ) production and host resistance to intravenous infection with Cryptococcus neoformans. In other studies, interleukin-18 (IL-18) activated NKT cells in collaboration with IL-12, suggesting the possible contribution of this cytokine to α-GalCer-induced IFN-γ synthesis. Here we examined the role of IL-18 in α-GalCer-induced Th1 response by using IL-18KO mice with this infection. In these mice, levels of IFN-γ in serum and its synthesis in vitro by spleen cells stimulated with live organisms were not reduced, but rather enhanced, compared to those in wild-type (WT) mice, while such production was completely absent in IL-12KO mice. The enhanced production of IFN-γ correlated with increased IL-12 synthesis but not with reduced production of IL-4, which was rather increased. IFN-γ synthesis in IL-18KO mice was abolished by neutralizing anti-IL-12 antibody and significantly inhibited by neutralization of endogenous IL-4 with a specific monoclonal antibody. In addition, administration of recombinant IL-4 significantly enhanced the production of IFN-γ in WT mice. Finally, the enhanced production of IFN-γ in IL-18KO mice correlated with increased host defense against cryptococcal infection, as indicated by enhancement in α-GalCer-related clearance of microorganisms. Our results indicated that in IL-18KO mice, IFN-γ synthesis was enhanced through overproduction of IL-12 and IL-4 after intravenous infection with C. neoformans and a ligand-specific activation of Vα14+ NKT cells.

scholarly journals Inhibition of T Helper Cell Type 2 Cell Differentiation and Immunoglobulin E Response by Ligand-Activated Vα14 Natural Killer T Cells

1999 ◽  
Vol 190 (6) ◽  
pp. 783-792 ◽  
Author(s):  
Junqing Cui ◽  
Naohiro Watanabe ◽  
Tetsu Kawano ◽  
Masakatsu Yamashita ◽  
Tohru Kamata ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Natural Killer ◽  
Nkt Cells ◽  
Minor Effect ◽  
Th2 Cell ◽  
Th Cell ◽  
Ifn Γ ◽  
Deficient Mice ◽  
Natural Killer T

Murine Vα14 natural killer T (NKT) cells are thought to play a crucial role in various immune responses, including infectious, allergic, and autoimmune diseases. Because Vα14 NKT cells produce large amounts of both interleukin (IL)-4 and interferon (IFN)-γ upon in vivo stimulation with a specific ligand, α-galactosylceramide (α-GalCer), or after treatment with anti-CD3 antibody, a regulatory role on helper T (Th) cell differentiation has been proposed for these cells. However, the identity of the cytokine produced by Vα14 NKT cells that play a dominant role on the Th cell differentiation still remains controversial. Here, we demonstrate by using Vα14 NKT-deficient mice that Vα14 NKT cells are dispensable for the induction of antigen-specific immunoglobulin (Ig)E responses induced by ovalbumin immunization or Nippostrongylus brasiliensis infection. However, upon in vivo activation with α-GalCer, Vα14 NKT cells are found to suppress antigen-specific IgE production. The suppression appeared to be IgE specific, and was not detected in either Vα14 NKT– or IFN-γ–deficient mice. Consistent with these results, we also found that ligand-activated Vα14 NKT cells inhibited Th2 cell differentiation in an in vitro induction culture system. Thus, it is likely that activated Vα14 NKT cells exert a potent inhibitory effect on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-γ. In marked contrast, our studies have revealed that IL-4 produced by Vα14 NKT cells has only a minor effect on Th2 cell differentiation.

86: Activation of Natural Killer T (NKT) Cells by Alpha-Galactosylceramide Mediates Clearance of E. Coli in Murine Urinary Tract Infection

2004 ◽  
Vol 171 (4S) ◽  
pp. 22-23
Author(s):  
Shingo Minagawa ◽  
Chikara Ohyama ◽  
Shingo Hatakeyama ◽  
Kazunari Sato ◽  
Shigeru Sato ◽  
...  
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Natural Killer ◽  
Nkt Cells ◽  
E Coli ◽  
Natural Killer T

scholarly journals Cytokines and T-Lymphocute count in patients in the acute and chronic phases of Bartonella bacilliformis infection in an endemic area in peru: a pilot study

2011 ◽  
Vol 53 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Erick Huarcaya ◽  
Ivan Best ◽  
Juan Rodriguez-Tafur ◽  
Ciro Maguiña ◽  
Nelson Solórzano ◽  
...  
Keyword(s):  
Pilot Study ◽  
Acute Phase ◽  
Chronic Phase ◽  
Peripheral Tolerance ◽  
Bartonella Bacilliformis ◽  
Cross Sectional ◽  
Bacillary Angiomatosis ◽  
Cd8 T Lymphocyte ◽  
Ifn Γ ◽  
Anti Inflammatory Cytokine

Human Bartonellosis has an acute phase characterized by fever and hemolytic anemia, and a chronic phase with bacillary angiomatosis-like lesions. This cross-sectional pilot study evaluated the immunology patterns using pre- and post-treatment samples in patients with Human Bartonellosis. Patients between five and 60 years of age, from endemic areas in Peru, in the acute or chronic phases were included. In patients in the acute phase of Bartonellosis a state of immune peripheral tolerance should be established for persistence of the infection. Our findings were that elevation of the anti-inflammatory cytokine IL-10 and numeric abnormalities of CD4+ and CD8+ T-Lymphocyte counts correlated significantly with an unfavorable immune state. During the chronic phase, the elevated levels of IFN-γ and IL-4 observed in our series correlated with previous findings of endothelial invasion of B. henselae in animal models.

Sign in / Sign up

Export Citation Format

Share Document