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Immunology
c-Raf participates in adaptive immune response of Nile tilapia via regulating lymphocyte activation.
Dec 12, 2018   Fish & Shellfish Immunology
Wei X, Zhao T, Ai K, Zhang Y, Li H, Yang J
c-Raf participates in adaptive immune response of Nile tilapia via regulating lymphocyte activation.
Dec 12, 2018
Fish & Shellfish Immunology
RAF proto-oncogene serine/threonine-protein kinase (c-Raf) is a MAP kinase kinase kinase (MAPKKK) that participates in the Erk1/2 pathway and plays an important role in lymphocyte activation. However, the study on how c-Raf regulates adaptive immunity in non-mammal is still limited. In present study, based on analysis of sequence characteristics of c-Raf from Oreochromis niloticus (On-c-Raf), we investigated its regulation roles on teleost lymphocyte activation. The On-c-Raf was highly conserved during evolution, which was composed of a Raf-like Ras-binding domain (RBD), a protein kinase C conserved region 1 (C1) domain and a serine/threonine protein kinase catalytic (S_TKc) domain. Its mRNA showed a wide distribution in tissues of O. niloticus and with the highest expression in gill. After Aeromonas hydrophila infection, during the adaptive immune stage transcription level of On-c-Raf was significantly upregulated on day 8, but came back to original level on day 16 and 30, suggesting the potential involvement of On-c-Raf in primary response but not memory formation. Furthermore, On-c-Raf mRNA in leukocytes of Nile tilapias was obviously induced by in vitro stimulation of T cell mitogen PHA. More importantly, in vitro stimulation of lymphocytes agonist PMA augmented phosphorylation level of On-c-Raf in leukocytes detected by western-blot and immunofluorescent. Thus, c-Raf regulated lymphocyte activation of Nile tilapia on both mRNA and phosphorylation level. Together, our results revealed that the c-Raf from teleost Nile tilapia engaged in adaptive immune response by regulating lymphocytes activation. Since the regulatory mechanism of lymphocyte-mediated adaptive immunity is largely unknown in teleost, our study provided important evidences to understand teleost adaptive immunity, and also shed a novel perspective for the evolution of adaptive immune system.
Mitochondrial Dynamics Is Critical for the Full Pluripotency and Embryonic Developmental Potential of Pluripotent Stem Cells.
Dec 11, 2018   Cell Metabolism
Zhong X, Cui P, Cai Y, Wang L, He X,   . . . . . .   , Zhao X, Li W, Zhang H, Zhou Q, Gao P
Mitochondrial Dynamics Is Critical for the Full Pluripotency and Embryonic Developmental Potential of Pluripotent Stem Cells.
Dec 11, 2018
Cell Metabolism
While the pluripotency of stem cells is known to determine the fate of embryonic development, the mechanisms underlying the acquisition and maintenance of full pluripotency largely remain elusive. Here, we show that the balance between mitochondrial fission and fusion is critical for the full pluripotency of stem cells. By analyzing induced pluripotent stem cells with differential developmental potential, we found that excess mitochondrial fission is associated with an impaired embryonic developmental potential. We further uncover that the disruption of mitochondrial dynamics impairs the differentiation and embryonic development of pluripotent stem cells; most notably, pluripotent stem cells that display excess mitochondrial fission fail to produce live-born offspring by tetraploid complementation. Mechanistically, excess mitochondrial fission increases cytosolic Ca2+ entry and CaMKII activity, leading to ubiquitin-mediated proteasomal degradation of β-Catenin protein. Our results reveal a previously unappreciated fundamental role for mitochondrial dynamics in determining the full pluripotency and embryonic developmental potential of pluripotent stem cells.
A Click-Chemistry Linked 2'3'-cGAMP Analog.
Dec 11, 2018   Chemistry (Weinheim An Der Bergstrasse, Germany)
Dialer CR, Stazzoni S, Drexler DJ, Müller FM, Veth S, Pichler A, Okamura H, Witte G, Hopfner KP, Carell T
A Click-Chemistry Linked 2'3'-cGAMP Analog.
Dec 11, 2018
Chemistry (Weinheim An Der Bergstrasse, Germany)
2'3'-cGAMP is an uncanonical cyclic dinucleotide where one A and one G base are connected via a 3'-5' and a unique 2'-5' linkage. The molecule is produced by the cyclase cGAS in response to cytosolic DNA binding. cGAMP activates STING and hence one of the most powerful pathways of innate immunity. cGAMP analogs with uncharged linkages that feature better cellular penetrability are currently highly desired. Here, we report the synthesis of a cGAMP analog with one amide and one triazole linkage. The molecule is best prepared via a first Cu(I) catalysed click reaction which establishes the triazole, while the cyclization is achieved by macrolactamization.
Multi-type Galton-Watson Processes with Affinity-Dependent Selection Applied to Antibody Affinity Maturation.
Dec 11, 2018   Bulletin Of Mathematical Biology
Balelli I, Milišić V, Wainrib G
Multi-type Galton-Watson Processes with Affinity-Dependent Selection Applied to Antibody Affinity Maturation.
Dec 11, 2018
Bulletin Of Mathematical Biology
We analyze the interactions between division, mutation and selection in a simplified evolutionary model, assuming that the population observed can be classified into fitness levels. The construction of our mathematical framework is motivated by the modeling of antibody affinity maturation of B-cells in germinal centers during an immune response. This is a key process in adaptive immunity leading to the production of high-affinity antibodies against a presented antigen. Our aim is to understand how the different biological parameters affect the system's functionality. We identify the existence of an optimal value of the selection rate, able to maximize the number of selected B-cells for a given generation.
Cytidine deaminase enables Toll-like receptor 8 activation by cytidine or its analogs.
Dec 11, 2018   International Immunology
Furusho K, Shibata T, Sato R, Fukui R, Motoi Y, Zhang Y, Saitoh SI, Ichinohe T, Moriyama M, Nakamura S, Miyake K
Cytidine deaminase enables Toll-like receptor 8 activation by cytidine or its analogs.
Dec 11, 2018
International Immunology
Toll-like receptor 8 (TLR8), a sensor for pathogen-derived single-stranded RNA (ssRNA), binds to uridine (Uri) and ssRNA to induce defense responses. We here show that cytidine (Cyd) with ssRNA also activated TLR8 in peripheral blood leukocytes (PBLs) and a myeloid cell line U937, but not in an embryonic kidney cell line 293T. Cyd deaminase (CDA), an enzyme highly expressed in leukocytes, deaminates Cyd to Uri. CDA expression enabled TLR8 response to Cyd and ssRNA in 293T cells. CDA deficiency and a CDA inhibitor both reduced TLR8 responses to Cyd and ssRNA in U937. The CDA inhibitor also reduced PBL response to Cyd and ssRNA. A Cyd analogue, azacytidine, is used for the therapy of myelodysplastic syndrome and acute myeloid leukemia. Azacytidine with ssRNA induced tumor necrosis factor-α expression in U937 and PBLs in a manner dependent on CDA and TLR8. These results suggest that CDA enables TLR8 activation by Cyd or its analogues with ssRNA through deaminating activity. Nucleoside metabolism might impact TLR8 responses in a variety of situations such as the treatment with nucleoside analogues.
Targeting tumor cells with antibodies enhances anti-tumor immunity.
Dec 11, 2018   Biophysics Reports
Sun Z, Fu YX, Peng H
Targeting tumor cells with antibodies enhances anti-tumor immunity.
Dec 11, 2018
Biophysics Reports
Tumor-targeting antibodies were initially defined as a group of therapeutic monoclonal antibodies (mAb) that recognize tumor-specific membrane proteins, block cell signaling, and induce tumor-killing through Fc-driven innate immune responses. However, in the past decade, ample evidence has shown that tumor-targeting mAb (TTmAb) eradicates tumor cells via activation of cytotoxic T cells (CTLs). In this review, we specifically focus on how TTmAbs induce adaptive anti-tumor immunity and its potential in combination therapy with immune cytokines, checkpoint blockade, radiation, and enzyme-targeted small molecule drugs. Exploring the mechanisms of these preclinical studies and retrospective clinical data will significantly benefit the development of highly efficient and specific TTmAb-oriented anti-tumor remedies.
Role of Adaptive and Innate Immunity in Type 2 Diabetes Mellitus.
Dec 11, 2018   Journal Of Diabetes Research
Zhou T, Hu Z, Yang S, Sun L, Yu Z, Wang G
Role of Adaptive and Innate Immunity in Type 2 Diabetes Mellitus.
Dec 11, 2018
Journal Of Diabetes Research
After the recognition of the essential role of the immune system in the progression of type 2 diabetes mellitus, more studies are focused on the effects produced by the abnormal differentiation of components of the immune system. In patients suffering from obesity or T2DM, there were alterations in proliferation of T cells and macrophages, and impairment in function of NK cells and B cells, which represented abnormal innate and adaptive immunity. The abnormality of either innate immunity, adaptive immunity, or both was involved and interacted with each other during the progression of T2DM. Although previous studies have revealed the functional involvement of T cells in T2DM, and the regulation of metabolism by the innate or adaptive immune system during the pathogenesis of T2DM, there has been a lack of literature reviewing the relevant role of adaptive and innate immunity in the progression of T2DM. Here, we will review their relevant roles, aiming to provide new thought for the development of immunotherapy in T2DM.
Role of a fluid-phase PRR in fighting an intracellular pathogen: PTX3 in Shigella infection.
Dec 11, 2018   PLoS Pathogens
Ciancarella V, Lembo-Fazio L, Paciello I, Bruno AK, Jaillon S, Berardi S, Barbagallo M, Meron-Sudai S, Cohen D, Molinaro A, Rossi G, Garlanda C, Bernardini ML
Role of a fluid-phase PRR in fighting an intracellular pathogen: PTX3 in Shigella infection.
Dec 11, 2018
PLoS Pathogens
Shigella spp. are pathogenic bacteria that cause bacillary dysentery in humans by invading the colonic and rectal mucosa where they induce dramatic inflammation. Here, we have analyzed the role of the soluble PRR Pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity. Mice that had been intranasally infected with S. flexneri were rescued from death by treatment with recombinant PTX3. In vitro PTX3 exerts the antibacterial activity against Shigella, impairing epithelial cell invasion and contributing to the bactericidal activity of serum. PTX3 is produced upon LPS-TLR4 stimulation in accordance with the lipid A structure of Shigella. In the plasma of infected patients, the level of PTX3 amount only correlates strongly with symptom severity. These results signal PTX3 as a novel player in Shigella pathogenesis and its potential role in fighting shigellosis. Finally, we suggest that the plasma level of PTX3 in shigellosis patients could act as a biomarker for infection severity.
Molecular cloning and functional characterization of a short peptidoglycan recognition protein from triangle-shell pearl mussel (Hyriopsis cumingii).
Dec 12, 2018   Fish & Shellfish Immunology
Huang Y, Pan J, Li X, Ren Q, Zhao Z
Molecular cloning and functional characterization of a short peptidoglycan recognition protein from triangle-shell pearl mussel (Hyriopsis cumingii).
Dec 12, 2018
Fish & Shellfish Immunology
Peptidoglycan (PGN) is an important target of recognition in invertebrate innate immunity. PGN recognition proteins (PGRPs) are responsible for PGN recognition. In this study, we cloned and functionally analyzed a short PGRP (HcPGRP2) from the triangle-shell pearl mussel Hyriopsis cumingii. The full-length cDNA sequence of HcPGRP2 gene was 1185 bp containing an open reading frame of 882 bp encoding a 293 amino acid protein. HcPGRP2 was predicted to have two SH3b domains and a conserved C-terminal PGRP domain. Quantitative real-time RT-PCR showed that HcPGRP2 was expressed in all examined tissues and its expression was induced most significantly by Staphylococcus aureus and Vibrio parahaemolyticus in the hepatopancreas and gills. RNA interference by siRNA results revealed that HcPGRP2 was involved in the regulation of whey acidic protein, theromacin, and defensin expression. As a pattern-recognition receptor, recombinant HcPGRP2 (rHcPGRP2) protein can bind and agglutinate (Ca2+ dependent) all tested bacteria. rHcPGRP2 exhibited specific binding to PGN but not to lipopolysaccharide. Moreover, rHcPGRP2 inhibited the growth activities of S. aureus and V. parahaemolyticus in vitro and accelerated the clearance of V. parahaemolyticus in vivo. Overall, our results indicated that HcPGRP2 may play an important role in the antibacterial immune mechanisms of H. cumingii.
Leishmania infection: Misdiagnosis as cancer and tumor-promoting potential.
Dec 11, 2018   Acta Tropica
Schwing A, Pomares C, Majoor A, Boyer L, Marty P, Michel G
Leishmania infection: Misdiagnosis as cancer and tumor-promoting potential.
Dec 11, 2018
Acta Tropica
Given the prevalence of cancer and leishmaniasis worldwide, the presence of these two pathologies in the same tissue sample may be merely fortuitous. The clinical outcome of both diseases is under the control of innate and adaptive immunity, and in both cases these progressive diseases are characterized by an impaired host Th1 response. As a consequence, the Th2 cytokine microenvironment occurring in progressive leishmaniasis may potentially promote tumor cell proliferation and vice versa. On the other hand, clinical aspects of subclinical cutaneous or visceral leishmaniasis sometimes closely resemble those observed in various neoplasms thus leading to misdiagnosis. In this review, we present recent findings on the association between leishmaniasis and malignant disorders. Our review includes HIV positive, HIV negative subjects and patients whose HIV status has not been established. Leishmaniasis mimicking a malignant disorder was confirmed and extended to unreported neoplastic disorders including squamous cell carcinoma, T-cell and B-cell lymphoma, oral and intranasal tumors and granulomas. Thus, leishmaniasis should be considered in the differential diagnosis and course of various cancers in Leishmania endemic areas or in patients with travel history to these areas. We also listed recent reports showing that Leishmania can promote cancer development in immunocompromised as well as in immunocompetent patients. The potential mechanisms supporting this promoting effect are discussed.
Mapping of γ/δ T cells reveals Vδ2+ T cells resistance to senescence.
Dec 11, 2018   EBioMedicine
Xu W, Monaco G, Wong EH, Tan WLW, Kared H,   . . . . . .   , Ng TP, Foo R, Akbar AN, Fülöp T, Larbi A
Mapping of γ/δ T cells reveals Vδ2+ T cells resistance to senescence.
Dec 11, 2018
EBioMedicine
BACKGROUND: Immune adaptation with aging is a major of health outcomes. Studies in humans have mainly focus on αβ T cells while γδ T cells have been neglected despite their role in immunosurveillance. We investigated the impact of aging on γδ T cell subsets phenotypes, functions, senescence and their molecular response to stress. METHODS: Peripheral blood of young and old donors in Singapore have been used to assess the phenotype, functional capacity, proliferation capacity and gene expression of the various γδ T cell subsets. Peripheral blood mononuclear cells from apheresis cones and young donors have been used to characterize the telomere length, epigenetics profile and DNA damage response of the various γδ T cell subsets phenotype. FINDINGS: Our data shows that peripheral Vδ2+ phenotype, functional capacity (cytokines, cytotoxicity, proliferation) and gene expression profile are specific when compared against all other αβ and γδ T cells in aging. Hallmarks of senescence including telomere length, epigenetic profile and DNA damage response of Vδ2+ also differs against all other αβ and γδ T cells. INTERPRETATION: Our results highlight the differential impact of lifelong stress on γδ T cells subsets, and highlight possible mechanisms that enable Vδ2+ to be resistant to cellular aging. The new findings reinforce the concept that Vδ2+ have an "innate-like" behavior and are more resilient to the environment as compared to "adaptive-like" Vδ1+ T cells.
Neutralization of IL-18 by IL-18 binding protein ameliorates bleomycin-induced pulmonary fibrosis via inhibition of epithelial-mesenchymal transition.
Dec 11, 2018   Biochemical And Biophysical Research Communications
Zhang LM, Zhang Y, Fei C, Zhang J, Wang L, Yi ZW, Gao G
Neutralization of IL-18 by IL-18 binding protein ameliorates bleomycin-induced pulmonary fibrosis via inhibition of epithelial-mesenchymal transition.
Dec 11, 2018
Biochemical And Biophysical Research Communications
Idiopathic pulmonary fibrosis (IPF) is a fatal parenchymal lung disease with limited effective therapies. Interleukin (IL)-18 belongs to a rather large IL-1 gene family and is a proinflammatory cytokine, which acts in both acquired and innate immunity. We have previously reported that IL-18 play an important role in lipopolysaccharide-induced acute lung injury in mice. Persistent inflammation often drives fibrotic progression in the bleomycin (BLM) injury model. However, the role of IL-18 in pulmonary fibrosis (PF) is still unknown. IL-18 binding protein (IL-18BP) is able to neutralize IL-18 biological activity and has a protective effect against renal fibrosis. The aim of this study was to investigate the effects of IL-18BP on BLM-induced PF. In the present study, we found that IL-18 was upregulated in lungs of BLM-injured mice. Neutralization of IL-18 by IL-18BP improved the survival rate and ameliorated BLM-induced PF in mice, which was associated with attenuated pathological changes, reduced collagen deposition, and decreased content of transforming growth factor-β1 (TGF-β1). We further demonstrated that IL-18BP treatment suppressed the BLM-induced epithelial mesenchymal transition (EMT), characterized by decreased α-smooth muscle actin (α-SMA) and increased E-cadherin (E-cad) in vivo. In addition, we provided in vitro evidence demonstrating that IL-18 promoted EMT through upregulation of Snail-1 in A549 cells. In conclusion, our findings raise the possibility that the increase of IL-18 is involved in the development of BLM-induced PF through modulating EMT in a Snail-1-dependent manner. IL-18BP may be a worthwhile candidate option for PF therapy.
Structural Insights into the Mechanism of Dynamin Superfamily Proteins.
Dec 11, 2018   Trends In Cell Biology
Jimah JR, Hinshaw JE
Structural Insights into the Mechanism of Dynamin Superfamily Proteins.
Dec 11, 2018
Trends In Cell Biology
Dynamin superfamily proteins (DSPs) mediate membrane fission and fusion necessary for endocytosis, organelle biogenesis and maintenance, as well as for bacterial cytokinesis. They also function in the innate immune response to pathogens and in organizing the cytoskeleton. In this review, we summarize the current understanding of the molecular mechanism of DSPs, with emphasis on the structural basis of function. Studies from the past decade on the structure and mechanism of DSPs enable comparative analysis of shared mechanisms and unique features of this protein family.
Mepazine Inhibits RANK-Induced Osteoclastogenesis Independent of Its MALT1 Inhibitory Function.
Dec 05, 2018   Molecules (Basel, Switzerland)
Meloni L, Verstrepen L, Kreike M, Staal J, Driege Y, Afonina IS, Beyaert R
Mepazine Inhibits RANK-Induced Osteoclastogenesis Independent of Its MALT1 Inhibitory Function.
Dec 05, 2018
Molecules (Basel, Switzerland)
Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is an intracellular cysteine protease (paracaspase) that plays an integral role in innate and adaptive immunity. The phenothiazine mepazine has been shown to inhibit the proteolytic activity of MALT1 and is frequently used to study its biological role. MALT1 has recently been suggested as a therapeutic target in rheumatoid arthritis. Here, we analyzed the effect of mepazine on the receptor activator of nuclear factor κ-B (RANK)-induced osteoclastogenesis. The treatment of mouse bone marrow precursor cells with mepazine strongly inhibited the RANK ligand (RANKL)-induced formation of osteoclasts, as well as the expression of several osteoclast markers, such as TRAP, cathepsin K, and calcitonin. However, RANKL induced osteoclastogenesis equally well in bone marrow cells derived from wild-type and Malt1 knock-out mice. Furthermore, the protective effect of mepazine was not affected by MALT1 deficiency. Additionally, the absence of MALT1 did not affect RANK-induced nuclear factor κB (NF-κB) and activator protein 1 (AP-1) activation. Overall, these studies demonstrate that MALT1 is not essential for RANK-induced osteoclastogenesis, and implicate a MALT1-independent mechanism of action of mepazine that should be taken into account in future studies using this compound.
NF-κB p65 dimerization and DNA-binding is important for inflammatory gene expression.
Dec 11, 2018   FASEB Journal : Official Publication Of The Federation Of American Societies For Experimental Biology
Riedlinger T, Liefke R, Meier-Soelch J, Jurida L, Nist A, Stiewe T, Kracht M, Schmitz ML
NF-κB p65 dimerization and DNA-binding is important for inflammatory gene expression.
Dec 11, 2018
FASEB Journal : Official Publication Of The Federation Of American Societies For Experimental Biology
Increasing evidence shows that many transcription factors execute important biologic functions independent from their DNA-binding capacity. The NF-κB p65 (RELA) subunit is a central regulator of innate immunity. Here, we investigated the relative functional contribution of p65 DNA-binding and dimerization in p65-deficient human and murine cells reconstituted with single amino acid mutants preventing either DNA-binding (p65 E/I) or dimerization (p65 FL/DD). DNA-binding of p65 was required for RelB-dependent stabilization of the NF-κB p100 protein. The antiapoptotic function of p65 and expression of the majority of TNF-α-induced genes were dependent on p65's ability to bind DNA and to dimerize. Chromatin immunoprecipitation with massively parallel DNA sequencing experiments revealed that impaired DNA-binding and dimerization strongly diminish the chromatin association of p65. However, there were also p65-independent TNF-α-inducible genes and a subgroup of p65 binding sites still allowed some residual chromatin association of the mutants. These sites were enriched in activator protein 1 (AP-1) binding motifs and showed increased chromatin accessibility and basal transcription. This suggests a mechanism of assisted p65 chromatin association that can be in part facilitated by chromatin priming and cooperativity with other transcription factors such as AP-1.-Riedlinger, T., Liefke, R., Meier-Soelch, J., Jurida, L., Nist, A., Stiewe, T., Kracht, M., Schmitz, M. L. NF-κB p65 dimerization and DNA-binding is important for inflammatory gene expression.
Impact of HLA allele-KIR pairs on HIV clinical outcome in South Africa.
Dec 06, 2018   The Journal Of Infectious Diseases
Mori M, Leitman E, Walker B, Ndung'u T, Carrington M, Goulder P
Impact of HLA allele-KIR pairs on HIV clinical outcome in South Africa.
Dec 06, 2018
The Journal Of Infectious Diseases
Background: HLA class I contributes to HIV immune control through antigen presentation to both cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. However, by contrast with investigations of CTL, studies of NK cells in HIV control through HLA-killer immunoglobulin-like receptor (KIR) interactions remain sparse in African cohorts. Methods: 312 treatment naïve, chronically HIV-infected adults were recruited from South Africa, and the effects of HLA-KIR pairs on clinical outcome were statistically analyzed. Results: There was no significant difference in viral load among all subjects with HLA alleles from the HLA-C1 group (p=0.1). However, differences in HLA-C type significantly influenced viremia among 247 KIR2DL3 positives (p=0.04), suggesting that specific HLA-KIR interactions contribute to immune control. Higher viral load (p=0.02) and lower CD4+ T cell counts (p=0.008) were observed in subjects with HLA-C*16:01+KIR2DL3+. Longitudinal analysis showed more rapid progression to AIDS among HLA-C*16:01+KIR2DL3+ positives (aHR 1.9, p=0.03) than in subjects without this genotype, independent of CD4+ T cell count and viral load. Conclusions: These highlight the existence of unique anti-HIV innate immunity within distinct populations and the contribution of KIR on NK cells and some CTLs to the well-described HLA-mediated impact on HIV disease progression.
SUMO conjugation to the pattern recognition receptor FLS2 triggers intracellular signalling in plant innate immunity.
Dec 12, 2018   Nature Communications
Orosa B, Yates G, Verma V, Srivastava AK, Srivastava M, Campanaro A, De Vega D, Fernandes A, Zhang C, Lee J, Bennett MJ, Sadanandom A
SUMO conjugation to the pattern recognition receptor FLS2 triggers intracellular signalling in plant innate immunity.
Dec 12, 2018
Nature Communications
Detection of conserved microbial patterns by host cell surface pattern recognition receptors (PRRs) activates innate immunity. The FLAGELLIN-SENSITIVE 2 (FLS2) receptor perceives bacterial flagellin and recruits another PRR, BAK1 and the cytoplasmic-kinase BIK1 to form an active co-receptor complex that initiates antibacterial immunity in Arabidopsis. Molecular mechanisms that transmit flagellin perception from the plasma-membrane FLS2-associated receptor complex to intracellular events are less well understood. Here, we show that flagellin induces the conjugation of the SMALL UBIQUITIN-LIKE MODIFIER (SUMO) protein to FLS2 to trigger release of BIK1. Disruption of FLS2 SUMOylation can abolish immune responses, resulting in susceptibility to bacterial pathogens in Arabidopsis. We also identify the molecular machinery that regulates FLS2 SUMOylation and demonstrate a role for the deSUMOylating enzyme, Desi3a in innate immunity. Flagellin induces the degradation of Desi3a and enhances FLS2 SUMOylation to promote BIK1 dissociation and trigger intracellular immune signalling.
Robust adaptive immune response against Babesia microti infection marked by low parasitemia in a murine model of sickle cell disease.
Dec 13, 2018   Blood Advances
Yi W, Bao W, Rodriguez M, Liu Y, Singh M, Ramlall V, Cursino-Santos JR, Zhong H, Elton CM, Wright GJ, Mendelson A, An X, Lobo CA, Yazdanbakhsh K
Robust adaptive immune response against Babesia microti infection marked by low parasitemia in a murine model of sickle cell disease.
Dec 13, 2018
Blood Advances
The intraerythrocytic parasite Babesia microti is the number 1 cause of transfusion-transmitted infection and can induce serious, often life-threatening complications in immunocompromised individuals including transfusion-dependent patients with sickle cell disease (SCD). Despite the existence of strong long-lasting immunological protection against a second infection in mouse models, little is known about the cell types or the kinetics of protective adaptive immunity mounted following Babesia infection, especially in infection-prone SCD that are thought to have an impaired immune system. Here, we show, using a mouse B microti infection model, that infected wild-type (WT) mice mount a very strong adaptive immune response, characterized by (1) coordinated induction of a robust germinal center (GC) reaction; (2) development of follicular helper T (TFH) cells that comprise ∼30% of splenic CD4+ T cells at peak expansion by 10 days postinfection; and (3) high levels of effector T-cell cytokines, including interleukin 21 and interferon γ, with an increase in the secretion of antigen (Ag)-specific antibodies (Abs). Strikingly, the Townes SCD mouse model had significantly lower levels of parasitemia. Despite a highly disorganized splenic architecture before infection, these mice elicited a surprisingly robust adaptive immune response (including comparable levels of GC B cells, TFH cells, and effector cytokines as control and sickle trait mice), but higher immunoglobulin G responses against 2 Babesia-specific proteins, which may contain potential immunogenic epitopes. Together, these studies establish the robust emergence of adaptive immunity to Babesia even in immunologically compromised SCD mice. Identification of potentially immunogenic epitopes has implications to identify long-term carriers, and aid Ag-specific vaccine development.
ISRE-Reporter Mouse Reveals High Basal and Induced Type I IFN Responses in Inflammatory Monocytes.
Dec 05, 2018   Cell Reports
Uccellini MB, García-Sastre A
ISRE-Reporter Mouse Reveals High Basal and Induced Type I IFN Responses in Inflammatory Monocytes.
Dec 05, 2018
Cell Reports
Type I and type III interferons (IFNs) are critical for controlling viral infections. However, the precise dynamics of the IFN response have been difficult to define in vivo. Signaling through type I IFN receptors leads to interferon-stimulated response element (ISRE)-dependent gene expression and an antiviral state. As an alternative to tracking IFN, we used an ISRE-dependent reporter mouse to define the cell types, localization, and kinetics of IFN responding cells during influenza virus infection. We find that measurable IFN responses are largely limited to hematopoietic cells, which show a high sensitivity to IFN. Inflammatory monocytes display high basal IFN responses, which are enhanced upon infection and correlate with infection of these cells. We find that inflammatory monocyte development is independent of IFN signaling; however, IFN is critical for chemokine production and recruitment following infection. The data reveal a role for inflammatory monocytes in both basal IFN responses and responses to infection.
CMV Primes Functional Alternative Signaling in Adaptive Δg NK Cells but Is Subverted by Lentivirus Infection in Rhesus Macaques.
Dec 05, 2018   Cell Reports
Shah SV, Manickam C, Ram DR, Kroll K, Itell H, Permar SR, Barouch DH, Klatt NR, Reeves RK
CMV Primes Functional Alternative Signaling in Adaptive Δg NK Cells but Is Subverted by Lentivirus Infection in Rhesus Macaques.
Dec 05, 2018
Cell Reports
Despite burgeoning evidence demonstrating the adaptive properties of natural killer (NK) cells, mechanistic data explaining these phenomena are lacking. Following antibody sensitization, NK cells lacking the Fc receptor (FcR) signaling chain (Δg) acquire adaptive features, including robust proliferation, multifunctionality, rapid killing, and mobilization to sites of virus exposure. Using the rhesus macaque model, we demonstrate the systemic distribution of Δg NK cells expressing memory features, including downregulated Helios and Eomes. Furthermore, we find that Δg NK cells abandon typical γ-chain/Syk in lieu of CD3ζ-Zap70 signaling. FCγRIIIa (CD16) density, mucosal homing, and function are all coupled to this alternate signaling, which in itself requires priming by rhesus cytomegalovirus (rhCMV). Simian immunodeficiency virus (SIV) infections further expand gut-homing adaptive NK cells but result in pathogenic suppression of CD3ζ-Zap70 signaling and function. Herein, we provide a mechanism of virus-dependent alternative signaling that may explain the acquisition of adaptive features by primate NK cells and could be targeted for future vaccine or curative therapies.
Sirtuin 5 Deficiency Does Not Compromise Innate Immune Responses to Bacterial Infections.
Dec 05, 2018   Frontiers In Immunology
Heinonen T, Ciarlo E, Théroude C, Pelekanou A, Herderschee J, Le Roy D, Roger T
Sirtuin 5 Deficiency Does Not Compromise Innate Immune Responses to Bacterial Infections.
Dec 05, 2018
Frontiers In Immunology
Sirtuin 5 (SIRT5) is a member of the family of NAD+-dependent lysine/histone deacetylases. SIRT5 resides mainly in the mitochondria where it catalyzes deacetylation, demalonylation, desuccinylation, and deglutarylation of lysine to regulate metabolic and oxidative stress response pathways. Pharmacologic inhibitors of SIRT5 are under development for oncologic conditions, but nothing is known about the impact of SIRT5 on antimicrobial innate immune defenses. Using SIRT5 knockout mice, we show that SIRT5 deficiency does not affect immune cell development, cytokine production and proliferation by macrophages and splenocytes exposed to microbial and immunological stimuli. Moreover, preclinical models suggest that SIRT5 deficiency does not worsen endotoxemia, Klebsiella pneumoniae and Streptococcus pneumoniae pneumonia, Escherichia coli peritonitis, listeriosis, and staphylococcal infection. Altogether, these data support the safety profile in terms of susceptibility to infections of SIRT5 inhibitors under development.
Potent Cas9 Inhibition in Bacterial and Human Cells by AcrIIC4 and AcrIIC5 Anti-CRISPR Proteins.
Dec 13, 2018   MBio
Lee J, Mir A, Edraki A, Garcia B, Amrani N, Lou HE, Gainetdinov I, Pawluk A, Ibraheim R, Gao XD, Liu P, Davidson AR, Maxwell KL, Sontheimer EJ
Potent Cas9 Inhibition in Bacterial and Human Cells by AcrIIC4 and AcrIIC5 Anti-CRISPR Proteins.
Dec 13, 2018
MBio
In their natural settings, CRISPR-Cas systems play crucial roles in bacterial and archaeal adaptive immunity to protect against phages and other mobile genetic elements, and they are also widely used as genome engineering technologies. Previously we discovered bacteriophage-encoded Cas9-specific anti-CRISPR (Acr) proteins that serve as countermeasures against host bacterial immunity by inactivating their CRISPR-Cas systems (A. Pawluk, N. Amrani, Y. Zhang, B. Garcia, et al., Cell 167:1829-1838.e9, 2016, https://doi.org/10.1016/j.cell.2016.11.017). We hypothesized that the evolutionary advantages conferred by anti-CRISPRs would drive the widespread occurrence of these proteins in nature (K. L. Maxwell, Mol Cell 68:8-14, 2017, https://doi.org/10.1016/j.molcel.2017.09.002; A. Pawluk, A. R. Davidson, and K. L. Maxwell, Nat Rev Microbiol 16:12-17, 2018, https://doi.org/10.1038/nrmicro.2017.120; E. J. Sontheimer and A. R. Davidson, Curr Opin Microbiol 37:120-127, 2017, https://doi.org/10.1016/j.mib.2017.06.003). We have identified new anti-CRISPRs using the same bioinformatic approach that successfully identified previous Acr proteins (A. Pawluk, N. Amrani, Y. Zhang, B. Garcia, et al., Cell 167:1829-1838.e9, 2016, https://doi.org/10.1016/j.cell.2016.11.017) against Neisseria meningitidis Cas9 (NmeCas9). In this work, we report two novel anti-CRISPR families in strains of Haemophilus parainfluenzae and Simonsiella muelleri, both of which harbor type II-C CRISPR-Cas systems (A. Mir, A. Edraki, J. Lee, and E. J. Sontheimer, ACS Chem Biol 13:357-365, 2018, https://doi.org/10.1021/acschembio.7b00855). We characterize the type II-C Cas9 orthologs from H. parainfluenzae and S. muelleri, show that the newly identified Acrs are able to inhibit these systems, and define important features of their inhibitory mechanisms. The S. muelleri Acr is the most potent NmeCas9 inhibitor identified to date. Although inhibition of NmeCas9 by anti-CRISPRs from H. parainfluenzae and S. muelleri reveals cross-species inhibitory activity, more distantly related type II-C Cas9s are not inhibited by these proteins. The specificities of anti-CRISPRs and divergent Cas9s appear to reflect coevolution of their strategies to combat or evade each other. Finally, we validate these new anti-CRISPR proteins as potent off-switches for Cas9 genome engineering applications.IMPORTANCE As one of their countermeasures against CRISPR-Cas immunity, bacteriophages have evolved natural inhibitors known as anti-CRISPR (Acr) proteins. Despite the existence of such examples for type II CRISPR-Cas systems, we currently know relatively little about the breadth of Cas9 inhibitors, and most of their direct Cas9 targets are uncharacterized. In this work we identify two new type II-C anti-CRISPRs and their cognate Cas9 orthologs, validate their functionality in vitro and in bacteria, define their inhibitory spectrum against a panel of Cas9 orthologs, demonstrate that they act before Cas9 DNA binding, and document their utility as off-switches for Cas9-based tools in mammalian applications. The discovery of diverse anti-CRISPRs, the mechanistic analysis of their cognate Cas9s, and the definition of Acr inhibitory mechanisms afford deeper insight into the interplay between Cas9 orthologs and their inhibitors and provide greater scope for exploiting Acrs for CRISPR-based genome engineering.
Purinergic targeting enhances immunotherapy of CD73+ solid tumors with piggyBac-engineered chimeric antigen receptor natural killer cells.
Dec 11, 2018   Journal For Immunotherapy Of Cancer
Wang J, Lupo KB, Chambers AM, Matosevic S
Purinergic targeting enhances immunotherapy of CD73+ solid tumors with piggyBac-engineered chimeric antigen receptor natural killer cells.
Dec 11, 2018
Journal For Immunotherapy Of Cancer
BACKGROUND: The anti-tumor immunity of natural killer (NK) cells can be paralyzed by the CD73-induced generation of immunosuppressive adenosine from precursor ATP within the hypoxic microenvironment of solid tumors. In an effort to redirect purinergic immunosuppression of NK cell anti-tumor function, we showed, for the first time, that immunometabolic combination treatment with NKG2D-engineered CAR-NK cells alongside blockade of CD73 ectonucleotidase activity can result in significant anti-tumor responses in vivo. METHODS: NK cells were engineered non-virally with NKG2D.CAR-presenting vectors based on the piggyBac transposon system with DAP10 and CD3ζ co-signaling domains. The anti-tumor immunity of NKG2D.CAR.NK cells in combination with CD73 targeting was evaluated against multiple solid tumor targets in vitro and humanized mouse xenografts in immunodeficient tumor-bearing mice in vivo. Intratumoral migration was evaluated via immunohistochemical staining, while degranulation capacity and IFN-γ production of NK cells were measured in response to solid tumor targets. RESULTS: Our results showed that CD73 blockade can mediate effective purinergic reprogramming and enhance anti-tumor cytotoxicity both in vitro and in vivo by enhancing the killing ability of CAR-engineered NK cells against CD73+ solid tumor targets via mechanisms that might imply alleviation from adenosinergic immunometabolic suppression. CD73 blockade improved the intratumoral homing of CD56+ CAR-NK cells in vivo. These engineered NK cells showed synergistic therapeutic efficacy in combination with CD73 targeting against CD73+ human lung cancer xenograft models. Interestingly, CD73 blockade could inhibit tumor growth in vivo independently of adaptive immune cells, innate immunity or NK cell-mediated ADCC. CONCLUSIONS: Immunotherapies targeting the adenosinergic signaling cascade, which act by neutralizing CD73 ectoenzymatic activity, had thus far not been evaluated in humanized tumor models, nor had the implication of innate immunity been investigated. Taken together, our pre-clinical efficacy data demonstrate, for the first time, the potential of targeting CD73 to modulate purinergic signaling and enhance adoptive NK cell immunotherapy via mechanisms that could implicate autocrine tumor control as well as by mediating adenosinergic signaling.
Nitrite Enhances MC-LR-Induced Changes on Splenic Oxidation Resistance and Innate Immunity in Male Zebrafish.
Dec 05, 2018   Toxins
Lin W, Guo H, Wang L, Zhang D, Wu X, Li L, Li D, Tang R
Nitrite Enhances MC-LR-Induced Changes on Splenic Oxidation Resistance and Innate Immunity in Male Zebrafish.
Dec 05, 2018
Toxins
Hazardous contaminants, such as nitrite and microcystin-leucine arginine (MC-LR), are released into water bodies during cyanobacterial blooms and may adversely influence the normal physiological function of hydrobiontes. The combined effects of nitrite and MC-LR on the antioxidant defense and innate immunity were evaluated through an orthogonal experimental design (nitrite: 0, 29, 290 μM; MC-LR: 0, 3, 30 nM). Remarkable increases in malondialdehyde (MDA) levels have suggested that nitrite and/or MC-LR exposures induce oxidative stress in fish spleen, which were indirectly confirmed by significant downregulations of total antioxidant capacity (T-AOC), glutathione (GSH) contents, as well as transcriptional levels of antioxidant enzyme genes cat1, sod1 and gpx1a. Simultaneously, nitrite and MC-LR significantly decreased serum complement C3 levels as well as the transcriptional levels of splenic c3b, lyz, il1β, ifnγ and tnfα, and indicated that they could jointly impact the innate immunity of fish. The severity and extent of splenic lesions were aggravated by increased concentration of nitrite or MC-LR and became more serious in combined groups. The damages of mitochondria and pseudopodia in splenic macrophages suggest that oxidative stress exerted by nitrite and MC-LR aimed at the membrane structure of immune cells and ultimately disrupted immune function. Our results clearly demonstrate that nitrite and MC-LR exert synergistic suppressive effects on fish innate immunity via interfering antioxidant responses, and their joint toxicity should not be underestimated in eutrophic lakes.
Toll-like receptor 2 regulates metabolic reprogramming in gastric cancer via superoxide dismutase 2.
Dec 11, 2018   International Journal Of Cancer
Liu YD, Yu L, Ying L, Balic J, Gao H, Deng NT, West A, Yan F, Ji CB, Gough D, Tan P, Jenkins BJ, Li JK
Toll-like receptor 2 regulates metabolic reprogramming in gastric cancer via superoxide dismutase 2.
Dec 11, 2018
International Journal Of Cancer
Toll-like receptors (TLRs) play critical roles in host defence following recognition of conserved microbial- and host-derived components, and their dysregulation is a common feature of various inflammation-associated cancers, including gastric cancer (GC). Despite the recent recognition that metabolic reprogramming is a hallmark of cancer, the molecular effectors of altered metabolism during tumorigenesis remain unclear. Here, using bioenergetics function assays on human GC cells, we reveal that ligand-induced activation of TLR2, predominantly through TLR1/2 heterodimer, augments both oxidative phosphorylation (OXPHOS) and glycolysis, with a bias towards glycolytic activity. Notably, DNA microarray-based expression profiling of human cancer cells stimulated with TLR2 ligands demonstrated significant enrichment of gene-sets for oncogenic pathways previously implicated in metabolic regulation, including reactive oxygen species (ROS), p53 and Myc. Moreover, the redox gene encoding the manganese-dependent mitochondrial enzyme, superoxide dismutase (SOD)2, was strongly induced at the mRNA and protein levels by multiple signalling pathways downstream of TLR2, namely JAK-STAT3, JNK MAPK and NF-κB. Furthermore, siRNA-mediated suppression of SOD2 ameliorated the TLR2-induced metabolic shift in human GC cancer cells. Importantly, patient-derived tissue microarrays and bioinformatics interrogation of clinical datasets indicated that upregulated expression of TLR2 and SOD2 were significantly correlated in human GC, and the TLR2-SOD2 axis was associated with multiple clinical parameters of advanced stage disease, including distant metastasis, microvascular invasion and stage, as well as poor survival. Collectively, our findings reveal a novel TLR2-SOD2 axis as a potential biomarker for therapy and prognosis in cancer. This article is protected by copyright. All rights reserved.

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