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1.
Adv Exp Med Biol ; 1209: 7-22, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31728862

RESUMO

Autophagy is a fully competent cellular machinery able to carry out the clearance of macromolecules via fusion with the lysosome. Many studies conducted in recent years have revealed that autophagy not only plays a critical role in maintaining cell homeostasis, but can also promote bacterial elimination. Additionally, autophagy exists in most eukaryotic cells including immune cells, such as lymphocytes, neutrophils, eosinophils, mast cells, and natural killer cells. Presently, there are numerous studies focusing on the roles of autophagy in regulating immune response. Autophagy regulates the innate and adaptive immunity by modulating cell differentiation, survival, phagocytosis, antigen presentation, degranulation, and cytokine production. In this chapter, we will summarize how autophagy participates explicitly in the survival and function of the mammalian adaptive and innate immune cells.


Assuntos
Imunidade Adaptativa , Autofagia , Imunidade Inata , Imunidade Adaptativa/imunologia , Animais , Autofagia/imunologia , Sobrevivência Celular/imunologia , Imunidade Inata/imunologia , Mamíferos/imunologia
2.
J Biol Regul Homeost Agents ; 33(5): 1321-1326, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31663301

RESUMO

It is now well-known that interleukins (ILs) play a pivotal role in shaping innate immunity: inflammatory ILs are responsible for all innate aspects of immune response, from the very first vascular reactions to the chronic non-specific response to inflammation; while anti-inflammatory ILs are responsible for keeping adaptive immunity at bay. The interactions between ILs and adaptive immunity have been long considered secondary to the effects on the innate immune system, but in recent years it has appeared more clearly that IL direct interactions with adaptive immunity are extremely important both in physiologic and pathologic immune response. In the present review we analyze the role of inflammatory ILs (IL-1, IL-6, IL-33 and IL-37) on adaptive immunity and briefly discuss the possible therapeutic perspectives of IL-blockade in adaptive immunity disorders.


Assuntos
Imunidade Adaptativa , Citocinas/imunologia , Humanos , Interleucina-1 , Interleucina-33 , Interleucina-6
3.
Adv Exp Med Biol ; 1186: 99-119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31654387

RESUMO

There is an increasing effort toward generating replacement cells for neuronal application due to the nonregenerative nature of these tissues. While much progress has been made toward developing methodologies to generate these cells, there have been limited improvements in functional restoration. Some of these are linked to the degenerative and often nonreceptive microenvironment that the new cells need to integrate into. In this chapter, we will focus on the status and role of the immune microenvironment of the retina during homeostasis and disease states. We will review changes in both innate and adaptive immunity as well as the role of immune rejection in stem cell replacement therapies. The chapter will end with a discussion of immune-modulatory strategies that have helped to ameliorate these effects and could potentially improve functional outcome for cell replacement therapies for the eye.


Assuntos
Retina , Transplante de Células-Tronco , Imunidade Adaptativa , Microambiente Celular/imunologia , Humanos , Imunidade Inata , Imunomodulação , Neurônios/fisiologia , Retina/imunologia , Degeneração Retiniana/imunologia , Degeneração Retiniana/patologia , Degeneração Retiniana/terapia
4.
Adv Exp Med Biol ; 1172: 21-62, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31628650

RESUMO

Molecules encoded by the Major Histocompatibility Complex (MHC) bind self or foreign peptides and display these at the cell surface for recognition by receptors on T lymphocytes (designated T cell receptors-TCR) or on natural killer (NK) cells. These ligand/receptor interactions govern T cell and NK cell development as well as activation of T memory and effector cells. Such cells participate in immunological processes that regulate immunity to various pathogens, resistance and susceptibility to cancer, and autoimmunity. The past few decades have witnessed the accumulation of a huge knowledge base of the molecular structures of MHC molecules bound to numerous peptides, of TCRs with specificity for many different peptide/MHC (pMHC) complexes, of NK cell receptors (NKR), of MHC-like viral immunoevasins, and of pMHC/TCR and pMHC/NKR complexes. This chapter reviews the structural principles that govern peptide/MHC (pMHC), pMHC/TCR, and pMHC/NKR interactions, for both MHC class I (MHC-I) and MHC class II (MHC-II) molecules. In addition, we discuss the structures of several representative MHC-like molecules. These include host molecules that have distinct biological functions, as well as virus-encoded molecules that contribute to the evasion of the immune response.


Assuntos
Imunidade Adaptativa , Imunidade Inata , Complexo Principal de Histocompatibilidade , Receptores de Antígenos de Linfócitos T , Linfócitos T , Imunidade Adaptativa/imunologia , Animais , Humanos , Imunidade Inata/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Células Matadoras Naturais/química , Receptores de Células Matadoras Naturais/imunologia , Linfócitos T/imunologia
6.
Nat Rev Gastroenterol Hepatol ; 16(11): 662-675, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31548710

RESUMO

Multiple new therapeutic approaches are currently being developed to achieve sustained, off-treatment suppression of HBV, a persistent hepatotropic infection that kills ~2,000 people a day. A fundamental therapeutic goal is the restoration of robust HBV-specific adaptive immune responses that are able to maintain prolonged immunosurveillance of residual infection. Here, we provide insight into key components of successful T cell and B cell responses to HBV, discussing the importance of different specificities and effector functions, local intrahepatic immunity and pathogenic potential. We focus on the parallels and interactions between T cell and B cell responses, highlighting emerging areas for future investigation. We review the potential for different immunotherapies in development to restore or release endogenous adaptive immunity by direct or indirect approaches, including limitations and risks. Finally, we consider an alternative HBV treatment strategy of replacing failed endogenous immunity with infusions of highly targeted T cells or antibodies.


Assuntos
Imunidade Adaptativa/imunologia , Hepatite B Crônica/imunologia , Hepatite B Crônica/terapia , Humanos
7.
Eur J Pharm Biopharm ; 145: 1-6, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31560955

RESUMO

Both Gram-positive and Gram-negative bacteria can release nano-sized lipid bilayered structures, known as membrane vesicles (MVs). These MVs play an important role in bacterial survival by orchestrating interactions between bacteria and between bacteria and host. The major constituents of MVs are proteins, lipids and nucleic acids. Due to the immunogenicity of the membrane lipids and/or proteins of the MVs, in combination with adjuvant danger signals and the repeating patterns on the nanosized surface, MVs can effectively stimulate the innate and adaptive immune system. Since they are non-replicating, they are safer than attenuated vaccines. In addition, by genetic engineering of the donor cells, further improvements to their safety profile, immunogenicity and yield can be achieved. To date, one MV-based vaccine against Neisseria meningitidis (N. meningitidis) serogroup B was approved. Other (engineered) MVs in the pipeline study are mostly in the preclinical phase.


Assuntos
Bactérias/imunologia , Bicamadas Lipídicas/imunologia , Lipídeos de Membrana/imunologia , Membranas/imunologia , Vacinas/imunologia , Imunidade Adaptativa/imunologia , Adjuvantes Imunológicos , Animais , Formação de Anticorpos/imunologia , Proteínas de Bactérias/imunologia , Humanos
8.
Anticancer Res ; 39(9): 4957-4963, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519601

RESUMO

BACKGROUND/AIM: Adjuvant radiotherapy (RT) damages multiple layers of skin, muscle, blood vessels and blood cells that are included within the RT area. Indirect, bystander systemic effects could also develop in cells not directly hit by radiation. MATERIALS AND METHODS: Ninety-three female patients recovering from breast cancer surgery and 82 female healthy blood donors were analyzed. For identification of systemic adaptive and innate immune response, rapid and low-cost blood-based biomarkers were assayed. RESULTS: Post-operated breast cancer patients had a decreased number of circulating adaptive immune response cells but increased number of circulating immunosuppressive myeloid subpopulations. RT decreased the number of T-cells and platelets without influencing the number of immunosuppressive myeloid subpopulations. Alterations in the number and phenotypes of T-cell subpopulations were associated with SNPs. CONCLUSION: The combination of RT and immunotherapy might provide optimal treatment for cancer patients.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/imunologia , Imunidade Celular/genética , Imunidade Celular/efeitos da radiação , Contagem de Leucócitos , Fenótipo , Polimorfismo de Nucleotídeo Único , Imunidade Adaptativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Estudos de Casos e Controles , Feminino , Humanos , Imunidade Inata , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Radioterapia Adjuvante , Linfócitos T/imunologia , Linfócitos T/metabolismo
9.
DNA Cell Biol ; 38(11): 1170-1177, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31502877

RESUMO

Host response to viral infection is a highly regulated process involving engagement of various host factors, cytokines, chemokines, and stimulatory signals that pave the way for an antiviral immune response. The response is manifested in terms of viral sequestration, phagocytosis, and inhibition of genome replication, and, finally, if required, lymphocyte-mediated clearance of virally infected cells. During this process, cross-talk between viral and host factors can shape disease outcomes and immunopathology. Bone marrow stromal antigen 2 (BST-2), also know as tetherin, is induced by type I interferon produced in response to viral infections, as well as in certain cancers. BST-2 has been shown to be a host restriction factor of virus multiplication through its ability to physically tether budding virions and restrict viral spread. However, BST-2 has other roles in the host antiviral response. This review focuses on the diverse functions of BST-2 and its downstream signaling pathways in regulating host immune responses.


Assuntos
Antígenos CD/fisiologia , Imunomodulação/genética , Vírion/imunologia , Vírion/metabolismo , Imunidade Adaptativa/genética , Animais , Antígenos CD/genética , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/fisiologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunomodulação/imunologia , Viroses/genética , Viroses/imunologia
10.
DNA Cell Biol ; 38(11): 1257-1268, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31553224

RESUMO

Recent analyses suggest bacterial and/or mitochondrion-like ancestry for giant viruses (Megavirales sensu latu): amoeban mitochondrial gene arrangements resemble those of their candidate homologs in megaviral genomes. This presumed ancestral synteny decreases with genome size across megaviral families at large and within Poxviridae. In this study, analyses focus on Phycodnaviridae, a polyphyletic group of giant viruses infecting Haplophyta, Stramenopiles, and other algae, using syntenies between algal mitogene arrangements and chloroplast genomes and Rickettsia prowazekii as positive controls. Mitogene alignment qualities with Rickettsia are much higher than with viral genomes. Mitogenome synteny with some viruses is higher, for others lower than with Rickettsia, despite lower alignments qualities. In some algae, syntenies among cohosted chloroplast, virus, and mitochondrion are higher, in others lower than expected. This suggests gene order coevolution in cohosted genomes, different coregulations of organelle metabolisms for different algae, and viral mitogenome mimicry, to hijack organelle-committed cellular resources and/or escape cellular defenses/genetic immunity systems. This principle might explain high synteny between human mitochondria and the pathogenic endocellular alphaproteobacterium R. prowazekii beyond common ancestry. Results indicate that putative bacteria/mitochondrion-like genomic ancestors of Phycodnaviridae originated before or at the mitochondrion-bacteria split, and ulterior functional constraints on gene arrangements of cohosted genomes.


Assuntos
Cloroplastos/genética , Evolução Molecular , Mitocôndrias/genética , Mimetismo Molecular/fisiologia , Phycodnaviridae/genética , Sintenia/genética , Imunidade Adaptativa/genética , Genoma Mitocondrial/genética , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune/genética , Organelas/genética , Filogenia , Análise de Sequência de DNA
12.
Immunity ; 51(1): 12-14, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315030

RESUMO

Appropriate priming of tolerogenic or effector immune responses is crucial for intestinal homeostasis. Recently in Nature, Esterházy et al. (2019) reveal how compartmentalization of lymphatic drainage to functionally distinct lymph nodes facilitates the simultaneous induction of tolerogenic and effector responses.


Assuntos
Drenagem , Linfonodos , Imunidade Adaptativa , Intestinos
13.
Microbiol Immunol ; 63(9): 379-391, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31310013

RESUMO

The immune system with large number of molecules protects the host against a plethora of continuously evolving microbes. Major histocompatibility complex (MHC) molecules serve as cardinal elements of the adaptive immune system responsible for the activation of the adaptive immunity in the host. The present study reports MHCI molecule in freshwater carp, Catla catla, and its differential expression in immunologically relevant tissues post-infection with Gram-negative and Gram-positive bacteria. The MHCI sequence of C. catla had 502 bp nucleotides encoding putative 146 amino acids. The phylogenetic analysis exhibited its evolutionary conservation within the Cyprinidae family and formed a different clade with the higher vertebrates. Simultaneously, CXCR3 and CXCR4 chemokines were cloned and characterized for their expression in infected tissues. Analysis of immunologically relevant tissues of the infected fish exhibited an increase of MHCI gene expression and the down-regulation of CXCR3 and CXCR4 chemokines, indicating a tricky interaction between the innate and adaptive immune system. It was found that intestine, skin and spleen played a crucial role in the contribution of the defense activity which instigated the self-immunity. These immune activities can provide useful information to understand the interaction of self and non-self- immune system in freshwater fish, Catla catla.


Assuntos
Carpas/genética , Quimiocinas/genética , Clonagem Molecular/métodos , Cyprinidae/genética , Genes MHC Classe I/genética , Receptores CXCR3/genética , Receptores CXCR4/genética , Imunidade Adaptativa/genética , Sequência de Aminoácidos , Animais , Carpas/imunologia , Cyprinidae/imunologia , Regulação para Baixo , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Água Doce , Expressão Gênica , Filogenia , Alinhamento de Sequência , Pele/imunologia , Baço/imunologia
14.
Scand J Immunol ; 90(5): e12804, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31267559

RESUMO

Immune checkpoint inhibitors are among the newest, cutting-edge methods for the treatment of cancer. Currently, they primarily influence T cell adaptive immunotherapy targeting the PD-1/PD-L1 and CTLA-4/B7 signalling pathways. These inhibitors fight cancer by reactivating the patient's own adaptive immune system, with good results in many cancers. With the discovery of the "Don't Eat Me" molecule, CD47, antibody-based drugs that target the macrophage-related innate immunosuppressive signalling pathway, CD47-SIRPα, have been developed and have achieved stunning results in the laboratory and the clinic, but there remain unexplained instances of tumour immune escape. While investigating the immunological tolerance of cancer to anti-CD47 antibodies, a second "Don't Eat Me" molecule on tumour cells, beta 2 microglobulin (ß2m), a component of MHC class I, was described. Some tumour cells reduce their surface expression of MHC class I to escape T cell recognition. However, other tumour cells highly express ß2m complexed with the MHC class I heavy chain to send a "Don't Eat Me" signal by binding to leucocyte immunoglobulin-like receptor family B, member 1 (LILRB1) on macrophages, leading to a loss of immune surveillance. Investigating the mechanisms underlying this immunosuppressive MHC class I-LILRB1 signalling axis in tumour-associated macrophages will be useful in developing therapies to restore macrophage function and control MHC class I signalling in patient tumours. The goal is to promote adaptive immunity while suppressing the innate immune response to tumours. This work will identify new therapeutic targets for the development of pharmaceutical-based tumour immunotherapy.


Assuntos
Antígenos CD/imunologia , Tolerância Imunológica/imunologia , Receptor B1 de Leucócitos Semelhante a Imunoglobulina/imunologia , Neoplasias/terapia , Evasão Tumoral/imunologia , Microglobulina beta-2/imunologia , Imunidade Adaptativa/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunidade Inata/imunologia , Macrófagos/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia
16.
Fish Shellfish Immunol ; 92: 649-654, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265911

RESUMO

Singapore grouper iridovirus (SGIV) is the main grouper-infecting virus in southern China that causes serious economic losses. However, there is no effective way to control this viral disease. In this study, SGIV ORF19R (SGIV-19R) encoding a viral membrane protein was constructed into pcDNA3.1-HA and then was used to evaluate the immune protective effects in grouper Epinephelus coioides. Subcellular localization showed that SGIV-19R distributed in the cytoplasm and co-localization analysis indicated the protein partially co-localized with the endoplasmic reticulum (ER). RT-PCR and Western blot analyses confirmed the expression of the vaccine plasmids in grouper muscle tissues. Moreover, the transcription levels of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), myxovirus resistance 1 (Mx1) and immunoglobulin M (IgM) genes were significantly up-regulated in the spleen, liver and kidney of vaccinated groupers. SGIV challenge experiments showed the relative percent survival (RPS) was significantly enhanced in fish with 49.9% at the DNA dose of 45 µg pcDNA3.1-19R, while 75.0% RPS when using 90 µg pcDNA3.1-19R. Meanwhile, vaccination with pcDNA3.1-19R significantly reduced the virus replication, evidenced by a low viral load in the spleen of survivals groupers after SGIV challenge. These results imply that pcDNA3.1-19R could induce protective immunity in grouper, and might be a potential vaccine candidate for controlling SGIV disease.


Assuntos
Imunidade Adaptativa , Bass/imunologia , Doenças dos Peixes/prevenção & controle , Imunidade Inata , Ranavirus/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Vírus de DNA/imunologia , Infecções por Vírus de DNA/prevenção & controle , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/imunologia , Injeções Intramusculares/veterinária , Iridovirus/fisiologia , Distribuição Aleatória , Proteínas da Matriz Viral/imunologia
17.
Vet Immunol Immunopathol ; 213: 109885, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31307670

RESUMO

Protec™ is a commercial aquafeed (Skretting Italia) containing a combination of glucans, vitamin C, vitamin E and zinc (immune support pack). No research information concerning its capability to improve fish immune response is available, so in this study the potential immunomodulatory effects of Protec™ were investigated in rainbow trout (Oncorhynchus mykiss). Head kidney (HK) leukocytes from adult fish (100 g, n = 6) were in vitro incubated with Protec™ immune support pack resulting in significantly higher respiratory burst activity and proliferation. Specifically, sonicated Protec™ immune support pack (160 µg/ml) induced a respiratory burst response similar to that promoted by zymosan and lipopolysaccharide (LPS), while non-sonicated Protec™ immune support pack induced a response comparable to that of cells stimulated with phorbol myristate acetate (PMA). Moreover, the proliferation of leukocytes exposed to sonicated Protec™ immune support pack (20 µg/ml) was significantly higher than that of cells stimulated with zymosan, and it was comparable to the proliferation of cells stimulated with phytohaemagglutinin (PHA) and LPS. Afterwards, a feeding trial was performed in a rainbow trout farm. Two groups of juvenile rainbow trout (10 g) were acclimated for 7 weeks before the experiment and fed daily with a commercial control diet (Optiline HE, Skretting Italia) at 2% BW/day. At the end of acclimation, one group of fish was fed with Protec™ diet (Skretting Italia) at 2% BW/day whereas the other group continued to feed the control diet at the same level for further 4 weeks. Then, fish were sampled (HK leukocytes from n = 6 fish/group, serum from n = 12 fish/group) or intraperitoneally vaccinated against lactococcosis (n = 160/dietary group/time point). Fish fed the same diets for further 4 weeks after vaccination, then feeding returned to the control diet in both groups until the end of the trial. The specific antibody response was recorded at 4 and 8 weeks after vaccination (n = 12 fish/group). The administration of Protec™ significantly enhanced the respiratory burst activity of leukocytes and the synthesis of specific IgM against Lactococcus garvieae, whereas the serum lysozyme activity was unaffected. The present research suggests that the administration of Protec™ can improve both innate and adaptive immune response of rainbow trout, proving to be an interesting strategy for enhancing the immune reactivity of fish to vaccines.


Assuntos
Ração Animal , Anticorpos Antibacterianos/sangue , Infecções por Bactérias Gram-Positivas/veterinária , Imunidade Inata , Lactococcus , Oncorhynchus mykiss/imunologia , Imunidade Adaptativa , Adjuvantes Imunológicos/administração & dosagem , Animais , Proliferação de Células , Dieta/veterinária , Feminino , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Positivas/imunologia , Imunoglobulina M/sangue , Leucócitos/imunologia , Oncorhynchus mykiss/microbiologia , Explosão Respiratória
18.
Fish Shellfish Immunol ; 92: 913-924, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31306761

RESUMO

A feeding trial was performed to compare the effects of five ethanol herbal extracts (bhumi amla, Phyllanthus amarus Schum and Thonn [Pa]; guava, Psidium guajava L. [Pg]; sensitive plant, Mimosa pudica L. [Mp]; neem, Azadirachta indica A. Juss [Ai] and asthma plant, Euphorbia hirta L. [Eh]) on the immune response and disease resistance against Edwardsiella ictaluri infection of striped catfish (Pangasianodon hypophthalmus). Fish were fed diets supplemented with two doses of each plant extract (0% [basal diet], 0.4% Eh [Eh0.4], 2.0% Eh [Eh2.0], 0.2% Pa [Pa0.2], 1.0% Pa [Pa1.0], 0.2% Pg [Pg0.2], 1.0% Pg [Pg1.0], 0.4% Mp [Mp0.4], 2.0% Mp [Mp2.0], 0.4% Ai [Ai0.4], 2.0% Ai [Ai2.0]) for 8 weeks. Results showed that hematological parameters (total red blood cells, white blood cells, lymphocytes, monocytes, and neutrophils) of fish fed extract-based diets were significantly higher than in those fed the control diet (p < 0.05) after 4 and 8 weeks. Plasma lysozyme activity increased in fish whose diets contained both doses of Eh (p < 0.05) in week 4 (W4), whereas lysozyme activity increased in fish fed 0.2% Pa and Pg, and 2.0% Ai and Eh (p < 0.05) in week 8 (W8). The lysozyme levels in skin mucus did not significantly differ between treatments (p > 0.05) in W4 and after the bacterial challenge test. At the end of the feeding trial, levels of ACH50 significantly increased in most of extract groups compared to the control group (p < 0.05). Total immunoglobulin increased considerably in both the plasma and skin mucus of fish fed extract-supplemented diets after 8 weeks. In addition, dietary supplementation with Pg, Mp, Pa0.2, Eh2.0, and Ai0.4 for 8 weeks considerably reduced the cumulative mortality against E. ictaluri infection in striped catfish. The results suggest that plant extracts possibly modulate the striped catfish immune response in a time and dose dependent manner. Specifically, diets enriched with extracts of P. guajava at 0.2 and 1.0%, or M. pudica at 2.0% for 8 weeks, have great potential for improving striped catfish health by enhancing the immune system and reducing mortality against bacterial challenges.


Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Peixes-Gato/imunologia , Resistência à Doença/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Extratos Vegetais/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Edwardsiella ictaluri/fisiologia , Infecções por Enterobacteriaceae/imunologia , Doenças dos Peixes/imunologia , Extratos Vegetais/administração & dosagem , Distribuição Aleatória
19.
Nat Commun ; 10(1): 3001, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31278272

RESUMO

Type III-A CRISPR-Cas systems are prokaryotic RNA-guided adaptive immune systems that use a protein-RNA complex, Csm, for transcription-dependent immunity against foreign DNA. Csm can cleave RNA and single-stranded DNA (ssDNA), but whether it targets one or both nucleic acids during transcription elongation is unknown. Here, we show that binding of a Thermus thermophilus (T. thermophilus) Csm (TthCsm) to a nascent transcript in a transcription elongation complex (TEC) promotes tethering but not direct contact of TthCsm with RNA polymerase (RNAP). Biochemical experiments show that both TthCsm and Staphylococcus epidermidis (S. epidermidis) Csm (SepCsm) cleave RNA transcripts, but not ssDNA, at the transcription bubble. Taken together, these results suggest that Type III systems primarily target transcripts, instead of unwound ssDNA in TECs, for immunity against double-stranded DNA (dsDNA) phages and plasmids. This reveals similarities between Csm and eukaryotic RNA interference, which also uses RNA-guided RNA targeting to silence actively transcribed genes.


Assuntos
Imunidade Adaptativa/genética , Sistemas CRISPR-Cas/genética , Staphylococcus epidermidis/genética , Thermus thermophilus/genética , Elongação da Transcrição Genética/imunologia , Bacteriófagos/imunologia , Sistemas CRISPR-Cas/imunologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/imunologia , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/imunologia , DNA de Cadeia Simples/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Plasmídeos/imunologia , RNA Guia/genética , RNA Guia/imunologia , RNA Guia/metabolismo , Staphylococcus epidermidis/imunologia , Thermus thermophilus/imunologia
20.
Nat Immunol ; 20(7): 783-792, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31213714

RESUMO

Adaptation is the ability of cells, tissues and organisms to rapidly and reversibly modify their properties to maximize fitness in a changing environment. The activity of immune-system components unfolds in the remarkably heterogeneous milieus to which they are exposed in different tissues, during homeostasis or during various acute or chronic pathological states. Therefore, adaptation is essential for immune cells to tune their responses to a large variety of contexts and conditions. The adaptation of immune cells reflects the integration of multiple inputs acting simultaneously or in a temporal sequence, which eventually leads to transcriptional reprogramming and to various functional consequences, some of which extend beyond the duration of the stimulus. A range of adaptive responses have been observed in both adaptive immune cells and innate immune cells; these are referred to with terms such as 'plasticity', 'priming', 'training', 'exhaustion' and 'tolerance', among others, all of which can be useful for defining a certain immunological process or outcome but whose underlying molecular frameworks are often incompletely understood. Here we review and analyze mechanisms of adaptation and memory in immunity with the aim of providing basic concepts that rationalize the properties and molecular bases of these essential processes.


Assuntos
Adaptação Fisiológica , Imunidade , Memória Imunológica , Imunidade Adaptativa , Animais , Regulação da Expressão Gênica , Histonas/metabolismo , Humanos , Hipersensibilidade/imunologia , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Tolerância Imunológica , Imunidade Inata , Especificidade de Órgãos/imunologia , Fenótipo , Transdução de Sinais
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