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1.
PLoS One ; 19(6): e0302432, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38935763

RESUMO

Digital transformation, as a significant shift in optimizing enterprise resource allocation and enhancing information connectivity, offers the opportunity to stimulate the endogenous dynamics of corporate green governance. Employing a sample of 3,002 listed companies in China, a fixed-effects model, and the entropy power method to formulate a green governance index system, this study examines how digital transformation affects corporate green governance concerning carbon peaking and carbon neutrality objectives. According to these findings, the implementation of the digital transformation improves corporate green governance, each unit increase in digital transformation correlates with a 1.91% enhancement in green governance. Moreover, an examination of the mechanisms shows that green governance can be promoted by addressing information asymmetry and enhancing operational efficiency. Additionally, the association between corporate green governance and digital transformation is moderated favorably by strategic aggressiveness. Furthermore, our results indicate that digital transformation contributes significantly to the advancement of green governance within enterprises located in areas with high digital financing and strong technology integration capacities. Digitalization has a stronger effect on promoting green governance for enterprises in pilot regions than in non-pilot regions in terms of carbon emission trading. This study not only assists enterprises in elucidating the developmental trajectory of digital transformation amid carbon peaking and carbon neutrality goals but also provides a reference for decision-making on how digital technology can empower corporate green governance and promote sustainable economic growth.


Assuntos
Carbono , China , Conservação dos Recursos Naturais/métodos , Tecnologia Digital
2.
J Immunother Cancer ; 9(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34344725

RESUMO

Adoptively transferred T cell-based cancer therapies have shown incredible promise in treatment of various cancers. So far therapeutic strategies using T cells have focused on manipulation of the antigen-recognition machinery itself, such as through selective expression of tumor-antigen specific T cell receptors or engineered antigen-recognition chimeric antigen receptors (CARs). While several CARs have been approved for treatment of hematopoietic malignancies, this kind of therapy has been less successful in the treatment of solid tumors, in part due to lack of suitable tumor-specific targets, the immunosuppressive tumor microenvironment, and the inability of adoptively transferred cells to maintain their therapeutic potentials. It is critical for therapeutic T cells to overcome immunosuppressive environmental triggers, mediating balanced antitumor immunity without causing unwanted inflammation or autoimmunity. To address these hurdles, chimeric receptors with distinct signaling properties are being engineered to function as allies of tumor antigen-specific receptors, modulating unique aspects of T cell function without directly binding to antigen themselves. In this review, we focus on the design and function of these chimeric non-antigen receptors, which fall into three broad categories: 'inhibitory-to-stimulatory' switch receptors that bind natural ligands, enhanced stimulatory receptors that interact with natural ligands, and synthetic receptor-ligand pairs. Our intent is to offer detailed descriptions that will help readers to understand the structure and function of these receptors, as well as inspire development of additional novel synthetic receptors to improve T cell-based cancer therapy.


Assuntos
Engenharia Celular/métodos , Neoplasias/terapia , Receptores de Antígenos Quiméricos/imunologia , Humanos
3.
Commun Biol ; 3(1): 306, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32533049

RESUMO

Melanoma represents the most serious type of skin cancer. Although recent years have seen advances using targeted and immunotherapies, most patients remain at high risk for tumor recurrence. Here we show that IRAK-M, a negative regulator of MyD88 signaling, is deficient or low in melanoma and expression levels correlate with patient survival. Inducing IRAK-M expression using genetic approaches or epigenetic modifiers initiates apoptosis by prompting its interaction with TRAF6 via IRAK-M's C-terminal domain. This complex recruits and degrades calpastatin which stimulates calpain activity and triggers caspase-3-dependent but caspase-8,-9-independent apoptosis. Using a drug screen, we identified compounds that induced IRAK-M expression. Administration of IRAK-M-inducing drugs reduced tumor growth in mice but was ineffective against IRAK-M knock-down tumors. These results uncover a previously uncharacterized apoptosis pathway, emphasize IRAK-M as a potential therapeutic target and suggest that the anticancer activity of certain drugs could do so through their ability to induce IRAK-M expression.


Assuntos
Apoptose , Proteínas de Ligação ao Cálcio/antagonistas & inibidores , Caspase 3/metabolismo , Regulação Neoplásica da Expressão Gênica , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Melanoma/patologia , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Caspase 3/genética , Proliferação de Células , Feminino , Humanos , Quinases Associadas a Receptores de Interleucina-1/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Melanoma/genética , Melanoma/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Cancer Immunol Res ; 7(9): 1523-1534, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31266784

RESUMO

Monocyte-derived dendritic cell (moDC)-based cancer therapies intended to elicit antitumor T-cell responses have limited efficacy in most clinical trials. However, potent and sustained antitumor activity in a limited number of patients highlights the therapeutic potential of moDCs. In vitro culture conditions used to generate moDCs can be inconsistent, and moDCs generated in vitro are less effective than natural DCs. On the basis of our study highlighting the ability for certain kinase inhibitors to enhance tumor antigenicity, we therefore screened kinase inhibitors for their ability to improve DC immunogenicity. We identified AKT inhibitor MK2206, DNA-PK inhibitor NU7441, and MEK inhibitor trametinib as the compounds most effective at modulating moDC immunogenicity. The combination of these drugs, referred to as MKNUTRA, enhanced moDC activity over treatment with individual drugs while exhibiting minimal toxicity. An evaluation of 335 activation and T-cell-suppressive surface proteins on moDCs revealed that MKNUTRA treatment more effectively matured cells and reduced the expression of tolerogenic proteins as compared with control moDCs. MKNUTRA treatment imparted to ICT107, a glioblastoma (GBM) DC-based vaccine that has completed phase II trials, an increased ability to stimulate patient-derived autologous CD8+ T cells against the brain tumor antigens IL13Rα2(345-354) and TRP2(180-188) In vivo, treating ICT107 with MKNUTRA, prior to injection into mice with an established GBM tumor, reduced tumor growth kinetics. This response was associated with an increased frequency of tumor-reactive lymphocytes within tumors and in peripheral tissues. These studies broaden the application of targeted anticancer drugs and highlight their ability to increase moDC immunogenicity.


Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Neoplasias/imunologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Comunicação Celular , Cromonas/farmacologia , Células Dendríticas/metabolismo , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Camundongos , Morfolinas/farmacologia , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/terapia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
5.
Sci Signal ; 11(526)2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29666308

RESUMO

It has long been appreciated that most autoimmune disorders are characterized by increased prevalence in females, suggesting a potential role for sex hormones in the etiology of autoimmunity. To study how estrogen receptor α (ERα) contributes to autoimmune diseases, we generated mice in which ERα was deleted specifically in T lymphocytes. We found that ERα deletion in T cells reduced their pathogenic potential in a mouse model of colitis and correlated with transcriptomic changes that affected T cell activation. ERα deletion in T cells contributed to multiple aspects of T cell function, including reducing T cell activation and proliferation and increasing the expression of Foxp3, which encodes a critical transcription factor for the differentiation and function of regulatory T cells. Thus, these data demonstrate that ERα in T cells plays an important role in inflammation and suggest that ERα-targeted immunotherapies could be used to treat autoimmune disorders.


Assuntos
Autoimunidade/imunologia , Proliferação de Células , Receptor alfa de Estrogênio/imunologia , Inflamação/imunologia , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Animais , Autoimunidade/genética , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Colite/genética , Colite/imunologia , Colite/metabolismo , Modelos Animais de Doenças , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Inflamação/genética , Inflamação/metabolismo , Ativação Linfocitária/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T/metabolismo
6.
Cancer Res ; 77(24): 7049-7058, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29055013

RESUMO

T cell-based immunotherapies are a promising approach for patients with advanced cancers. However, various obstacles limit T-cell efficacy, including suboptimal T-cell receptor (TCR) activation and an immunosuppressive tumor environment. Here, we developed a fusion protein by linking CD8α and MyD88 (CD8α:MyD88) to enhance CD8+ T-cell responses to weakly immunogenic and poorly expressed tumor antigens. CD8α:MyD88-engineered T cells exhibited increased proliferation and expression of effector and costimulatory molecules in a tumor antigen-dependent manner. These effects were accompanied by elevated activation of TCR and Toll-like receptor signaling-related proteins. CD8α:MyD88-expressing T cells improved antitumor responses in mice. Enhanced antitumor activity was associated with a unique tumor cytokine/chemokine signature, improved T-cell infiltration, reduced markers of T-cell exhaustion, elevated levels of proteins associated with antigen presentation, and fewer macrophages with an immunosuppressive phenotype in tumors. Given these observations, CD8α:MyD88 represents a unique and versatile approach to help overcome immunosuppression and enhance T-cell responses to tumor antigens. Cancer Res; 77(24); 7049-58. ©2017 AACR.


Assuntos
Antígenos de Neoplasias/imunologia , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/farmacologia , Animais , Apresentação de Antígeno/efeitos dos fármacos , Apresentação de Antígeno/imunologia , Antígenos CD8/genética , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/fisiologia , Células Cultivadas , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/genética , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fator 88 de Diferenciação Mieloide/genética , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Proteínas Recombinantes de Fusão/genética
7.
Appl Microbiol Biotechnol ; 100(20): 8693-9, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27640192

RESUMO

Escherichia coli strain Nissle 1917 (EcN) has been used as a probiotic. Genetic engineering has enhanced the utility of EcN in several vaccine and pharmaceutical preparations. We discuss in this mini review the genetics and physical properties of EcN. We also discuss the numerous genetic engineering strategies employed for EcN-based vaccine development, including recombinant plasmid transfer, genetic engineering of cryptic plasmids or the EcN chromosome, EcN bacterial ghosts and its outer membrane vesicles. We also provide a current update on the progress and the challenges regarding the use of EcN in vaccine development.


Assuntos
Escherichia coli/imunologia , Escherichia coli/metabolismo , Engenharia Genética , Probióticos/administração & dosagem , Vacinas Sintéticas/imunologia , Escherichia coli/genética , Vacinas Sintéticas/genética
8.
PLoS One ; 11(6): e0158432, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27348426

RESUMO

Wnt/ß-catenin signaling pathway plays essential roles in mammalian development and tissue homeostasis. MicroRNAs (miRNAs) are a class of regulators involved in modulating this pathway. In this study, we screened miRNAs regulating Wnt/ß-catenin signaling by using a TopFlash based luciferase reporter. Surprisingly, we found that miR-142 inhibited Wnt/ß-catenin signaling, which was inconsistent with a recent study showing that miR-142-3p targeted Adenomatous Polyposis Coli (APC) to upregulate Wnt/ß-catenin signaling. Due to the discordance, we elaborated experiments by using extensive mutagenesis, which demonstrated that the stem-loop structure was important for miR-142 to efficiently suppress Wnt/ß-catenin signaling. Moreover, the inhibitory effect of miR-142 relies on miR-142-3p rather than miR-142-5p. Further, we found that miR-142-3p directly modulated translation of Ctnnb1 mRNA (encoding ß-catenin) through binding to its 3' untranslated region (3' UTR). Finally, miR-142 was able to repress cell cycle progression by inhibiting active Wnt/ß-catenin signaling. Thus, our findings highlight the inhibitory role of miR-142-3p in Wnt/ß-catenin signaling, which help to understand the complex regulation of Wnt/ß-catenin signaling.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/genética , Via de Sinalização Wnt , Regiões 3' não Traduzidas , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Proliferação de Células , Humanos , Camundongos , MicroRNAs/química , Conformação de Ácido Nucleico , Biossíntese de Proteínas/genética , Proteínas Wnt/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
9.
Cell Mol Immunol ; 12(5): 525-32, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25942597

RESUMO

Foxp3(+) regulatory T (Treg) cells are considered a sub-lineage of CD4(+) T cells that are protective against autoimmunity due to their essential roles in maintaining immune homeostasis and self-tolerance. However, Treg cells are unstable in vivo in terms of lineage specialization and suppressive function. These unstable Treg cells play roles in the pathogenesis of diseases, which cause safety concerns regarding human Treg cell therapy. In this review, we highlight recent findings that demonstrate the pathogenic conversion of Treg cells in different disease models.


Assuntos
Doenças Autoimunes/imunologia , Saúde , Linfócitos T Reguladores/imunologia , Humanos , Imunidade , Modelos Imunológicos , Neoplasias/imunologia
10.
J Biol Chem ; 289(51): 35139-48, 2014 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-25361764

RESUMO

The instability of regulatory T (Treg) cells is involved in the pathogenesis of autoimmune diseases and also highlights safety concerns with regard to clinical Treg cell therapy. Cell-intrinsic molecular events linked to this Treg cell instability in vivo cells, which leads to safety concerns regardingare still obscure. Here we developed a novel luciferase-based reporter system and performed an unbiased screening for kinases that potentially modulate Foxp3 function. We found that the active form of COT/Tpl2 specifically inhibits the DNA binding activity of Foxp3 through a MEK-ERK-dependent pathway. Moreover, Treg cell-specific expression of activated MEK1 led to dysregulation of Treg function and instability of Foxp3 expression in vivo. Our results support the hypothesis that outside inflammatory signals act through the COT/Tpl2-MEK-ERK signaling pathway to destabilize the Treg lineage.


Assuntos
Ativação Linfocitária/imunologia , MAP Quinase Quinase 1/imunologia , Sistema de Sinalização das MAP Quinases/imunologia , Linfócitos T Reguladores/imunologia , Animais , Western Blotting , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Ativação Enzimática/imunologia , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Células HEK293 , Humanos , Luciferases/genética , Luciferases/metabolismo , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/imunologia , MAP Quinase Quinase Quinases/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/imunologia , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , Linfócitos T Reguladores/metabolismo
11.
Antiviral Res ; 106: 80-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24680956

RESUMO

The activation of ERK and p38 signal cascade in host cells has been demonstrated to be essential for picornavirus enterovirus 71 (EV71) replication and up-regulation of virus-induced cyclooxygenase-2 (COX-2)/prostaglandins E2 (PGE2) expression. The aim of this study was to examine the effects of sorafenib, a clinically approved anti-cancer multi-targeted kinase inhibitor, on the propagation and pathogenesis of EV71, with a view to its possible mechanism and potential use in the design of therapy regimes for Hand foot and mouth disease (HFMD) patients with life threatening neurological complications. In this study, non-toxic concentrations of sorafenib were shown to inhibit the yield of infectious progeny EV71 (clinical BC08 strain) by about 90% in three different cell types. A similar inhibitory effect of sorafenib was observed on the synthesis of both viral genomic RNA and the VP1 protein. Interestingly, sorafenib exerted obvious inhibition of the EV71 internal ribosomal entry site (IRES)-mediated translation, the first step in picornavirus replication, by linking it to a firefly luciferase reporter gene. Sorafenib was also able to prevent both EV71-induced CPE and the activation of ERK and p38, which contributes to up-regulation COX-2/PGE2 expression induced by the virus. Overall, this study shows that sorafenib strongly inhibits EV71 replication at least in part by regulating viral IRES-dependent translation of viral proteins, indicating a novel potential strategy for the treatment of HFMD patients with severe neurological complications. To our knowledge, this is the first report that investigates the mechanism by which sorafenib inhibits EV71 replication.


Assuntos
Antivirais/farmacologia , Enterovirus Humano A/efeitos dos fármacos , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Virais/biossíntese , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Efeito Citopatogênico Viral/efeitos dos fármacos , Enterovirus Humano A/crescimento & desenvolvimento , Enterovirus Humano A/fisiologia , Humanos , Niacinamida/farmacologia , Sorafenibe , Proteínas Virais/antagonistas & inibidores
12.
J Basic Microbiol ; 53(7): 600-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22961625

RESUMO

Type VI secretion system (T6SS) has increasingly been believed to participate in the infection process for many bacterial pathogens, but its role in the virulence of Salmonella typhimurium remains unclear. To look into this, we deleted the T6SS cluster from the genome of S. typhimurium 14028s and analyzed the phenotype of the resulting T6SS knockout mutant (T6SSKO mutant) in vitro and in vivo. We found that the T6SSKO mutant exhibited reduced capability in colonizing the spleen and liver in an in vivo colonization competition model in BALB/c mice infected by the oral route. Additionally, infection via intraperitoneal administration also showed that the T6SSKO mutant was less capable of colonizing the mouse spleen and liver than the wild-type strain. We did not detect significant differences between the T6SSKO and wild-type strains in epithelial cell invasion tests. However, in the macrophage RAW264.7 cell line, the T6SSKO mutant survived and proliferated significantly more poorly than the wild-type strain. These findings indicate that T6SS gene cluster is required for full virulence of S. typhimurium 14028s in BALB/c mice, possibly due to its roles in bacterial survival and proliferation in macrophages.


Assuntos
Família Multigênica , Salmonelose Animal/microbiologia , Salmonella typhimurium/genética , Salmonella typhimurium/patogenicidade , Fatores de Virulência/genética , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Linhagem Celular , Proliferação de Células , Células HeLa , Humanos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Salmonella typhimurium/metabolismo , Virulência/genética , Fatores de Virulência/metabolismo
13.
Microb Pathog ; 51(3): 121-32, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21575704

RESUMO

Bacterial pathogens display a variety of protection mechanisms against the inhibitory and lethal effects of host cationic antimicrobial peptides (CAMPs). To identify Yersinia pestis genes involved in CAMP resistance, libraries of DSY101 (KIM6 caf1 pla psa) minitransposon Tn5AraOut mutants were selected at 37°C for resistance to the model CAMPs polymyxin B or protamine. This approach targeted genes that needed to be repressed (null mutations) or induced (upstream P(BAD) insertions) for the detection of CAMP resistance, and predictably for improved pathogen fitness in mammalian hosts. Ten mutants demonstrated increased resistance to polymyxin B or protamine, with the mapped mutations pointing towards genes suspected to participate in modifying membrane components, genes encoding transport proteins or enzymes, or the regulator of a ferrous iron uptake system (feoC). Not all the mutants were resistant to both CAMPs used for selection. None of the polymyxin B- and only some protamine-resistant mutants, including the feoC mutant, showed increased resistance to rat bronchoalveolar lavage fluid (rBALF) known to contain cathelicidin and ß-defensin 1. Thus, findings on bacterial resistance to polymyxin B or protamine don't always apply to CAMPs of the mammalian innate immune system, such as the ones in rBALF.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana , Yersinia pestis/efeitos dos fármacos , Elementos de DNA Transponíveis , Mutagênese Insercional , Polimixina B/farmacologia , Protaminas/farmacologia , Yersinia pestis/genética
14.
PLoS One ; 4(2): e4510, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19229335

RESUMO

BACKGROUND: Although over 1400 Salmonella serovars cause usually self-limited gastroenteritis in humans, a few, e.g., Salmonella typhi and S. paratyphi C, cause typhoid, a potentially fatal systemic infection. It is not known whether the typhoid agents have evolved from a common ancestor (by divergent processes) or acquired similar pathogenic traits independently (by convergent processes). Comparison of different typhoid agents with non-typhoidal Salmonella lineages will provide excellent models for studies on how similar pathogens might have evolved. METHODOLOGIES/PRINCIPAL FINDINGS: We sequenced a strain of S. paratyphi C, RKS4594, and compared it with previously sequenced Salmonella strains. RKS4594 contains a chromosome of 4,833,080 bp and a plasmid of 55,414 bp. We predicted 4,640 intact coding sequences (4,578 in the chromosome and 62 in the plasmid) and 152 pseudogenes (149 in the chromosome and 3 in the plasmid). RKS4594 shares as many as 4346 of the 4,640 genes with a strain of S. choleraesuis, which is primarily a swine pathogen, but only 4008 genes with another human-adapted typhoid agent, S. typhi. Comparison of 3691 genes shared by all six sequenced Salmonella strains placed S. paratyphi C and S. choleraesuis together at one end, and S. typhi at the opposite end, of the phylogenetic tree, demonstrating separate ancestries of the human-adapted typhoid agents. S. paratyphi C seemed to have suffered enormous selection pressures during its adaptation to man as suggested by the differential nucleotide substitutions and different sets of pseudogenes, between S. paratyphi C and S. choleraesuis. CONCLUSIONS: S. paratyphi C does not share a common ancestor with other human-adapted typhoid agents, supporting the convergent evolution model of the typhoid agents. S. paratyphi C has diverged from a common ancestor with S. choleraesuis by accumulating genomic novelty during adaptation to man.


Assuntos
Genes Bacterianos/genética , Genoma Bacteriano , Filogenia , Salmonella/genética , Animais , Humanos , Salmonella arizonae/genética , Salmonella paratyphi C/genética , Salmonella typhi/genética , Seleção Genética , Análise de Sequência de DNA , Especificidade da Espécie , Suínos
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