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1.
Nature ; 560(7717): 253-257, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30069049

RESUMO

Acetylation of histones by lysine acetyltransferases (KATs) is essential for chromatin organization and function1. Among the genes coding for the MYST family of KATs (KAT5-KAT8) are the oncogenes KAT6A (also known as MOZ) and KAT6B (also known as MORF and QKF)2,3. KAT6A has essential roles in normal haematopoietic stem cells4-6 and is the target of recurrent chromosomal translocations, causing acute myeloid leukaemia7,8. Similarly, chromosomal translocations in KAT6B have been identified in diverse cancers8. KAT6A suppresses cellular senescence through the regulation of suppressors of the CDKN2A locus9,10, a function that requires its KAT activity10. Loss of one allele of KAT6A extends the median survival of mice with MYC-induced lymphoma from 105 to 413 days11. These findings suggest that inhibition of KAT6A and KAT6B may provide a therapeutic benefit in cancer. Here we present highly potent, selective inhibitors of KAT6A and KAT6B, denoted WM-8014 and WM-1119. Biochemical and structural studies demonstrate that these compounds are reversible competitors of acetyl coenzyme A and inhibit MYST-catalysed histone acetylation. WM-8014 and WM-1119 induce cell cycle exit and cellular senescence without causing DNA damage. Senescence is INK4A/ARF-dependent and is accompanied by changes in gene expression that are typical of loss of KAT6A function. WM-8014 potentiates oncogene-induced senescence in vitro and in a zebrafish model of hepatocellular carcinoma. WM-1119, which has increased bioavailability, arrests the progression of lymphoma in mice. We anticipate that this class of inhibitors will help to accelerate the development of therapeutics that target gene transcription regulated by histone acetylation.


Assuntos
Benzenossulfonatos/farmacologia , Senescência Celular/efeitos dos fármacos , Histona Acetiltransferases/antagonistas & inibidores , Hidrazinas/farmacologia , Linfoma/tratamento farmacológico , Linfoma/patologia , Sulfonamidas/farmacologia , Acetilação/efeitos dos fármacos , Animais , Benzenossulfonatos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Desenvolvimento de Medicamentos , Fibroblastos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Acetiltransferases/deficiência , Histona Acetiltransferases/genética , Histonas/química , Histonas/metabolismo , Hidrazinas/uso terapêutico , Linfoma/enzimologia , Linfoma/genética , Lisina/química , Lisina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Sulfonamidas/uso terapêutico
2.
J Infect Dis ; 224(5): 903-913, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33417695

RESUMO

BACKGROUND: Staphylococcus aureus causes community- and hospital-acquired pneumonia linked to a high mortality rate. The emergence and rapid transmission of multidrug-resistant S. aureus strains has become a serious health concern, highlighting the challenges associated with the development of a vaccine to combat S. aureus pneumonia. METHODS: This study evaluated the effects of intrapulmonary immunization on the immune response and protection against S. aureus lung infection in a respiratory mouse model using a subunit vaccine. RESULTS: Compared with the intranasal immunized mice, the intrapulmonarily immunized mice had lower levels of pulmonary bacterial colonization and lethality, accompanied by alleviated lung inflammation with reduced proinflammatory cytokines and increased levels of interleukin-10 and antimicrobial peptide following intrapulmonary challenge. Optimal protection was associated with increased pulmonary antibodies and resident memory T cells. Moreover, intrapulmonary immunization provided long-lasting pulmonary protection for at least 6 months, with persistent cellular and humoral immunity in the lungs. CONCLUSIONS: Vaccine reaching the deep lung by intrapulmonary immunization plays a significant role in the induction of efficacious and long-lasting immunity against S. aureus in the lung parenchyma. Hence, intrapulmonary immunization can be a strategy for the development of a vaccine against S. aureus pneumonia.Immunization through the intrapulmonary route with a subunit of S. aureus vaccine elicited tissue resident memory T cells and antigen-specific antibodies in the lungs, and provided optimal and long-term protection against S. aureus pneumonia.


Assuntos
Células T de Memória , Pneumonia Estafilocócica/prevenção & controle , Staphylococcus aureus/imunologia , Vacinação , Animais , Peptídeos Antimicrobianos , Pulmão , Staphylococcus aureus Resistente à Meticilina , Camundongos , Pneumonia Estafilocócica/imunologia
3.
Infect Immun ; 89(6)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33685942

RESUMO

Porcine pleuropneumonia is a common infectious disease of pigs caused by Actinobacillus pleuropneumoniae Interferon gamma (IFN-γ) expression increases in the lung of pigs after A. pleuropneumoniae infection, but the role of IFN-γ during the infection is still obscure. In this study, an IFN-γ-/- mouse infection model was established, and bacterial load, levels of inflammatory cytokines, and types of neutrophils in the lungs were studied at different times post-A. pleuropneumoniae infection. We found that wild-type (WT) mice were more susceptible to A. pleuropneumoniae than IFN-γ-/- mice. At 6 h postinfection (hpi), the expression of interleukin 18 (IL-18) and IL-1ß in the lungs of IFN-γ-/- mice was significantly increased compared to WT mice. The bacterial load and levels of inflammatory cytokines (IL-1ß and IL-6) of IFN-γ-/- mice were significantly reduced at 12 hpi compared to WT mice. After an initial loss, the numbers of lung polymorphonuclear (PMN)-I cells dramatically increased in the lungs of IFN-γ-/- but not WT mice, whereas PMN-II cells continually decreased. Finally, in vivo administration of IL-18 significantly reduced clinical scores and bacterial load in the lungs of A. pleuropneumoniae-infected mice. This study identifies IFN-γ as a target for regulating the inflammatory response in the lung and provides a basis for understanding the course of clinical bacterial pneumonia and for the formulation of treatment protocols.


Assuntos
Infecções por Actinobacillus/imunologia , Infecções por Actinobacillus/metabolismo , Actinobacillus pleuropneumoniae/imunologia , Interações Hospedeiro-Patógeno , Interleucina-18/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Infecções por Actinobacillus/microbiologia , Infecções por Actinobacillus/patologia , Animais , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Knockout , Infiltração de Neutrófilos , Neutrófilos/patologia
4.
J Infect Dis ; 220(10): 1679-1687, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31287878

RESUMO

BACKGROUND: Streptococcus suis is an emerging zoonotic agent. Its natural habitat is the tonsils, which are the main portals of S. suis entry into the bloodstream of pigs. The remarkable variability of the bacteria and complex pathogenic mechanisms make the development of a vaccine a difficult task. METHOD: Five conserved virulence factors involved in critical events of S. suis pathogenesis were combined and used as an intranasal vaccine (V5). The effect of V5 was investigated with intranasal and systemic challenge models. RESULTS: V5 induced antibody and T-cell responses at the mucosal site and systemically. The immunity promoted clearance of S. suis from the nasopharynx independent of S. suis serotypes and reduced lethality after systemic challenge with S. suis serotype 2. Moreover, mice that survived sepsis from intravenous infection developed meningitis, whereas none of these mice showed neuropathological symptoms after V5 receipt. CONCLUSION: Intranasal immunization with multiple conserved virulence factors decreases S. suis colonization at the nasopharynx across serotypes and inhibits the dissemination of the bacteria in the host. The protective mucosal immunity effects would potentially reduce the S. suis reservoir and prevent S. suis disease in pigs.


Assuntos
Antígenos de Bactérias/imunologia , Meningite Pneumocócica/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus suis/imunologia , Fatores de Virulência/imunologia , Administração Intranasal , Animais , Anticorpos Antibacterianos/sangue , Modelos Animais de Doenças , Feminino , Imunidade nas Mucosas , Meningite Pneumocócica/imunologia , Camundongos Endogâmicos C57BL , Nasofaringe/microbiologia , Vacinas Estreptocócicas/administração & dosagem , Linfócitos T/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia
5.
Proc Natl Acad Sci U S A ; 112(1): 238-43, 2015 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-25535343

RESUMO

Influenza infection predisposes the host to secondary bacterial pneumonia, which is a major cause of mortality during influenza epidemics. The molecular mechanisms underlying the bacterial coinfection remain elusive. Neuraminidase (NA) of influenza A virus (IAV) enhances bacterial adherence and also activates TGF-ß. Because TGF-ß can up-regulate host adhesion molecules such as fibronectin and integrins for bacterial binding, we hypothesized that activated TGF-ß during IAV infection contributes to secondary bacterial infection by up-regulating these host adhesion molecules. Flow cytometric analyses of a human lung epithelial cell line indicated that the expression of fibronectin and α5 integrin was up-regulated after IAV infection or treatment with recombinant NA and was reversed through the inhibition of TGF-ß signaling. IAV-promoted adherence of group A Streptococcus (GAS) and other coinfective pathogens that require fibronectin for binding was prevented significantly by the inhibition of TGF-ß. However, IAV did not promote the adherence of Lactococcus lactis unless this bacterium expressed the fibronectin-binding protein of GAS. Mouse experiments showed that IAV infection enhanced GAS colonization in the lungs of wild-type animals but not in the lungs of mice deficient in TGF-ß signaling. Taken together, these results reveal a previously unrecognized mechanism: IAV NA enhances the expression of cellular adhesins through the activation of TGF-ß, leading to increased bacterial loading in the lungs. Our results suggest that TGF-ß and cellular adhesins may be potential pharmaceutical targets for the prevention of coinfection.


Assuntos
Coinfecção/microbiologia , Coinfecção/virologia , Vírus da Influenza A/enzimologia , Neuraminidase/metabolismo , Receptores de Superfície Celular/metabolismo , Infecções Estreptocócicas/complicações , Fator de Crescimento Transformador beta/metabolismo , Animais , Aderência Bacteriana , Moléculas de Adesão Celular/metabolismo , Contagem de Colônia Microbiana , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Fibronectinas/metabolismo , Humanos , Influenza Humana/patologia , Influenza Humana/virologia , Pulmão/patologia , Camundongos , Modelos Biológicos , Neuraminidase/antagonistas & inibidores , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/virologia , Ligação Proteica , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/fisiologia , Fator de Crescimento Transformador beta/antagonistas & inibidores
6.
J Infect Dis ; 215(4): 644-652, 2017 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-28011917

RESUMO

Background: The role of Toll-like receptors (TLRs) in adaptive immunity is incompletely understood. Recurrent human infections by group A streptococcus (GAS) and associated autoimmune conditions suggest that the immunity to GAS is intricately regulated and that TLRs may be involved in the regulation. Methods: This study investigated adaptive mucosal immune responses to GAS in TLR2-/- and TLR4-/- mice with an intranasal infection model. Results: Flow cytometric analyses of nasal-associated lymphoid tissue (NALT) cells showed that robust T helper 17 (Th17) cell responses to GAS in wild-type (WT) mice were reduced in TLR2-/- mice by 50%. Conversely, antibody levels and follicular T and B cells in the germinal center of NALT were significantly higher in TLR2-/- than in WT mice. However, antibody response to soluble antigens coimmunized with GAS was similar in WT and TLR2-/- mice. Moreover, the adaptive clearance of GAS in TLR2-/- mice was as efficient as in WT mice, whereas it was significantly impaired in TLR4-/- mice in which antibody responses were significantly lower than in WT mice. Conclusions: Activation of TLR2 by GAS is responsible for massive Th17 activation and deficient antibody response, which may increase predisposition to GAS-related autoimmunity and reduce protection efficiency.


Assuntos
Formação de Anticorpos , Infecções Estreptocócicas/imunologia , Células Th17/imunologia , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologia , Imunidade Adaptativa , Adesinas Bacterianas/administração & dosagem , Adesinas Bacterianas/imunologia , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/sangue , Endopeptidases/administração & dosagem , Endopeptidases/imunologia , Imunidade nas Mucosas , Imunização , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Vacinas Estreptocócicas/administração & dosagem , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia
7.
Chemosphere ; 358: 142080, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38642773

RESUMO

Perfluorooctanoic acid (PFOA) and atrazine are two endocrine disruptors that are widely found in waters. Negative effects of PFOA and atrazine have been studied individually, but few data have focused on their combined effects. Here, zebrafish embryos were used as model to investigate the combined toxicity of PFOA and atrazine. The acute toxicity of atrazine (11.9 mg/L) to zebrafish embryos was much higher than that of perfluorooctanoic acid (224.6 mg/L) as shown by the 120h-LC50 value. Developmental effects, including delayed yolk sac absorption, spinal curvature, and liver abnormalities, were observed in both one- and two-component exposures. Notably, the rate of embryonic malformations in the co-exposure group was more than twice as high as that of single component exposure in the concentration range of 1/8-1/2 EC50, which indicated a synergistic effect of the binary mixture. The synergistic effect of PFOA-atrazine was further validated by combinatorial index (CI) modeling. In addition, changes of amino acid metabolites, reactive oxygen species and superoxide dismutase indicated that oxidative stress might be the main pathway for enhanced toxicity under co-exposure condition. Overall, co-exposure of PFOA and atrazine resulted in stronger developmental effects and more complicated amino acid metabolic response toward zebrafish, compared with single component exposure.


Assuntos
Atrazina , Caprilatos , Embrião não Mamífero , Fluorocarbonos , Poluentes Químicos da Água , Peixe-Zebra , Peixe-Zebra/embriologia , Animais , Atrazina/toxicidade , Fluorocarbonos/toxicidade , Caprilatos/toxicidade , Poluentes Químicos da Água/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sinergismo Farmacológico
8.
Proc Natl Acad Sci U S A ; 107(13): 5937-42, 2010 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-20231435

RESUMO

Recurrent group A Streptococcus (GAS) tonsillitis and associated autoimmune diseases indicate that the immune response to this organism can be ineffective and pathological. TGF-beta1 is recognized as an essential signal for generation of regulatory T cells (Tregs) and T helper (Th) 17 cells. Here, the impact of TGF-beta1 induction on the T-cell response in mouse nasal-associated lymphoid tissue (NALT) following intranasal (i.n.) infections is investigated. ELISA and TGF-beta1-luciferase reporter assays indicated that persistent infection of mouse NALT with GAS sets the stage for TGF-beta1 and IL-6 production, signals required for promotion of a Th17 immune response. As predicted, IL-17, the Th17 signature cytokine, was induced in a TGF-beta1 signaling-dependent manner in single-cell suspensions of both human tonsils and NALT. Intracellular cytokine staining and flow cytometry demonstrated that CD4(+) IL-17(+) T cells are the dominant T cells induced in NALT by i.n. infections. Moreover, naive mice acquired the potential to clear GAS by adoptive transfer of CD4(+) T cells from immunized IL-17A(+)/(+) mice but not cells from IL-17A(-)/(-) mice. These experiments link specific induction of TGF-beta1 by a bacterial infection to an in vivo Th17 immune response and show that this cellular response is sufficient for protection against GAS. The association of a Th17 response with GAS infection reveals a potential mechanism for destructive autoimmune responses in humans.


Assuntos
Interleucina-17/metabolismo , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/patologia , Streptococcus pyogenes , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/patologia , Fator de Crescimento Transformador beta1/biossíntese , Animais , Diferenciação Celular/imunologia , Citocinas/biossíntese , Feminino , Humanos , Imunidade Celular , Interleucina-17/deficiência , Interleucina-17/genética , Listeria monocytogenes/imunologia , Listeria monocytogenes/patogenicidade , Listeriose/imunologia , Listeriose/patologia , Tecido Linfoide/imunologia , Tecido Linfoide/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Cavidade Nasal/imunologia , Cavidade Nasal/patologia , Transdução de Sinais/imunologia , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/patogenicidade , Células Th1/imunologia , Células Th1/patologia , Tonsilite/imunologia , Tonsilite/patologia
9.
Vaccines (Basel) ; 11(9)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37766135

RESUMO

Group B streptococcus (GBS) commonly colonizes the vaginal tract and is a leading cause of life-threatening neonatal infections and adverse pregnancy outcomes. No effective vaccine is clinically available. Conserved bacterial virulence factors, including those of GBS, have been employed as vaccine components. We investigated serotype-independent protection against GBS by intranasal immunization with six conserved GBS virulence factors (GBSV6). GBSV6 induced systemic and vaginal antibodies and T cell responses in mice. The immunity reduced mouse mortality and vaginal colonization by various GBS serotypes and protected newborn mice of immunized dams against GBS challenge. Intranasal GBSV6 immunization also provided long-lasting protective immunity and had advantages over intramuscular GBSV6 immunization regarding restricting vaginal GBS colonization. Our findings indicate that intranasal immunization targeting multiple conserved GBS virulence factors induces serotype-independent immunity, which protects against GBS infection systemically and vaginally in dams and prevents newborn death. The study presents valuable strategies for GBS vaccine development.

10.
Biochim Biophys Acta Mol Basis Dis ; 1869(3): 166629, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36563916

RESUMO

Recurrent streptococcal tonsillitis exacerbates psoriasis. Studies have indicated that T cells responding to streptococcal antigens in the skin are involved in the pathogenesis of the disease. However, a direct link between streptococcal tonsillitis and psoriasis has not been evidenced. In the present study, the impact of intranasal (i.n.) streptococcal infection on psoriasis was investigated using the imiquimod (IMQ) psoriasis mouse model. The results showed that repeated i.n. infection with group A Streptococcus (GAS) induced a robust and persistent Th17 response in the nasal-associated lymphoid tissue (NALT) and exacerbated IMQ-mediated psoriatic skin lesions. ELISpot and flow cytometry analyses revealed that GAS-reactive tissue-resident memory T cells (TRM) were present in the skin of GAS-infected mice and produced IL-17/IL-23 axis cytokines in response to IMQ, compared to mice uninfected with GAS. In addition, i.n. infection with Streptococcus pneumoniae (Sp), a pathogen not associated with the development of psoriasis, also induced a persistent Th17 response in NALT but did not exacerbate IMQ-induced psoriatic inflammation nor elicited Sp-specific T cells in the skin. The results provide in vivo evidence that GAS-associated psoriasis is dependent on the skin GAS-specific TRM cells induced by GAS nasopharyngeal infection and can be later activated by environmental triggers, leading to psoriatic inflammation. Reducing the reservoir of Th17 cells, which are source of skin TRM cells, may constitute a promising treatment for psoriasis.


Assuntos
Dermatite , Psoríase , Infecções Estreptocócicas , Tonsilite , Animais , Camundongos , Imiquimode , Inflamação , Células T de Memória , Psoríase/patologia , Infecções Estreptocócicas/complicações
11.
Microbiol Spectr ; 11(4): e0536722, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37358434

RESUMO

Mycobacterium tuberculosis (Mtb) is highly resistant to host oxidative killing. We hypothesized that the evolutionary adaptation of M. smegmatis to hydrogen peroxide (H2O2) would endow the nonpathogenic Mycobacterium persistent in a host. In the study, we screened a highly H2O2-resistant strain (mc2114) via evolutionary H2O2 adaptation in vitro. The MIC of mc2114 to H2O2 is 320 times that of wild-type mc2155. Mouse infection experiments showed that mc2114, similar to Mtb, was persistent in the lungs and caused high lethality in mice with restricted responses of NOX2, ROS, IFN-γ, decreased macrophage apoptosis, and overexpressed inflammatory cytokines in the lungs. Whole-genome sequencing analysis revealed that mc2114 harbored 29 single nucleotide polymorphisms in multiple genes; one of them was on the furA gene that caused FurA deficiency-mediated overexpression of KatG, a catalase-peroxidase to detoxify ROS. Complementation of mc2114 with a wild-type furA gene reversed lethality and hyper-inflammatory response in mice with rescued overexpression of KatG and inflammatory cytokines, whereas NOX2, ROS, IFN-γ, and macrophage apoptosis remained reduced. The results indicate that although FurA regulates KatG expression, it does not contribute significantly to the restriction of ROS response. Instead, FurA deficiency is responsible for the detrimental pulmonary inflammation that contributes to the severity of the infection, a previously nonrecognized function of FurA in mycobacterial pathogenesis. The study also indicates that mycobacterial resistance to oxidative burst results from complex mechanisms involving adaptive genetic changes in multiple genes. IMPORTANCE Mycobacterium tuberculosis (Mtb) causes human tuberculosis (TB), which has killed more people in human history than any other microorganism. However, the mechanisms underlying Mtb pathogenesis and related genes have not yet been fully elucidated, which impedes the development of effective strategies for containing and eradicating TB. In the study, we generated a mutant of M. smegmatis (mc2114) with multiple mutations by an adaptive evolutionary screen with H2O2. One of the mutations in furA caused a deficiency of FurA, which mediated severe inflammatory lung injury and higher lethality in mice by overexpression of inflammatory cytokines. Our results indicate that FurA-regulated pulmonary inflammation plays a critical role in mycobacterial pathogenesis in addition to the known downregulation of NOX2, ROS, IFN-γ responses, and macrophage apoptosis. Further analysis of the mutations in mc2114 would identify more genes related to the increased pathogenicity and help in devising new strategies for containing and eradicating TB.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Animais , Camundongos , Peróxido de Hidrogênio/farmacologia , Peróxido de Hidrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Mycobacterium tuberculosis/metabolismo , Tuberculose/microbiologia , Citocinas/genética , Citocinas/metabolismo , Inflamação , Estresse Oxidativo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
12.
Vaccines (Basel) ; 10(1)2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35062763

RESUMO

Group A Streptococcus (GAS) causes a variety of diseases globally. The DNases in GAS promote GAS evasion of neutrophil killing by degrading neutrophil extracellular traps (NETs). Sda1 is a prophage-encoded DNase associated with virulent GAS strains. However, protective immunity against Sda1 has not been determined. In this study, we explored the potential of Sda1 as a vaccine candidate. Sda1 was used as a vaccine to immunize mice intranasally. The effect of anti-Sda1 IgG in neutralizing degradation of NETs was determined and the protective role of Sda1 was investigated with intranasal and systemic challenge models. Antigen-specific antibodies were induced in the sera and pharyngeal mucosal site after Sda1 immunization. The anti-Sda1 IgG efficiently prevented degradation of NETs by supernatant samples from different GAS serotypes with or without Sda1. Sda1 immunization promoted clearance of GAS from the nasopharynx independent of GAS serotypes but did not reduce lethality after systemic GAS challenge. Anti-Sda1 antibody can neutralize degradation of NETs by Sda1 and other phage-encoded DNases and decrease GAS colonization at the nasopharynx across serotypes. These results indicate that Sda1 can be a potential vaccine candidate for reduction in GAS reservoir and GAS tonsillitis-associated diseases.

13.
Entertain Comput ; 43: 100511, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35991001

RESUMO

Remote collaboration tools for conferencing and presentation are gaining significant popularity during the COVID-19 pandemic period. Most prior work has drawbacks, such as a) limited support for media types, b) lack of interactivity, for example, an efficient replay mechanism, c) large bandwidth consumption for screen sharing tools. In this paper, we propose a general-purpose multimedia collaboration platform-CWcollab. It supports collaboration on general multimedia by using simple messages to represent media controls with an object-prioritized synchronization approach. Thus, CWcollab can not only support fine-grained accurate collaboration, but also rich functionalities such as replay of these collaboration events. The evaluation shows hundreds of kilobytes can be enough to store the events in a collaboration session for accurate replays, compared with hundreds of megabytes of Google Meet.

14.
Microbiol Spectr ; 10(1): e0114421, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35196817

RESUMO

Vaccination through the upper respiratory tract (URT) is highly effective for the prevention of respiratory infectious diseases. Toll-like receptor (TLR)-based adjuvants are immunostimulatory and considered potential adjuvant candidates. However, the patterns of immune response to different TLRs at the URT have not been revealed. In this study, SPF mice were preexposed to TLR agonists intranasally to simulate the status of humans. Inflammatory response to TLR agonists and TLR signal-mediated adaptive immune responses were analyzed. The results revealed that similar to human tonsils, inflammatory response to stimulation with TLR4 or TLR2 agonist was attenuated in agonist-exposed mice but not in mice without this exposure. In contrast, TLR9 or TLR3 agonist preexposure did not affect the inflammatory response to restimulation by matching agonists. For the adaptive immune response, after agonist preexposure the antibody response to antigens adjuvanted with TLR4 or TLR2 agonist was substantially restricted, whereas, both antibody and T cell responses to antigens adjuvanted with TLR9 or TLR3 agonist were activated as robustly as in mice without agonist exposure. Moreover, we demonstrate that the mechanisms underlying the differential activation of TLRs are regulated at the level of TLR expression in innate and adaptive immune cells. These results indicate that TLRs on the cell surface (TLR4 and 2) and in the endolysosomal compartments (TLR9 and 3) display distinct immune response patterns. The findings provide important information for the use of TLR agonists as mucosal adjuvants and enhance our understanding of immune responses to bacterial and viral infections in the respiratory mucosa. IMPORTANCE Agonists of TLRs are potential adjuvant candidates for mucosal vaccination. We demonstrated that the TLR-mediated inflammatory and antibody responses in the URT of SPF mice exposed to extracellular TLR agonists were substantially restricted. In contrast, inflammatory and adaptive immune responses, including B and T cell activation, were not desensitized in mice exposed to intracellular TLR agonists. The distinct responsive patterns of extra and intracellular TLRs regulated at TLR expression in immune cells. The results indicated that TLRs differentially impact the innate and adaptive immune response in the URT, which contributes to the selection of TLR-based mucosal adjuvants and helps understand the difference between the immune response in bacterial and viral infections.


Assuntos
Infecções Respiratórias/imunologia , Receptores Toll-Like/imunologia , Imunidade Adaptativa , Animais , Linfócitos B/imunologia , Citocinas/genética , Citocinas/imunologia , Feminino , Humanos , Imunidade Inata , Camundongos , Camundongos Endogâmicos C57BL , Infecções Respiratórias/genética , Transdução de Sinais , Linfócitos T/imunologia , Receptores Toll-Like/genética
15.
Front Microbiol ; 13: 1055694, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36687603

RESUMO

The double selection of environment adaptation and host specificity forced the diversification of rhizobia in nature. In the tropical region of China, Medicago polymorpha and Medicago lupulina are widely distributed, particularly in purple soil. However, the local distribution and diversity of rhizobia associated with these legumes has not been systematically investigated. To this end, root nodules of M. polymorpha and M. lupulina grown in purple soil at seven locations in Yunnan Province of China were collected for rhizobial isolation. The obtained rhizobia were characterized by RFLP of 16S-23S rRNA intergenic spacer, BOXAIR fingerprinting, and phylogeny of housekeeping and symbiosis genes. As result, a total of 91 rhizobial strains were classified into species Sinorhizobium medicae and S. meliloti, while three nodC gene types were identified among them. S. medicae containing nodC of type I was dominant in farmlands associated with M. polymorpha; while S. meliloti harboring nodC of type III was dominant in wild land nodulated by M. lupulina. For both rhizobial species, greater genetic diversity was detected in the populations isolated from their preferred host plant. A high level of genetic differentiation was observed between the two Sinorhizobium species, and gene flow was evident within the populations of the same species derived from different soil types, indicating that rhizobial evolution is likely associated with the soil features. To examine the effects of environmental features on rhizobial distribution, soil physicochemical traits and rhizobial genotypes were applied for constrained analysis of principle coordinates, which demonstrated that soil features like pH, nitrogen and sodium were the principle factors governing the rhizobial geographical distribution. Altogether, both S. medicae and S. meliloti strains could naturally nodulate with M. polymorpha and M. lupulina, but the rhizobium-legume symbiosis compatibility determined by both the host species and soil factors was also highlighted.

16.
Cell Rep ; 35(7): 109159, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34010655

RESUMO

During influenza A epidemics, bacterial coinfection is a major cause of increased morbidity and mortality. However, the roles of host factors in regulating influenza A virus (IAV)-triggered bacterial coinfection remain elusive. Cyclophilin A (CypA) is an important regulator of infection and immunity. Here, we show that IAV-induced CypA expression facilitates group A Streptococcus (GAS) coinfection both in vitro and in vivo. Upon IAV infection, CypA interacts with focal adhesion kinase (FAK) and inhibited E3 ligase cCbl-mediated, K48-linked ubiquitination of FAK, which positively regulates integrin α5 expression and actin rearrangement via the FAK/Akt signaling pathway to facilitate GAS colonization and invasion. Notably, CypA deficiency or inhibition by cyclosporine A significantly inhibits IAV-triggered GAS coinfection in mice. Collectively, these findings reveal that CypA is critical for GAS infection, and induction of CypA expression is another way for IAV to promote bacterial coinfection, suggesting that CypA is a promising therapeutic target for the secondary bacterial infection.


Assuntos
Coinfecção/microbiologia , Ciclofilina A/metabolismo , Vírus da Influenza A/patogenicidade , Streptococcus pneumoniae/virologia , Humanos
17.
iScience ; 23(12): 101767, 2020 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-33251497

RESUMO

Bacterial coinfection is a major cause of influenza-associated mortality. Most people have experienced infections with bacterial pathogens commonly associated with influenza A virus (IAV) coinfection before IAV exposure; however, bacterial clearance through the immunological memory response (IMR) in coinfected patients is inefficient, suggesting that the IMR to bacteria is impaired during IAV infection. Adoptive transfer of CD4+ T cells from mice that had experienced bacterial infection into IAV-infected mice revealed that memory protection against bacteria was weakened in the latter. Additionally, memory Th17 cell responses were impaired due to an IFN-γ-dependent reduction in Th17 cell proliferation and delayed migration of CD4+ T cells into the lungs. A bacterium-specific antibody-mediated memory response was also substantially reduced in coinfected mice, independently of IFN-γ. These findings provide additional perspectives on the pathogenesis of coinfection and suggest additional strategies for the treatment of defective antibacterial immunity and the design of bacterial vaccines against coinfection.

18.
J Agric Food Chem ; 68(20): 5752-5762, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32283023

RESUMO

Garlic-specialized metabolites contribute to both spicy flavor and healthy function of garlic. Their accumulation pattern and regulatory mechanism vary greatly at different environments and maturities. Herein, metabolomics models were built to evaluate and predict the quality and chemical composition variances of four garlic varieties in two regions at six growth stages. A total of 91 metabolites were identified, and their accumulation pattern during growth in three varieties of garlic in Shandong was similar but obviously distinct from that planted in Heilongjiang. Active metabolism for organosulfur compounds and amino acids was observed, and most metabolites with the "γ-glutamyl-" group were the storage compounds of nitrogen and sulfur in garlic because they increased remarkably during growth. The levels of functional components in garlic varied among different stages, and reliable prediction models for these compounds were provided, which may give a new idea for the estimation of garlic quality and confirmation of the best harvest time.


Assuntos
Alho/química , Extratos Vegetais/química , Raízes de Plantas/crescimento & desenvolvimento , Aminoácidos/química , Aminoácidos/metabolismo , Antioxidantes/química , Antioxidantes/metabolismo , Alho/crescimento & desenvolvimento , Alho/metabolismo , Metabolômica , Extratos Vegetais/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Compostos de Enxofre/química , Compostos de Enxofre/metabolismo
19.
Int Immunopharmacol ; 78: 106013, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31806571

RESUMO

There is an urgent need for efficient vaccines against the highly pathogenic avian influenza A viral strain H7N9. The duration and intensity of the immune response to H7N9 critically impacts the epidemiology of influenza viral infection at the population level. However, the insufficient immunogenicity of H7N9 raises concerns about vaccine efficacy. In this study, we evaluated the impact of immunization routes and the adjuvant CpG on the immune response to a split H7N9 vaccine in mice. Determination of humoral and cellular responses to the vaccine revealed that after four vaccine doses, high titers of H7N9-specific serum IgG, determined by the influenza hemagglutination inhibition (HI) assay, were induced through the intramuscular (i.m.) route and lasted for at least 40 weeks. CpG-adjuvanted immunization increased the levels of long-lived IFN-γ+ T cells and raised the Th1-biased IgG2a/IgG1 response ratio. In addition, aside from mucosal IgA, CpG-adjuvanted intranasal (i.n.) immunization elicited serum IgG and cellular responses of a similar duration and intensity to CpG-adjuvanted i.m. immunization. Mouse challenge assays demonstrated that 24 weeks following i.m. immunization without CpG or CpG-adjuvanted immunization through the i.m. or i.n. routes, both offered a high level of protection against H7N9 infection. These results indicate that efficient long-term protection against H7N9 can be achieved via the optimization of vaccination strategies, such as immunization doses, routes, and adjuvants.


Assuntos
Anticorpos Antivirais/sangue , Ilhas de CpG/imunologia , Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Imunogenicidade da Vacina , Vacinas contra Influenza/administração & dosagem , Influenza Humana/sangue , Influenza Humana/imunologia , Influenza Humana/virologia , Injeções Intramusculares , Camundongos , Células Th1/imunologia , Fatores de Tempo , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia
20.
Front Immunol ; 11: 1902, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32973788

RESUMO

Pulmonary tuberculosis (PTB) is a risk factor for COPD. Our previous study revealed more severe emphysema in COPD patients (mostly smokers) with prior tuberculosis. However, the mechanisms of interactions between cigarette smoke (CS) and Mycobacterium tuberculosis (Mtb) are unknown. In this study, we found that the frequencies of both M1 and M2 macrophages, and levels of MMP9 and MMP12 in bronchoalveolar lavage were increased in PTB patients with smoking. Between-group analysis showed that the frequency of M1 macrophages was higher in non-smoker PTB patients while more M2 macrophages were found in smokers without PTB, as compared to the non-smoker healthy controls. Bacille Calmette-Guérin (BCG) infection in CS extract (CSE)-incubated MH-S cells further enhanced secretion of M1-related (iNOS, IFN-γ and TNF-α) and M2-related (TGF-ß and IL-10) cytokines, reactive oxygen species (ROS) production and cellular apoptosis, concomitantly with up-regulation of MMP9 and MMP12, but not TIMP1. Moreover, BCG infection in acutely CS-exposed mice promoted macrophage polarization toward both M1 and M2 phenotypes, along with increased lung inflammatory infiltration. MMP9 and MMP12, but not TIMP1, were further up-regulated in lung tissues and BAL fluid after BCG infection in this model. Taken together, Mtb Infection promoted CS-exposed macrophages to polarize toward both M1 and M2 phenotypes, along with enhanced production of MMP9 and MMP12. These findings provide insights into the mechanistic interplay between CS exposure and tuberculosis in the pathogenesis of COPD.


Assuntos
Fumar Cigarros/efeitos adversos , Macrófagos Alveolares/microbiologia , Metaloproteinase 12 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Mycobacterium tuberculosis/patogenicidade , Doença Pulmonar Obstrutiva Crônica/microbiologia , Fumantes , Tuberculose Pulmonar/microbiologia , Adulto , Idoso , Animais , Estudos de Casos e Controles , Linhagem Celular , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Patógeno , Humanos , Macrófagos Alveolares/enzimologia , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , não Fumantes , Fenótipo , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/enzimologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/diagnóstico , Adulto Jovem
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