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2.
Phys Chem Chem Phys ; 26(24): 17075-17082, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38842020

RESUMO

The topological and magnetic properties induced by topological defects in graphene have attracted attention. Here, we study a novel topological defect structure for graphene nanoribbons interspersed with C558-line defects along the armchair boundary, which possesses topological properties and is tritopic. Using strain engineering to regulate the magnitude of hopping at defects, the position of the energy level can be easily changed to achieve a topological phase transition. We also discuss the local magnetic moment and the ferromagnetic ground state in the context of line defects. This leads to spin polarization of the whole system. Finally, when C558 graphene nanoribbons are controlled by a nonlocal exchange magnetic field, spin-polarized quantum conductivity occurs near the Fermi level. Consequently, spin filtering can be achieved by varying the incident energy of the electrons. Our results provide new insights into realizing topological and spin electronics in low-dimensional quantum devices.

3.
Nature ; 542(7641): 318-323, 2017 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-28076346

RESUMO

Spliceosome rearrangements facilitated by RNA helicase PRP16 before catalytic step two of splicing are poorly understood. Here we report a 3D cryo-electron microscopy structure of the human spliceosomal C complex stalled directly after PRP16 action (C*). The architecture of the catalytic U2-U6 ribonucleoprotein (RNP) core of the human C* spliceosome is very similar to that of the yeast pre-Prp16 C complex. However, in C* the branched intron region is separated from the catalytic centre by approximately 20 Å, and its position close to the U6 small nuclear RNA ACAGA box is stabilized by interactions with the PRP8 RNase H-like and PRP17 WD40 domains. RNA helicase PRP22 is located about 100 Å from the catalytic centre, suggesting that it destabilizes the spliced mRNA after step two from a distance. Comparison of the structure of the yeast C and human C* complexes reveals numerous RNP rearrangements that are likely to be facilitated by PRP16, including a large-scale movement of the U2 small nuclear RNP.


Assuntos
Microscopia Crioeletrônica , Splicing de RNA , Spliceossomos/metabolismo , Spliceossomos/ultraestrutura , Adenosina/metabolismo , Sequência de Bases , Biocatálise , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/ultraestrutura , RNA Helicases DEAD-box/química , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/ultraestrutura , Éxons/genética , Humanos , Íntrons/genética , Modelos Moleculares , Movimento , Domínios Proteicos , Fatores de Processamento de RNA/química , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de RNA/ultraestrutura , Estabilidade de RNA , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/ultraestrutura , Ribonuclease H/química , Ribonuclease H/metabolismo , Ribonucleoproteínas Nucleares Pequenas/química , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Ribonucleoproteínas Nucleares Pequenas/ultraestrutura , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/enzimologia , Spliceossomos/química
4.
Cancer Immunol Immunother ; 71(7): 1549-1567, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34739560

RESUMO

Immune checkpoint inhibitors (ICIs) for programmed death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) have become preferred treatment strategies for several advanced cancers. However, response rates for these treatments are limited, which encourages the search for new ICI candidates. Recent reports have underscored significant roles of B7 homolog 3 protein (B7-H3) in tumor immunity and disease progression. While its multifaceted roles are being elucidated, B7-H3 has already entered clinical trials as a therapeutic target. In this review, we overview the recent results of clinical trials evaluating the antitumor activity and safety of B7-H3 targeting drugs. On this basis, we also discuss the challenges and opportunities arising from the application of these drugs. Finally, we point out current gaps to address in the understanding of B7-H3 function and regulation in order to fully unleash the future clinical utility of B7-H3-based therapies for the treatment of cancer.


Assuntos
Imunoterapia , Neoplasias , Antígeno B7-H1/metabolismo , Humanos , Imunoterapia/métodos , Neoplasias/terapia
5.
Phys Chem Chem Phys ; 24(28): 17337-17347, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35819058

RESUMO

AEIn2As2 (AE = Ca, Sr, Ba), as a new crucial nonmagnetic thermoelectric candidate, needs to be understood in terms of its potential electronic structure properties and topological characteristics in both experimental and theoretical studies. Here we report that AEIn2As2 with Zintl phases will undergo insulator-metal phase transition and topological quantum phase transition under pressure modulation based on first-principles calculations. Firstly, band inversion occurred between the In(As)-s and As(In)-p states in the structures of AEIn2As2 with the P63/mmc space group in the absence of pressure and identified that they are all non-trivial topological insulators. Next, Bader charge and AIM topology analysis elucidate the nature of pressure-induced chemical bond enhancement. Lastly, we have discovered pressure-controllable band gap closure while the topologically protected surface states disappear, realizing insulator-metal phase transition and topological quantum phase transition. Our research not only enriches the family of topological insulators but also provides a good platform for the study of thermoelectric properties.

6.
Cancer Cell Int ; 20: 279, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32617077

RESUMO

BACKGROUND: Alternative splicing (AS) may cause structural and functional variations in the protein to promote the proliferation of tumor cells. However, there is no comprehensive analysis of the clinical significance of AS in Helicobacter pylori-negative gastric cancer (HP - GC). METHODS: The clinical, gene expression profile data and AS events of 138 HP - GC patients were obtained from the database named the cancer genome atlas. Differently expressed AS (DEAS) events were determined by a comparison of the PSI values between HP - GC samples and adjacent normal samples. Unsupervised clustering analysis, proportional regression and Kaplan-Meier analysis were used to explore the association between clinical data and immune features and to establish two nomograms about the prognosis of HP - GC. Finally, splicing networks were constructed using Cytoscape. RESULTS: A total of 48141 AS events and 1041 DEAS events were found in HP - GC. Various functions and pathways of DEAS events parent genes were enriched, such as cell-substrate junction, cell leading edge, focal adhension, and AMPK signaling. Seven overall survival (OS)-related and seven disease-free survival (DFS)-related AS events were used to construct the prognostic signatures. Based on the independent prognostic factors, two nomograms were established and showed excellent performance. Then, splicing regulatory networks among the correlations suggested that splicing factors were significantly associated with prognostic DEASs. Finally, the unsupervised clustering analysis revealed that DEAS-based clusters were associated with clinical characteristics, tumor microenvironment, tumor mutation burden, and immune features. CONCLUSION: Seven OS-related and seven DFS-related AS events have been found to be correlated with the prognosis of HP - GC and can be used as prognostic factors to establish an effective nomogram.

7.
Ann Surg Oncol ; 26(11): 3745-3755, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31087180

RESUMO

BACKGROUND: A recent study showed that circulating exosomal PD-L1 is an effective predictor for anti-PD-1 therapy in melanomas. Exosomal PD-L1 induced immunosuppression microenvironments in cancer patients. However, its prognostic value and immunosuppressive effect in gastric cancer (GC) were poorly understood. METHODS: We retrospectively evaluated the prognostic value of exosomal PD-L1 and soluble PD-L1 in preoperative plasma of 69 GC patients. The correlation between exosomal PD-L1 and the T cell counts or cytokine in the plasma was evaluated in 31 metastatic GC patients before chemotherapy. RESULTS: Overall survival (OS) was significantly lower in the high exosomal PD-L1 group compared with the low exosomal PD-L1 group (P = 0.004). Exosomal PD-L1 was an independent prognostic factor in GC (n = 69, 95% confidence interval = 1.142-7.669, P = 0.026). However, soluble PD-L1 showed no correlation with OS (P = 0.139). Additionally, exosomal PD-L1 in the plasma samples of 31 metastatic GC patients was negatively associated with CD4+ T cell count (P = 0.001, R = - 0.549), CD8+ T-cell count (P = 0.054, R = - 0.349), and granzyme B (P = 0.002, R = - 0.537), indicating that exosomal PD-L1 was associated with immunosuppressive status of GC patients. GC cells also secreted exosomal PD-L1 and were positively associated with the amount of PD-L1 in corresponding GC cell lines. Besides, exosomal PD-L1 significantly decreased T-cell surface CD69 and PD-1 expressions compared with soluble PD-L1 due to its stable and MHC-I expression. CONCLUSIONS: Overall, exosomal PD-L1 predicts the worse survival and reflects the immune status in GC patients, resulting from a stronger T-cell dysfunction due to its stable and MHC-I expression.


Assuntos
Adenocarcinoma/secundário , Antígeno B7-H1/sangue , Antígeno B7-H1/imunologia , Exossomos/metabolismo , Terapia de Imunossupressão , Neoplasias Gástricas/patologia , Adenocarcinoma/sangue , Adenocarcinoma/imunologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/imunologia , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/sangue , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/cirurgia , Taxa de Sobrevida
8.
Exp Cell Res ; 373(1-2): 180-187, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30367831

RESUMO

Although anti-programmed death ligand-1 (PD-L1) therapy has shown light in treatment of gastric cancer, only a limited number of patients respond to the treatment. In addition to its immunosuppressive effect, PD-L1 is involved in other functions of tumor cells. Previously study showed that PD-L1 promoted EMT in lung cancer cells. However, the other effect and role of PD-L1 in gastric cancer remains unclear. In the present study, we first demonstrated that PD-L1 promoted the proliferation and migration in gastric cancer cell lines. We found that another STAT family member, STAT5a, is involved in regulating the expression of PD-L1 in gastric cancer. Additionally, Cbl-b interacted and ubiquitated STAT5a, down-regulated the expression of STAT5a and PD-L1. Moreover, bioinformatics predictions and experimental data showed that Cbl-b is a target gene of the microRNA miR-940. We further found that miR-940 promoted the proliferation and migration of gastric cancer in vivo and in vitro. Taken together, our findings suggest that miR-940/Cbl-b/STAT5a axis regulated the expression of PD-L1, which promotes the proliferation and migration of gastric cancer cells.


Assuntos
Antígeno B7-H1/metabolismo , MicroRNAs/metabolismo , Neoplasias Gástricas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antígeno B7-H1/biossíntese , Antígeno B7-H1/fisiologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células Jurkat , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Proto-Oncogênicas c-cbl/genética , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Fator de Transcrição STAT5/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Neoplasias Gástricas/fisiopatologia , Proteínas Supressoras de Tumor/metabolismo , Ubiquitinação , Regulação para Cima
9.
Clin Lab ; 65(11)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710433

RESUMO

BACKGROUND: A noninvasive, fast, highly sensitive and simple test is needed for cancer screening in addition to the detection of biomarkers in blood. Recently, the patent (CN102565055A) for the Urinary Monohydroxyphenyl Metabolites Assay (UMM-A) was authorized, and the effectiveness of clinical application has yet to be studied further. METHODS: A retrospective study was conducted consisting of 432 cancer patients, 28 benign tumor patients, 117 non-cancerous diseases patients, and 120 healthy donors to analyze the levels of monohydroxyphenyl metabolites in the urine sample. A logistic regression model was used to study the possible confounding factors affecting the diagnostic performance and to test the probability of a case to be positive for UMM-A. RESULTS: Compared with healthy donors, non-cancerous disease, and benign tumor subjects, the positive rate and MM level of UMM-A in cancer patients have significantly increased. After the 246 retreated cancer patients were excluded, and 186 untreated cancer patients were included, with the same specificity to 77.0%, the sensitivity improved from 66.7 to 89.8%, the negative predictive value improved from 58.6 to 91.4%. CONCLUSIONS: The present study has provided important information on the diagnostic characteristics of UMM-A for untreated cancer and its potential application in cancer screening.


Assuntos
Biomarcadores Tumorais/urina , Detecção Precoce de Câncer/métodos , Neoplasias/diagnóstico , Fenóis/urina , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hidroxilação , Masculino , Pessoa de Meia-Idade , Neoplasias/urina , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Urinálise
10.
BMC Cancer ; 18(1): 462, 2018 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-29690901

RESUMO

BACKGROUND: Programmed death-ligand 1 (PD-L1) is an immunosuppressor that plays an important role in cancer treatments. Although majority of the studies demonstrated that PD-L1 expression was regulated by cellular intrinsic and extrinsic controls, and IFN-γ was a key molecule of extrinsic control, other studies imply that other cytokines play important roles in PD-L1 expression. In this study, we investigated the regulation of PD-L1 by chemokine signaling pathway in gastric cancer (GC) cells. METHODS: Bioinformatics was used to explore the PD-L1-related genes in GC and propose a hypothesis. PD-L1 and CXCR3 expression were detected by western blot in SGC7901 and MKN74 cell lines. Meanwhile, PD-L1 and CXCR3 expressions were immunohistochemically assessed for their relevance. Moreover, PD-L1, pSTAT3 and pAkt were detected after treatment with CXCL9/10/11. Furthermore,PD-L1, pSTAT3 and pAkt were evaluated after blocking chemokine signaling in SGC7901 cells. RESULTS: Based on online database analysis, CXCL9/10/11-CXCR3 is proposed to upregulate PD-L1 expression by activating the STAT and PI3K-Akt pathways. This hypothesis was confirmed by in vitro and vivo experiments. CXCR3 and PD-L1 were expressed in GC cell lines and tissues, and the expression of CXCR3 and PD-L1 was positively related. PD-L1 was upregulated after treatment with CXCL9/10/11, accompanied by activation of STAT3 and Akt. After blocking chemokine signaling, upregulation of PD-L1 and activation of STAT3 and Akt were diminished. CONCLUSIONS: CXCL9/10/11-CXCR3 upregulated the expression of PD-L1 by activating the STAT and PI3K-Akt signaling pathways in GC cells. There was a significant positive correlation between the expression of PD-L1 and CXCR3 in gastric cancer patient tissues.


Assuntos
Antígeno B7-H1/genética , Quimiocinas CXC/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Antígeno B7-H1/metabolismo , Biomarcadores , Linhagem Celular Tumoral , Quimiocina CXCL10/metabolismo , Quimiocina CXCL11/metabolismo , Quimiocina CXCL9/metabolismo , Biologia Computacional/métodos , Humanos , Imuno-Histoquímica , Anotação de Sequência Molecular , Estadiamento de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores CXCR3/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Neoplasias Gástricas/patologia
11.
BMC Cancer ; 18(1): 681, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29940895

RESUMO

BACKGROUND: MicroRNAs can be used in the prognosis of malignancies; however, their regulatory mechanisms are unknown, especially in pancreatic ductal adenocarcinoma (PDAC). METHODS: In 120 PDAC specimens, miRNA levels were assessed by quantitative real time polymerase chain reaction (qRT-PCR). Then, the role of miR-29b-2-5p in cell proliferation was evaluated both in vitro (Trypan blue staining and cell cycle analysis in the two PDAC cell lines SW1990 and Capan-2) and in vivo using a xenograft mouse model. Next, bioinformatics methods, a luciferase reporter assay, Western blot, and immunohistochemistry (IHC) were applied to assess the biological effects of Cbl-b inhibition by miR-29b-2-5p. Moreover, the relationship between Cbl-b and p53 was evaluated by immunoprecipitation (IP), Western blot, and immunofluorescence. RESULTS: From the 120 PDAC patients who underwent surgical resection, ten patients with longest survival and ten with shortest survival were selected. We found that high miR-29b-2-5p expression was associated with good prognosis (p = 0.02). The validation cohort confirmed miR-29b-2-5p as an independent prognostic factor in PDAC (n = 100, 95% CI = 0.305-0.756, p = 0.002). Furthermore, miR-29b-2-5p inhibited cell proliferation, induced cell cycle arrest, and promoted apoptosis both in vivo and in vitro. Interestingly, miR-29b-2-5p directly bound the Cbl-b gene, down-regulating its expression and reducing Cbl-b-mediated degradation of p53. Meanwhile, miR-29b-2-5p expression was negatively correlated with Cbl-b in PDAC tissues (r = - 0.33, p = 0.001). CONCLUSIONS: Taken together, these findings indicated that miR-29b-2-5p improves prognosis in PDAC by targeting Cbl-b to promote p53 expression, and would constitute an important prognostic factor in PDAC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Adenocarcinoma/patologia , Carcinoma Ductal Pancreático/patologia , MicroRNAs/fisiologia , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-cbl/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Prognóstico , Proteína Supressora de Tumor p53/fisiologia
12.
BMC Cancer ; 18(1): 507, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29720121

RESUMO

BACKGROUND: Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance. METHODS: MTT and colony formation assays were used to measure cell viability and proliferation. Western blot was used to detect protein expression and protein complex formations were detected by immunoprecipitation and immunofluorescence. SiRNA was used to examine the function of HER2 in of BT474 cells. An in vivo xenograft animal model was established to examine the role of c-Cbl in tumor growth. RESULTS: MTT and colony formation assay showed that BT474 cells are resistant to tamoxifen and T47D cells are sensitive to tamoxifen. Immunoprecipitation experiments revealed ER-c-Src-HER2 complex formation in BT474 cells but not in T47D cells. However, ER-c-Src-HER2 complex formation was detected after overexpressing HER2 in T47D cells and these cells were more resistant to tamoxifen. HER2 knockdown by siRNA in BT474 cells reduced ER-c-Src-HER2 complex formation and reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was also disrupted and tamoxifen resistance was reversed in BT474 cells by the c-Src inhibitor PP2 and HER2 antibody trastuzumab. Nystatin, a lipid raft inhibitor, reduced ER-c-Src-HER2 complex formation and partially reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was disrupted by overexpression of c-Cbl but not by the c-Cbl ubiquitin ligase mutant. In addition, c-Cbl could reverse tamoxifen resistance in BT474 cells, but the ubiquitin ligase mutant had no effect. The effect of c-Cbl was validated in BT474 tumor-bearing nude mice in vivo. Immunofluorescence also revealed ER-c-Src-HER2 complex formation was reduced in tumor tissues of nude mice with c-Cbl overexpression. CONCLUSIONS: Our results suggested that c-Cbl can reverse tamoxifen resistance in HER2-overexpressing breast cancer cells by inhibiting the formation of the ER-c-Src-HER2 complex.


Assuntos
Neoplasias da Mama/patologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Animais , Neoplasias da Mama/metabolismo , Proteína Tirosina Quinase CSK , Linhagem Celular Tumoral , Feminino , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Quinases da Família src/metabolismo
13.
Appl Microbiol Biotechnol ; 99(16): 6765-74, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25957149

RESUMO

No commercial vaccines are currently available for enterovirus 71 (EV71) infection. Oral virus-like particle (VLP) vaccines are regarded as a better choice for prevention from food-borne diseases compared with injected whole virus vaccines. Unfortunately, the application of oral VLP vaccines produced from transgenic plants was limited due to the concerns of gene contamination. Alternatively, using transgenic mushrooms retains the advantages of transgenic plants and tremendously reduce risks of gene contamination. Polycistronic expression vectors harboring the glyceraldehyde-3-phospho-dehydrogenase promoter to codrive EV71 structural protein P1 and protease 3C using the 2A peptide of porcine teschovirus-1 were constructed and introduced into Flammulina velutipes via Agrobacterium tumefaciens-mediated transformation. The analyses of the genomic PCR, Southern blotting, and RT-PCR showed that the genes of P1 and 3C were integrated into the chromosomal DNA through a single insertion, and their resulting mRNAs were transcribed. The Western blotting analysis combined with LC-MS/MS demonstrated that EV71 VLPs were composed of the four subunit proteins digested from P1 polyprotein by 3C protease. Through the use of a single particle electron microscope, images of 1705 particles with diameter similar to the EV71 viron were used for 3D reconstruction. Protrusions were observed on the surface in the 2D class averages, and a 3D reconstruction of the VLPs was obtained. In conclusion, EV71 VLPs were successfully produced in transgenic F. velutipes using a polycistronic expression strategy, which indicates that this approach is promising for the development of oral vaccines produced in mushrooms.


Assuntos
Enterovirus Humano A/genética , Flammulina/metabolismo , Proteínas Virais/metabolismo , Virossomos/metabolismo , Agrobacterium tumefaciens , Southern Blotting , Western Blotting , Cromatografia Líquida , Flammulina/genética , Perfilação da Expressão Gênica , Imageamento Tridimensional , Microscopia Eletrônica , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas em Tandem , Teschovirus/genética , Transformação Genética , Proteínas Virais/genética , Virossomos/genética
14.
Hepatology ; 57(4): 1620-31, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23175475

RESUMO

UNLABELLED: Interleukin (IL)-27, a newly discovered IL-12 family cytokine, is composed of p28 and EBI3. In this study, CD11c-p28(f/f) conditional knockout mice were generated to delete p28 specifically in dendritic cells (DCs). We demonstrated that in the absence of DC-derived p28, these mice were highly susceptible to both low and higher concentrations of concanavalin A (ConA) (5 mg/kg or 10 mg/kg), with extremely early and steady high levels of interferon-γ (IFN-γ) in sera. Neutralizing IFN-γ prevented ConA-induced liver damage in these mice, indicating a critical role of IFN-γ in this pathological process. Interestingly, the main source of the increased IFN-γ in CD11c-p28(f/f) mice was CD4+ T cells, but not natural killer T (NKT) cells. Depletion of CD4+ , but not NK1.1+ , cells completely abolished liver damage, whereas transferring CD4+ T cells from CD11c-p28(f/f) mice, but not from wild-type mice or CD11c-p28(f/f) -IFN-γ(-/-) double knockout mice to CD4(-/-) mice, restored the increased liver damage. Further studies defined higher levels of IFN-γ and T-bet messenger RNA in naïve CD4+ T cells from CD11c-p28(f/f) mice, and these CD4+ T cells were highly responsive to both low and higher concentrations of anti-CD3, indicating a programmed functional alternation of CD4+ T cells. CONCLUSION: We provide a unique model for studying the pathology of CD4+ T cell-mediated liver injury and reveal a novel function of DC-derived p28 on ConA-induced fulminant hepatitis through regulation of the intrinsic ability for IFN-γ production by CD4+ T cells.


Assuntos
Linfócitos T CD4-Positivos/patologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/fisiopatologia , Concanavalina A/efeitos adversos , Suscetibilidade a Doenças/patologia , Interferon gama/fisiologia , Animais , Antígeno CD11c/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Interferon gama/genética , Interleucina-17/genética , Interleucina-17/fisiologia , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/patologia , Masculino , Camundongos , Camundongos Knockout
15.
J Infect Dis ; 208(8): 1294-304, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23847059

RESUMO

BACKGROUND: γδ T cells comprise a small subset of T cells and play a protective role against cancer and viral infections; however, their precise role in patients with chronic hepatitis B remains unclear. METHODS: Flow cytometry and immunofunctional assays were performed to analyze the impact of Vδ2 γδ (Vδ2) T cells in 64 immune-activated patients, 22 immune-tolerant carriers, and 30 healthy controls. RESULTS: The frequencies of peripheral and hepatic Vδ2 T cells decreased with disease progression from immune tolerant to immune activated. In the latter group of patients, the decreases in peripheral and intrahepatic frequencies of Vδ2 T cells reversely correlated with alanine aminotransferase levels and histological activity index. These activated terminally differentiated memory phenotypic Vδ2 T cells exhibited impaired abilities in proliferation and chemotaxis, while maintained a relative intact interferon (IFN) γ production. Importantly, Vδ2 T cells, in vitro, significantly suppressed the production of cytokines associated with interleukin 17-producing CD4+ T (Th17) cells through both cell contact-dependent and IFN-γ-dependent mechanisms. CONCLUSIONS: Inflammatory microenvironment in IA patients result in decreased numbers of Vδ2 T cells, which play a novel role by regulating the pathogenic Th17 response to protect the liver in patients with chronic hepatitis B.


Assuntos
Hepatite B Crônica/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/imunologia , Células Th17/imunologia , Adolescente , Adulto , Processos de Crescimento Celular/imunologia , Quimiotaxia de Leucócito , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Hepatite B Crônica/metabolismo , Hepatite B Crônica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
16.
J Exp Clin Cancer Res ; 43(1): 8, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167055

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal solid tumors. The tumor immune microenvironment (TIME) formed by interactions among cancer cells, immune cells, cancer-associated fibroblasts (CAF), and extracellular matrix (ECM) components drives PDAC in a more immunosuppressive direction: this is a major cause of therapy resistance and poor prognosis. In recent years, research has advanced our understanding of the signaling mechanism by which TIME components interact with the tumor and the evolution of immunophenotyping. Through revolutionary technologies such as single-cell sequencing, we have gone from simply classifying PDACs as "cold" and "hot" to a more comprehensive approach of immunophenotyping that considers all the cells and matrix components. This is key to improving the clinical efficacy of PDAC treatments. In this review, we elaborate on various TIME components in PDAC, the signaling mechanisms underlying their interactions, and the latest research into PDAC immunophenotyping. A deep understanding of these network interactions will contribute to the effective combination of TIME-based therapeutic approaches, such as immune checkpoint inhibitors (ICI), adoptive cell therapy, therapies targeting myeloid cells, CAF reprogramming, and stromal normalization. By selecting the appropriate integrated therapies based on precise immunophenotyping, significant advances in the future treatment of PDAC are possible.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/patologia , Resultado do Tratamento , Transdução de Sinais , Microambiente Tumoral
17.
Biomed Pharmacother ; 171: 116058, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38171240

RESUMO

Kirsten rats sarcoma viral oncogene (KRAS), the first discovered human oncogene, has long been recognized as "undruggable". KRAS mutations frequently occur in multiple human cancers including non-small cell lung cancer(NSCLC), colorectal cancer(CRC) and pancreatic ductal adenocarcinoma(PDAC), functioning as a "molecule switch" determining the activation of various oncogenic signaling pathways. Except for its intrinsic pro-tumorigenic role, KRAS alteration also exhibits an unique immune signature characterized by elevated PD-L1 level and high tumor mutational burden(TMB). KRAS mutation shape an immune suppressive microenvironment by impeding effective T cells infiltration and recruiting suppressive immune cells including myeloid-derived suppressor cells(MDSCs), regulatory T cells(Tregs), cancer associated fibroblasts(CAFs). In immune checkpoint inhibitor(ICI) era, NSCLC patients with mutated KRAS tend to be more responsive to ICI than patients with intact KRAS. The hallmark for KRAS mutation is the existence of multiple kinds of co-mutations. Different types of co-alterations have distinct tumor microenvironment(TME) signatures and responses to ICI. TP53 co-mutation possess a "hot" TME and achieve higher response to immunotherapy while other loss of function mutation correlated with a "colder" TME and a poor outcome to ICI-based therapy. The groundbreaking discovery of KRAS G12C inhibitors significantly improved outcomes for this KRAS subtype even though efficacy was limited to NSCLC patients. KRAS G12C inhibitors also restore the suppressive TME, creating an opportunity for combinations with ICI. However, an inevitable challenge to KRAS inhibitors is drug resistance. Promising combination strategies such as combination with SHP2 is an approach deserve further exploration because of their immune modulatory effect.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Neoplasias Pancreáticas , Animais , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/patologia , Mutação , Proteínas Proto-Oncogênicas p21(ras)/genética , Microambiente Tumoral
18.
Front Immunol ; 15: 1328145, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38298192

RESUMO

Despite the clear benefits demonstrated by immunotherapy, there is still an inevitable off-target effect resulting in serious adverse immune reactions. In recent years, the research and development of Drug Delivery System (DDS) has received increased prominence. In decades of development, DDS has demonstrated the ability to deliver drugs in a precisely targeted manner to mitigate side effects and has the advantages of flexible control of drug release, improved pharmacokinetics, and drug distribution. Therefore, we consider that combining cancer immunotherapy with DDS can enhance the anti-tumor ability. In this paper, we provide an overview of the latest drug delivery strategies in cancer immunotherapy and briefly introduce the characteristics of DDS based on nano-carriers (liposomes, polymer nano-micelles, mesoporous silica, extracellular vesicles, etc.) and coupling technology (ADCs, PDCs and targeted protein degradation). Our aim is to show readers a variety of drug delivery platforms under different immune mechanisms, and analyze their advantages and limitations, to provide more superior and accurate targeting strategies for cancer immunotherapy.


Assuntos
Nanopartículas , Neoplasias , Humanos , Portadores de Fármacos/uso terapêutico , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Imunoterapia/métodos
19.
Int Immunopharmacol ; 134: 112224, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38723370

RESUMO

Immunotherapy is becoming increasingly important, but the overall response rate is relatively low in the treatment of gastric cancer (GC). The application of tumor mutational burden (TMB) in predicting immunotherapy efficacy in GC patients is limited and controversial, emphasizing the importance of optimizing TMB-based patient selection. By combining TMB and major histocompatibility complex (MHC) related hub genes, we established a novel TM-Score. This score showed superior performance for immunotherapeutic selection (AUC = 0.808) compared to TMB, MSI status, and EBV status. Additionally, it predicted the prognosis of GC patients. Subsequently, a machine learning model adjusted by the TM-Score further improved the accuracy of survival prediction (AUC > 0.8). Meanwhile, we found that GC patients with low TM-Score had a higher mutation frequency, higher expression of HLA genes and immune checkpoint genes, and higher infiltration of CD8+ T cells, CD4+ helper T cells, and M1 macrophages. This suggests that TM-Score is significantly associated with tumor immunogenicity and tumor immune environment. Notably, based on the RNA-seq and scRNA-seq, it was found that AKAP5, a key component gene of TM-Score, is involved in anti-tumor immunity by promoting the infiltration of CD4+ T cells, NK cells, and myeloid cells. Additionally, siAKAP5 significantly reduced MHC-II mRNA expression in the GC cell line. In addition, our immunohistochemistry assays confirmed a positive correlation between AKAP5 and human leukocyte antigen (HLA) expression. Furthermore, AKAP5 levels were higher in patients with longer survival and those who responded to immunotherapy in GC, indicating its potential value in predicting prognosis and immunotherapy outcomes. In conclusion, TM-Score, as an optimization of TMB, is a more precise biomarker for predicting the immunotherapy efficacy of the GC population. Additionally, AKAP5 shows promise as a therapeutic target for GC.


Assuntos
Imunoterapia , Aprendizado de Máquina , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/terapia , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidade , Imunoterapia/métodos , Prognóstico , Biomarcadores Tumorais/genética , Proteínas de Ancoragem à Quinase A/genética , Microambiente Tumoral/imunologia , Mutação , Resultado do Tratamento
20.
Arthritis Rheum ; 64(9): 2896-906, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22576707

RESUMO

OBJECTIVE: To analyze the effects of a novel compound, NK-007, on the prevention and treatment of collagen-induced arthritis (CIA) and the underlying mechanisms. METHODS: We determined the effect of NK-007 on lipopolysaccharide (LPS)-triggered tumor necrosis factor α (TNFα) production by murine splenocytes and a macrophage cell line (RAW 264.7) by enzyme-linked immunosorbent assay, intracellular cytokine staining, and Western blotting. The LPS-boosted CIA model was adopted, and NK-007 or vehicle was administered at different time points after immunization. Mice were monitored for clinical severity of arthritis, and joint tissues were used for histologic examination, cytokine detection, and immunohistochemical staining. Finally, stability of TNFα production and Th17 cell differentiation were studied using quantitative polymerase chain reaction and flow cytometry. RESULTS: NK-007 significantly suppressed LPS-induced TNFα production in vitro. Administration of NK-007 completely blocked CIA development and delayed its progression. Furthermore, treatment with NK-007 at the onset of arthritis significantly inhibited the progress of joint inflammation. Administration of NK-007 also suppressed production of TNFα, interleukin-6 (IL-6), and IL-17A in the joint and reduced percentages of IL-17+ cells among CD4+ and γ/δ T cells in draining lymph nodes. We further demonstrated that NK-007 acted on the stability of TNFα messenger RNA and reduced Th17 cell differentiation. In addition, it significantly inhibited levels of IL-6 and IL-17A in human coculture assay. CONCLUSION: For its effects on the development and progression of CIA and for its therapeutic effect on CIA, NK-007 has great potential to be a therapeutic agent for human rheumatoid arthritis.


Assuntos
Artrite Experimental/tratamento farmacológico , Diferenciação Celular/efeitos dos fármacos , Indolizinas/uso terapêutico , Fenantrenos/uso terapêutico , Células Th17/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Artrite Experimental/imunologia , Artrite Experimental/metabolismo , Diferenciação Celular/imunologia , Linhagem Celular , Indolizinas/farmacologia , Interleucina-17/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos DBA , Fenantrenos/farmacologia , Estabilidade de RNA/efeitos dos fármacos , Estabilidade de RNA/imunologia , Células Th17/imunologia , Células Th17/metabolismo
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