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1.
Mol Cell ; 70(5): 961-970.e5, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29883611

RESUMO

HIV-1 expresses several accessory proteins to counteract host anti-viral restriction factors to facilitate viral replication and disease progression. One such protein, Vpr, has been implicated in affecting multiple cellular processes, but its mechanism remains elusive. Here we report that Vpr targets TET2 for polyubiquitylation by the VprBP-DDB1-CUL4-ROC1 E3 ligase and subsequent degradation. Genetic inactivation or Vpr-mediated degradation of TET2 enhances HIV-1 replication and substantially sustains expression of the pro-inflammatory cytokine interleukin-6 (IL-6). This process correlates with reduced recruitment of histone deacetylase 1 and 2 to the IL-6 promoter, thus enhancing its histone H3 acetylation level during resolution phase. Blocking IL-6 signaling reduced the ability of Vpr to enhance HIV-1 replication. We conclude that HIV-1 Vpr degrades TET2 to sustain IL-6 expression to enhance viral replication and disease progression. These results suggest that disrupting the Vpr-TET2-IL6 axis may prove clinically beneficial to reduce both viral replication and inflammation during HIV-1 infection.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/metabolismo , HIV-1/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Monócitos/virologia , Proteínas Proto-Oncogênicas/metabolismo , Replicação Viral , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo , Sítios de Ligação , Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Dioxigenases , Células HEK293 , HIV-1/genética , HIV-1/crescimento & desenvolvimento , HIV-1/patogenicidade , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Interleucina-6/genética , Células Jurkat , Monócitos/enzimologia , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases , Proteólise , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais , Células THP-1 , Ubiquitina-Proteína Ligases , Ubiquitinação , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/genética
2.
J Infect Dis ; 216(12): 1579-1591, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29045701

RESUMO

Background: Regulatory T cells (Tregs) suppress T-cell immune activation and human immunodeficiency virus type 1 (HIV-1) replication, but the role of Tregs in HIV-1 reservoir persistence is poorly defined. Methods: Tregs were depleted by denileukin diftitox in humanized mice with chronic HIV-1 infection. Viral replication in lineage cells was determined by p24 expression. Levels of HIV-1 RNA and DNA in human cells, as well as replication-competent-virus-producing cells, were measured to quantified viral replication and reservoirs. Results: Treg depletion resulted in a blip of HIV-1 replication in T cells but not in myeloid cells. The major activated reservoir cells were memory CD4+ T cells in vivo. Interestingly, the transient activation of viral replication led to HIV-1 reservoir reduction after viremia resuppression, as indicated by the quantity of HIV-1 DNA and replication-competent-virus-producing cells. Furthermore, we demonstrated that Tregs use cyclic adenosine monophosphate (cAMP)-dependent protein kinase A pathway to inhibit HIV-1 activation and replication in resting conventional T cells in vitro. Conclusion: Tregs suppress HIV-1 replication in T cells and contribute to HIV-1 reservoir persistence. cAMP produced in Tregs is involved in their suppression of viral gene activation and expression. Treg depletion combined with combination antiretroviral therapy provides a novel strategy for HIV-1 cure.


Assuntos
AMP Cíclico/metabolismo , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/crescimento & desenvolvimento , Linfócitos T Auxiliares-Indutores/virologia , Linfócitos T Reguladores/imunologia , Replicação Viral , Animais , DNA Viral/análise , Modelos Animais de Doenças , Proteína do Núcleo p24 do HIV/análise , Humanos , Procedimentos de Redução de Leucócitos , Camundongos , Camundongos SCID , RNA Viral/análise , Carga Viral
3.
Retrovirology ; 13: 22, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-27026376

RESUMO

BACKGROUND: CD4 T cell depletion during HIV-1 infection is associated with AIDS disease progression, and the HIV-1 Env protein plays an important role in the process. Together with CXCR4, CCR5 is one of the two co-receptors that interact with Env during virus entry, but the role of CCR5 in Env-induced pathogenesis is not clearly defined. We have investigated CD4 T cell depletion mechanisms caused by the Env of a highly pathogenic CXCR4/CCR5 dual-tropic HIV-1 isolate R3A. RESULTS: We report here that R3A infection induced depletion of both infected and uninfected "bystander" CD4 T cells, and treatment with CCR5 antagonist TAK-779 inhibited R3A-induced bystander CD4 T cell depletion without affecting virus replication. To further define the role of Env-CCR5 interaction, we utilized an Env-mutant of R3A, termed R3A-5/6AA, which has lost CCR5 binding capability. Importantly, R3A-5/6AA replicated to the same level as wild type R3A by using CXCR4 for viral infection. We found the loss of CCR5 interaction resulted in a significant reduction of bystander CD4 T cells death during R3A-5/6AA infection, whereas stimulation of CCR5 with MIP1-ß increased bystander pathogenesis induced by R3A-5/6AA. We confirmed our findings using a humanized mouse model, where we observed similarly reduced pathogenicity of the mutant R3A-5/6AA in various lymphoid organs in vivo. CONCLUSION: We provide the first evidence that shows CCR5 interaction with a dual-tropic HIV-1 Env played a significant role in Env-induced depletion of CD4 T cells.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Receptores CCR5/metabolismo , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Animais , Células Cultivadas , Humanos , Camundongos SCID
4.
JCI Insight ; 7(6)2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35167491

RESUMO

Two HER2-specific mAbs, trastuzumab and pertuzumab (T+P), combined with chemotherapy comprise standard-of-care treatment for advanced HER2+ breast cancers (BC). While this antibody combination is highly effective, its synergistic mechanism-of-action (MOA) remains incompletely understood. Past studies have suggested that the synergy underlying this combination occurs through the different mechanisms elicited by these antibodies, with pertuzumab suppressing HER2 heterodimerization and trastuzumab inducing antitumor immunity. However, in vivo evidence for this synergy is lacking. In this study, we found that the therapeutic efficacy elicited by their combination occurs through their joint ability to activate the classical complement pathway, resulting in both complement-dependent cytotoxicity and complement-dependent cellular phagocytosis of HER2+ tumors. We also demonstrate that tumor C1q expression is positively associated with survival outcome in HER2+ BC patients and that complement regulators CD55 and CD59 were inversely correlated with outcome, suggesting the clinical importance of complement activity. Accordingly, inhibition of C1q in mice abolished the synergistic therapeutic activity of T+P therapy, whereas knockdown of CD55 and CD59 expression enhanced T+P efficacy. In summary, our study identifies classical complement activation as a significant antitumor MOA for T+P therapy that may be functionally enhanced to potentially augment clinical therapeutic efficacy.


Assuntos
Neoplasias da Mama , Receptor ErbB-2 , Animais , Anticorpos Monoclonais Humanizados , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Complemento C1q , Feminino , Humanos , Camundongos , Fagocitose , Receptor ErbB-2/metabolismo , Trastuzumab/farmacologia , Trastuzumab/uso terapêutico
5.
J Immunother Cancer ; 10(3)2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35361727

RESUMO

BACKGROUND: The majority of colorectal carcinomas (CRCs) are insensitive to programmed death protein-1/programmed death-ligand 1 (anti-PD-1/PD-L1) immune checkpoint inhibitor (ICI) antibodies. While there are many causes for ICI insensitivity, recent studies suggest that suppression of innate immune gene expression in tumor cells could be a root cause of this insensitivity and an important factor in the evolution of tumor immunosuppression. METHODS: We first assessed the reduction of mitochondrial antiviral signaling gene (MAVS) and related RIG-I pathway gene expression in several patient RNA expression datasets. We then engineered MAVS expressing tumor cells and tested their ability to elicit innate and adaptive anti-tumor immunity using both in vitro and in vivo approaches, which we then confirmed using MAVS expressing viral vectors. Finally, we observed that MAVS stimulated PD-L1 expression in multiple cell types and then assessed the combination of PD-L1 ICI antibodies with MAVS tumor expression in vivo. RESULTS: MAVS was significantly downregulated in CRCs, but its re-expression could stimulate broad cellular interferon-related responses, in both murine and patient-derived CRCs. In vivo, local MAVS expression elicited significant anti-tumor responses in both immune-sensitive and insensitive CRC models, through the stimulation of an interferon responsive axis that provoked tumor antigen-specific adaptive immunity. Critically, we found that tumor-intrinsic MAVS expression triggered systemic adaptive immune responses that enabled abscopal CD8 +T cell cytotoxicity against distant CRCs. As MAVS also induced PD-L1 expression, we further found synergistic anti-tumor responses in combination with anti-PD-L1 ICIs. CONCLUSION: These data demonstrate that intratumoral MAVS expression results in local and systemic tumor antigen-specific T cell responses, which could be combined with PD-L1 ICI to permit effective anti-tumor immunotherapy in ICI resistant cancers.


Assuntos
Neoplasias Colorretais , Inibidores de Checkpoint Imunológico , Animais , Antivirais , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/métodos , Camundongos , Transdução de Sinais
6.
Cancer Res ; 81(18): 4641-4651, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34145037

RESUMO

Monoclonal antibodies (mAb) are a major component of cancer therapy. In this review, we summarize the different therapeutic mAbs that have been successfully developed against various tumor-expressed antigens and examine our current understanding of their different mechanisms of antitumor action. These mechanisms of action (MOA) largely center on the stimulation of different innate immune effector processes, which appear to be principally responsible for the efficacy of most unconjugated mAb therapies against cancer. This is evident in studies of mAbs targeting antigens for hematologic cancers, with emerging data also demonstrating the critical nature of innate immune-mediated mechanisms in the efficacy of anti-HER2 mAbs against solid HER2+ cancers. Although HER2-targeted mAbs were originally described as inhibitors of HER2-mediated signaling, multiple studies have since demonstrated these mAbs function largely through their engagement with Fc receptors to activate innate immune effector functions as well as complement activity. Next-generation mAbs are capitalizing on these MOAs through improvements to enhance Fc-activity, although regulation of these mechanisms may vary in different tumor microenvironments. In addition, novel antibody-drug conjugates have emerged as an important means to activate different MOAs. Although many unknowns remain, an improved understanding of these immunologic MOAs will be essential for the future of mAb therapy and cancer immunotherapy.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Animais , Anticorpos Monoclonais/química , Antineoplásicos Imunológicos/química , Biomarcadores Tumorais , Tomada de Decisão Clínica , Terapia Combinada , Gerenciamento Clínico , Suscetibilidade a Doenças , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/etiologia , Humanos , Imunoconjugados/química , Imunoconjugados/farmacologia , Imunoconjugados/uso terapêutico , Terapia de Alvo Molecular/efeitos adversos , Terapia de Alvo Molecular/métodos , Neoplasias/etiologia , Neoplasias/patologia , Prognóstico , Resultado do Tratamento
7.
Cancer Res ; 80(15): 3088-3100, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32366475

RESUMO

IL26 is a unique amphipathic member of the IL10 family of cytokines that participates in inflammatory signaling through a canonical receptor pathway. It also directly binds DNA to facilitate cellular transduction and intracellular inflammatory signaling. Although IL26 has almost no described role in cancer, our in vivo screen of inflammatory and cytokine pathway genes revealed IL26 to be one of the most significant inflammatory mediators of mammary engraftment and lung metastatic growth in triple-negative breast cancer (TNBC). Examination of human breast cancers demonstrated elevated IL26 transcripts in TNBC specimens, specifically in tumor cells as well as in Th17 CD4+ T cells within clinical TNBC specimens. IL26 did not have an autocrine effect on human TNBC cells, but rather its effect on engraftment and growth in vivo required neutrophils. IL26 enhanced mouse-derived DNA induction of inflammatory cytokines, which were collectively important for mammary and metastatic lung engraftment. To neutralize this effect, we developed a novel IL26 vaccine to stimulate antibody production and suppress IL26-enhanced engraftment in vivo, suggesting that targeting this inflammatory amplifier could be a unique means to control cancer-promoting inflammation in TNBC and other autoimmune diseases. Thus, we identified IL26 as a novel key modulator of TNBC metastasis and a potential therapeutic target in TNBC as well as other diseases reliant upon IL26-mediated inflammatory stimulation. SIGNIFICANCE: These findings identify IL26 as a unique, clinically relevant, inflammatory amplifier that enhances TNBC engraftment and dissemination in association with neutrophils, which has potential as a therapeutic target. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/15/3088/F1.large.jpg.


Assuntos
Adesão Celular , Interleucinas/fisiologia , Transplante de Neoplasias , Neutrófilos/fisiologia , Neoplasias de Mama Triplo Negativas/patologia , Animais , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Células Cultivadas , DNA de Neoplasias/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Progressão da Doença , Armadilhas Extracelulares/efeitos dos fármacos , Armadilhas Extracelulares/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Mediadores da Inflamação/farmacologia , Mediadores da Inflamação/fisiologia , Interleucinas/genética , Interleucinas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Transplante de Neoplasias/imunologia , Transplante de Neoplasias/patologia , Neutrófilos/patologia , Neoplasias de Mama Triplo Negativas/genética , Ensaios Antitumorais Modelo de Xenoenxerto
8.
JCI Insight ; 4(24)2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31689243

RESUMO

The HER2-specific monoclonal antibody (mAb), trastuzumab, has been the mainstay of therapy for HER2+ breast cancer (BC) for approximately 20 years. However, its therapeutic mechanism of action (MOA) remains unclear, with antitumor responses to trastuzumab remaining heterogeneous and metastatic HER2+ BC remaining incurable. Consequently, understanding its MOA could enable rational strategies to enhance its efficacy. Using both murine and human versions of trastuzumab, we found its antitumor activity dependent on Fcγ receptor stimulation of tumor-associated macrophages (TAMs) and antibody-dependent cellular phagocytosis (ADCP), but not cellular cytotoxicity (ADCC). Trastuzumab also stimulated TAM activation and expansion, but did not require adaptive immunity, natural killer cells, and/or neutrophils. Moreover, inhibition of the innate immune ADCP checkpoint, CD47, significantly enhanced trastuzumab-mediated ADCP and TAM expansion and activation, resulting in the emergence of a unique hyperphagocytic macrophage population, improved antitumor responses, and prolonged survival. In addition, we found that tumor-associated CD47 expression was inversely associated with survival in HER2+ BC patients and that human HER2+ BC xenografts treated with trastuzumab plus CD47 inhibition underwent complete tumor regression. Collectively, our study identifies trastuzumab-mediated ADCP as an important antitumor MOA that may be clinically enabled by CD47 blockade to augment therapeutic efficacy.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Antígeno CD47/antagonistas & inibidores , Fagocitose/efeitos dos fármacos , Trastuzumab/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Mama/patologia , Neoplasias da Mama/imunologia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Antígeno CD47/imunologia , Antígeno CD47/metabolismo , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Fagocitose/imunologia , Prognóstico , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
9.
J Clin Invest ; 127(1): 269-279, 2017 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-27941247

RESUMO

Despite the efficient suppression of HIV-1 replication that can be achieved with combined antiretroviral therapy (cART), low levels of type I interferon (IFN-I) signaling persist in some individuals. This sustained signaling may impede immune recovery and foster viral persistence. Here we report studies using a monoclonal antibody to block IFN-α/ß receptor (IFNAR) signaling in humanized mice (hu-mice) that were persistently infected with HIV-1. We discovered that effective cART restored the number of human immune cells in HIV-1-infected hu-mice but did not rescue their immune hyperactivation and dysfunction. IFNAR blockade fully reversed HIV-1-induced immune hyperactivation and rescued anti-HIV-1 immune responses in T cells from HIV-1-infected hu-mice. Finally, we found that IFNAR blockade in the presence of cART reduced the size of HIV-1 reservoirs in lymphoid tissues and delayed HIV-1 rebound after cART cessation in the HIV-1-infected hu-mice. We conclude that low levels of IFN-I signaling contribute to HIV-1-associated immune dysfunction and foster HIV-1 persistence in cART-treated hosts. Our results suggest that blocking IFNAR may provide a potential strategy to enhance immune recovery and reduce HIV-1 reservoirs in individuals with sustained elevations in IFN-I signaling during suppressive cART.


Assuntos
Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Interferon Tipo I/imunologia , Receptor de Interferon alfa e beta/antagonistas & inibidores , Recuperação de Função Fisiológica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Doença Crônica , Modelos Animais de Doenças , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/patologia , Humanos , Interferon Tipo I/genética , Camundongos , Camundongos Mutantes , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/imunologia , Recuperação de Função Fisiológica/genética , Recuperação de Função Fisiológica/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia
10.
Cell Host Microbe ; 19(4): 515-528, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-27078069

RESUMO

Understanding the negative regulators of antiviral immune responses will be critical for advancing immune-modulated antiviral strategies. NLRX1, an NLR protein that negatively regulates innate immunity, was previously identified in an unbiased siRNA screen as required for HIV infection. We find that NLRX1 depletion results in impaired nuclear import of HIV-1 DNA in human monocytic cells. Additionally, NLRX1 was observed to reduce type-I interferon (IFN-I) and cytokines in response to HIV-1 reverse-transcribed DNA. NLRX1 sequesters the DNA-sensing adaptor STING from interaction with TANK-binding kinase 1 (TBK1), which is a requisite for IFN-1 induction in response to DNA. NLRX1-deficient cells generate an amplified STING-dependent host response to cytosolic DNA, c-di-GMP, cGAMP, HIV-1, and DNA viruses. Accordingly, Nlrx1(-/-) mice infected with DNA viruses exhibit enhanced innate immunity and reduced viral load. Thus, NLRX1 is a negative regulator of the host innate immune response to HIV-1 and DNA viruses.


Assuntos
Infecções por Vírus de DNA/virologia , Vírus de DNA/fisiologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Interferon beta/imunologia , Proteínas de Membrana/imunologia , Proteínas Mitocondriais/metabolismo , Replicação Viral , Animais , Infecções por Vírus de DNA/imunologia , Regulação para Baixo , Feminino , Infecções por HIV/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/genética , Humanos , Imunidade Inata , Interferon beta/genética , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/genética , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
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