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1.
Yonsei Med J ; 62(2): 137-148, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33527793

RESUMO

PURPOSE: In organ transplantation, the need for immune modulation rather than immune suppression has been emphasized. In this study, we investigated whether combinatorial treatments of with thalidomide (TM) and dexamethasone (DX) might be new approaches to induce systemic immunomodulation on T cells and other immune cells that regulate the expression of co-inhibitory molecules. MATERIALS AND METHODS: Naïve splenic T cells from C57BL/6 mice were sort-purified and cultured in vitro for CD4+ T cell proliferation and regulatory T cell (Treg) conversion in the presence of TM or/and DX. Expression of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed death-1 (PD-1) in proliferated and converted T cells was quantified by flow cytometry. We also quantified in vivo expression of CTLA-4 and PD-1 on splenic CD4+ T cells and other immune cells isolated from TM- or/and DX-treated mice. Mixed lymphocytes reactions (MLR) were performed to evaluate the capacity of immune cells in carrying out immune responses. RESULTS: CTLA-4 expressions in effector T cells in vivo and in Tregs in vivo/vitro significantly increased upon TM/DX combinatorial treatment. Corresponding to increased CTLA-4 expression in T cells, the expression of ligand molecules for CTLA-4 significantly increased in splenic dendritic cells in TM/DX-treated groups. In addition, MLR results demonstrated that splenocytes isolated from TM/DX-treated mice significantly suppressed the proliferation of T cells isolated from other strains. CONCLUSION: Based on these results, we suggest that TM/DX combinatorial treatments might be efficient immunomodulatory methods for regulating T cell immunity.


Assuntos
Dexametasona/farmacologia , Imunomodulação/efeitos dos fármacos , Linfócitos T/imunologia , Talidomida/farmacologia , Animais , Antígeno CTLA-4/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Citometria de Fluxo , Ativação Linfocitária/efeitos dos fármacos , Teste de Cultura Mista de Linfócitos , Masculino , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/metabolismo , Baço/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T Reguladores/imunologia
2.
Nucleic Acids Res ; 49(3): 1235-1246, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33398344

RESUMO

We have identified chemical probes that simultaneously inhibit cancer cell progression and an immune checkpoint. Using the computational Site Identification by Ligand Competitive Saturation (SILCS) technology, structural biology and cell-based assays, we identify small molecules that directly and selectively bind to the RNA Recognition Motif (RRM) of hnRNP A18, a regulator of protein translation in cancer cells. hnRNP A18 recognizes a specific RNA signature motif in the 3'UTR of transcripts associated with cancer cell progression (Trx, VEGF, RPA) and, as shown here, a tumor immune checkpoint (CTLA-4). Post-transcriptional regulation of immune checkpoints is a potential therapeutic strategy that remains to be exploited. The probes target hnRNP A18 RRM in vitro and in cells as evaluated by cellular target engagement. As single agents, the probes specifically disrupt hnRNP A18-RNA interactions, downregulate Trx and CTLA-4 protein levels and inhibit proliferation of several cancer cell lines without affecting the viability of normal epithelial cells. These first-in-class chemical probes will greatly facilitate the elucidation of the underexplored biological function of RNA Binding Proteins (RBPs) in cancer cells, including their effects on proliferation and immune checkpoint activation.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Ligação a RNA/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Linhagem Celular Tumoral , Humanos , Ligantes , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Ressonância Magnética Nuclear Biomolecular , Biossíntese de Proteínas , RNA/metabolismo , Motivo de Reconhecimento de RNA , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo
3.
Nat Commun ; 12(1): 525, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483505

RESUMO

CTLA-4 is an important regulator of T-cell function. Here, we report that expression of this immune-regulator in mouse B-1a cells has a critical function in maintaining self-tolerance by regulating these early-developing B cells that express a repertoire enriched for auto-reactivity. Selective deletion of CTLA-4 from B cells results in mice that spontaneously develop autoantibodies, T follicular helper (Tfh) cells and germinal centers (GCs) in the spleen, and autoimmune pathology later in life. This impaired immune homeostasis results from B-1a cell dysfunction upon loss of CTLA-4. Therefore, CTLA-4-deficient B-1a cells up-regulate epigenetic and transcriptional activation programs and show increased self-replenishment. These activated cells further internalize surface IgM, differentiate into antigen-presenting cells and, when reconstituted in normal IgH-allotype congenic recipient mice, induce GCs and Tfh cells expressing a highly selected repertoire. These findings show that CTLA-4 regulation of B-1a cells is a crucial immune-regulatory mechanism.


Assuntos
Subpopulações de Linfócitos B/imunologia , Antígeno CTLA-4/imunologia , Homeostase/imunologia , Sistema Imunitário/imunologia , Tolerância Imunológica/imunologia , Animais , Subpopulações de Linfócitos B/metabolismo , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Diferenciação Celular/imunologia , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Sistema Imunitário/citologia , Sistema Imunitário/metabolismo , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
4.
Mol Immunol ; 131: 51-59, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33386150

RESUMO

During T-cell regulation, T-cell receptors and CD28 lead to signaling activation, while T-lymphocyte antigen 4 (CTLA-4) is known to lead to downregulation, similar to programmed cell death-1 (PD-1). In the cytoplasmic tails of CD28 and CTLA-4, phosphoinositide 3-kinase (PI3K) binds to the consensus sequence including phosphotyrosine via SH2 domains, N- and C-terminal SH2 domains (nSH2 and cSH2), of its regulatory subunit, p85. In this study, we determined the crystal structure of a CTLA-4-derived phosphopeptide in complex with a Cys-substituted mutant of cSH2, C656S/C659V/C670L, at a 1.1 Å resolution. Phosphotyrosine of the bound peptide is tightly accommodated by the residues Arg631, Arg649, Ser651, and Ser652, similar to the cSH2 wild-type recognition mode of CD28, as reported previously. Upon the Cys mutation, the cSH2 thermal stability increased while the CTLA-4 binding affinity slightly changed. The binding experiments also showed that the binding affinity of CTLA-4 by cSH2 was approximately two orders of magnitude lower than that of CD28. Similar to CD28 binding, the CTLA-4 binding affinity of nSH2 was lower than that of cSH2. The complex structure of nSH2 and CTLA-4 was modeled, and compared with the crystal structure of cSH2 mutant and CTLA-4. The difference in the binding affinity between CD28 and CTLA-4, along with the difference between nSH2 and cSH2, could be explained by the 3D structures, which would be closely correlated with the respective T-cell signaling.


Assuntos
Antígeno CTLA-4/metabolismo , Citoplasma/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Domínios de Homologia de src/fisiologia , Sequência de Aminoácidos , Antígenos CD28/metabolismo , Escherichia coli/metabolismo , Mutação/genética , Fosfopeptídeos/metabolismo , Transdução de Sinais/fisiologia , Linfócitos T/metabolismo
5.
Life Sci ; 270: 119124, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33508291

RESUMO

The outbreak of SARS-CoV-2 in Wuhan of China in December 2019 and its worldwide spread has turned into the COVID-19 pandemic. Respiratory disorders, lymphopenia, cytokine cascades, and the immune responses provoked by this virus play a major and fundamental role in the severity of the symptoms and the immunogenicity which it causes. Owing to the decrease in the inflammatory responses' regulation in the immune system and the sudden increase in the secretion of cytokines, it seems that an investigation of inhibitory immune checkpoints can influence theories regarding this disease's treatment methods. Acquired cell-mediated immune defense's T-cells have a key major contribution in clearing viral infections thus reducing the severity of COVID-19's symptoms. The most important diagnostic feature in individuals with COVID-19 is lymphocyte depletion, most importantly, T-cells. Due to the induction of interferon-γ (INF-γ) production by neutrophils and monocytes, which are abundantly present in the peripheral blood of the individuals with COVID-19, the expression of inhibitory immune checkpoints including, PD-1 (programmed death), PD-L1 and CTLA4 on the T-cells' surface is enhanced. The purpose of this review is to discuss the functions of these checkpoints and their effects on the dysfunction and exhaustion of T-cells, making them almost ineffective in individuals with COVID-19, especially in the cases with extreme symptoms.


Assuntos
Antígeno B7-H1/metabolismo , Antígeno CTLA-4/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/imunologia , /metabolismo , Humanos , Monócitos/imunologia
6.
PLoS One ; 15(8): e0237465, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785290

RESUMO

BACKGROUND: Tumor-infiltrating lymphocytes include tumor-reactive lymphocytes and regulatory T-cells. However, the prognostic value of tumor-infiltrating lymphocytes in oral squamous cell carcinoma (OSCC) remains unclear. METHODS: We used immunohistochemistry to evaluate the presence of tumor-infiltrating FoxP3⁺ T-cells and CTLA-4⁺ cells in four distinct histological compartments (tumor parenchyma and stroma at the tumor center, and parenchyma and stroma at the invasive front) and assessed the association between the prevalence of these cells and the histopathological status of 137 patients with OSCC. RESULTS: Five-year overall survival, disease-specific survival, and recurrence-free survival were favorable in patients with high numbers of FoxP3⁺ T-cells in the parenchyma of the invasive front. Recurrence-free survival and metastasis-free survival were decreased in patients with high numbers of CTLA-4⁺ cells in the parenchyma of the invasive front. CONCLUSIONS: The presence of FoxP3⁺ T-cells in the parenchyma of the invasive front may be a useful prognostic factor. Our results indicate that FoxP3⁺ T-cells may exert site-specific anti-tumor effects but may not play an immunosuppressive role in OSCC. In addition, our results suggest that CTLA-4+ cells suppress the function of FoxP3+ T-cells and promote anti-tumor immunity in OSCC.


Assuntos
Antígeno CTLA-4/metabolismo , Carcinoma de Células Escamosas/patologia , Fatores de Transcrição Forkhead/metabolismo , Neoplasias Bucais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Feminino , Humanos , Imuno-Histoquímica , Linfócitos do Interstício Tumoral/citologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Neoplasias Bucais/mortalidade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Taxa de Sobrevida , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo
7.
PLoS Pathog ; 16(8): e1008696, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760139

RESUMO

HLA-B*35Px is associated with HIV-1 disease rapid progression to AIDS. However, the mechanism(s) underlying this deleterious effect of this HLA allele on HIV-1 infection outcome has not fully understood. CD8+ T cells play a crucial role to control the viral replication but impaired CD8+ T cells represent a major hallmark of HIV-1 infection. Here, we examined the effector functions of CD8+ T cells restricted by HLA-B*35Px (HLA-B*35:03 and HLA-B*35:02), HLA-B*27/B57 and non-HLA-B*27/B57 (e.g. HLA-A*01, A*02, A*03, A*11, A*24, A*26, B*40, B*08, B*38, B*44). CD8+ T cells restricted by HLA-B*35Px exhibited an impaired phenotype compared with those restricted by HLA-B*27/B57 and even non-HLA-B*27/B57. CD8+ T cells restricted by non-HLA-B*27/B57 when encountered their cognate epitopes upregulated TIM-3 and thus became suppressed by regulatory T cells (Tregs) via TIM-3: Galectin-9 (Gal-9). Strikingly, CD8+ T cells restricted by HLA-B*35Px expressed fewer TIM-3 and therefore did not get suppressed by Tregs, which was similar to CD8+ T cells restricted by HLA-B*27/B57. Instead, CD8+ T cells restricted by HLA-B*35Px upon recognition of their cognate epitopes upregulated CTLA-4. The transcriptional and impaired phenotype (e.g. poor effector functions) of HIV-specific CD8+ T cells restricted by HLA-B*35 was related to persistent CTLA-4, elevated Eomes and blimp-1 but poor T-bet expression. As such, anti-CTLA-4 antibody, Ipilimumab, reversed the impaired proliferative capacity of antigen-specific CD8+ T cells restricted by HLA-B*35Px but not others. This study supports the concept that CD8+ T resistance to Tregs-mediated suppression is related to allele restriction rather than the epitope specificity. Our results aid to explain a novel mechanism for the inability of HIV-specific CD8+ T cells restricted by HLA-B*35Px to control viral replication.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígeno CTLA-4/metabolismo , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Antígeno HLA-B35/imunologia , Replicação Viral , Antígeno CTLA-4/imunologia , Citocinas/metabolismo , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/metabolismo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária/imunologia , Fenótipo , Linfócitos T Reguladores/imunologia
9.
PLoS One ; 15(6): e0233578, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497097

RESUMO

The B7 family represents one of the best-studied subgroups within the Ig superfamily, yet new interactions continue to be discovered. However, this binding promiscuity represents a major challenge for defining the biological contribution of each specific interaction. We developed a strategy for addressing these challenges by combining cell microarray and high-throughput FACS methods to screen for promiscuous binding events, map binding interfaces, and generate functionally selective reagents. Applying this approach to the interactions of mPD-L1 with its receptor mPD-1 and its ligand mB7-1, we identified the binding interface of mB7-1 on mPD-L1 and as a result generated mPD-L1 mutants with binding selectivity for mB7-1 or mPD-1. Next, using a panel of mB7-1 mutants, we mapped the binding sites of mCTLA-4, mCD28 and mPD-L1. Surprisingly, the mPD-L1 binding site mapped to the dimer interface surface of mB7-1, placing it distal from the CTLA-4/CD28 recognition surface. Using two independent approaches, we demonstrated that mPD-L1 and mB7-1 bind in cis, consistent with recent reports from Chaudhri A et al. and Sugiura D et al. We further provide evidence that while CTLA-4 and CD28 do not directly compete with PD-L1 for binding to B7-1, they can disrupt the cis PD-L1:B7-1 complex by reorganizing B7-1 on the cell surface. These observations offer new functional insights into the regulatory mechanisms associated with this group of B7 family proteins and provide new tools to elucidate their function in vitro and in vivo.


Assuntos
Complexo Antígeno-Anticorpo/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-H1/metabolismo , Proteínas Mutantes/metabolismo , Animais , Antígenos de Superfície/metabolismo , Antígeno B7-1/genética , Antígeno B7-H1/genética , Sítios de Ligação , Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Antígeno CTLA-4/metabolismo , Células HEK293 , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Transfecção
10.
PLoS One ; 15(6): e0234778, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32569289

RESUMO

Acute graft-versus-host-disease (GVHD), limits the use of hematopoietic cell transplant (HCT) to treat a variety of malignancies. Any new therapeutic approach must satisfy three requirements: 1) Prevent GVHD, 2) Maintain anti-pathogen immunity, and 3) Maintain anti-tumor immunity. In prior studies we have shown that the selective photosensitizer 2-Se-Cl eliminates highly alloreactive lymphocytes from the graft prior to HCT preventing GVHD and that antiviral immune responses were preserved following incubation with 2-Se-Cl. In this report, we investigated whether 2-Se-Cl treatment preserves antitumor immunity, and then used high dimensional flow cytometry to identify the determinants of successful immune reconstitution. Donor C57BL/6 splenocytes were cocultured for 4 days with irradiated BALB/c splenocytes and then exposed to 2-Se-Cl. Photodepletion (PD)-treated splenocytes were then infused into lethally irradiated BALB/c mice inoculated with A20 leukemia/lymphoma cells. Recipient mice that received PD-treated splenocytes survived > 100 days without evidence of GVHD or leukemia. In contrast, mice that did not receive PD-treated cells at time of HCT died of leukemia progression. Multiparameter flow cytometry of cytokines and surface markers on peripheral blood samples 15 days after HCT demonstrated unique patterns of immune reconstitution. We found that before clinical disease onset GVHD was marked by functionally exhausted T cells, while tumor clearance and long-term survival were associated with an expansion of polyfunctional T cells, monocytes, and DCs early after transplantation. Taken together these results demonstrate that 2-Se-Cl photodepletion is a new treatment that can facilitate HCT by preventing GVHD while preserving antiviral and anti-tumor immunity.


Assuntos
Doença Enxerto-Hospedeiro/prevenção & controle , Fármacos Fotossensibilizantes/farmacologia , Compostos de Selênio/farmacologia , Animais , Antígeno CTLA-4/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/efeitos da radiação , Feminino , Leucemia/imunologia , Leucemia/terapia , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/efeitos da radiação , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/imunologia
11.
Proc Natl Acad Sci U S A ; 117(25): 14331-14341, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513686

RESUMO

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, with approximately four new cases per 100,000 persons per year. Standard treatment for AML consists of induction chemotherapy with remission achieved in 50 to 75% of cases. Unfortunately, most patients will relapse and die from their disease, as 5-y survival is roughly 29%. Therefore, other treatment options are urgently needed. In recent years, immune-based therapies have led to unprecedented rates of survival among patients with some advanced cancers. Suppression of T cell function in the tumor microenvironment is commonly observed and may play a role in AML. We found that there is a significant association between T cell infiltration in the bone marrow microenvironment of newly diagnosed patients with AML and increased overall survival. Functional studies aimed at establishing the degree of T cell suppression in patients with AML revealed impaired T cell function in many patients. In most cases, T cell proliferation could be restored by blocking the immune checkpoint molecules PD-1, CTLA-4, or TIM3. Our data demonstrate that AML establishes an immune suppressive environment in the bone marrow, in part through T cell checkpoint function.


Assuntos
Medula Óssea/metabolismo , Leucemia Mieloide Aguda/metabolismo , Linfócitos T/metabolismo , Microambiente Tumoral/fisiologia , Medula Óssea/imunologia , Antígeno CTLA-4/metabolismo , Proliferação de Células , Citocinas/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/imunologia
12.
Nat Commun ; 11(1): 2168, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358520

RESUMO

Gut microbiota composition influences the clinical benefit of immune checkpoints in patients with advanced cancer but mechanisms underlying this relationship remain unclear. Molecular mechanism whereby gut microbiota influences immune responses is mainly assigned to gut microbial metabolites. Short-chain fatty acids (SCFA) are produced in large amounts in the colon through bacterial fermentation of dietary fiber. We evaluate in mice and in patients treated with anti-CTLA-4 blocking mAbs whether SCFA levels is related to clinical outcome. High blood butyrate and propionate levels are associated with resistance to CTLA-4 blockade and higher proportion of Treg cells. In mice, butyrate restrains anti-CTLA-4-induced up-regulation of CD80/CD86 on dendritic cells and ICOS on T cells, accumulation of tumor-specific T cells and memory T cells. In patients, high blood butyrate levels moderate ipilimumab-induced accumulation of memory and ICOS + CD4 + T cells and IL-2 impregnation. Altogether, these results suggest that SCFA limits anti-CTLA-4 activity.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/metabolismo , Ácidos Graxos Voláteis/sangue , Neoplasias/sangue , Neoplasias/metabolismo , Animais , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Biomarcadores Tumorais/metabolismo , Butiratos/sangue , Células Dendríticas/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/genética , Humanos , Ipilimumab/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Propionatos/sangue , RNA Ribossômico 16S/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo
13.
J Cancer Res Clin Oncol ; 146(6): 1441-1450, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32248302

RESUMO

INTRODUCTION: Poliovirus receptor (PVR) is a tumor promoter and a regulatory checkpoint that enhances immunosuppression. We investigated PVR expression by applying immunohistochemistry (IHC) staining. A positive association existed between PVR expression and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) expression in patients with surgically resected non-small-cell lung cancer (NSCLC). PVR expression is a prognosis predictor of lung adenocarcinoma. PURPOSE: To investigate the prognostic significance of PVR expression and CTLA4 expression for surgically resected NSCLC. PATIENTS AND METHODS: The medical records of 108 Chinese patients with primary NSCLC who underwent surgery were retrospectively reviewed. The expression of PVR and CTLA4 were measured through IHC. Clinical characteristics, the association between PVR and CTLA4, and the prognostic significance of PVR were analyzed. RESULTS: A significant positive association was observed between PVR and CTLA4 expression in NSCLC (P = 0.016). PVR had a high positive rate among females, nonsmokers, and patients with adenocarcinoma and advanced lung cancer. The overall survival (OS) of patients with negative PVR expression was significantly longer than that of patients with positive PVR expression (P = 0.049), especially among females (P = 0.03) and nonsmokers (P = 0.025). Multivariate analysis results showed that advanced tumor stage and PVR expression were independent prognosis predictors of poor OS. CONCLUSION: PVR can potentially serve as a prognostic predictor and biomarker for NSCLC and cancer anti-CTLA4 immunotherapy response.


Assuntos
Antígeno CTLA-4/metabolismo , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Receptores Virais/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
14.
Adv Exp Med Biol ; 1248: 7-32, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185705

RESUMO

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is an inhibitory receptor belonging to the CD28 immunoglobulin subfamily, expressed primarily by T-cells. Its ligands, CD80 and CD86, are typically found on the surface of antigen-presenting cells and can either bind CD28 or CTLA-4, resulting in a costimulatory or a co-inhibitory response, respectively. Because of its dampening effect, CTLA-4 is a crucial regulator of T-cell homeostasis and self-tolerance. The mechanisms by which CTLA-4 exerts its inhibitory function can be categorized as either cell-intrinsic (affects the CTLA-4 expressing T-cell) or cell-extrinsic (affects secondary cells). Research from the last decade has shown that CTLA-4 mainly acts in a cell-extrinsic manner via its competition with CD28, CTLA-4-mediated trans-endocytosis of CD80 and CD86, and its direct tolerogenic effects on the interacting cell. Nonetheless, intrinsic CTLA-4 signaling has been implicated in T-cell motility and the regulation of CTLA-4 its subcellular localization amongst others. CTLA-4 is well recognized as a key immune checkpoint and has gained significant momentum as a therapeutic target in the field of autoimmunity and cancer. In this chapter, we describe the role of costimulation in immune response induction as well as the main mechanisms by which CTLA-4 can inhibit this process.


Assuntos
Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Animais , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Antígenos CD28/metabolismo , Humanos , Ativação Linfocitária
15.
Adv Exp Med Biol ; 1248: 227-250, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185713

RESUMO

In this chapter, we will sketch a story that begins with the breakdown of chromosome homeostasis and genomic stability. Genomic alterations may render tumor cells eternal life at the expense of immunogenicity. Although antitumor immunity can be primed through neoantigens or inflammatory signals, tumor cells have evolved countermeasures to evade immune surveillance and strike back by modulating immune checkpoint related pathways. At present, monoclonal antibody drugs targeting checkpoints like PD-1 and CTLA-4 have significantly prolonged the survival of a variety of cancer patients, and thus have marked a great achievement in the history of antitumor therapy. Nevertheless, this is not the end of the story. As the relationship between genomic alteration and checkpoint expression is being delineated though the advances of preclinical animal models and emerging technologies, novel checkpoint targets are on the way to be discovered.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Descoberta de Drogas , Neoplasias/tratamento farmacológico , Neoplasias/genética , Animais , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Pontos de Checagem do Ciclo Celular/imunologia , Humanos , Neoplasias/imunologia , Neoplasias/patologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo
16.
J Leukoc Biol ; 107(4): 695-706, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32202341

RESUMO

In secondary lymphoid organs, pathogen-derived and endogenous danger molecules are recognized by pattern recognition receptors, leading to adaptive proinflammatory immune responses. This conceptual rule does not apply directly to the liver, as hepatic immune cells tolerate gut-derived bacterial molecules from the flora. Therefore, the recognition of danger and proinflammatory stimuli differs between the periphery and the liver. However, the tolerant nature of the liver must be overcome in the case of infections or cancer, for example. The central paradigm is the basis for danger recognition and the balance between inflammation and tolerance in the liver. Here, we observed functional integration, with activated peripheral T lymphocytes playing a role in the induction of a proinflammatory environment in the liver in the presence of Trypanosoma cruzi antigens. When only parasite extract was orally administered, it led to the up-regulation of hepatic tolerance markers, but oral treatment plus adoptively transferred activated splenic T lymphocytes led to a proinflammatory response. Moreover, treated/recipient mice showed increased levels of TNF, IFN-γ, IL-6, and CCL2 in the liver and increased numbers of effector and/or effector memory T lymphocytes and F4/80+ cells. There was a reduction in FoxP3+ Treg cells, NKT cells, and γδ T lymphocytes with increased liver damage in the presence of activated peripheral T cells. Our results show that the induction of a proinflammatory liver response against T. cruzi danger molecules is at least partially dependent on cooperation with activated peripheral T cells.


Assuntos
Antígenos de Protozoários/imunologia , Inflamação/patologia , Fígado/patologia , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Trypanosoma cruzi/imunologia , Transferência Adotiva , Animais , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/metabolismo , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Citocinas/metabolismo , Linfócitos Intraepiteliais/imunologia , Macrófagos do Fígado/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células T Matadoras Naturais/imunologia , Parasitos/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/parasitologia , Linfócitos T Reguladores/imunologia
17.
Parasite Immunol ; 42(6): e12711, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32171024

RESUMO

AIMS: Alveolar echinococcosis is a severe chronic helminthic infection that mimics a tumour-like disease. This study aimed at investigating in vitro interactions between Echinococcus multilocularis vesicular fluid (VF) and different immune checkpoints (PD-1/PD-L1, CTLA-4, LAG-3 and TIM-3). METHODS AND RESULTS: Peripheral blood mononuclear cells (PBMC) from healthy blood donors were isolated by Ficoll. Natural killer (NK) cells were selected. Each type of cell was stimulated individually with E. multilocularis-VF. Expression of the different immune checkpoints was measured by flow cytometry on day 3 and day 6; all supernatants were used for immunoassays. Cells and supernatants from 22 healthy donors were analysed. A significant increase of PD-1, PD-L1, LAG-3 and TIM-3 was observed upon E. multilocularis-VF exposure for NK cells on day 3 (P < .05, Wilcoxon signed-rank test). A significant increase of PD-L1 and CTLA-4 was observed upon E. multilocularis-VF exposure for T cells on day 6 (P < .05, Wilcoxon signed-rank test), which was associated with increased levels of Th1 and Th2 cytokines P < .05, Wilcoxon signed-rank test). CONCLUSION: These preliminary data suggest that immune checkpoints could be a way for E. multilocularis to modulate the host immune response during alveolar echinococcosis.


Assuntos
Equinococose/imunologia , Echinococcus multilocularis/imunologia , Células Matadoras Naturais/imunologia , Animais , Antígenos CD/metabolismo , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/metabolismo , Citocinas/imunologia , Equinococose/parasitologia , Equinococose/patologia , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Leucócitos Mononucleares/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Células Th1/imunologia , Células Th2/imunologia
18.
Nat Commun ; 11(1): 931, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32071302

RESUMO

Intrinsic malignant brain tumors, such as glioblastomas are frequently resistant to immune checkpoint blockade (ICB) with few hypermutated glioblastomas showing response. Modeling patient-individual resistance is challenging due to the lack of predictive biomarkers and limited accessibility of tissue for serial biopsies. Here, we investigate resistance mechanisms to anti-PD-1 and anti-CTLA-4 therapy in syngeneic hypermutated experimental gliomas and show a clear dichotomy and acquired immune heterogeneity in ICB-responder and non-responder tumors. We made use of this dichotomy to establish a radiomic signature predicting tumor regression after pseudoprogression induced by ICB therapy based on serial magnetic resonance imaging. We provide evidence that macrophage-driven ICB resistance is established by CD4 T cell suppression and Treg expansion in the tumor microenvironment via the PD-L1/PD-1/CD80 axis. These findings uncover an unexpected heterogeneity of response to ICB in strictly syngeneic tumors and provide a rationale for targeting PD-L1-expressing tumor-associated macrophages to overcome resistance to ICB.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Glioma/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Animais , Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-1/imunologia , Antígeno B7-1/metabolismo , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/imunologia , Feminino , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/imunologia , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Imagem por Ressonância Magnética , Masculino , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
19.
Cancer Immunol Immunother ; 69(4): 653-662, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32025849

RESUMO

Immune checkpoint inhibitors, including ipilimumab (IPI), achieve a clinical benefit in a small proportion of melanoma patients highlighting the need to investigate predictive biomarkers. In this study, we characterized tumor infiltrating lymphocytes (TILs), focusing on the CTLA-4+ subset, and evaluated their possible predictive significance. We characterized TIL density, cell type, and localization in 40 melanoma lesions from 17 patients treated with IPI. Associations of TILs with IPI timing, tissue localization, and response to IPI were estimated using a linear mixed-effects modelling approach. We found that most of TIL subsets increased in situ upon IPI therapy, with particular reference to FoxP3+ cells. TILs and TIL subsets, such as CD3+, CD45RO+, CTLA-4+, CD4+, CD8+ T cells, CD20+ B cells, and NKp46+ NK cells, showed significantly different spatial distributions in the tumor microenvironment being higher at the invasive margin (IM) as compared to the tumor center (TC) (P value < 0.001 for TIL score and P value < 0.05 for all subsets). Remarkably, high TIL score and density of CD3+, CD8+ T cells, and CTLA-4+ immune cells were significantly associated with a better response to IPI (P values = 0.002, 0.023, 0.007, and 0.001, respectively, for responders vs non-responders). In conclusion, we provide a detailed analysis of CTLA-4+ TIL distribution in melanoma tissues taking into account localization, relationship with CD3+/CD8+ TILs, and changes in response to IPI treatment. We identified that CTLA-4+ TILs may represent a marker of IPI response, alone or with CD3+/CD8+ subsets, although this requires confirmation in larger studies.


Assuntos
Antígeno CTLA-4/antagonistas & inibidores , Ipilimumab/uso terapêutico , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Melanoma/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Imunológicos/uso terapêutico , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Feminino , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Melanoma/imunologia , Melanoma/metabolismo , Pessoa de Meia-Idade , Estudos Retrospectivos , Microambiente Tumoral/imunologia
20.
Cancer Immunol Immunother ; 69(4): 629-640, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32020256

RESUMO

The efficacy of immunotherapies in cancer treatment becomes more and more apparent not only in different solid tumors but also in hematological malignancies. However, in acute myeloid leukemia (AML), mechanisms to increase the efficacy of immunotherapeutic approaches have to be further elucidated. Targeting leukemic progenitor and stem cells (LPC/LSC) by specific CTL, for instance, in an adjuvant setting or in minimal residual disease, might be an option to prevent relapse of AML or to treat MRD. Therefore, we investigated the influence of immune checkpoint inhibitors on LAA-specific immune responses by CTL against leukemic myeloid blasts and colony-forming cells including leukemic progenitor cells (CFC/LPC). In functional immunoassays like CFU/CFI (colony-forming units/immunoassays) and ELISpot analysis, we detected specific LAA-directed immune responses against CFC/LPC that are postulated to be the source population of relapse of the disease. The addition of nivolumab (anti-PD-1) significantly increases LAA-directed immune responses against CFC/LPC, no effect is seen when ipilimumab (anti-CTLA-4) is added. The combination of ipilimumab and nivolumab does not improve the effect compared to nivolumab alone. The anti-PD1-directed immune response correlates to PD-L1 expression on progenitor cells. Our data suggest that immunotherapeutic approaches have the potential to target malignant CFC/LPC and anti-PD-1 antibodies could be an immunotherapeutic approach in AML. Moreover, combination with LAA-directed vaccination strategies might also open interesting application possibilities.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ipilimumab/uso terapêutico , Leucemia Mieloide/terapia , Células-Tronco Neoplásicas/efeitos dos fármacos , Nivolumabe/uso terapêutico , Linfócitos T/imunologia , Doença Aguda , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Humanos , Imunoterapia/métodos , Ipilimumab/administração & dosagem , Leucemia Mieloide/imunologia , Leucemia Mieloide/metabolismo , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/metabolismo , Nivolumabe/administração & dosagem , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Linfócitos T/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Resultado do Tratamento
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