RESUMO
BACKGROUND: Uncontrolled immune response with T cell activation has a key role in the pathogenesis of systemic sclerosis (SSc), a disorder that is characterized by generalized fibrosis affecting particularly the lungs and skin. Costimulatory molecules are key players during immune activation, and recent evidence supports a role of CD28 and ICOS in the development of fibrosis. We herein investigated the efficacy of acazicolcept (ALPN-101), a dual ICOS/CD28 antagonist, in two complementary SSc-related mouse models recapitulating skin fibrosis, interstitial lung disease, and pulmonary hypertension. METHODS: Expression of circulating soluble ICOS and skin-expressed ICOS was investigated in SSc patients. Thereafter, acazicolcept was evaluated in the hypochlorous acid (HOCL)-induced dermal fibrosis mouse model and in the Fra-2 transgenic (Tg) mouse model. In each model, mice received 400 µg of acazicolcept or a molar-matched dose of an Fc control protein twice a week for 6 weeks. After 6 weeks, skin and lung were evaluated. RESULTS: ICOS was significantly increased in the sera from SSc patients and in SSc skin biopsies as compared to samples from healthy controls. Similar body weight changes were observed between Fc control and acazicolcept groups in both HOCL and Fra-2 Tg mice suggesting a good tolerance of acazicolcept treatment. In mice challenged with HOCL, acazicolcept induced a significant decrease in dermal thickness, collagen content, myofibroblast number, and inflammatory infiltrates characterized by B cells, T cells, neutrophils, and macrophages. In the Fra-2 Tg mouse model, acazicolcept treatment reduced lung collagen content, fibrillar collagen, histological fibrosis score, and right ventricular systolic pressure (RVSP). A reduction in frequency of CD4+ and T effector memory cells and an increase in the percentage of CD4+ T naïve cells in spleen and lung of acazicolcept-treated Fra-2 Tg mice was observed as compared to Fc control-treated Fra-2 Tg mice. Moreover, acazicolcept reduced CD69 and PD-1 expression on CD4+ T cells from the spleen and the lung. Target engagement by acazicolcept was demonstrated by blockade of CD28 and ICOS detection by flow cytometry in treated mice. CONCLUSIONS: Our results confirm the importance of costimulatory molecules in inflammatory-driven fibrosis. Our data highlight a key role of ICOS and CD28 in SSc. Using complementary models, we demonstrated that dual ICOS/CD28 blockade by acazicolcept decreased dermal and pulmonary fibrosis and alleviated pulmonary hypertension. These results pave the way for subsequent research on ICOS/CD28-targeted therapies.
Assuntos
Antígenos CD28/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Escleroderma Sistêmico , Anticorpos de Cadeia Única/farmacologia , Animais , Antígenos CD28/metabolismo , Modelos Animais de Doenças , Humanos , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Camundongos , Camundongos Transgênicos , Fibrose Pulmonar/metabolismo , Escleroderma Sistêmico/tratamento farmacológico , Escleroderma Sistêmico/patologia , Pele/patologiaRESUMO
ALPN-101 (ICOSL vIgD-Fc) is an Fc fusion protein of a human inducible T cell costimulatory ligand (ICOSL) variant immunoglobulin domain (vIgD) designed to inhibit the cluster of differentiation 28 (CD28) and inducible T cell costimulator (ICOS) pathways simultaneously. A first-in-human study evaluated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of ALPN-101 in healthy adult subjects. ALPN-101 was generally well-tolerated with no evidence of cytokine release, clinically significant immunogenicity, or severe adverse events following single subcutaneous (SC) doses up to 3 mg/kg or single intravenous (IV) doses up to 10 mg/kg or up to 4 weekly IV doses of up to 1 mg/kg. ALPN-101 exhibited a dose-dependent increase in exposure with an estimated terminal half-life of 4.3-8.6 days and SC bioavailability of 60.6% at 3 mg/kg. Minimal to modest accumulation in exposure was observed with repeated IV dosing. ALPN-101 resulted in a dose-dependent increase in maximum target saturation and duration of high-level target saturation. Consistent with its mechanism of action, ALPN-101 inhibited cytokine production in whole blood stimulated by Staphylococcus aureus enterotoxin B ex vivo, as well as antibody responses to keyhole limpet hemocyanin immunization, reflecting immunomodulatory effects upon T cell and T-dependent B cell responses, respectively. In conclusion, ALPN-101 was well-tolerated in healthy subjects with dose-dependent PK and PD consistent with the known biology of the CD28 and ICOS costimulatory pathways. Further clinical development of ALPN-101 in inflammatory and/or autoimmune diseases is therefore warranted.
Assuntos
Antígenos CD28 , Imunossupressores , Proteína Coestimuladora de Linfócitos T Induzíveis , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Administração Intravenosa , Antígenos CD28/antagonistas & inibidores , Antígenos CD28/metabolismo , Voluntários Saudáveis , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/farmacocinética , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismoRESUMO
CTLA4-Ig/abatacept dampens activation of naive T cells by blocking costimulation via CD28. It is an approved drug for rheumatoid arthritis but failed to deliver efficacy in a number of other autoimmune diseases. One explanation is that activated T cells rely less on CD28 signaling and use alternate coreceptors for effector function. ICOS is critical for activation of T-dependent humoral immune responses, which drives pathophysiology of IgG-mediated autoimmune diseases. In this study, we asked whether CD28 and ICOS play nonredundant roles for maintenance of T-dependent responses in mouse models. Using a hapten-protein immunization model, we show that during an ongoing germinal center response, combination treatment with CTLA4-Ig and ICOS ligand (ICOSL) blocking Ab completely dissolves ongoing germinal center responses, whereas single agents show only partial activity. Next, we took two approaches to engineer a therapeutic molecule that blocks both pathways. First, we engineered CTLA4-Ig to enhance binding to ICOSL while retaining affinity to CD80/CD86. Using a library approach, binding affinity of CTLA4-Ig to human ICOSL was increased significantly from undetectable to 15-42 nM; however, the affinity was still insufficient to completely block binding of ICOSL to ICOS. Second, we designed a bispecific costimulation inhibitor with high-affinity CTLA4 extracellular domains fused to anti-ICOSL Ab termed bifunctional costimulation inhibitor. With this bispecific approach, we achieved complete inhibition of CD80 and CD86 binding to CD28 as well as ICOS binding to ICOSL. Such bispecific molecules may provide greater therapeutic benefit in IgG-mediated inflammatory diseases compared with CTLA4-Ig alone.
Assuntos
Antígenos CD28/metabolismo , Antígeno CTLA-4/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/farmacologia , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Abatacepte/farmacologia , Animais , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Feminino , Centro Germinativo/efeitos dos fármacos , Centro Germinativo/metabolismo , Imunidade Humoral/efeitos dos fármacos , Imunoglobulina G/metabolismo , Ligante Coestimulador de Linfócitos T Induzíveis/metabolismo , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/metabolismoRESUMO
BACKGROUND: Chronic graft-versus-host disease (GVHD) is a significant cause of morbidity and mortality in transplant patients. We have previously shown that 3 doses of an anti-inducible costimulator (ICOS) mAb transiently ameliorated symptoms and extended survival of dogs affected by chronic GVHD over that of control dogs. The purpose of this study was to specifically correlate changes in T-cell populations in the peripheral blood with anti-ICOS treatment and chronic GVHD progression and regression to reach a better understanding of the mechanism of the disease and prioritize future studies. METHODS: Peripheral blood cells from canines transplanted with DLA-mismatched bone marrow and peripheral blood mononuclear cells to generate chronic GVHD were analyzed by flow cytometry using a panel of antibodies specific to helper and cytolytic T cells. RESULTS: Chronic GVHD was specifically associated with an increase in CD4+ICOS+ cells, ICOS+ cells expressing IL-17A, and CD8+ cells generating granzyme B. Treatment with anti-ICOS mAb at onset of chronic GVHD symptoms specifically targeted IL-17A+-expressing cells, transiently relieved symptoms, and lengthened survival but was unable to reduce the percentage of CD8+ T-cells expressing granzyme B. CONCLUSIONS: These studies suggested a role for both CD4+ and CD8+ T cells in pathogenesis of chronic GVHD in the canine model. We propose that future studies should focus on further extending survival by developing a treatment that would control both CD4+ and CD8+ T cells.
Assuntos
Anticorpos Monoclonais/farmacologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Doença Enxerto-Hospedeiro/tratamento farmacológico , Imunossupressores/farmacologia , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Interleucina-17/metabolismo , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Cultivadas , Doença Crônica , Citocinas/metabolismo , Citotoxicidade Imunológica , Modelos Animais de Doenças , Cães , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/metabolismo , Granzimas/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/metabolismoRESUMO
BACKGROUND: Upadacitinib is an oral selective Janus kinase inhibitor to treat rheumatoid arthritis. The efficacy and safety of upadacitinib as compared with abatacept, a T-cell costimulation modulator, in patients with rheumatoid arthritis refractory to biologic disease-modifying antirheumatic drugs (DMARDs) are unclear. METHODS: In this 24-week, phase 3, double-blind, controlled trial, we randomly assigned patients in a 1:1 ratio to receive oral upadacitinib (15 mg once daily) or intravenous abatacept, each in combination with stable synthetic DMARDs. The primary end point was the change from baseline in the composite Disease Activity Score for 28 joints based on the C-reactive protein level (DAS28-CRP; range, 0 to 9.4, with higher scores indicating more disease activity) at week 12, assessed for noninferiority. Key secondary end points at week 12 were the superiority of upadacitinib over abatacept in the change from baseline in the DAS28-CRP and the percentage of patients having clinical remission according to a DAS28-CRP of less than 2.6. RESULTS: A total of 303 patients received upadacitinib, and 309 patients received abatacept. From baseline DAS28-CRP values of 5.70 in the upadacitinib group and 5.88 in the abatacept group, the mean change at week 12 was -2.52 and -2.00, respectively (difference, -0.52 points; 95% confidence interval [CI], -0.69 to -0.35; P<0.001 for noninferiority; P<0.001 for superiority). The percentage of patients having remission was 30.0% with upadacitinib and 13.3% with abatacept (difference, 16.8 percentage points; 95% CI, 10.4 to 23.2; P<0.001 for superiority). During the treatment period, one death, one nonfatal stroke, and two venous thromboembolic events occurred in the upadacitinib group, and more patients in the upadacitinib group than in the abatacept group had elevated hepatic aminotransferase levels. CONCLUSIONS: In patients with rheumatoid arthritis refractory to biologic DMARDs, upadacitinib was superior to abatacept in the change from baseline in the DAS28-CRP and the achievement of remission at week 12 but was associated with more serious adverse events. Longer and larger trials are required in order to determine the effect and safety of upadacitinib in patients with rheumatoid arthritis. (Funded by AbbVie; SELECT-CHOICE Clinicaltrials.gov number, NCT03086343.).
Assuntos
Abatacepte/uso terapêutico , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Inibidores de Janus Quinases/uso terapêutico , Abatacepte/efeitos adversos , Administração Oral , Antirreumáticos/efeitos adversos , Artrite Reumatoide/sangue , Proteína C-Reativa/análise , Método Duplo-Cego , Tolerância a Medicamentos , Feminino , Compostos Heterocíclicos com 3 Anéis/efeitos adversos , Humanos , Infusões Intravenosas , Análise de Intenção de Tratamento , Inibidores de Janus Quinases/efeitos adversos , Masculino , Pessoa de Meia-Idade , Indução de RemissãoRESUMO
Therapeutic targeting of immune checkpoints has garnered significant attention in the area of cancer immunotherapy, in which efforts have focused in particular on cytotoxic T lymphocyte antigen 4 (CTLA4) and PD1, both of which are members of the CD28 family. In autoimmunity, these same pathways can be targeted to opposite effect: to curb the over-exuberant immune response. The CTLA4 checkpoint serves as an exemplar, whereby CTLA4 activity is blocked by antibodies in cancer immunotherapy and augmented by the provision of soluble CTLA4 in autoimmunity. Here, we review the targeting of co-stimulatory molecules in autoimmune diseases, focusing in particular on agents directed at members of the CD28 or tumour necrosis factor receptor families. We present the state of the art in co-stimulatory blockade approaches, including rational combinations of immune inhibitory agents, and discuss the future opportunities and challenges in this field.
Assuntos
Doenças Autoimunes/terapia , Antígenos CD28/antagonistas & inibidores , Antígeno CTLA-4/antagonistas & inibidores , Imunoterapia/métodos , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Receptores OX40/antagonistas & inibidores , Doenças Autoimunes/imunologia , Humanos , Transdução de SinaisRESUMO
Follicular helper T cells (Tfhs) are essential for germinal center (GC) B cell maturation and antibody development. However, the intrinsic mechanisms that regulate Tfh differentiation are largely unknown. Here, we demonstrate that the frequencies of Tfhs and GC B cells, as well as interleukin-21 (IL-21) and anti-ovalbumin (OVA) antibodies, are markedly decreased in forkhead box O3 (Foxo3) knockout mice immunized with OVA. Using mixed bone marrow chimeras and lymphocyte-repopulated Rag1-/- mice proves that wild-type (WT), but not Foxo3-deficient T cells provoke GC B cell maturation and antibody production. Deficiency of Foxo3 inhibits inducible T cell co-stimulator (ICOS)-induced Tfh differentiation. Chromatin immunoprecipitation assay results suggest that Foxo3 is able to bind to the IL-21 promoter and regulate IL-21 secretion. In conclusion, our study unveils a critical role of Foxo3 in the regulation of Tfh differentiation and IL-21 production. Modulating Foxo3 activity may be beneficial for enhancing or preventing antibody-mediated immune responses.
Assuntos
Proteína Forkhead Box O3/imunologia , Células T Auxiliares Foliculares/imunologia , Animais , Diferenciação Celular/imunologia , Proteína Forkhead Box O3/deficiência , Imunidade Humoral , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Subunidade alfa de Receptor de Interleucina-21/genética , Subunidade alfa de Receptor de Interleucina-21/imunologia , Masculino , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Células T Auxiliares Foliculares/citologiaRESUMO
BACKGROUND: Allergic asthma is characterized by chronic inflammation and remodelling of the airways, associated with dysregulated type 2 immune responses and allergen-specific IgE. T follicular helper cells (TFH ) are crucial in T-dependent B-cell responses and have been implicated in allergic airway disease (AAD). TFH , unlike other CD4+ T cells, are uniquely reliant on continuous ICOS signalling to maintain their phenotype after T-cell priming; therefore, disrupting this signal can impair TFH responses. However, the contribution of TFH to disease during chronic aero-allergen exposure and the therapeutic potential of targeting these cells have not been evaluated. METHODS: To establish AAD, female BALB/c mice were repeatedly exposed to house dust mite or Alternaria alternata three times a week for up to 5 weeks. To examine the impact of TFH on AAD, mice were allergen exposed for 5 weeks and co-administered anti-ICOS Ligand-targeted antibodies, three times a week for the last 2 weeks. RESULTS: TFH were first observed in the lung-draining lymph nodes and with further exposure were also found locally within the lungs. TFH accumulated with sustained allergen exposure, alongside germinal centre (GC) B cells. Blockade of ICOS signalling after AAD establishment successfully depleted TFH but did not affect the differentiation of other CD4+ T-cell subsets. This reduced GC responses, allergen-specific IgE, inflammation, pulmonary IL-13 and airway hyper-responsiveness. CONCLUSIONS: TFH are crucial in the regulation of AAD and the ICOS/ICOS-L pathway could represent a novel therapeutic target in allergic asthma.
Assuntos
Asma/tratamento farmacológico , Ligante Coestimulador de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Asma/patologia , Linfócitos B/imunologia , Feminino , Centro Germinativo/imunologia , Centro Germinativo/patologia , Ligante Coestimulador de Linfócitos T Induzíveis/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Pyroglyphidae/imunologiaRESUMO
There is increasing interest recently in developing intranasal vaccines against respiratory tract infections. The antibody response is critical for vaccine-induced protection, and T follicular helper cells (TFH) are considered important for mediating the antibody response. Most data supporting the role for TFH in the antibody response are from animal studies, and direct evidence from humans is limited, apart from the presence of TFH-like cells in blood. We studied the activation and induction of TFH and their role in the anti-influenza antibody response induced by a live-attenuated influenza vaccine (LAIV) in human nasopharynx-associated lymphoid tissue (NALT). TFH activation in adenotonsillar tissues was analyzed by flow cytometry, and anti-hemagglutinin (anti-HA) antibodies were examined following LAIV stimulation of tonsillar mononuclear cells (MNC). Induction of antigen-specific TFH by LAIV was studied by flow cytometry analysis of induced TFH and CD154 expression. LAIV induced TFH proliferation, which correlated with anti-HA antibody production, and TFH were shown to be critical for the antibody response. Induction of TFH from naive T cells by LAIV was shown in newly induced TFH expressing BCL6 and CD21, followed by the detection of anti-HA antibodies. Antigen specificity of LAIV-induced TFH was demonstrated by expression of the antigen-specific T cell activation marker CD154 upon challenge by H1N1 virus antigen or HA. LAIV-induced TFH differentiation was inhibited by BCL6, interleukin-21 (IL-21), ICOS, and CD40 signaling blocking, and that diminished anti-HA antibody production. In conclusion, we demonstrated the induction by LAIV of antigen-specific TFH in human NALT that provide critical support for the anti-influenza antibody response. Promoting antigen-specific TFH in NALT by use of intranasal vaccines may provide an effective vaccination strategy against respiratory infections in humans.IMPORTANCE Airway infections, such as influenza, are common in humans. Intranasal vaccination has been considered a biologically relevant and effective way of immunization against airway infection. The vaccine-induced antibody response is crucial for protection against infection. Recent data from animal studies suggest that one type of T cells, TFH, are important for the antibody response. However, data on whether TFH-mediated help for antibody production operates in humans are limited due to the lack of access to human immune tissue containing TFH In this study, we demonstrate the induction of TFH in human immune tissue, providing critical support for the anti-influenza antibody response, by use of an intranasal influenza vaccine. Our findings provide direct evidence that TFH play a critical role in vaccine-induced immunity in humans and suggest a novel strategy for promoting such cells by use of intranasal vaccines against respiratory infections.
Assuntos
Anticorpos Antivirais/imunologia , Hemaglutininas Virais/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Ativação Linfocitária/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vacinas Atenuadas/imunologia , Administração Intranasal , Adolescente , Adulto , Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Antígenos CD40/antagonistas & inibidores , Ligante de CD40/biossíntese , Células Cultivadas , Criança , Pré-Escolar , Humanos , Imunidade nas Mucosas/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Interleucinas/antagonistas & inibidores , Mucosa/imunologia , Nasofaringe/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-6/biossíntese , Receptores de Complemento 3d/biossíntese , Adulto JovemRESUMO
The ubiquitously expressed RNA-binding proteins Roquin-1 and Roquin-2 are essential for appropriate immune cell function and postnatal survival of mice. Roquin proteins repress target mRNAs by recognizing secondary structures in their 3'-UTRs and by inducing mRNA decay. However, it is unknown if other cellular proteins contribute to target control. To identify cofactors of Roquin, we used RNA interference to screen ~1500 genes involved in RNA-binding or mRNA degradation, and identified NUFIP2 as a cofactor of Roquin-induced mRNA decay. NUFIP2 binds directly and with high affinity to Roquin, which stabilizes NUFIP2 in cells. Post-transcriptional repression of human ICOS by endogenous Roquin proteins requires two neighboring non-canonical stem-loops in the ICOS 3'-UTR. This unconventional cis-element as well as another tandem loop known to confer Roquin-mediated regulation of the Ox40 3'-UTR, are bound cooperatively by Roquin and NUFIP2. NUFIP2 therefore emerges as a cofactor that contributes to mRNA target recognition by Roquin.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Proteínas Nucleares/genética , Proteínas de Ligação a RNA/genética , Receptores OX40/genética , Proteínas Repressoras/genética , Ubiquitina-Proteína Ligases/genética , Sequência de Aminoácidos , Animais , Sítios de Ligação , Linfócitos T CD4-Positivos/citologia , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Sequências Repetidas Invertidas , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/imunologia , Conformação de Ácido Nucleico , Cultura Primária de Células , Ligação Proteica , Estabilidade de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/imunologia , Receptores OX40/antagonistas & inibidores , Receptores OX40/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Repressoras/imunologia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Ubiquitina-Proteína Ligases/imunologiaRESUMO
The prognosis of follicular lymphoma (FL) patients is suspected to be influenced by tumor-infiltrating regulatory T cells (Treg). The mechanism of Treg enrichment in FL and their impact on malignant FL B cells remains to be elucidated. We analyzed 46 fresh lymph node biopsy samples, including FL (n = 20), diffuse large B-cell lymphoma (n = 10), classical Hodgkin lymphoma (n = 9), and reactive lymphadenitis (n = 7). Using multicolor flow cytometry and cell sorting, we observed an accumulation of CD25(high)CD127(low/neg) Tregs in FL tissues. These Tregs comprised activated ICOS(+) Tregs that were able to suppress not only conventional T cells, but also FL B cells. These FL B cells were able to express ICOSL in vitro and to generate CD25(high)FoxP3(high) Tregs expressing ICOS. Treg generation was associated with ICOS/ICOSL engagement and was abrogated by antagonist anti-ICOS and anti-ICOSL antibodies. Interactions between Tregs and FL B cells resulted in ICOSL downregulation on FL B cells. Our results highlight a key role for Tregs in FL pathogenesis and suggest that targeting the ICOS/ICOSL pathway may be a promising immunotherapy for FL treatment. Cancer Res; 76(16); 4648-60. ©2016 AACR.
Assuntos
Ligante Coestimulador de Linfócitos T Induzíveis/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/imunologia , Linfócitos do Interstício Tumoral/imunologia , Linfoma de Células B/imunologia , Linfócitos T Reguladores/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Separação Celular , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Ligante Coestimulador de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Camundongos , Reação em Cadeia da Polimerase , Transdução de Sinais/imunologia , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
As the most common cardiac disease, myocardial infarction is followed by hypertrophy of cardiac myocytes and reconstruction of ventricular structure. The up-regulation of a series of factors including metalloproteinases, inflammatory factors, and growth factors after primary infarction lead to the hypertrophy, apoptosis, necrosis, and fibroblast proliferation in cardiac muscle tissues. Recent studies have reported on the potency of small interfering RNA (siRNA) in treating cardiac diseases. We thus investigated the efficacy of inducible co-stimulatory molecule (ICOS)-specific siRNA silencing in myocardial hypertrophy in a cardiac infarction rat model. This cardiac infarction model was prepared by ligating the left anterior descending coronary artery. ICOS-siRNA treatment was administered in parallel with non-sense siRNA. After 18 days, the cross-sectional area of cardiac muscle tissues and the left ventricle weight index were measured, along with ICOS mRNA and protein expression levels, and pathological staining. Compared to those in the control groups, in myocardial infarcted rats, the application of ICOS-siRNA effectively decreased the left ventricle weight index, as well as the surface area of cardiac myocytes. Both mRNA and protein levels of ICOS were also significantly decreased. HE staining was consistent with these results. In conclusion, ICOS-targeted siRNA can effectively silence gene expression of ICOS, and provided satisfactory treatment efficacy for myocardial cell hypertrophy after infarction.
Assuntos
Hipertrofia/genética , Proteína Coestimuladora de Linfócitos T Induzíveis/biossíntese , Infarto do Miocárdio/genética , RNA Interferente Pequeno/administração & dosagem , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Terapia Genética/métodos , Ventrículos do Coração/patologia , Humanos , Hipertrofia/patologia , Hipertrofia/terapia , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , RatosRESUMO
Interactions between ICOS and ICOS ligand (ICOSL) are essential for the development of T follicular helper (Tfh) cells and thus the formation and maintenance of GC reactions. Given the conflicting reports on the requirement of other CD4(+) T-cell populations for ICOS signals, we have employed a range of in vivo approaches to dissect requirements for ICOS signals in mice during an endogenous CD4(+) T-cell response and contrasted this with CD28 signals. Genetic absence of ICOSL only modestly reduced the total number of antigen-specific CD4(+) T cells at the peak of the primary response, but resulted in a severely diminished number of both T central memory and T effector memory cells. Treatment with blocking anti-ICOS mAb during the primary response recapitulated these effects and caused a more substantial reduction than blocking CD28 signals with CTLA4Ig. During the memory phase of the response further signals through ICOS or CD28 were not required for survival. However, upon secondary challenge only Tfh cell expansion remained heavily ICOS-dependent, while CD28 signals were required for optimal expansion of all subsets. These data demonstrate the importance of ICOS signals specifically for memory CD4(+) T-cell formation, while highlighting the potential of therapeutically targeting this pathway.
Assuntos
Infecções Bacterianas/imunologia , Infecções Bacterianas/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Memória Imunológica , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Infecções Bacterianas/genética , Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/efeitos dos fármacos , Sobrevivência Celular/imunologia , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Camundongos , Camundongos Knockout , Transdução de SinaisRESUMO
Inducible co-stimulator (ICOS) is a member of CD28/Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) family and broadly expressed in activated CD4(+) T cells and induced regulatory CD4(+) T cells (CD4(+) iTreg). ICOS-related signal pathway could be activated by the interaction between ICOS and its ligand (ICOSL). In our previous work, we established a cost-effective system to generate a novel human allo-antigen specific CD4(hi) Treg by co-culturing their naïve precursors with allogeneic CD40-activated B cells in vitro. Here we investigate the role of ICOS in the generation and function of CD4(hi) Treg by interrupting ICOS-ICOSL interaction with ICOS-Ig. It is found that blockade of ICOS-ICOSL interaction impairs the induction and expansion of CD4(hi) Treg induced by allogeneic CD40-activated B cells. More importantly, CD4(hi) Treg induced with the addition of ICOS-Ig exhibits decreased suppressive capacity on alloantigen-specific responses. Dysfunction of CD4(hi) Treg induced with ICOS-Ig is accompanied with its decreased exocytosis and surface CTLA-4 expression. Through inhibiting endocytosis with E64 and pepstatin A, surface CTLA-4 expression and suppressive functions of induced CD4(hi) Treg could be partly reversed. Conclusively, our results demonstrate the beneficial role of ICOS-ICOSL signal pathway in the generation and function of CD4(hi) Treg and uncover a novel relationship between ICOS and CTLA-4.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Antígeno CTLA-4/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Linfócitos T Reguladores/metabolismo , Animais , Antígeno CTLA-4/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Citometria de Fluxo , Humanos , Ligante Coestimulador de Linfócitos T Induzíveis/genética , Ligante Coestimulador de Linfócitos T Induzíveis/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Camundongos , Células NIH 3T3 , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
Co-stimulatory molecules help to regulate interactions between T cells and antigen-presenting cells and may play an important role in the pathogenesis of lupus. Both work in murine models and some early studies in human lupus support further examination of these molecules as therapeutic targets. Complexities of lupus clinical trial variables may have hampered progress in this area but recent developments in the field may make interventional trials more feasible in the near future. To date biologics which provide direct blockade of interactions between CD40 and CD154, B7RP-1 and ICOS, and CD80 or CD86 with CD28 have been assessed in multicenter clinical trials. These data will be reviewed and critiqued.
Assuntos
Antígeno B7-1/antagonistas & inibidores , Antígeno B7-2/antagonistas & inibidores , Ligante de CD40/antagonistas & inibidores , Ligante Coestimulador de Linfócitos T Induzíveis/antagonistas & inibidores , Proteína Coestimuladora de Linfócitos T Induzíveis/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Animais , Ensaios Clínicos como Assunto , HumanosRESUMO
Human breast tumors are infiltrated by memory CD4(+) T cells along with increased numbers of regulatory T cells (Treg) and plasmacytoid dendritic cells (pDC) that facilitate immune escape and correlate with poor prognosis. Here, we report that inducible costimulatory molecule (ICOS), a T cell costimulatory molecule of the CTLA4/PD1/CD28 family, is expressed mostly by tumor-associated Treg in primary breast tumors. A large proportion of these ICOS(+) Treg were Ki67(+) and this evident proliferative expansion was found to rely on interactions with tumor-associated pDC. Indeed, tumor-associated Treg highly expanded in presence of pDC but failed to proliferate under CD3/CD28 signal. In vitro experiments revealed that the addition of a neutralizing anti-ICOS antibody blocked pDC-induced Treg expansion and interleukin-10 secretion by memory CD4(+) T cells, establishing a pivotal role for ICOS in this process. Supporting these findings, the presence of ICOS(+) cells in clinical specimens of breast cancer correlated with a poor prognosis. Together, our results highlight an important relationship between Treg and pDC in breast tumors, and show that ICOS/ICOS-L interaction is a central event in immunosuppression of tumor-associated memory CD4(+) T cells. These findings strongly rationalize antibody-mediated ICOS blockade as a powerful clinical strategy to correct immune escape and promote therapeutic responses in breast cancer.