RESUMO
The immune responses to cancer cells involve both innate and acquired immune cells. In the meantime, the most attention has been drawn to the adaptive immune cells, especially T cells, while, it is now well known that the innate immune cells, especially natural killer (NK) cells, play a vital role in defending against malignancies. While the immune cells are trying to eliminate malignant cells, cancer cells try to prevent the function of these cells and suppress immune responses. The suppression of NK cells in various cancers can lead to the induction of an exhausted phenotype in NK cells, which will impair their function. Recent studies have shown that the occurrence of this phenotype in various types of leukemic malignancies can affect the prognosis of the disease, and targeting these cells may be considered a new immunotherapy method in the treatment of leukemia. Therefore, a detailed study of exhausted NK cells in leukemic diseases can help both to understand the mechanisms of leukemia progression and to design new treatment methods by creating a deeper understanding of these cells. Here, we will comprehensively review the immunobiology of exhausted NK cells and their role in various leukemic malignancies. Video Abstract.
Assuntos
Leucemia , Humanos , Leucemia/terapia , Imunoterapia , Células Matadoras Naturais , FenótipoRESUMO
INTRODUCTION: Glioblastoma Multiforme (GBM) is one of the fatal cancers of the Central Nervous System (CNS). A variety of reasons exist for why previous immunotherapy strategies, especially Immune Checkpoint Blockers (ICBs), did not work in treating GBM patients. The cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a key immune checkpoint receptor. Its overexpression in cancer and immune cells causes tumor cell progression. CTLA-4 suppresses anti-tumor responses inside the GBM tumor-immune microenvironment. AREAS COVERED: It has been attempted to explain the immunobiology of CTLA-4 as well as its interaction with different immune cells and cancer cells that lead to GBM progression. Additionally, CTLA-4 targeting studies have been reviewed and CTLA-4 combination therapy, as a promising therapeutic target and strategy for GBM immunotherapy, is recommended. EXPERT OPINION: CTLA-4 could be a possible supplement for future cancer immunotherapies of GBM. However, many challenges remain such as the high toxicity of CTLA-4 blockers, and the unresponsiveness of most patients to immunotherapy. For the future clinical success of CTLA-4 blocker therapy, combination approaches with other targeted treatments would be a potentially effective strategy. Going forward, predictive biomarkers can be used to reduce trial timelines and increase the chance of success.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Neoplasias Encefálicas/tratamento farmacológico , Terapia Combinada , Antígeno CTLA-4/uso terapêutico , Glioblastoma/tratamento farmacológico , Imunoterapia , Microambiente Tumoral , Antígenos B7/metabolismoRESUMO
PURPOSE: Increasing the efficiency of unsuccessful immunotherapy methods is one of the most important research fields. Therefore, the use of combination therapy is considered as one of the ways to increase the effectiveness of the dendritic cell (DC) vaccine. In this study, the inhibition of immune checkpoint receptors such as LAG3 and PD-1 on T cells was investigated to increase the efficiency of T cells in response to the DC vaccine. METHODS: We used trimethyl chitosan-dextran sulfate-lactate (TMC-DS-L) nanoparticles (NPs) loaded with siRNA molecules to quench the PD-1 and LAG3 checkpoints' expression. RESULTS: Appropriate physicochemical characteristics of the generated NPs led to efficient inhibition of LAG3 and PD-1 on T cells, which was associated with increased survival and activity of T cells, ex vivo. Also, treating mice with established breast tumors (4T1) using NPs loaded with siRNA molecules in combination with DC vaccine pulsed with tumor lysate significantly inhibited tumor growth and increased survival in mice. These ameliorative effects were associated with increased anti-tumor T cell responses and downregulation of immunosuppressive cells in the tumor microenvironment and spleen. CONCLUSION: These findings strongly suggest that TMC-DS-L NPs loaded with siRNA could act as a novel tool in inhibiting the expression of immune checkpoints in the tumor microenvironment. Also, combination therapy based on inhibition of PD-1 and LAG3 in combination with DC vaccine is an effective method in treating cancer that needs to be further studied.
Assuntos
Neoplasias da Mama , Vacinas Anticâncer , Células Dendríticas , Inibidores de Checkpoint Imunológico , Linfócitos T , Animais , Antígenos CD , Neoplasias da Mama/imunologia , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Células Dendríticas/imunologia , Ácido Láctico/química , Camundongos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , RNA Interferente Pequeno , Linfócitos T/imunologia , Proteína do Gene 3 de Ativação de LinfócitosRESUMO
PURPOSE: The invention and application of new immunotherapeutic methods can compensate for the inefficiency of conventional cancer treatment approaches, partly due to the inhibitory microenvironment of the tumor. In this study, we tried to inhibit the growth of cancer cells and induce anti-tumor immune responses by silencing the expression of the ß-catenin in the tumor microenvironment and transmitting interleukin (IL)-15 cytokine to provide optimal conditions for the dendritic cell (DC) vaccine. METHODS: For this purpose, we used folic acid (FA)-conjugated SPION-carboxymethyl dextran (CMD) chitosan (C) nanoparticles (NPs) to deliver anti-ß-catenin siRNA and IL-15 to cancer cells. RESULTS: The results showed that the codelivery of ß-catenin siRNA and IL-15 significantly reduced the growth of cancer cells and increased the immune response. The treatment also considerably stimulated the performance of the DC vaccine in triggering anti-tumor immunity, which inhibited tumor development and increased survival in mice in two different cancer models. CONCLUSIONS: These findings suggest that the use of new nanocarriers such as SPION-C-CMD-FA could be an effective way to use as a novel combination therapy consisting of ß-catenin siRNA, IL-15, and DC vaccine to treat cancer.
Assuntos
Antineoplásicos/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Células Dendríticas/transplante , Portadores de Fármacos , Interleucina-15/administração & dosagem , Nanopartículas Magnéticas de Óxido de Ferro , Melanoma Experimental/terapia , RNA Interferente Pequeno/administração & dosagem , Terapêutica com RNAi , Neoplasias Cutâneas/terapia , beta Catenina/genética , Animais , Antineoplásicos/química , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/imunologia , Composição de Medicamentos , Feminino , Regulação Neoplásica da Expressão Gênica , Interleucina-15/química , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos Endogâmicos BALB C , RNA Interferente Pequeno/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Carga Tumoral/efeitos dos fármacos , Microambiente TumoralRESUMO
Following various immunotherapies, lack of proper anti-tumor immune responses is considered a significant problem in novel cancer therapeutic approaches. The expression of inhibitory checkpoint molecules on tumor-infiltrating T cells is one of the main reasons for the ineffectiveness of various immunotherapies. Therefore, we decided to inhibit two of the most important immune checkpoints expressed on tumor-associated T cells, PD-1 and A2aR. Ligation of PD-1 with PD-L1 and A2aR with adenosine significantly suppress T cell responses against tumor cells. Whitin tumors, specific inhibition of these molecules on T cells is of particular importance for successful immunotherapy as well as the elimination of treatment-associated side-effects. Thus, in this study, superparamagnetic iron oxide (SPION) nanoparticles (NPs) were covered by chitosan lactate (CL), functionalized with TAT peptide, and loaded with siRNA molecules against PD-1 and A2aR. Appropriate physicochemical properties of the prepared NPs resulted in efficient delivery of siRNA to tumor-derived T cells and suppressed the expression of A2aR and PD-1, ex vivo. T cell functions such as cytokine secretion and proliferation were considerably enhanced by the downregulation of these molecules which led to an increase in their survival time. Interestingly, treatment of CT26 and 4T1 mouse tumors with siRNA-loaded NPs not only inhibited tumor growth but also markedly increased anti-tumor immune responses and survival time. The results strongly support the efficacy of SPION-CL-TAT NPs loaded with anti-PD-1/A2aR siRNAs in cancer therapy and their further development for cancer patients in the near future.