scholarly journals Stem Cell-Derived Extracellular Vesicles as Immunomodulatory Therapeutics

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yoojin Seo ◽  
Hyung-Sik Kim ◽  
In-Sun Hong

Mesenchymal stem cells (MSCs) have been reported to possess regulatory functions on immune cells which make them alternative therapeutics for the treatment of inflammatory and autoimmune diseases. The interaction between MSCs and immune cells through paracrine factors might be crucial for these immunomodulatory effects of MSCs. Extracellular vesicles (EVs) are defined as bilayer membrane structures including exosomes and microvesicles which contain bioactive paracrine molecules affecting the characteristics of target cells. Recently, several studies have revealed that EVs derived from MSCs (MSC-EVs) can reproduce similar therapeutic impacts of parent MSCs; MSC-EVs could regulate proliferation, maturation, polarization, and migration of various immune effector cells and modulate the immune microenvironment depending on the context by delivering inflammatory cytokines, transcription factors, and microRNAs. Therefore, MSC-EVs can be applied as novel and promising tools for the treatment of immune-related disorders to overcome the limitations of conventional cell therapy regarding efficacy and toxicity issues. In this review, we will discuss current insights regarding the major outcomes in the evaluation of MSC-EV function against inflammatory disease models, as well as immune cells.

2017 ◽  
Vol 373 (1737) ◽  
pp. 20160481 ◽  
Author(s):  
Bastian Dörsam ◽  
Kathrin S. Reiners ◽  
Elke Pogge von Strandmann

Extracellular vesicles (EVs) are important players of intercellular signalling mechanisms, including communication with and among immune cells. EVs can affect the surrounding tissue as well as peripheral cells. Recently, EVs have been identified to be involved in the aetiology of several diseases, including cancer. Tumour cell-released EVs or exosomes have been shown to promote a tumour-supporting environment in non-malignant tissue and, thus, benefit metastasis. The underlying mechanisms are numerous: loss of antigen expression, direct suppression of immune effector cells, exchange of nucleic acids, alteration of the recipient cells' transcription and direct suppression of immune cells. Consequently, tumour cells can subvert the host's immune detection as well as suppress the immune system. On the contrary, recent studies reported the existence of EVs able to activate immune cells, thus promoting the tumour-directed immune response. In this article, the immunosuppressive capabilities of EVs, on the one hand, and their potential use in immunoactivation and therapeutic potential, on the other hand, are discussed. This article is part of the discussion meeting issue ‘Extracellular vesicles and the tumour microenvironment’.


Author(s):  
John C. Morris ◽  
Thomas A. Waldmann

Over the past decade, monoclonal antibodies have dramatically impacted the treatment of haematological malignancies, as evidenced by the effect of rituximab on the response rate and survival of patients with follicular and diffuse large B cell non-Hodgkin's lymphoma. Currently, only two monoclonal antibodies – the anti-CD33 immunotoxin gemtuzumab ozogamicin and the CD52-directed antibody alemtuzumab – are approved for treatment of relapsed acute myeloid leukaemia in older patients and B cell chronic lymphocytic leukaemia, respectively. Although not approved for such treatment, alemtuzumab is also active against T cell prolymphocytic leukaemia, cutaneous T cell lymphoma and Sézary syndrome, and adult T cell leukaemia and lymphoma. In addition, rituximab has demonstrated activity against B cell chronic lymphocytic and hairy cell leukaemia. Monoclonal antibodies targeting CD4, CD19, CD20, CD22, CD23, CD25, CD45, CD66 and CD122 are now being studied in the clinic for the treatment of leukaemia. Here, we discuss how these new antibodies have been engineered to reduce immunogenicity and improve antibody targeting and binding. Improved interactions with Fc receptors on immune effector cells can enhance destruction of target cells through antibody-dependent cellular cytotoxicity and complement-mediated cell lysis. The antibodies can also be armed with cellular toxins or radionuclides to enhance the destruction of leukaemia cells.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xin Li ◽  
Li li Liu ◽  
Ju lei Yao ◽  
Kai Wang ◽  
Hao Ai

MicroRNAs (miRNAs) are potential therapeutic targets in endometrial cancer, but the difficulties associated with their delivery to tumor target cells have hampered their applications. Human umbilical cord mesenchymal stem cells (hUCMSCs) have a well-recognized tumor-homing ability, emphasizing the capacity of tumor-targeted delivery of extracellular vesicles. hUCMSCs release extracellular vesicles rich in miRNAs, which play a vital role in intercellular communication. The purpose of this study was to verify a potential tumor suppressor microRNA, miR-302a, and engineered hUCMSC extracellular vesicles enriched with miR-302a for therapy of endometrial cancer. Here, we observed that miR-302a was significantly downregulated in endometrial cancer tissues when compared with adjacent tissues. Overexpression of miR-302a in endometrial cancer cells robustly suppressed cell proliferation and migration. Meanwhile, the proliferation and migration were significantly inhibited in endometrial cancer cells when cultured with miR-302a-loaded extracellular vesicles derived from hUCMSCs. Importantly, our data showed that engineered extracellular vesicles rich in miR-302 significantly inhibited the expression of cyclin D1 and suppressed AKT signaling pathway in endometrial cancer cells. These results suggested that exogenous miR-302a delivered by hUCMSC-derived extracellular vesicles has exciting potential as an effective anticancer therapy.


1993 ◽  
Vol 177 (6) ◽  
pp. 1821-1826 ◽  
Author(s):  
T J Schall ◽  
K Bacon ◽  
R D Camp ◽  
J W Kaspari ◽  
D V Goeddel

Lymphocyte trafficking is an essential process in immune and inflammatory functions which can be thought to contain at least two main components: adhesion and migration. Whereas adhesion molecules such as the selections are known to mediate the homing of leukocytes from the blood to the endothelium, the chemoattractant substances responsible for the migration of specific subsets of lymphocytes to sites of infection or inflammation are largely unknown. Here we show that two molecules in the chemokine (for chemoattractant cytokine) superfamily, human macrophage inflammatory protein 1 alpha (MIP-1 alpha) and MIP-1 beta, do not share identical attractant activities for lymphocyte subpopulations. When analyzed in vitro in microchemotaxis experiments, HuMIP-1 beta tends to attract CD4+ T lymphocytes, with some preference for T cells of the naive (CD45RA) phenotype. HuMIP-1 alpha, when tested in parallel with HuMIP-1 beta, is a more potent lymphocyte chemoattractant with a broader range of concentration-dependent chemoattractant specificities. HuMIP-1 alpha at a concentration of 100 pg/ml attracts B cells and cytotoxic T cells, whereas at higher concentrations (10 ng/ml), the migration of these cells appears diminished, and the migration of CD4+ T cells is enhanced. Thus, in this assay system, HuMIP-1 alpha and -1 beta have differential attractant activities for subsets of immune effector cells, with HuMIP-1 alpha having greater effects than HuMIP-1 beta, particularly on B cells.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yijia Li ◽  
Yangzhe Wu ◽  
Yi Hu

Cellular metabolism of both cancer and immune cells in the acidic, hypoxic, and nutrient-depleted tumor microenvironment (TME) has attracted increasing attention in recent years. Accumulating evidence has shown that cancer cells in TME could outcompete immune cells for nutrients and at the same time, producing inhibitory products that suppress immune effector cell functions. Recent progress revealed that metabolites in the TME could dysregulate gene expression patterns in the differentiation, proliferation, and activation of immune effector cells by interfering with the epigenetic programs and signal transduction networks. Nevertheless, encouraging studies indicated that metabolic plasticity and heterogeneity between cancer and immune effector cells could provide us the opportunity to discover and target the metabolic vulnerabilities of cancer cells while potentiating the anti-tumor functions of immune effector cells. In this review, we will discuss the metabolic impacts on the immune effector cells in TME and explore the therapeutic opportunities for metabolically enhanced immunotherapy.


2019 ◽  
Author(s):  
Kian F. Eichholz ◽  
Ian Woods ◽  
Gillian P. Johnson ◽  
Nian Shen ◽  
Michele Corrigan ◽  
...  

AbstractOsteocytes are mechanosensitive cells that are believed to play a fundamental role in coordinating bone mechanoadaptation via the secretion of paracrine factors. However, the exact mechanisms by which osteocytes relay mechanical signals to effector cells is poorly understood. In this study, we demonstrated that osteocytes subjected to a physiologic fluid shear secrete a distinct collection of factors that significantly enhance human MSC recruitment and osteogenesis. Utilising proteomics we generated an extensive map of proteins within the mechanically activated osteocyte secretome, identifying numerous paracrine factors that are modified by mechanical stimulation. Moreover, we identified the presence of extracellular vesicles (EVs) and further demonstrated that these mechanically activated osteocyte derived EVs (MAEVs) coordinate human MSCs recruitment and osteogenesis. This indicates that mechanical conditioning of parent cells can modify EVs and demonstrates the pro-osteogenic potential of MAEVs as a cell-free therapy to enhance bone regeneration and repair in diseases such as osteoporosis.


1992 ◽  
Vol 175 (6) ◽  
pp. 1467-1471 ◽  
Author(s):  
H G Bouwer ◽  
C S Nelson ◽  
B L Gibbins ◽  
D A Portnoy ◽  
D J Hinrichs

The immunologic mechanism of protective immunity to the intracellular parasite Listeria monocytogenes (Lm) is not well understood, however, antilisterial immunity can be adoptively transferred with T lymphocytes from Lm-immune donors. The Lm-immune cells are believed to produce macrophage-activating lymphokines, which leads to the eventual macrophage-dependent eradication of the bacterium. Increasing evidence suggests that immunity to Lm resides exclusively within the CD8+ T cell subset. It is possible that the Lm-immune CD8+ T cells function to release sequestered Lm from nonprofessional phagocytes to awaiting activated macrophage populations. This study was conducted to determine if listeriolysin O (LLO), which is an essential determinant of Lm pathogenicity, is also a target of the antilisterial immune response. We have found that target cells infected with a LLO+ Lm strain are lysed by Lm-immune cytotoxic cells, whereas target cells infected with a LLO- Lm mutant, or pulsed with a heat-killed Lm preparation, are not lysed by the Lm-immune effector cells. We have used a Bacillus subtilis (Bs) construct that expresses the LLO gene product and found that target cells infected with the LLO+ Bs construct are lysed by antilisterial cytotoxic cells. The antilisterial cytotoxic response is targeted against LLO, in that we have also used a Bs construct that expresses the perfringolysin (PLO) gene product and found that target cells infected with the PLO+ Bs are not lysed by antilisterial cytotoxic effector cells. These data strongly suggest that LLO is a target antigen of antilisterial immunity and may represent the dominant target during the expression of the immune response to Lm.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1353
Author(s):  
Andrea Díaz-Tejedor ◽  
Mauro Lorenzo-Mohamed ◽  
Noemí Puig ◽  
Ramón García-Sanz ◽  
María-Victoria Mateos ◽  
...  

Immunosuppression is a common feature of multiple myeloma (MM) patients and has been associated with disease evolution from its precursor stages. MM cells promote immunosuppressive effects due to both the secretion of soluble factors, which inhibit the function of immune effector cells, and the recruitment of immunosuppressive populations. Alterations in the expression of surface molecules are also responsible for immunosuppression. In this scenario, immunotherapy, as is the case of immunotherapeutic monoclonal antibodies (mAbs), aims to boost the immune system against tumor cells. In fact, mAbs exert part of their cytotoxic effects through different cellular and soluble immune components and, therefore, patients’ immunosuppressive status could reduce their efficacy. Here, we will expose the alterations observed in symptomatic MM, as compared to its precursor stages and healthy subjects, in the main immune populations, especially the inhibition of effector cells and the activation of immunosuppressive populations. Additionally, we will revise the mechanisms responsible for all these alterations, including the interplay between MM cells and immune cells and the interactions among immune cells themselves. We will also summarize the main mechanisms of action of the four mAbs approved so far for the treatment of MM. Finally, we will discuss the potential immune-stimulating effects of non-immunotherapeutic drugs, which could enhance the efficacy of immunotherapeutic treatments.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A699-A699
Author(s):  
Dmitry Zhigarev ◽  
Alexander MacFarlane ◽  
Christina Drenberg ◽  
Reza Nejati ◽  
Asya Varshavsky ◽  
...  

BackgroundAcute myeloid leukemia (AML) is a heterogeneous group of malignant bone marrow diseases, characterized by massive and uncontrolled proliferation of myeloid precursor cells, which alters normal blood cell ratios. This disease is common to older adults and collectively displays one of the lowest 5-year overall survival rates (<25%) among all cancers, currently representing the deadliest form of leukemia. Improved treatments are clearly needed, and immunotherapies are attractive candidate therapies to explore.There are currently several standard chemotherapeutic treatment schemes for AML, which could be divided into two major groups: (1) cytotoxic chemotherapy (“7+3” or daunorubicin-cytarabine) and (2) hypomethylating agents (HMAs). HMAs include both 5-azacytidine and decitabine, which are cytidine analogs that inhibit DNA methyltransferase, resulting in the hypomethylation of DNA and inducing expression of silenced gene loci. Currently, HMAs are routinely delivered in combination with the Bcl-2 inhibitor venetoclax.The goals of this study are to determine how these standard first line therapies can affect the frequency and functional integrity of effector immune cells in patients' blood and establish when the phenotype and function of immune cells are restored to identify time windows when second line immunotherapies could be most effective.MethodsMore than 100 blood samples were obtained from 33 previously untreated AML patients. More than 50 measurable biomarkers were analyzed using 14-color flow cytometry to assess immune phenotypes of T and NK cells in peripheral blood of AML patients prior to treatment and at up to four timepoints after initiation of treatment with HMA or chemotherapy.ResultsWe found several significant changes in immune cell phenotype and function that occur in response to these therapies. Treatment with HMAs was strikingly less impactful on immune cells in patients compared to previously published in vitro studies. Nevertheless, HMA treatment increased perforin levels in T and NK cells, inhibited IFN-gamma secretion by CD8+ T cells, and changed expression of several checkpoint molecules. While chemotherapy caused fewer phenotypic changes it dramatically decreased the total number of immune cells. We also determined viable, functional and phenotypical recovery periods for immune effector cells after the treatments.ConclusionsOur results are important for introducing new second line immunotherapies to these chemotherapeutic regimens for treating AML and to improve overall understanding of immune cell behavior under conditions of anti-tumor treatment.AcknowledgementsSupported by grants from Janssen and the U.S./Israel Binational Science Foundation.Ethics ApprovalThe study was approved by the Fox Chase Cancer Center Institutional Review Board, approval number 17-8010, and all patients provided informed consent before taking part in the study.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4358-4358
Author(s):  
Lung-Ji Chang ◽  
Yin Liang ◽  
Lily Lien ◽  
Chun- Rong Tong ◽  
Lu-Jia Dong ◽  
...  

Abstract Similar to virus infections, fungal infections are commonly seen in immunosuppressed transplant patients and can be life-threatening. Invasive Aspergillosis and Candidiasis are principal fungal infections among hematopoietic stem cell transplant (HSCT) patients, but Aspergillosis and other molds are the leading cause of deaths by fungal infections in immunocompromised allogeneic HSCT patients. The most effective treatment for fungal infections is preemptive and empirical anti-fungal therapies using agents such as fluconazole and amphotericin B deoxycholate (AmB-D). However, the success rate of antifungal therapy is generally low (in the 30–40% range) and associated with high toxicity. Both diagnosis and treatment for fungal infections are expensive and often ineffective. While improved formulations of AmB-D, second-generation triazoles, and echinocandins may be tolerable, newer generations of anti-fungal agents are very expensive. In animal studies, it has been shown that Aspergillosis can be successfully treated using Aspergillus-specific cytotoxic T cells (CTLs). Therefore, it is conceivable that CTLs specific to fungal antigens are effective in controlling fungal infections in allogeneic HSCT patients. To explore anti-fungal immune cell therapy, we used two different approaches to generate fungus-specific immune cells: Trichoderma and Rhizopus fungal lysates as antigen source to pulse dendritic cells (DCs), and pooled antigenic peptides to pulse DCs. The antigen-primed DCs were then co-cultured with lymphocytes to generate antigen-specific immune effector cells. The ex vivo generated anti-fungal immune cells displayed antigen-specific effector functions as illustrated by intracellular IFN-γ and CD107a staining. Interestingly, the fungus-specific immune effector cells are mostly CD4 T cells for all three species of fungal antigens. In a pilot clinical study, patients were selected when diagnosed with invasive aspergillosis based on galactomannan and beta-glucan assays, radiographs, CT scans, and/or blood cultures, or after an extended unsuccessful anti-fungal treatment with non-tolerable organ toxicity. Early indications suggest that the infusion of anti-fungal immune cells is safe, with therapeutic efficacy based on objective clinical evidence and importantly, is cost-effective. Nevertheless, more effective diagnosis and surveillance tools are needed to document the effectiveness of our anti-fungal immune cell treatment.


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