scholarly journals Black phosphorus-based photothermal therapy with aCD47-mediated immune checkpoint blockade for enhanced cancer immunotherapy

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhongjian Xie ◽  
Minhua Peng ◽  
Ruitao Lu ◽  
Xiangying Meng ◽  
Weiyuan Liang ◽  
...  

Abstract Here, we describe a combination strategy of black phosphorus (BP)-based photothermal therapy together with anti-CD47 antibody (aCD47)-based immunotherapy to synergistically enhance cancer treatment. Tumour resistance to immune checkpoint blockades in most cancers due to immune escape from host surveillance, along with the initiation of metastasis through immunosuppressive cells in the tumour microenvironment, remains a significant challenge for cancer immunotherapy. aCD47, an agent for CD47/SIRPα axis blockade, induces modest phagocytic activity and a low response rate for monotherapy, resulting in failures in clinical trials. We showed that BP-mediated ablation of tumours through photothermal effects could serve as an effective strategy for specific immunological stimulation, improving the inherently poor immunogenicity of tumours, which is particularly useful for enhancing cancer immunotherapy. BP in combination with aCD47 blockade activates both innate and adaptive immunities and promotes local and systemic anticancer immune responses, thus offering a synergistically enhanced effect in suppression of tumour progression and in inducing abscopal effects for inhibition of metastatic cancers. Our combination strategy provides a promising platform in which photothermal agents could help to enhance the therapeutic efficacy of immunotherapy.

2021 ◽  
Vol 15 ◽  
pp. 117955492110355
Author(s):  
Tianhang Li ◽  
Tianyao Liu ◽  
Wenjie Zhu ◽  
Shangxun Xie ◽  
Zihan Zhao ◽  
...  

Immune-checkpoint blockade (ICB) demonstrated inspiring effect and great promise in anti-cancer therapy. However, many obstacles, such as drug resistance and difficulty in patient selection, limited the efficacy of ICB therapy and awaited to be overcome. By timely identification and intervention of the key immune-suppressive promotors in the tumor microenvironment (TME), we may better understand the mechanisms of cancer immune-escape and use novel strategies to enhance the therapeutic effect of ICB. Myeloid-derived suppressor cell (MDSC) is recognized as a major immune suppressor in the TME. In this review, we summarized the roles MDSC played in the cancer context, focusing on its negative biologic functions in ICB therapy, discussed the strategies targeted on MDSC to optimize the diagnosis and therapy process of ICB and improve the efficacy of ICB therapy against malignancies.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A888-A888
Author(s):  
Laura Ridgley ◽  
Angus Dalgleish ◽  
Mark Bodman-Smith

BackgroundVγ9Vδ2 T-cells are a subset of cells with a crucial role in immunosurveillance which can be activated and expanded by multiple means to stimulate effector responses, often exploited in cancer immunotherapy. Little is known about the expression of checkpoint molecules on this cell population and whether the ligation of these molecules can regulate their activity. The aim of this study was to assess the expression of activatory and inhibitory markers on Vγ9Vδ2 T-cells to assess potential avenues of regulation to target with immunotherapy.MethodsPBMCs were isolated from healthy donors and the expression of activatory and inhibitory receptors was assessed on Vγ9Vδ2 T-cells by flow cytometry at baseline, following 24 hours activation and 14 days expansion using zoledronic acid (ZA) and Bacillus Calmette-Guerin (BCG), both with IL-2. Activation and expansion of Vδ2 cells was assessed by expression of CD69 and by frequency of Vδ2 cells, respectively. Production of effector molecules was also assessed following coculture with various tumour cell targets. The effect of immune checkpoint blockade on Vγ9Vδ2 T-cells was also assessed.ResultsVγ9Vδ2 T-cells constitutively expressed high levels of NK-associated activatory markers NKG2D and DNAM1 which remained high following stimulation with ZA and BCG. Vγ9Vδ2 T-cells expressed variable levels of checkpoint inhibitor molecules at baseline with high levels of BTLA, KLRG1 and NKG2A and intermediate levels of PD1, TIGIT and VISTA. Expression of checkpoint receptors were modulated following activation and expansion with ZA and BCG with decreased expression of BTLA and upregulation of numerous markers including PD1, TIGIT, TIM3, LAG3 and VISTA. Expression of these markers is further modulated upon coculture with tumour cell lines with changes reflecting activation of these cells with Vγ9Vδ2 T-cells expressing inhibitory receptors PD1 and NKG2A producing the highest level of TNF.ConclusionsOur data reveals unique characteristics of Vδ2 in terms of their expression of immune checkpoints, which provide a mechanism which may be utilised by tumour cells to subvert Vγ9Vδ2 T-cell cytotoxicity. Our work suggests different profiles of immune checkpoints dependent on the method of stimulation. This highlights importance of expansion method in the function of Vγ9Vδ2 T-cells. Furthermore, this work suggests important candidates for blockade by immune checkpoint therapy in order to increase the successful use of Vγ9Vδ2 T-cells in cancer immunotherapy.


Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5912
Author(s):  
Angèle Luby ◽  
Marie-Clotilde Alves-Guerra

Over the past decade, advances in cancer immunotherapy through PD1–PDL1 and CTLA4 immune checkpoint blockade have revolutionized the management of cancer treatment. However, these treatments are inefficient for many cancers, and unfortunately, few patients respond to these treatments. Indeed, altered metabolic pathways in the tumor play a pivotal role in tumor growth and immune response. Thus, the immunosuppressive tumor microenvironment (TME) reprograms the behavior of immune cells by altering their cellular machinery and nutrient availability to limit antitumor functions. Today, thanks to a better understanding of cancer metabolism, immunometabolism and immune checkpoint evasion, the development of new therapeutic approaches targeting the energy metabolism of cancer or immune cells greatly improve the efficacy of immunotherapy in different cancer models. Herein, we highlight the changes in metabolic pathways that regulate the differentiation of pro- and antitumor immune cells and how TME-induced metabolic stress impedes their antitumor activity. Finally, we propose some drug strategies to target these pathways in the context of cancer immunotherapy.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Huapan Fang ◽  
Zhaopei Guo ◽  
Jie Chen ◽  
Lin Lin ◽  
Yingying Hu ◽  
...  

AbstractImmunotherapy has become a powerful cancer treatment, but only a small fraction of patients have achieved durable benefits due to the immune escape mechanism. In this study, epigenetic regulation is combined with gene therapy-mediated immune checkpoint blockade to relieve this immune escape mechanism. PPD (i.e., mPEG-b-PLG/PEI-RT3/DNA) is developed to mediate plasmid-encoding shPD-L1 delivery by introducing multiple interactions (i.e., electrostatic, hydrogen bonding, and hydrophobic interactions) and polyproline II (PPII)-helix conformation, which downregulates PD-L1 expression on tumour cells to relieve the immunosuppression of T cells. Zebularine (abbreviated as Zeb), a DNA methyltransferase inhibitor (DNMTi), is used for the epigenetic regulation of the tumour immune microenvironment, thus inducing DC maturation and MHC I molecule expression to enhance antigen presentation. PPD plus Zeb combination therapy initiates a systemic anti-tumour immune response and effectively prevents tumour relapse and metastasis by generating durable immune memory. This strategy provides a scheme for tumour treatment and the inhibition of relapse and metastasis.


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