scholarly journals Oncolytic adenoviruses synergistically enhance anti-PD-L1 and anti-CTLA-4 immunotherapy by modulating the tumour microenvironment in a 4T1 orthotopic mouse model

2021 ◽  
Author(s):  
Huan Zhang ◽  
Weimin Xie ◽  
Yuning Zhang ◽  
Xiwen Dong ◽  
Chao Liu ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Mouse Model ◽  
Immune Checkpoint ◽  
Oncolytic Virus ◽  
Immune Escape ◽  
Tumour Microenvironment ◽  
Histopathological Analysis ◽  
Combination Immunotherapy ◽  
Orthotopic Mouse Model ◽  
Oncolytic Adenoviruses

AbstractEffective therapeutic strategies for triple-negative breast cancer (TNBC) are still lacking. Clinical data suggest that a large number of TNBC patients cannot benefit from single immune checkpoint inhibitor (ICI) treatment due to the immunosuppressive tumour microenvironment (TME). Therefore, combination immunotherapy is an alternative approach to overcome this limitation. In this article, we combined two kinds of oncolytic adenoviruses with ICIs to treat TNBC in an orthotopic mouse model. Histopathological analysis and immunohistochemistry as well as multiplex immunofluorescence were used to analyse the TME. The immunophenotype of the peripheral blood and spleen was detected by using flow cytometry. Oncolytic adenovirus-mediated immune activity in a coculture system of lytic supernatant and splenocytes supported the study of the mechanism of combination therapy in vitro. Our results showed that the combination of oncolytic adenoviruses with anti-programmed cell death-ligand 1 (anti-PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (anti-CTLA-4) (aPC) can significantly inhibit tumour growth and prolong survival in a TNBC model. The combination therapy synergistically enhanced the antitumour effect by recruiting CD8+ T and T memory cells, reducing the number of regulatory T cells and tumour-associated macrophages, and promoting the polarization of macrophages from the M2 to the M1 phenotype to regulate the TME. The rAd.GM regimen performed better than the rAd.Null treatment. Furthermore, aPC efficiently blocked oncolytic virus-induced upregulation of PD-L1 and CTLA-4. These findings indicate that oncolytic adenoviruses can reprogramme the immunosuppressive TME, while ICIs can prevent immune escape after oncolytic virus therapy by reducing the expression of immune checkpoint molecules. Our results provide a mutually reinforcing strategy for clinical combination immunotherapy.

Anlotinib enhanced penpulimab efficacy through remodeling of tumor vascular architecture and immune microenvironment in hPD-L1/hPD-1 humanized mouse model.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2581-2581
Author(s):  
Yunlong Shan ◽  
Chongjin Zhong ◽  
Qi Ni ◽  
Mengying Zhang ◽  
Guangji Wang ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Mouse Model ◽  
Immune Cells ◽  
Immune Checkpoint ◽  
Tumor Volume ◽  
Combined Therapy ◽  
Control Group ◽  
Tyrosine Kinase Receptor ◽  
Humanized Mouse ◽  
Humanized Mouse Model

2581 Background: Even though immune checkpoint inhibitor (ICI) such as anti-PD-1 mAb has emerged as effective treatment for tumor regression, the response rate of ICI monotherapy in solid tumor is low. Many studies have demonstrated that the efficacy of combination therapy of ICI and anti-angiogenesis was superior to monotherapy. Penpulimab (AK105), a humanized IgG1 mAb that blocks PD-1 binding to PD-L1, engineered to eliminate FcγR binding and ADCC/ADCP completely. Here, we explore a new combined therapy of penpulimab and anlotinib, an oral multi-targeted tyrosine kinase receptor inhibitor. Methods: MC38-hPD-L1 tumor-bearing B-hPD-1 humanized mouse model were conducted to investigate the effects of anlotinib (1 mg/kg, every day, p.o) or penpulimab (5 mg/kg, twice a week, i.p) alone or in combination. Immunofluorescence was applied to elucidate tumor vessel normalization. In vivo imaging was conducted to detect the distribution of AF647-labelled penpulimab after anlotinib treatment. Flow cytometry and other techniques were performed to investigate intratumoral immune cells. Results: After 3-week treatment, immunotherapeutic administration of anlotinib or penpulimab showed moderate inhibition of tumor growth (tumor volume: 66.5% and 58.4% of control group, respectively), while combined treatment of anlotinib with penpulimab significantly decreased tumor volume to 36.5% of control group. Tissue pathological and blood biochemical results showed no significant toxic and side effects. Immunohistochemistry revealed that anlotinib induced tumor vascular normalization, indicated by decreased CD31+ area, increased α-SMA around tumor vessels and reduced GLUT1+ area. Furthermore, anlotinib markedly enhanced the delivery of AF647-penpulimab into tumors. Combining anlotinib with penpulimab also promoted infiltration and activity of anti-tumoral immune cells by reducing the level of immune checkpoint TIM3 and increasing the IFNγ secretion from T cells. Conclusions: Our work provides a strong scientific rationale for the combination therapy of anlotinib and penpulimab to improve tumor microenvironment and immunotherapy, which highlights the clinical potential for this new combined therapy.

scholarly journals Results from a Meta-analysis of Combination of PD-1/PD-L1 and CTLA-4 Inhibitors in Malignant Cancer Patients: Does PD-L1 Matter?

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuqian Feng ◽  
Huimin Jin ◽  
Kaibo Guo ◽  
Yuying Xiang ◽  
Yiting Zhang ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Cancer Patients ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Malignant Tumors ◽  
Checkpoint Inhibitors ◽  
Meta Analysis ◽  
Objective Response ◽  
Progression Free Survival ◽  
Combination Immunotherapy

Background: Combination therapy with immune checkpoint inhibitors (ICIs) has been widely used for clinical treatment in recent years, which has a better survival benefit. However, not all patients can derive clinical benefit from combination immunotherapy. Therefore, it is necessary to explore the biomarkers of combination immunotherapy.Methods: We retrieved articles from electronic databases including PubMed, EMBASE and Cochrane. The statistical analysis was performed using RevMan software. Progression free survival (PFS), overall survival (OS) and objective response rate (ORR) were the outcome indicators. In the unselect population, we compared combination therapy with other treatments. In addition, we also conducted subgroup analysis on PFS, OS and ORR according to PD-L1 status.Results: Seven studies were included in the analysis for a total of 3,515 cases. In the unselected population, we found that combination therapy has longer PFS, OS, and better ORR than other treatments for cancer patients. The longer PFS was showed in PD-L1 ≥ 5% cases (HR = 0.64, 95% CI: 0.56–0.76; p < 0.001) than PD-L1 ≥ 1% cases (HR = 0.72, 95% CI: 0.66–0.79; p < 0.001), while ORR and OS have not related to the status of PD-L1.Conclusion: This study supported the efficacy of combination therapy with immune checkpoint inhibitors (ICIs), and also showed that PFS in patients with malignant tumors is positively correlated with PD-L1 expression. Due to the limited number of trials included, more high-quality clinical randomized controlled trials should be conducted to confirm the review findings.

scholarly journals Nanoconjugates to enhance PDT-mediated cancer immunotherapy by targeting the indoleamine-2,3-dioxygenase pathway

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xueyuan Yang ◽  
Weizhong Zhang ◽  
Wen Jiang ◽  
Anil Kumar ◽  
Shiyi Zhou ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Combination Treatment ◽  
Immune Checkpoint ◽  
Immune Escape ◽  
Checkpoint Inhibitors ◽  
In Vivo Studies ◽  
Tumor Immune Escape ◽  
Indoleamine 2,3 Dioxygenase ◽  
Composite Nanoparticle

Abstract Background Photodynamic therapy (PDT) may elicit antitumor immune response in addition to killing cancer cells. However, PDT as a monotherapy often fails to induce a strong immunity. Immune checkpoint inhibitors, which selectively block regulatory axes, may be used in combination with PDT to improve treatment outcomes. Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme and an important meditator of tumor immune escape. Combination therapy with PDT and IDO-targeted immune checkpoint blockage is promising but has been seldom been explored. Methods Herein we report a composite nanoparticle that allows for simultaneous delivery of photosensitizer and IDO inhibitor. Briefly, we separately load ZnF16Pc, a photosensitizer, and NLG919, an indoleamine 2,3-dioxygenase (IDO) inhibitor, into ferritin and poly(lactide-co-glycolic)-block-poly(ethylene glycol) (PEG-PLGA) nanoparticles; we then conjugate these two compartments to form a composite nanoparticle referred to as PPF NPs. We tested combination treatment with PPF NPs first in vitro and then in vivo in B16F10-tumor bearing C57/BL6 mice. Results Our results showed that PPF NPs can efficiently encapsulate both ZnF16Pc and NLG919. In vivo studies found that the combination treatment led to significantly improved tumor suppression and animal survival. Moreover, the treatment increased tumor infiltration of CD8+ T cells, while reducing frequencies of MDSCs and Tregs. 30% of the animals showed complete tumor eradication, and they successfully rejected a second tumor inoculation. Overall, our studies introduce a unique composite nanoplatform that allows for co-delivery of photosensitizer and IDO inhibitor with minimal inter-species interference, which is ideal for combination therapy.

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 ◽  
...  
Keyword(s):  
Cancer Immunotherapy ◽  
Immune Checkpoint ◽  
Photothermal Therapy ◽  
Immune Escape ◽  
Tumour Progression ◽  
Tumour Microenvironment ◽  
Immune Checkpoint Blockade ◽  
Black Phosphorus ◽  
Combination Strategy ◽  
Immunosuppressive Cells

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.

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