InVivoMAb anti-human PD-1 (CD279)

Cancer immunotherapy promises to treat challenging cancers including KRAS-mutated colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC). However, pre-clinical animal models that better mimic patient tumor and immune system interactions are required. While humanized mice are promising vehicles for pre-clinical immunotherapy testing, currently used cancer models retain limitations, such as lack of a human thymus for human leukocyte antigen (HLA)-based education of human T cells. As cytotoxic T lymphocyte (CTL) activity underlies many immunotherapies, we developed more clinically relevant KRAS-mutated CRC and PDAC humanized cancer models using transgenic NRG-A2 mice expressing HLA-A2.1 to enable HLA-class-I match between mouse tissues (including the thymus), the humanized immune system and human tumors. Using these novel humanized cancer models and a CTL-mediated combination (immuno)therapy with clinical potential, we were able to recapitulate the complexity and therapy-induced changes reported in patient biopsies, demonstrating the use of these HLA-matched models for pre-clinical validation of novel immunotherapies.

Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TILs) is a personalized immunotherapy that has shown promising clinical results in various tumor types. Although TILs are associated with improved survival in patients with ovarian cancer (OC), their therapeutic efficacy remains limited. Therefore, novel strategies to enhance the anti-tumor activity of TILs are needed to improve outcomes in OC treatment.

Immune checkpoint combination therapy, particularly dual LAG-3/PD-1 blockade, demonstrates superior clinical efficacy over monotherapy in cancers like melanoma, yet its mechanistic synergy requires further validation. In this study, we established a cell co-culture model by co-culturing LAG-3+PD-1+ Jurkat cells induced by phytohemagglutinin (PHA) and human tumor cells with high expression of LAG-3 and PD-1 major ligands to characterize the combination effect of LBL-007 with anti-PD-1 antibodies and the mechanism of action in cancer immunotherapy. The results showed that the combination of LBL-007 and anti-PD-1 antibodies in the cell co-culture model enhanced the ability of activated Jurkat cells to kill tumor cells compared with monotherapy. Furthermore, this combination also inhibited the apoptosis of Jurkat cells and promoted IL-2, IL-10, and TNF secretion from Jurkat cells. Tumor cell death via apoptosis induced by activated Jurkat cells was observed, which was enhanced by combined LBL-007 and anti-PD-1 antibody treatment. The combination of LBL-007 and anti-PD-1 antibodies delayed tumor growth and promoted tumor cell apoptosis compared with monotherapy in human LAG-3 transgenic mice subjected to transplantation with colorectal tumor cells. Taken together, the combination of LBL-007 and anti-PD-1 antibodies plays an enhanced antitumor role by improving T cell viability and activity as well as by promoting T cell-induced apoptosis, thereby suggesting this combination as a potential effective strategy for cancer immunotherapy.

Immune checkpoint inhibitors targeting the interaction between PD1 and PDL1 are effective for immunotherapy in non-small cell lung cancer (NSCLC). However, only subgroups of patients respond to therapy, suggesting the existence of resistance mechanisms.

Subtle variations of micronutrients in the tumor microenvironment often coincide with tumor progression and immune disorders. Nevertheless, the underlying mechanisms of how micronutrients, such as metal ions, influence tumor-intrinsic properties and tumor-immune crosstalk remain inadequately characterized. Here, our integrative analysis of multi-center single-cell, spatial transcriptome sequencing, and bulk RNA sequencing (RNA-seq) cohorts reveals that nasopharyngeal carcinoma (NPC)-specific SRY-box transcription factor 4 (SOX4) governs microenvironmental and cellular zinc metabolism through its downstream target, SLC39A14 (ZIP14), a membrane zinc uptake transporter. Mechanistically, NPC cells enhance zinc uptake and activate Wnt/β-catenin signaling to initiate tumor growth, creating a zinc-deficient niche hostile to T cells. Zinc deficiency of tumor-infiltrating CD8+ T cells impairs LCK phosphorylation and T cell receptor (TCR) signaling, compromising their effector function. Our study elucidates the idea that the SOX4-ZIP14-zinc metabolism axis has a multifactorial effect in NPC, fostering the malignant phenotypes of NPC and suppressing the T cell response through the deprivation of zinc metabolism.

As a part of the commensal microbiome, the regulatory role of the intratumoral microbiome in tumor immunity is gradually revealed. However, the relationship between the intratumoral microbiome and the efficacy of immune checkpoint inhibitors (ICIs) clinical treatment remains unclear. Here, we collect RNA sequencing (RNA-seq) data and clinical information from publicly available ICIs therapy cohorts. By developing an improved bioinformatics pipeline to identify the intratumoral microbiome and performing a comprehensive association analysis, we find that the intratumoral microbiome is associated with response to ICIs and characteristics of the tumor microenvironment (TME). In vivo experiments demonstrate that intratumoral injection of Burkholderia cepacia, Priestia megaterium, or Corynebacterium kroppenstedtii, which were selected from our analysis results, would synergize with anti-PD-1 therapy to inhibit tumor growth and enhance antitumor immunity. Our findings highlight the essential role of the intratumoral microbiome in the clinical effectiveness differences of ICIs, suggesting its potential in future ICIs combination therapy.

The N6-methyladenosine (m6A) methylase WTAP has been identified as a proto-oncogene in multiple cancers, including hepatocellular carcinoma (HCC). Interestingly, although WTAP expression does not differ between normal liver and HCC tissues or across different stages of HCC, patients with higher WTAP expression exhibit significantly shorter median survival times (MSTs). Here, we found that WTAP was upregulated in tumor-infiltrating CD8+ T cells, which were more enriched in HCC patients compared to the controls. HCC patients also displayed higher PD1 levels and a greater proportion of exhausted CD8+ T cells (TCF+ PD1+). Moreover, WTAP promoted PD1 expression and suppressed the proliferation and immune activity of CD8+ T cells. In the co-culture system, WTAP-overexpressing CD8+ T cells enhanced the malignancy of HCC cells. Notably, WTAP silencing further augmented the boosting effect of PD1 silencing on CD8+ T cell immune activity and strengthened its inhibitory effect on HCC cell growth. As an m6A "writer", WTAP increased the m6A level of PD1 mRNA, thereby promoting YTHDF1-mediated translation of PD1. Finally, in the HuNSG xenograft tumor model, WTAP knockdown not only alleviated CD8+ T cell exhaustion and inhibited tumor progression but also synergistically enhanced the antitumor efficacy of anti-PD1 therapy. In conclusion, WTAP promoted CD8+ T cell exhaustion and HCC progression by facilitating the m6A modification and translation of PD1 mRNA.

Immunotherapy has emerged as a promising approach for cancer treatment, with oncolytic adenoviruses showing power as immunotherapeutic agents. In this study, we investigated the immunotherapeutic potential of an adenovirus construct expressing CXCL9, CXCL10, or IL-15 in clear cell renal cell carcinoma (ccRCC) tumor models. Our results demonstrated robust cytokine secretion upon viral treatment, suggesting effective transgene expression. Subsequent analysis using resistance-based transwell migration and microfluidic chip assays demonstrated increased T-cell migration in response to chemokine secretion by infected cells in both 2D and 3D cell models. Flow cytometry analysis revealed CXCR3 receptor expression across T-cell subsets, with the highest percentage found on CD8+ T-cells, underscoring their key role in immune cell migration. Alongside T-cells, we also detected NK-cells in the tumors of immunocompromised mice treated with cytokine-encoding adenoviruses. Furthermore, we identified potential immunogenic antigens that may enhance the efficacy and specificity of our armed oncolytic adenoviruses in ccRCC. Overall, our findings using ccRCC cell line, in vivo humanized mice, physiologically relevant PDCs in 2D and patient-derived organoids (PDOs) in 3D suggest that chemokine-armed adenoviruses hold promise for enhancing T-cell migration and improving immunotherapy outcomes in ccRCC. Our study contributes to the development of more effective ccRCC treatment strategies by elucidating immune cell infiltration and activation mechanisms within the tumor microenvironment (TME) and highlights the usefulness of PDOs for predicting clinical relevance and validating novel immunotherapeutic approaches. Overall, our research offers insights into the rational design and optimization of viral-based immunotherapies for ccRCC.

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. Inhibitors targeting the programmed cell death 1 (PD-1) immune checkpoint have improved MCC patient outcomes by boosting antitumor T cell immunity. Here, we identify PD-1 as a growth-promoting receptor intrinsic to MCC cells. In human MCC lines and clinical tumors, RT-PCR-based sequencing, immunoblotting, flow cytometry, and immunofluorescence analyses demonstrated PD-1 gene and protein expression by MCC cells. MCC-PD-1 ligation enhanced, and its inhibition or silencing suppressed, in vitro proliferation and in vivo tumor xenograft growth. Consistently, MCC-PD-1 binding to PD-L1 or PD-L2 induced, while antibody-mediated PD-1 blockade inhibited, protumorigenic mTOR signaling, mitochondrial (mt) respiration, and ROS generation. Last, pharmacologic inhibition of mTOR or mtROS reversed MCC-PD-1:PD-L1-dependent proliferation and synergized with PD-1 checkpoint blockade in suppressing tumorigenesis. Our results identify an MCC-PD-1-mTOR-mtROS axis as a tumor growth-accelerating mechanism, the blockade of which might contribute to clinical response in patients with MCC.

Radiation-induced sarcomas (RIS) have a poor prognosis and lack effective treatments. Its genome and tumor microenvironment are not well characterized and need further exploration.

Targeting tumor-associated blood vessels to increase immune infiltration may enhance treatment effectiveness, yet limited data exist regarding anti-angiogenesis effects on the tumor microenvironment (TME). We hypothesized that dual targeting of angiogenesis with immune checkpoints would improve both intracranial and extracranial disease. We used subcutaneous and left ventricle melanoma models to evaluate anti-PD-1/anti-VEGF and anti-PD-1/lenvatinib (pan-VEGFR inhibitor) combinations. Cytokine/chemokine profiling and flow cytometry were performed to assess signaling and immune-infiltrating populations. An in vitro blood-brain barrier (BBB) model was utilized to study intracranial treatment effects on endothelial integrity and leukocyte transmigration. Anti-PD-1 with either anti-VEGF or lenvatinib improved survival and decreased tumor growth in systemic melanoma murine models; treatment increased Th1 cytokine/chemokine signaling. Lenvatinib decreased tumor-associated macrophages but increased plasmacytoid DCs early in treatment; this effect was not evident with anti-VEGF. Both lenvatinib and anti-VEGF resulted in decreased intratumoral blood vessels. Although anti-VEGF promoted endothelial stabilization in an in vitro BBB model, while lenvatinib did not, both regimens enabled leukocyte transmigration. The combined targeting of PD-1 and VEGF or its receptors promotes enhanced melanoma antitumor activity, yet their effects on the TME are quite different. These studies provide insights into dual anti-PD-1 and anti-angiogenesis combinations.

The discovery of immune checkpoints and the development of their specific inhibitors was acclaimed as a major breakthrough in cancer therapy. However, only a limited patient cohort shows sufficient response to therapy. Hence, there is a need for identifying new checkpoints and predictive biomarkers with the objective of overcoming immune escape and resistance to treatment. Having been associated with both, treatment response and failure, LDL seems to be a double-edged sword in anti-PD1 immunotherapy. Being embedded into complex metabolic conditions, the impact of LDL on distinct immune cells has not been sufficiently addressed. Revealing the effects of LDL on T cell performance in tumor immunity may enable individual treatment adjustments in order to enhance the response to routinely administered immunotherapies in different patient populations. The object of this work was to investigate the effect of LDL on T cell activation and tumor immunity in-vitro.

To evaluate the feasibility of syngeneic mouse models of breast cancer by analyzing the efficacy of immune checkpoint inhibitors (ICIs) and potential predictive biomarkers.

Rhabdomyosarcoma (RMS) is the most common soft tissue cancer in children. Treatment outcomes, particularly for relapsed/refractory or metastatic disease, have not improved in decades. The current lack of novel therapies and low tumor mutational burden suggest that chimeric antigen receptor (CAR) T-cell therapy could be a promising approach to treating RMS. Previous work identified FGF receptor 4 (FGFR4, CD334) as being specifically upregulated in RMS, making it a candidate target for CAR T cells. We tested the feasibility of an FGFR4-targeted CAR for treating RMS using an NSG mouse with RH30 orthotopic (intramuscular) tumors. The first barrier we noted was that RMS tumors produce a collagen-rich stroma, replete with immunosuppressive myeloid cells, when T-cell therapy is initiated. This stromal response is not seen in tumor-only xenografts. When scFV-based binders were selected from phage display, CARs targeting FGFR4 were not effective until our screening approach was refined to identify binders to the membrane-proximal domain of FGFR4. Having improved the CAR, we devised a pharmacologic strategy to augment CAR T-cell activity by inhibiting the myeloid component of the T-cell-induced tumor stroma. The combined treatment of mice with anti-myeloid polypharmacy (targeting CSF1R, IDO1, iNOS, TGFbeta, PDL1, MIF, and myeloid misdifferentiation) allowed FGFR4 CAR T cells to successfully clear orthotopic RMS tumors, demonstrating that RMS tumors, even with very low copy-number targets, can be targeted by CAR T cells upon reversal of an immunosuppressive microenvironment.

The loss of tumor antigens and depletion of CD8 T cells caused by the PD-1/PD-L1 pathway are important factors for tumor immune escape. In recent years, there has been increasing research on traditional Chinese medicine in tumor treatment. Cycloastragenol (CAG), an effective active molecule in Astragalus membranaceus, has been found to have antiviral, anti-aging, anti-inflammatory, and other functions. However, its antitumor effect and mechanism are not clear.

Cancer immunotherapies have shown clinical success in various types of tumors but the patient response rate is low, particularly in breast cancer. Here we report that malignant breast cancer cells can transfer active TGF-β type II receptor (TβRII) via tumor-derived extracellular vesicles (TEV) and thereby stimulate TGF-β signaling in recipient cells. Up-take of extracellular vesicle-TβRII (EV-TβRII) in low-grade tumor cells initiates epithelial-to-mesenchymal transition (EMT), thus reinforcing cancer stemness and increasing metastasis in intracardial xenograft and orthotopic transplantation models. EV-TβRII delivered as cargo to CD8+ T cells induces the activation of SMAD3 which we demonstrated to associate and cooperate with TCF1 transcription factor to impose CD8+ T cell exhaustion, resulting in failure of immunotherapy. The levels of TβRII+ circulating extracellular vesicles (crEV) appears to correlate with tumor burden, metastasis and patient survival, thereby serve as a non-invasive screening tool to detect malignant breast tumor stages. Thus, our findings not only identify a possible mechanism by which breast cancer cells can promote T cell exhaustion and dampen host anti-tumor immunity, but may also identify a target for immune therapy against the most devastating breast tumors.

The overall response rate for anti-PD-1 therapy remains modest in hepatocellular carcinoma (HCC). We found that a combination of IFNα and anti-PD-1-based immunotherapy resulted in enhanced antitumor activity in patients with unresectable HCC. In both immunocompetent orthotopic and spontaneous HCC models, IFNα therapy synergized with anti-PD-1 and the combination treatment led to significant enrichment of cytotoxic CD27+CD8+ T cells. Mechanistically, IFNα suppressed HIF1α signaling by inhibiting FosB transcription in HCC cells, resulting in reduced glucose consumption capacity and consequentially establishing a high-glucose microenvironment that fostered transcription of the T-cell costimulatory molecule Cd27 via mTOR-FOXM1 signaling in infiltrating CD8+ T cells. Together, these data reveal that IFNα reprograms glucose metabolism within the HCC tumor microenvironment, thereby liberating T-cell cytotoxic capacities and potentiating the PD-1 blockade-induced immune response. Our findings suggest that IFNα and anti-PD-1 cotreatment is an effective novel combination strategy for patients with HCC.

TIGIT/CD155 has attracted widespread attention as a new immune checkpoint and a potential target for cancer immunotherapy. In our study, we evaluated the role of TIGIT/CD155 checkpoints in the progression of cervical cancer.