Publications by authors named "Zhichen Sun"

The use of CAR-T cells in treating solid tumors frequently faces significant challenges, mainly due to the heterogeneity of tumor antigens. This study assessed the efficacy of an acidity-targeting transition-aided universal chimeric antigen receptor T (ATT-CAR-T) cell strategy, which is facilitated by an acidity-targeted transition. Specifically, the EGFRvIII peptide was attached to the N-terminus of a pH-low insertion peptide.

View Article and Find Full Text PDF
Article Synopsis
  • - STING (Stimulator of Interferon Genes) is a crucial immune protein that detects danger signals from DNA, leading to immune responses such as activation of interferons and cell death, but its roles in various immune and cancer cells are not fully understood.
  • - Research using a new nanoparticle called PolySTING revealed that conventional type 1 dendritic cells (cDC1s) are vital for STING-induced rejection of tumors, while the STING status in these immune cells, rather than in the tumors themselves, is key to effective anti-cancer responses.
  • - The study found that specific chemokine responses in cDC1s were linked to patient survival, and the presence of STING-activated cDC1
View Article and Find Full Text PDF
Article Synopsis
  • STING is an immune protein that detects danger signals from DNA, playing a key role in activating immune responses and is found in various cell types including cancer cells.
  • The study shows that type 1 conventional dendritic cells (cDC1) are crucial for STING-mediated rejection of tumors, and the effectiveness of a special nanoparticle treatment (PolySTING) relies on the presence of STING in these immune cells, not the cancer cells.
  • Research highlights that the presence of activated cDC1 correlates with patient survival in lung cancer and can be indicative of the effectiveness of immunotherapy treatments like pembrolizumab.
View Article and Find Full Text PDF

T cell receptor-engineered T (TCR-T) cell therapy has demonstrated therapeutic effects in basic research and clinical trials for treating solid tumors. Due to the peptide-dependent recognition and the human leukocyte antigen (HLA)-restriction, TCR-T cell therapy is generally custom designed to target individual antigens. The lack of suitable universal targets for tumor cells significantly limits its clinical applications.

View Article and Find Full Text PDF

Background: In situ tumor vaccine has been gradually becoming a hot research field for its advantage of achieving personalized tumor therapy without prior antigen identification. Various in situ tumor vaccine regimens have been reported to exert considerable antitumor efficacy in preclinical and clinical studies. However, the design of in situ tumor vaccines still needs further optimization and the underlying immune mechanism also waits for deeper investigation.

View Article and Find Full Text PDF

Background: Although immune checkpoint blockade (ICB) and adoptive T cell transfer (ACT) therapy have achieved impressive clinical outcomes, majority of patients do not respond to immunotherapy. Tumor-infiltrating T cells, a critical factor to immunotherapy, is dynamically changing. Therefore, a reliable real-time in vivo imaging system for tumor-infiltrating T cells, but not immunohistochemical analyses, will be more valuable to predict response and guide immunotherapy.

View Article and Find Full Text PDF

Chimeric antigen receptor (CAR)-T cell therapy is a transformative treatment against advanced malignancies. Unfortunately, once administrated in vivo, CAR-T cells become out of artificial control, and fierce response to CAR-T therapy may cause severe adverse events, represented by cytokine-release syndrome and on-target/off-tumor effects. Here, a nanomodified switch strategy is developed, leading to sustained and precise "on-tumor only" activation of CAR-T cells.

View Article and Find Full Text PDF

Immune checkpoint blockade (ICB)-based immunotherapy depends on functional tumour-infiltrating lymphocytes (TILs), but essential cytokines are less understood. Here we uncover an essential role of endogenous IL-2 for ICB responsiveness and the correlation between insufficient IL-2 signalling and T-cell exhaustion as tumours progress. To determine if exogenous IL-2 in the tumour microenvironment can overcome ICB resistance, we engineered mesenchymal stem cells (MSCs) to successfully deliver IL-2 mutein dimer (SIL2-EMSC) to TILs.

View Article and Find Full Text PDF

Lactate is a key metabolite produced from glycolytic metabolism of glucose molecules, yet it also serves as a primary carbon fuel source for many cell types. In the tumor-immune microenvironment, effect of lactate on cancer and immune cells can be highly complex and hard to decipher, which is further confounded by acidic protons, a co-product of glycolysis. Here we show that lactate is able to increase stemness of CD8 T cells and augments anti-tumor immunity.

View Article and Find Full Text PDF

Background: Chimeric antigen receptor (CAR)-T cell therapy has demonstrated remarkable success in the treatment of hematologic malignancies, while the success has not yet been replicated in solid tumors. To some extent, the disappointing results can be attributed to the paucity and heterogeneity of target antigens in solid tumors since adequate antigens are the cornerstone for CAR-T cells to recognize and attack tumor cells.

Methods: We established a target-redirected universal CAR-T (TRUE CAR-T) cell therapeutic modality, in which exogenous antigens are loaded onto fusogenic nanoparticles to achieve in situ modification of cell membrane in solid tumors, providing targets for subsequent CAR-T cell therapy.

View Article and Find Full Text PDF

PD-1 signaling on T cells is the major pathway that limits T cell immunity, but the efficacy of anti-PD-1 therapy has been limited to a small proportion of patients with advanced cancers. We fortuitously observed that anti-PD-1 therapy depends on IL-2 signaling, which raises the possibility that a lack of IL-2 limits anti-PD-1-induced effector T cell expansion. To selectively deliver IL-2 to PD-1+CD8+ tumor-infiltrating lymphocytes (TILs), we engineered a low-affinity IL-2 paired with anti-PD-1 (PD-1-laIL-2), which reduced affinity to peripheral Treg cells but enhanced avidity to PD-1+CD8+ TILs.

View Article and Find Full Text PDF

Bispecific T-cell engagers (BiTEs) preferentially targeting tumour-associated antigens and stimulating CD3-mediated signalling are being used in patients to treat acute B-cell lymphoblastic leukemia. However, the potency of BiTEs in solid tumours is limited by their short half-life and their severe toxicity at relevant therapeutic doses. Here we report the design and in vivo performance of a bispecific antibody that simultaneously targets the murine T-cell co-receptor CD3ε and the murine immune checkpoint programmed-death ligand 1 (PD-L1).

View Article and Find Full Text PDF

As a potent lymphocyte activator, interleukin-2 (IL-2) is an FDA-approved treatment for multiple metastatic cancers. However, its clinical use is limited by short half-life, low potency, and severe in vivo toxicity. Current IL-2 engineering strategies exhibit evidence of peripheral cytotoxicity.

View Article and Find Full Text PDF

Stimuli-sensitive nanomaterials with cooperative response are capable of converting subtle and gradual biological variations into robust outputs to improve the precision of diagnostic or therapeutic outcomes. In this study, we report the design, synthesis and characterization of a series of degradable ultra-pH sensitive (dUPS) polymers that amplify small acidic pH changes to efficacious therapeutic outputs. A hydrolytically active polycarbonate backbone is used to construct the polymer with pH-dependent degradation kinetics.

View Article and Find Full Text PDF

Export of lactic acid from glycolytic cancer cells to the extracellular tumor milieu has been reported to enhance tumor growth and suppress antitumor immunity. In this study, a pH-activatable nanodrug is reported for tumor-targeted inhibition of monocarboxylate transporter-1 (MCT1) that reverses lactic acid-induced tumor immunosuppression. The nanodrug is composed of an MCT1 inhibitor (AZD3965) loaded inside the ultra-pH-sensitive nanoparticles (AZD-UPS NPs).

View Article and Find Full Text PDF

The lack of sufficient functional tumor-infiltrating lymphocytes in the tumor microenvironment (TME) is one of the primary indications for the poor prognosis of patients with cancer. In this study, we developed an Erbitux-based IL-21 tumor-targeting fusion protein (Erb-IL21) to prolong the half-life and improve the antitumor efficacy of IL-21. Compared with Erb-IL2, Erb-IL21 demonstrated much lower toxicity in vivo.

View Article and Find Full Text PDF

Background: Cervical cancer stem cells (CCSCs) represent a subpopulation of tumor cells that possess self-renewal capacity and numerous intrinsic mechanisms of resistance to conventional chemotherapy and radiotherapy. These cells play a crucial role in relapse and metastasis of cervical cancer. Therefore, eradication of CCSCs is the primary objective in cervical cancer therapy.

View Article and Find Full Text PDF

Objective: The use of hepatic artery infusion (HAI) as a regional therapy against liver metastasis has rarely been reported in gastric cancer. This study aimed to evaluate the efficacy and safety of HAI oxaliplatin plus oral S-1 chemotherapy in first-line palliative therapy for gastric cancer with multiple liver metastases (GCLM).

Methods: We reviewed the records of five patients with GCLM who received HAI oxaliplatin (70-80 mg/m 2 hrs d1,15) administered via a port-catheter system and S-1 with oral (35-40 mg/m twice daily for d1-14, 28 days for one cycle).

View Article and Find Full Text PDF

While IL-2 can potently activate both NK and T cells, its short in vivo half-life, severe toxicity, and propensity to amplify Treg cells are major barriers that prevent IL-2 from being widely used for cancer therapy. In this study, we construct a recombinant IL-2 immunocytokine comprising a tumor-targeting antibody (Ab) and a super mutant IL-2 (sumIL-2) with decreased CD25 binding and increased CD122 binding. The Ab-sumIL2 significantly enhances antitumor activity through tumor targeting and specific binding to cytotoxic T lymphocytes (CTLs).

View Article and Find Full Text PDF

Background: Recent genomic and bioinformatic technological advances have made it possible to dissect the immune response to personalized neoantigens encoded by tumor-specific mutations. However, timely and efficient identification of neoantigens is still one of the major obstacles to using personalized neoantigen-based cancer immunotherapy.

Methods: Two different pipelines of neoantigens identification were established in this study: (1) Clinical grade targeted sequencing was performed in patients with refractory solid tumor, and mutant peptides with high variant allele frequency and predicted high HLA-binding affinity were de novo synthesized.

View Article and Find Full Text PDF

Tumor-targeting antibodies were initially defined as a group of therapeutic monoclonal antibodies (mAb) that recognize tumor-specific membrane proteins, block cell signaling, and induce tumor-killing through Fc-driven innate immune responses. However, in the past decade, ample evidence has shown that tumor-targeting mAb (TTmAb) eradicates tumor cells via activation of cytotoxic T cells (CTLs). In this review, we specifically focus on how TTmAbs induce adaptive anti-tumor immunity and its potential in combination therapy with immune cytokines, checkpoint blockade, radiation, and enzyme-targeted small molecule drugs.

View Article and Find Full Text PDF

Though lymphotoxin (LT) is highly expressed by type I helper T (Th1) cells, its contribution to CD4 T cell differentiation during infections and diseases remains a mystery. In HSV-1 infection, we observed that LTβR signaling is required to limit the Th1 response. Using bone marrow chimeric mice, mixed-T-cell chimeric mice, and LTβR in vivo blockades, we unexpectedly observed that LT, especially T cell-derived LT, played an indispensable role in limiting the Th1 response.

View Article and Find Full Text PDF

Many patients remain unresponsive to intensive PD-1/PD-L1 blockade therapy despite the presence of tumor-infiltrating lymphocytes. We propose that impaired innate sensing might limit the complete activation of tumor-specific T cells after PD-1/PD-L1 blockade. Local delivery of type I interferons (IFNs) restores antigen presentation, but upregulates PD-L1, dampening subsequent T-cell activation.

View Article and Find Full Text PDF