Pan-cancer analysis: predictive role of TAP1 in cancer prognosis and response to immunotherapy.

BACKGROUND: Transporter associated with antigen processing 1 (TAP1) is a molecule involved in processing and presentation of major histocompatibility complex class I restricted antigens, including tumor-associated antigens. TAP1 participates in tumor immunity, and is aberrantly expressed in multiple cancer types; METHODS: Transcriptome profiles were obtained from The Cancer Genome Atlas and Genotype-Tissue Expression databases. Genetic alterations, protein distribution, and interaction information for TAP1 were downloaded from cBioPortal, Human Protein Atlas and Compartmentalized Protein-Protein Interaction, respectively. Single-cell analyses of TAP1 across cancers were conducted via the Tumor Immune Single-cell Hub website. Gene set enrichment analysis was employed to investigate TAP1-associated functional mechanisms and processes. Immune cell infiltration was explored using Tumor Immune Estimation Resource 2.0. Pan-cancer correlations between TAP1 expression and immunotherapy biomarkers were explored using the Spearman's correlation test. Associations with immunotherapy responses were also investigated using clinicopathological and prognostic information from cohorts of patients with cancer receiving immune checkpoint inhibitors. RESULTS: TAP1 expression was elevated in most cancer types and exhibited distinct prognostic value. Immune cells expressed more TAP1 than malignant cells within most tumors. TAP1 expression was significantly correlated with immune-related pathways, T-lymphocyte infiltration, and immunotherapeutic biomarkers. Clinical cohort validation revealed a significant correlation with immune therapeutic effects and verified the prognostic role of TAP1 in immunotherapy. Western blot assay indicated that TAP1 is upregulated in glioblastoma compared with adjacent normal brain tissues. CONCLUSION: TAP1 is a robust tumor prognostic biomarker and a novel predictor of clinical prognosis and immunotherapeutic responses in various cancer types.

Emerging Immunotherapy for Acute Myeloid Leukemia.

Several immune checkpoint molecules and immune targets in leukemic cells have been investigated. Recent studies have suggested the potential clinical benefits of immuno-oncology (IO) therapy against acute myeloid leukemia (AML), especially targeting CD33, CD123, and CLL-1, as well as immune checkpoint inhibitors (e.g., anti-PD (programmed cell death)-1 and anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) antibodies) with or without conventional chemotherapy. Early-phase clinical trials of chimeric antigen receptor (CAR)-T or natural killer (NK) cells for relapsed/refractory AML showed complete remission (CR) or marked reduction of marrow blasts in a few enrolled patients. Bi-/tri-specific antibodies (e.g., bispecific T-cell engager (BiTE) and dual-affinity retargeting (DART)) exhibited 11-67% CR rates with 13-78% risk of cytokine-releasing syndrome (CRS). Conventional chemotherapy in combination with anti-PD-1/anti-CTLA4 antibody for relapsed/refractory AML showed 10-36% CR rates with 7-24 month-long median survival. The current advantages of IO therapy in the field of AML are summarized herein. However, although cancer vaccination should be included in the concept of IO therapy, it is not mentioned in this review because of the paucity of relevant evidence.

Light-enhanced VEGF121/rGel induce immunogenic cell death and increase the antitumor activity of αCTLA4 treatment.

Background: Immune-checkpoint inhibitors (ICIs) represent a revolution in cancer therapy and are currently implemented as standard therapy within several cancer indications. Nevertheless, the treatment is only effective in a subset of patients, and immune-related adverse effects complicate the improved survival. Adjuvant treatments that can improve the efficacy of ICIs are highly warranted, not only to increase the response rate, but also to reduce the therapeutic ICI dosage. Several treatment modalities have been suggested as ICI adjuvants including vascular targeted treatments and photodynamic therapy (PDT). Photochemical internalization (PCI) is a drug delivery system, based on PDT. PCI is long known to generate an immune response in murine models and was recently shown to enhance the cellular immune response of a vaccine in a clinical study. In the present work we evaluated PCI in combination with the vascular targeting toxin VEGF121/rGel with respect to induction of immune-mediated cell death as well as in vitro ICI enhancement. Methods: DAMP signaling post VEGF121/rGel-PCI was assessed in CT26 and MC38 murine colon cancer cell lines. Hypericin-PDT, previously indicated as an highly efficient DAMP inducer (but difficult to utilize clinically), was used as a control. ATP release was detected by a bioluminescent kit while HMGB1 and HSP90 relocalization and secretion was detected by fluorescence microscopy and western blotting. VEGF121/rGel-PCI was further investigated as an αCTLA enhancer in CT26 and MC38 tumors by measurement of tumor growth delay. CD8+ Dependent efficacy was evaluated in vivo using a CD8+ antibody. Results: VEGF121/rGel-PCI was shown to induce increased DAMP signaling as compared to PDT and VEGF121/rGel alone and the magnitude was found similar to that induced by Hypericin-PDT. Furthermore, a significant CD8+ dependent enhanced αCTLA-4 treatment effect was observed when VEGF121/rGel-PCI was used as an adjuvant in both tumor models. Conclusions: VEGF121/rGel-PCI describes a novel concept for ICI enhancement which induces a rapid CD8+ dependent tumor eradication in both CT26 and MC38 tumors. The concept is based on the combination of intracellular ROS generation and vascular targeting using a plant derived toxin and will be developed towards clinical utilization.

Corrigendum: Light-enhanced VEGF121/rGel induce immunogenic cell death and increase the antitumor activity of αCTLA4 treatment.

[This corrects the article DOI: 10.3389/fimmu.2023.1278000.].

Direct and Indirect Modulation of T Cells by VEGF-A Counteracted by Anti-Angiogenic Treatment.

Vascular endothelial growth factor A is known to play a central role in tumor angiogenesis. Several studies showed that VEGF-A is also an immunosuppressive factor. In tumor-bearing hosts, VEGF-A can modulate immune cells (DC, MDSC, TAM) to induce the accumulation of regulatory T-cells while simultaneously inhibiting T-cell functions. Furthermore, VEGFR-2 expression on activated T-cells and FoxP3high regulatory T-cells also allow a direct effect of VEGF-A. Anti-angiogenic agents targeting VEGF-A/VEGFR contribute to limit tumor-induced immunosuppression. Based on interesting preclinical studies, many clinical trials have been conducted to investigate the efficacy of anti-VEGF-A/VEGFR treatments combined with immune checkpoint blockade leading to the approvement of these associations in different tumor locations. In this review, we focus on the impact of VEGF-A on immune cells especially regulatory and effector T-cells and different therapeutic strategies to restore an antitumor immunity.