This special feature contains three review articles that summarize recent advances pertaining to tumor immunobiology. Normalization of antitumor immunity through checkpoint inhibitors has achieved significant clinical success and benefited many cancer patients. However, not all cancer patients respond to these treatments, and among the responders, some may develop resistance and others may suffer autoimmunity that requires intervention. Tumor immunotherapy holds promise for further improving the survival of cancer patients, but deeper understanding of immunological networks that regulate anti- and pro-tumor immunity is needed. The review papers collected in this issue cover a few topics that may stimulate future interest in the relevant research field.
Humans ; Immunotherapy, Adoptive/methods* ; Lymphatic Vessels/physiology* ; MicroRNAs/physiology* ; Neoplasms/therapy* ; Receptors, Chimeric Antigen/immunology* ; T-Lymphocytes/immunology*

This phase I clinical trial (NCT01935843) is to evaluate the safety, feasibility, and activity of chimeric antigen receptor-engineered T cell (CART) immunotherapy targeting human epidermal growth factor receptor 2 (HER2) in patients with advanced biliary tract cancers (BTCs) and pancreatic cancers (PCs). Eligible patients with HER2-positive (>50%) BTCs and PCs were enrolled in the trial. Well cultured CART-HER2 cells were infused following the conditioning treatment composed of nab-paclitaxel (100-200 mg/m) and cyclophosphamide (15-35 mg/kg). CAR transgene copy number in the peripheral blood was serially measured to monitor the expansion and persistence of CART-HER2 cells in vivo. Eleven enrolled patients received 1 to 2-cycle CART-HER2 cell infusion (median CAR T cell 2.1 × 10/kg). The conditioning treatment resulted in mild-to-moderate fatigue, nausea/vomiting, myalgia/arthralgia, and lymphopenia. Except one grade-3 acute febrile syndrome and one abnormal elevation of transaminase (>9 ULN), adverse events related to the infusion of CART-HER2 cells were mild-to-moderate. Post-infusion toxicities included one case of reversible severe upper gastrointestinal hemorrhage which occurred in a patient with gastric antrum invaded by metastasis 11 days after the CART-HER2 cell infusion, and 2 cases of grade 1-2 delayed fever, accompanied by the release of C-reactive protein and interleukin-6. All patients were evaluable for assessment of clinical response, among which 1 obtained a 4.5-months partial response and 5 achieved stable disease. The median progression free survival was 4.8 months (range, 1.5-8.3 months). Finally, data from this study demonstrated the safety and feasibility of CART-HER2 immunotherapy, and showed encouraging signals of clinical activity.
Aged ; Biliary Tract Neoplasms ; immunology ; therapy ; Female ; Humans ; Immunotherapy, Adoptive ; Male ; Middle Aged ; Pancreatic Neoplasms ; immunology ; therapy ; Receptor, ErbB-2 ; immunology ; Receptors, Chimeric Antigen ; immunology ; T-Lymphocytes ; immunology

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.
ADP-ribosyl Cyclase 1/immunology* ; B-Cell Maturation Antigen/immunology* ; Humans ; Immunotherapy, Adoptive/methods* ; Multiple Myeloma/therapy* ; Receptors, Chimeric Antigen/immunology* ; Receptors, G-Protein-Coupled/immunology* ; Signaling Lymphocytic Activation Molecule Family/immunology* ; Syndecan-1/immunology* ; T-Lymphocytes/immunology*

Cancer stem cells (CSCs), a subpopulation of tumor cells, have self-renewal and multi-lineage differentiation abilities that play an important role in cancer initiation, maintenance, and metastasis. An accumulation of evidence indicates that CSCs can cause conventional therapy failure and cancer recurrence because of their treatment resistance and self-regeneration characteristics. Therefore, approaches that specifically and efficiently eliminate CSCs to achieve a durable clinical response are urgently needed. Currently, treatments with chimeric antigen receptor-modified T (CART) cells have shown successful clinical outcomes in patients with hematologic malignancies, and their safety and feasibility in solid tumors was confirmed. In this review, we will discuss in detail the possibility that CART cells inhibit CSCs by specifically targeting their cell surface markers, which will ultimately improve the clinical response for patients with various types of cancer. A number of viewpoints were summarized to promote the application of CSC-targeted CART cells in clinical cancer treatment. This review covers the key aspects of CSC-targeted CART cells against cancers in accordance with the premise of the model, from bench to bedside and back to bench.
Humans ; Molecular Targeted Therapy ; methods ; Neoplasms ; immunology ; pathology ; therapy ; Neoplastic Stem Cells ; pathology ; Receptors, Chimeric Antigen ; metabolism ; T-Lymphocytes ; immunology ; metabolism ; Translational Medical Research

Lung cancer is the most common incident cancer and the leading cause of cancer death. In recent years, the development of tumor immunotherapy especially chimeric antigen receptor T (CAR-T) cell has shown a promising future. Epidermal growth factor receptor variant III (EGFRvIII) is a tumor-specific mutation expressed in various types of tumors and has been detected in non-small cell lung cancer with a mutation rate of 10%. Thus, EGFRvIII is a potential antigen for targeted lung cancer therapy. In this study, CAR vectors were constructed and transfected into virus-packaging cells. Then, activated T cells were infected with retrovirus harvested from stable virus-producing single clone cell lines. CAR expression on the surfaces of the T cells was detected by flow cytometry and Western blot. The function of CAR-T targeting EGFRvIII was then evaluated. The EGFRvIII-CAR vector was successfully constructed and confirmed by DNA sequencing. A stable virus-producing cell line was produced from a single clone by limited dilution. The culture conditions for the cell line, including cell density, temperature, and culture medium were optimized. After infection with retrovirus, CAR was expressed on more than 90% of the T cells. The proliferation of CAR-T cells were induced by cytokine and specific antigen in vitro. More importantly, EGFRvIII-CART specifically and efficiently recognized and killed A549-EGFRvIII cells with an effector/target ratio of 10:1 by expressing and releasing cytokines, including perforin, granzyme B, IFN-γ, and TNF-α. The in vivo study indicated that the metastasis of A549-EGFRvIII cells in mice were inhibited by EGFRvIII-CART cells, and the survival of the mice was significantly prolonged with no serious side effects. EGFRvIII-CART showed significantly efficient antitumor activity against lung cancer cells expressing EGFRvIII in vivo and in vitro. Therefore, CAR-T targeting EGFRvIII is a potential therapeutic strategy in preventing recurrence and metastasis of lung cancer after surgery.
Animals ; Carcinoma, Non-Small-Cell Lung ; immunology ; therapy ; Cell Line, Tumor ; ErbB Receptors ; immunology ; metabolism ; Female ; Humans ; Immunotherapy, Adoptive ; methods ; Lung Neoplasms ; immunology ; therapy ; Mice ; Mice, Inbred NOD ; Receptors, Chimeric Antigen ; immunology ; T-Lymphocytes ; immunology ; Xenograft Model Antitumor Assays

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. This malignancy is associated with poor prognosis and high mortality. Novel approaches for prolonging the overall survival of patients with advanced HCC are urgently needed. The antitumor activities of adoptive cell transfer therapy (ACT), such as strategies based on tumor-infiltrating lymphocytes and cytokine-induced killer cells, are more effective than those of traditional strategies. Currently, chimeric antigen receptor T-cell (CAR-T) immunotherapy has achieved numerous breakthroughs in the treatment of hematological malignancies, including relapsed or refractory lymphoblastic leukemia and refractory large B-cell lymphoma. Nevertheless, this approach only provides a modest benefit in the treatment of solid tumors. The clinical results of CAR-T immunotherapy for HCC that could be obtained at present are limited. Some published studies have demonstrated that CAR-T could inhibit tumor growth and cause severe side effects. In this review, we summarized the current application of ACT, the challenges encountered by CAR-T technology in HCC treatment, and some possible strategies for the future direction of immunotherapeutic research.
Adoptive Transfer ; methods ; Carcinoma, Hepatocellular ; immunology ; therapy ; Humans ; Immunotherapy, Adoptive ; methods ; Liver Neoplasms ; immunology ; therapy ; Lymphocytes, Tumor-Infiltrating ; cytology ; Randomized Controlled Trials as Topic ; Receptors, Chimeric Antigen ; T-Lymphocytes ; cytology

The activation mechanism of chimeric antigen receptor (CAR)-engineered T cells may differ substantially from T cells carrying native T cell receptor, but this difference remains poorly understood. We present the first comprehensive portrait of single-cell level transcriptional and cytokine signatures of anti-CD19/4-1BB/CD28/CD3ζ CAR-T cells upon antigen-specific stimulation. Both CD4 helper T (T) cells and CD8 cytotoxic CAR-T cells are equally effective in directly killing target tumor cells and their cytotoxic activity is associated with the elevation of a range of T1 and T2 signature cytokines, e.g., interferon γ, tumor necrotic factor α, interleukin 5 (IL5), and IL13, as confirmed by the expression of master transcription factor genes TBX21 and GATA3. However, rather than conforming to stringent T1 or T2 subtypes, single-cell analysis reveals that the predominant response is a highly mixed T1/T2 function in the same cell. The regulatory T cell activity, although observed in a small fraction of activated cells, emerges from this hybrid T1/T2 population. Granulocyte-macrophage colony stimulating factor (GM-CSF) is produced from the majority of cells regardless of the polarization states, further contrasting CAR-T to classic T cells. Surprisingly, the cytokine response is minimally associated with differentiation status, although all major differentiation subsets such as naïve, central memory, effector memory, and effector are detected. All these suggest that the activation of CAR-engineered T cells is a canonical process that leads to a highly mixed response combining both type 1 and type 2 cytokines together with GM-CSF, supporting the notion that polyfunctional CAR-T cells correlate with objective response of patients in clinical trials. This work provides new insights into the mechanism of CAR activation and implies the necessity for cellular function assays to characterize the quality of CAR-T infusion products and monitor therapeutic responses in patients.
Antigens ; metabolism ; CTLA-4 Antigen ; metabolism ; Cell Differentiation ; drug effects ; Cell Line ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; drug effects ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Lymphocyte Activation ; drug effects ; immunology ; Lymphocyte Subsets ; drug effects ; metabolism ; Phenotype ; Proteomics ; Receptors, Chimeric Antigen ; metabolism ; Single-Cell Analysis ; methods ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1 Cells ; cytology ; drug effects ; Th2 Cells ; cytology ; drug effects ; Transcription, Genetic ; drug effects ; Up-Regulation ; drug effects