Adoptive Immunotherapy For Leukemia With Ex vivo Expanded T Cells

Genome Engineering as a Therapeutic Approach in Cancer Therapy: A Comprehensive Review

Cancer is one of the foremost causes of mortality. The human genome remains stable over time. However, human activities and environmental factors have the power to influence the prevalence of certain types of mutations. This goes to the excessive progress of xenobiotics and industrial development that is expanding the territory for cancers to develop. The mechanisms involved in immune responses against cancer are widely studied. Genome editing has changed the genome-based immunotherapy process in the human body and has opened a new era for cancer treatment. In this review, recent cancer immunotherapies and the use of genome engineering technology are largely focused on.

The role of NFAT2/miR-20a-5p signaling pathway in the regulation of CD8+ naïve T cells activation and differentiation

T cell dysfunction is a common characteristic in leukemia patients that significantly impacts clinical treatment and prognosis. However, the mechanism underlying T cell dysfunction and its reversal remains unclear. In this study, in accordance with our previous findings, we found that the expression of NFAT2 and pri-miR-17 ~ 92 are lower in peripheral blood CD3⁺ T cells from chronic myelogenous leukemia (CML) patients by gene expression analysis. We further demonstrate that the NFAT2-induced activation, differentiation, and expression of cytokines in human umbilical cord blood CD8⁺ naïve T cells are miR-20a-5p dependent. We also preliminarily explored the relationship between NFAT2 and miR-20a-5p in naive T cells. These results suggest that NFAT2 and miR-20a are crucial for regulating functional CD8⁺ T cells. Additionally, their alteration may be related to CD8⁺ T cell dysfunction in CML patients; thus, NFAT2 and miR-20a-5p may be considered potential targets for revising T cell function in leukemia immunotherapy.

Neoantigen: A New Breakthrough in Tumor Immunotherapy

Cancer immunotherapy works by stimulating and strengthening the body’s anti-tumor immune response to eliminate cancer cells. Over the past few decades, immunotherapy has shown remarkable efficacy in the treatment of cancer, particularly the success of immune checkpoint blockade targeting CTLA-4, PD-1 and PDL1, which has led to a breakthrough in tumor immunotherapy. Tumor neoantigens, a new approach to tumor immunotherapy, include antigens produced by tumor viruses integrated into the genome and antigens produced by mutant proteins, which are abundantly expressed only in tumor cells and have strong immunogenicity and tumor heterogeneity. A growing number of studies have highlighted the relationship between neoantigens and T cells’ recognition of cancer cells. Vaccines developed against neoantigens are now being used in clinical trials in various solid tumors. In this review, we summarized the latest advances in the classification of immunotherapy and the process of classification, identification and synthesis of tumor-specific neoantigens, as well as their role in current cancer immunotherapy. Finally, the application prospects and existing problems of neoantigens were discussed.

T cells targeting multiple tumor-associated antigens as a postremission treatment to prevent or delay relapse in acute myeloid leukemia

Background

Relapse is a major problem in acute myeloid leukemia (AML) and adversely affects survival. Tumor-associated antigen-specific cytotoxic T lymphocyte (TAA-CTLs)-based therapy was introduced and increasingly used clinically to kill tumor cells via tumor antigen activation.

Method

In this study, we expanded autologous lymphocytes reactive to five TAA (NY-ESO-1, MAGE-A3, WT1, Survivin, and PRAME) and evaluated its safety and efficacy in 9 patients with AML at high risk of relapse.

Results

Before first TAA-CTL infusion, 5 patients were minimal residual disease (MRD) positive, whereas 4 were MRD negative. Patients received TAA-CTL infusion for 1–3 times. None of them had obvious adverse reactions during or post the infusion. Of the 4 MRD-negative patients who were infused with TAA-CTLs, one developed relapsed disease. Among 5 MRD+ patients, there was a demonstrable antileukemic effect of the TAA-CTLs alone without any concomitant chemotherapy in 2 patients, as demonstrated by the negative of MRD in bone marrow after TAA-CTL infusion.

Conclusions

In summary, we have observed preliminary indications of activity and safety after administration of autologous TAA-CTLs in patients with AML. The ultimate question of clinical efficacy, however, will need to be addressed in a larger trial with larger homogeneous patient population.