Next-generation sequencing technologies accelerate advances in T-cell therapy for cancer

Antigen loss following CAR-T cell therapy: Mechanisms, implications, and potential solutions

Chimeric Antigen Receptor T-cell (CAR-T cell) therapy has emerged as a groundbreaking immunotherapeutic approach for treating various hematological malignancies. CAR-T cells are engineered to express synthetic receptors that target specific antigens on cancer cells, leading to their eradication. While the therapy has shown remarkable efficacy, a significant challenge that has been observed in 30%-70% of patients showing recurrent disease is antigen loss or downregulation. We searched PubMed/MEDLINE, EMBASE, and Google scholar for articles on antigen loss/escape following Chimeric antigen receptor T-cell therapy in malignancies. Antigen loss refers to the loss or reduction in the expression of the target antigen on cancer cells, rendering CAR-T cells ineffective. This phenomenon poses a significant clinical concern, as it can lead to disease relapse and limited treatment options. This review explores the mechanisms underlying antigen loss following CAR-T cell therapy, its implications on treatment outcomes, and potential strategies to overcome the problem.

Design of Personalized Neoantigen RNA Vaccines Against Cancer Based on Next-Generation Sequencing Data

The good clinical results of immune checkpoint inhibitors (ICIs) in recent cancer therapy and the success of RNA vaccines against SARS-nCoV2 have provided important lessons to the scientific community. On the one hand, the efficacy of ICI depends on the number and immunogenicity of tumor neoantigens (TNAs) which unfortunately are not abundantly expressed in many cancer subtypes. On the other hand, novel RNA vaccines have significantly improved both the stability and immunogenicity of mRNA and its efficient delivery, this way overcoming past technique limitations and also allowing a quick vaccine development at the same time. These two facts together have triggered a resurgence of therapeutic cancer vaccines which can be designed to include individual TNAs and be synthesized in a timeframe short enough to be suitable for the tailored treatment of a given cancer patient.In this chapter, we explain the pipeline for the synthesis of TNA-carrying RNA vaccines which encompasses several steps such as individual tumor next-generation sequencing (NGS), selection of immunogenic TNAs, nucleic acid synthesis, drug delivery systems, and immunogenicity assessment, all of each step comprising different alternatives and variations which will be discussed.

Anti-tumour effect of neo-antigen-reactive T cells induced by RNA mutanome vaccine in mouse lung cancer

PURPOSE

Mutation-specific T-cell response to epithelial cancers and T-cell-based immunotherapy has been successfully used to treat several human solid cancers. We aimed to investigate the anti-tumour effect of neo-antigen-reactive T(NRT) cells induced by RNA mutanome vaccine, which may serve as a feasible and effective therapeutic approach for lung cancer.

METHODS

We predicted candidate neo-antigens according to the mutant gene analysis by sequencing the mouse Lewis cells and C57BL/6 mouse tail tissue. RNA vaccine was prepared with the neo-antigens as the template. We assessed antitumor efficacy, cytokine secretion and pathological changes after adoptive transfer of NRT cells in vitro and vivo experiments.

RESULTS

We identified 10 non-synonymous somatic mutations and successfully generated NRT cells. The percentage of T-cell activation proportion was increased from 0.072% in conventional T cells to 9.96% in NRT cells. Interferon-γ secretion augmented from 17.8 to 24.2% as well. As an in vivo model, adoptive NRT cell infusion could promote active T-cell infiltration into the tumour tissue and could delay tumour progression.

CONCLUSION

NRT cells induced by RNA mutanome vaccine exert a significant anti-tumour effect in mouse lung cancer, and adoptive NRT cell therapy might be considered a feasible, effective therapeutic approach for lung cancer.