Melanoma is a highly aggressive skin cancer, especially in advanced stages. While current treatments such as targeted therapies and immunotherapies have made significant progress, challenges like drug resistance and limited effectiveness in some patients persist. Therefore, ongoing development of novel therapies, particularly for late-stage melanoma, is crucial.
In this study, we explored the expression of interleukin-13 receptor subunit alpha-2 (IL13Rα2) in melanoma patient-derived xenograft models. We investigated IL13Rα2 as a potential target for melanoma treatment by employing an IL13Rα2-CD3 bispecific T-cell engager (BTE). We tested the effect of IL13Rα2-CD3 BTE on T cell activity by flow cytometry. We studied the potency of IL13Rα2-CD3 BTE in tumor killing assay in vitro. For in vivo studies, we administered DNA expression cassettes encoding IL13Rα2-CD3 BTE (IL13Rα2-CD3 DNA encoding BTE (dBTE)) into immunodeficient mice for direct in vivo expression. The mice were challenged with A375 cells and then treated with IL-13Rα2-CD3 dBTE versus control and reconstituted with human peripheral blood mononuclear cells (PBMCs) or T cells. Tumor development was monitored, and T cell infiltration in the tumor was analyzed throughflow cytometry.
Our findings revealed heterogeneous expression of IL-13Rα2, particularly in samples from advanced stages of melanoma. The IL13Rα2-CD3 BTE facilitated T-cell activation and proliferation by bridging melanoma cells and T cells. We also observed the ability of IL13Rα2-CD3 BTE to direct T cells to kill multiple melanoma patient-derived cell lines through xCELLigence assay in vitro, including those with various mutations associated with late-stage metastatic melanoma. IL13Rα2-CD3 dBTE expressed in vivo led to notable tumor regression through inducing increased T-cell infiltration and activation within the tumor microenvironment.
These promising findings underscore the potential of targeting IL13Rα2 as a relevant target for the development of biologics including dBTE aimed at treating specific subsets of melanoma.
© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.

Chimeric antigen receptor T cells (CAR T cells) with T stem (TSCM) cell-like phenotypic characteristics promote sustained antitumor effects. We performed an unbiased and automated high-throughput screen of a kinase-focused compound set to identify kinase inhibitors (KIs) that preserve human TSCM cell-like CAR T cells. We identified three KIs, UNC10225387B, UNC10225263A and UNC10112761A, that combined in vitro increased the frequency of CD45RA+CCR7+TCF1hi TSCM cell-like CAR T cells from both healthy donors and patients with cancer. KI-treated CAR T cells showed enhanced antitumor effects both in vitro and in vivo in mouse tumor models. The KI cocktail maintains TSCM cell-like phenotype preferentially in CAR T cells originating from naive T cells and causes transcriptomic changes without arresting T cell activation or modulating the chromatin organization. Specific kinases, ITK, ADCK3, MAP3K4 and CDK13, targeted by the KI cocktail in a dose-dependent manner are directly associated with the preservation of TSCM cell-like CAR T cells. Knockdown of these kinases individually or in combination enriches for TSCM cell-like CAR T cells, but only CAR T cells generated in the presence of the KI cocktail show robust expansion and differentiation on stimulation with tumor cells. Overall, transient pharmacological inhibition of strategically targeted kinases maintains stem-like features in CAR T cells and improves their antitumor activity.
© 2025. The Author(s).

CRISPR technologies have begun to revolutionize T cell therapies; however, conventional CRISPR-Cas9 genome-editing tools are limited in their safety, efficacy, and scope. To address these challenges, we developed multiplexed effector guide arrays (MEGA), a platform for programmable and scalable regulation of the T cell transcriptome using the RNA-guided, RNA-targeting activity of CRISPR-Cas13d. MEGA enables quantitative, reversible, and massively multiplexed gene knockdown in primary human T cells without targeting or cutting genomic DNA. Applying MEGA to a model of CAR T cell exhaustion, we robustly suppressed inhibitory receptor upregulation and uncovered paired regulators of T cell function through combinatorial CRISPR screening. We additionally implemented druggable regulation of MEGA to control CAR activation in a receptor-independent manner. Lastly, MEGA enabled multiplexed disruption of immunoregulatory metabolic pathways to enhance CAR T cell fitness and anti-tumor activity in vitro and in vivo. MEGA offers a versatile synthetic toolkit for applications in cancer immunotherapy and beyond.
Copyright © 2024 Elsevier Inc. All rights reserved.

Autoimmune inflammation is characterized by tissue infiltration and expansion of antigen-specific T cells. Although this inflammation is often limited to specific target tissues, it remains yet to be explored whether distinct affected sites are infiltrated with the same, persistent T cell clones. Here, we performed CyTOF analysis and T cell receptor (TCR) sequencing to study immune cell composition and (hyper-)expansion of circulating and joint-derived Tregs and non-Tregs in juvenile idiopathic arthritis (JIA). We studied different joints affected at the same time, as well as over the course of relapsing-remitting disease. We found that the composition and functional characteristics of immune infiltrates are strikingly similar between joints within one patient, and observed a strong overlap between dominant T cell clones, especially Treg, of which some could also be detected in circulation and persisted over the course of relapsing-remitting disease. Moreover, these T cell clones were characterized by a high degree of sequence similarity, indicating the presence of TCR clusters responding to the same antigens. These data suggest that in localized autoimmune disease, there is autoantigen-driven expansion of both Teffector and Treg clones that are highly persistent and are (re)circulating. These dominant clones might represent interesting therapeutic targets.
© 2023, Mijnheer, Servaas et al.

One key barrier to curative therapies for HIV is the limited understanding of HIV persistence. HIV provirus integration sites (ISs) within BACH2 are common, and almost all sites mapped to date are located upstream of the start codon in the same transcriptional orientation as the gene. These unique features suggest the possibility of insertional mutagenesis at this location. Using CRISPR/Cas9-based homology-directed repair in primary human CD4+ T cells, we directly modeled the effects of HIV integration within BACH2 Integration of the HIV long terminal repeat (LTR) and major splice donor increased BACH2 mRNA and protein levels, altered gene expression, and promoted selective outgrowth of an activated, proliferative, and T regulatory-like cell population. In contrast, introduction of the HIV-LTR alone or an HIV-LTR-major splice donor construct into STAT5B, a second common HIV IS, had no functional impact. Thus, HIV LTR-driven BACH2 expression modulates T cell programming and leads to cellular outgrowth and unique phenotypic changes, findings that support a direct role for IS-dependent HIV-1 persistence.
Copyright © 2022 by The American Association of Immunologists, Inc.