Patients who receive chimeric antigen receptor (CAR)–T cells that are enriched in memory T cells exhibit better disease control as a result of increased expansion and persistence of the CAR-T cells. Human memory T cells include stem-like CD8 ⁺ memory T cell progenitors that can become either functional stem-like T (T _STEM ) cells or dysfunctional T progenitor exhausted (T _PEX ) cells. To that end, we demonstrated that T _STEM cells were less abundant in infused CAR-T cell products in a phase 1 clinical trial testing Lewis Y-CAR-T cells (NCT03851146), and the infused CAR-T cells displayed poor persistence in patients. To address this issue, we developed a production protocol to generate T _STEM -like CAR-T cells enriched for expression of genes in cell replication pathways. Compared with conventional CAR-T cells, T _STEM -like CAR-T cells had enhanced proliferative capacity and increased cytokine secretion after CAR stimulation, including after chronic CAR stimulation in vitro. These responses were dependent on the presence of CD4 ⁺ T cells during T _STEM -like CAR-T cell production. Adoptive transfer of T _STEM -like CAR-T cells induced better control of established tumors and resistance to tumor rechallenge in preclinical models. These more favorable outcomes were associated with increased persistence of T _STEM -like CAR-T cells and an increased memory T cell pool. Last, T _STEM -like CAR-T cells and anti–programmed cell death protein 1 (PD-1) treatment eradicated established tumors, and this was associated with increased tumor-infiltrating CD8 ⁺ CAR ⁺ T cells producing interferon-γ. In conclusion, our CAR-T cell protocol generated T _STEM -like CAR-T cells with enhanced therapeutic efficacy, resulting in increased proliferative capacity and persistence in vivo.

Chimeric antigen receptors (CAR) are genetically engineered receptors that can recognise specific antigens and subsequently activate downstream signalling. Human T cells engineered to express a CAR, also known as CAR-T cells, can target a specific tumour antigen on the cell surface to mediate a cytotoxic response against the tumour. CAR-T cell therapy has achieved remarkable success in treating hematologic malignancies, but not in solid tumours. Currently, extensive research is being carried out to make CAR-T cells a therapy for solid tumours. To date, most of the research interest in the field has focused on cytotoxic T lymphocytes as the carrier of CAR products. However, in addition to T cells, the CAR design can be introduced in other immune cells, such as natural killer (NK)/NKT cells, γδ T cells, mucosal-associated invariant T (MAIT) cells, dendritic cells (DC), macrophages, regulatory T cells (Treg), B cells, etc. Some of the CAR-engineered immune cells, such as CAR- γδ T and CAR-NK/NK-T cells, are directly involved in the anti-tumour response, demonstrated in preclinical studies and/or clinical trials. CAR-Tregs showed promising therapeutic potential in treating autoimmune diseases. In particular, B cells engineered with chimeric receptors can be used as a platform for long-term delivery of therapeutic proteins, such as recombinant antibodies or protein replacement, in an antigen-specific manner. CAR technology is one of the most powerful engineering platforms in immunotherapy, especially for the treatment of cancers. In this review, we will discuss the recent application of the CAR design in non-CAR-T cells and future opportunities in immunotherapy.

Immunomodulatory drugs (IMiDs) are effective treatments for patients with multiple myeloma. IMiDs have pleotropic effects including targeting the myeloma cells directly, and improving the anti-myeloma immune response. In the absence of myeloma cells, lenalidomide and pomalidomide induce CD4⁺T cell secretion of IL-2 and indirect activation of Natural Killer (NK) cells. In the context of T cell receptor ligation, IMiDs enhance T cell proliferation, cytokine release and Th1 responses, bothin vivoandin vitro. Furthermore, combination treatment of IMiDs and myeloma-targeting monoclonal antibodies eg. daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7), checkpoint inhibitors, or bispecific T cell engagers showed synergistic effects, mainly via enhanced T and NK cell dependent cellular toxicity and T cell proliferation. Conversely, the corticosteroid dexamethasone can impair the immune modulatory effects of IMiDs, indicating that careful choice of myeloma drugs in combination with IMiDs is key for the best anti-myeloma therapeutic efficacy. This review presents an overview of the role for T cells in the overall anti-myeloma effects of immunomodulatory drugs.

Despite recent progress in lymphoma immunotherapy, outcomes for patients with peripheral T cell lymphomas (PTCLs) remain poor. The challenge of PTCLs reflects the profound biological heterogeneity and relative rarity of this disease group and its resistance to conventional chemotherapy, as well as the formidable challenge of generating definitive clinical evidence. However, deepening insight into the immunogenomic and microenvironmental basis of PTCL has revealed diverse mechanisms of immune escape, spanning defects in antigen presentation, apoptotic signaling, adhesion, and extensive tumor microenvironmental remodeling. These vulnerabilities provide a sound rationale for novel immunotherapeutic strategies—checkpoint inhibitors, CAR-T and NK cell platforms, bispecific antibodies, oncolytic viruses, and immunomodulatory agents. Early studies show encouraging but inconsistent activity, and the variability in response highlights the urgent need for biomarker-driven stratification to deliver personalized approaches and clinically meaningful efficacy. This review synthesizes the current literature on the immune dysregulation of PTCLs, as well as advances in PTCL immunotherapy, outlining the biological rationale underpinning these approaches. We discuss approaches to molecular, transcriptomic, and microenvironmental profiling with circulating biomarkers that could enable adaptive trial designs and personalized treatment strategies. Together, these developments chart a path away from empiricism and toward precision therapy in PTCLs.

Biomarkers that predict response to combined radiation and anti-PD-1 therapy in clear cell renal cell carcinoma (ccRCC) are poorly defined. RAPPORT trial (NCT02855203) is a prospective phase I/II study of stereotactic ablative body radiotherapy (SABR) and pembrolizumab in 30 patients with oligometastatic ccRCC. The primary endpoint was safety; secondary endpoints included overall survival, time to local progression, distant progression-free survival, objective and disease control rates, duration of response and patient-reported pain. Here, we report the pre-specified exploratory translational analyses. In pre-treatment tumours, responders had greater intra-tumoural cytotoxic T cell infiltration in close proximity to tumour cells, whereas non-responders showed enrichment of immunosuppressive, TGF-β and angiogenic signatures. In peripheral blood post-treatment, responders developed a proliferative burst of activated CD8⁺ T cells and sustained sharing of pre-existing tumour-enriched TCR clones. These findings identify trafficking and maintenance of pre-existing tumour-enriched T cell clones as determinants of response to SABR plus anti-PD-1 in ccRCC.