The central question driving the research is one of the most pressing in modern tumor immunology: why do immune responses against cancer so often fade before the disease is eliminated? Durable cancer control depends not merely on generating a large army of cytotoxic CD8⁺ T cells at the moment of treatment, but on producing memory-like cells capable of persisting, self-renewing, and re-launching attacks months or years later. Central memory CD8⁺ T cells—identifiable by their co-expression of the surface markers CD62L and CD44—are the cellular custodians of long-term immunity. Yet the tumor microenvironment, a hostile mixture of metabolic depletion, suppressive cytokines, and dysfunctional antigen-presenting cells, systematically blocks the formation of these cells, leaving patients with short-lived effector responses that collapse under the relentless pressure of tumor regrowth.

Dendritic cells sit at the heart of this problem. As the body’s professional antigen-presenting cells, they are the teachers of the adaptive immune system: they capture tumor antigens, process them into peptide fragments, and present them to naive T cells in lymph nodes, effectively deciding whether those T cells become short-lived killers or long-lived memory guardians. Previous work had already implicated SHP1—short for Src homology region 2 domain-containing phosphatase 1—in fostering an immunosuppressive dendritic cell state that facilitates tumor immune escape. Earlier studies, including research showing that vitamin E can reinvigorate dendritic cells by targeting SHP1, had established the phosphatase as a kind of checkpoint molecule within these cells. What remained unknown was whether SHP1 exerted control over TCF-1, the transcription factor encoded by the Tcf7 gene that is widely regarded as indispensable for central memory CD8⁺ T cell formation and that operates in intimate conversation with canonical Wnt/β-catenin signaling.

To dissect this relationship, the research team—led by Bing Li, Huilin Lu, and Jiayi Huang of Guangzhou Medical University, with corresponding authors Ting Lei, Xiaoming Tan, and Yuan Zhang—constructed an elegant experimental system combining in vitro co-culture and in vivo genetics. They generated SHP1-deficient DC2.4 dendritic cell lines and primary bone marrow-derived dendritic cells, then co-cultured these modified cells with OT-1 T cells, a widely used laboratory T cell lineage whose T cell receptors specifically recognize ovalbumin peptide presented on MHC class I molecules. This reductionist platform allowed the researchers to precisely measure T cell proliferation, central memory differentiation, cytotoxic killing capacity, and TCF-1 expression under controlled conditions where the only variable was the presence or absence of SHP1 in the dendritic cells.

The results were striking. When SHP1 was downregulated in dendritic cells, the co-cultured CD8⁺ T cells proliferated far more vigorously, generated dramatically increased populations of CD62L⁺ CD44⁺ central memory cells, and killed B16-F10-OVA melanoma cells with markedly enhanced efficiency. All of these changes were accompanied by elevated TCF-1 expression within the T cells, suggesting that the dendritic cell phosphatase was exerting its influence through this master regulator of memory fate. To confirm that the phenomenon was not merely a petri-dish artifact, the team turned to a mouse model in which SHP1 was selectively deleted in dendritic cells—so-called SHP1 conditional knockout mice. When these animals were challenged with EO771 breast tumors, tumor growth was significantly suppressed compared with controls, and analysis of the tumor microenvironment revealed increased frequencies of both IFN-γ-producing CD8⁺ T cells—the hallmark of active cytotoxic engagement—and TCF-1⁺ CD8⁺ T cells, the memory-precursor pool from which durable antitumor responses are sustained.

The mechanistic heart of the paper lies in its dissection of the TCF-1/Wnt/β-catenin axis. TCF-1 is not an isolated actor; it functions as the nuclear endpoint of the canonical Wnt signaling cascade, a pathway in which Wnt ligands stabilize β-catenin, allowing the protein to translocate to the nucleus and partner with TCF/LEF family transcription factors to activate memory-associated gene programs. In resting cells, glycogen synthase kinase-3 phosphorylates β-catenin, tagging it for proteasomal destruction; Wnt activation halts this phosphorylation, causing both active and total β-catenin to accumulate. The researchers found that when T cells were cultured with SHP1-deficient dendritic cells, they exhibited increased levels of active β-catenin, total β-catenin, and the downstream Wnt target genes c-Myc and Cyclin D1—the latter two driving the proliferative burst characteristic of expanding memory precursors. Concurrently, the ratio of phosphorylated β-catenin to total β-catenin dropped, the molecular signature of pathway activation.

Crucially, the team performed the loss-of-function experiments needed to prove causation rather than mere correlation. When Tcf7 was silenced in the OT-1 T cells, the ability of SHP1-deficient dendritic cells to promote central memory formation was completely abrogated, establishing TCF-1 as the non-negotiable mediator of the effect. The investigators then went one step further and silenced Ctnnb1, the gene encoding β-catenin itself, in T cells. This maneuver eliminated not only the enhanced proliferation and memory generation but also the improved cytotoxic activity that SHP1-deficient dendritic cells had otherwise conferred. In other words, the entire phenomenon—proliferation, memory differentiation, and tumor-killing potency—flows through a single linear signaling route: dendritic cell SHP1 restrains TCF-1 expression and Wnt/β-catenin activation in CD8⁺ T cells, and removing SHP1 releases the pathway to drive memory formation.

The therapeutic implications are considerable. Checkpoint blockade immunotherapies such as anti-PD-1 antibodies have transformed the treatment landscape for melanoma, lung cancer, and other malignancies, but a large fraction of patients either fail to respond or relapse, in large part because their tumors lack the stem-like, TCF-1⁺ T cell populations that sustain long-term immune pressure. A growing body of literature links TCF-1⁺ CD8⁺ T cell abundance to favorable prognosis and immunotherapy response across cancer types, from microsatellite-unstable gastric cancer to lung cancer and melanoma. The new findings suggest that dendritic cell SHP1 represents an upstream, druggable node controlling whether those critical stem-like populations are generated in the first place. If pharmacological inhibition of SHP1 in dendritic cells—or strategies that mimic its absence—can be developed safely, it could convert “cold,” T cell–excluded tumors into immunologically active ones while simultaneously endowing patients with the memory reservoir needed to prevent recurrence.

There are also intriguing resonances with prior nutritional and metabolic research. A 2022 study in Cancer Discovery demonstrated that vitamin E enhances cancer immunotherapy by reinvigorating dendritic cells through targeting SHP1, hinting that the phosphatase may be modulated by lipid-soluble dietary factors. The new work provides a mechanistic explanation for how such interventions might work: by lifting SHP1’s restraint on the TCF-1/Wnt/β-catenin axis, nutrient-derived signals could indirectly promote the formation of the central memory T cells that anchor durable immune surveillance. This places SHP1 at the intersection of metabolism, dendritic cell biology, and T cell fate specification—a convergence point that immunologists are increasingly viewing as fertile ground for next-generation therapeutics.

The authors are careful to frame the work as preclinical. The experiments relied on murine models—the OT-1 transfer system, B16-F10-OVA melanoma, and EO771 mammary carcinoma—and human validation remains an essential next step. Dendritic cells are a heterogeneous family, encompassing cross-presenting cDC1 subsets, inflammatory monocyte-derived populations, and tolerogenic plasmacytoid variants, and it is not yet clear whether SHP1’s memory-suppressive function is uniform across all of these lineages or confined to particular subsets. Moreover, because Wnt/β-catenin signaling plays context-dependent roles in tumors themselves—including promoting immune exclusion when activated within cancer cells—any therapeutic strategy would need to target the pathway selectively in dendritic cell–T cell synapses rather than systemically. The study was supported by the National Natural Science Foundation of China and the Guangdong Basic and Applied Basic Research Foundation, and the animal protocols were approved by the institutional ethics committee of Qingyuan Hospital Affiliated to Guangzhou Medical University.

Even with those caveats, the paper adds a compelling new layer to the emerging picture of dendritic cells as master architects of CD8⁺ T cell fate in cancer. Rather than serving as passive antigen delivery vehicles, these cells actively calibrate the memory versus effector decision through intracellular phosphatase signaling—and SHP1, long known as a brake on immune activation, now appears to be a brake specifically on the immune system’s memory-forming machinery. For a field wrestling with why immunotherapy triumphs are so often temporary, the demonstration that a single dendritic cell-intrinsic molecule governs TCF-1 expression, Wnt/β-catenin activation, central memory formation, and ultimately tumor control in living animals offers both a conceptual advance and a concrete target. If future studies confirm the axis in human tumors and identify safe ways to inhibit dendritic cell SHP1 in patients, the promise of immunotherapies that confer not just transient tumor shrinkage but genuine, memory-anchored cancer cures will have moved a decisive step closer to reality.

CAR T-cell therapy begins with the removal of immune cells called T cells from a patient’s blood. In a laboratory, these cells are genetically modified to carry chimeric antigen receptors, molecular structures that allow them to recognize specific proteins on cancer cells. The engineered cells are multiplied and then infused back into the patient, where they can seek out and destroy malignant cells. This approach has produced dramatic and sometimes durable remissions in several blood cancers, including certain leukemias, lymphomas and multiple myeloma. But once activated, CAR T cells can release large quantities of inflammatory signaling molecules, including cytokines. The resulting immune cascade can affect the blood-brain barrier, alter the function of cells supporting the nervous system and allow inflammation to spread into the brain. ICANS often develops alongside or after cytokine release syndrome, another immune-related complication of CAR T-cell treatment.

The neurological symptoms of ICANS can emerge rapidly, sometimes within days of CAR T-cell infusion. Early signs may include difficulty finding words, trouble writing, reduced attention, disorientation or unusual sleepiness. As the condition progresses, patients may experience severe confusion, tremors, weakness, seizures or loss of consciousness. Clinicians monitor patients closely using neurological assessments, laboratory tests and, when necessary, brain imaging or electroencephalography. Current treatment relies heavily on corticosteroids, which suppress broad inflammatory activity and can be lifesaving. However, steroids may also produce substantial side effects, including immune suppression, metabolic disturbances, muscle weakness and psychological effects. They can also interfere with the activity of therapeutic immune cells, raising concern that controlling toxicity could come at the expense of the anticancer response. The UC Irvine researchers say a more precise, mechanism-based approach could help protect the brain while preserving the benefits of CAR T-cell therapy.

The new study places mitochondrial dysfunction at the center of that proposed mechanism. Mitochondria are best known as the organelles that generate adenosine triphosphate, or ATP, the chemical energy that powers cellular activity. They also regulate calcium balance, control programmed cell death and influence the production of inflammatory molecules. When mitochondria become damaged or overloaded, they can generate excessive reactive oxygen species, unstable molecules capable of injuring proteins, membranes and DNA. Mitochondrial stress can also alter the behavior of immune cells, pushing them toward prolonged activation and increased cytokine production. In the context of CAR T-cell therapy, the researchers suggest that this metabolic disruption could intensify systemic inflammation, weaken the protective functions of the blood-brain barrier and contribute to neuronal and glial injury. Rather than viewing ICANS solely as an uncontrolled cytokine reaction, the framework presents it as a disorder involving the interaction of immune activation, cellular metabolism and brain vascular biology.

This perspective could open the door to a different class of interventions. The authors identify mitochondrial-targeting drugs as potential steroid-sparing candidates—medications that might reduce the biological drivers of neurotoxicity without broadly shutting down the immune response. Depending on their mechanisms, such drugs could help limit oxidative stress, stabilize mitochondrial membranes, improve energy metabolism, regulate calcium handling or reduce inflammatory signaling linked to damaged mitochondria. Some compounds with these properties are already used for other medical conditions, while others have been studied in neurological, metabolic or inflammatory diseases. Repurposing them could be faster and less expensive than developing a new medicine from the beginning because existing data may already describe their absorption, dosing, toxicity and interactions with other drugs. The authors emphasize, however, that a safety history in one disease does not automatically establish safety during CAR T-cell therapy, when patients may be medically fragile and experiencing intense immune activation.

“Our work points to mitochondrial dysfunction as a promising therapeutic target for serious neurological complications of CAR T-cell therapy,” said lead author Atena Zahedi, assistant professor of clinical pharmacy practice in UC Irvine’s School of Pharmacy & Pharmaceutical Sciences. “By identifying existing drugs that may be repurposed, we hope to accelerate the development of safer treatment strategies for patients receiving these lifesaving therapies.” The proposal is especially relevant because the timing of ICANS can leave physicians with few options beyond supportive care, intensive monitoring and corticosteroids. A drug capable of interrupting mitochondrial stress early in the process could, in principle, be administered before neurological injury becomes severe. It might also be paired with current treatments, allowing clinicians to use lower steroid doses or shorten steroid exposure. Such possibilities remain hypothetical until tested in carefully designed laboratory studies and clinical trials.

For co-author Shawn Griffin, an oncology pharmacist and associate clinical professor of clinical pharmacy practice at UC Irvine, the practical appeal lies in the possibility of moving promising candidates toward patients more rapidly. “One of the greatest opportunities in this work is identifying existing drugs that may be repurposed to better manage the neurological side effects associated with CAR T-cell therapy,” Griffin said. “Because many of these medications already have established safety profiles, they could potentially move into clinical evaluation more quickly than developing entirely new drugs.” Even so, repurposing requires rigorous screening. Researchers must determine whether a candidate reaches the brain at an effective concentration, whether it interferes with CAR T-cell expansion or cancer killing, how it interacts with corticosteroids and other supportive medicines, and whether its benefits outweigh risks such as cardiac, hepatic or metabolic toxicity. Biomarkers of mitochondrial injury and inflammation could eventually help doctors identify which patients are most likely to benefit.

The research also carries a personal dimension for co-author Onwodi Ifejeokwu, who lost a family member to B-cell lymphoma in 2021. During the illness, she witnessed how cancer and its treatment could affect the brain, an experience that helped shape her interest in neuro-immuno-oncology. She now works with Zahedi, Griffin and senior author Erin Dean on research aimed at improving the quality of life of patients receiving advanced cancer therapies. Dean, a medical oncologist at UC Irvine’s Chao Family Comprehensive Cancer Center, is leading related clinical research efforts designed to evaluate new approaches to patient care. The team’s collaboration brings together clinical pharmacy, oncology and neuro-immunology, reflecting the complexity of ICANS itself. The syndrome cannot be fully understood through a single lens: immune cells, endothelial cells, neurons, glial cells, blood vessels and energy metabolism may all contribute to the final neurological outcome.

The study does not report a proven treatment or claim that mitochondrial drugs can currently prevent ICANS. Instead, it offers a translational roadmap for testing the hypothesis. Future work will need to establish which mitochondrial pathways are altered during CAR T-cell therapy, define the sequence linking immune activation to neurological symptoms and identify reliable indicators of impending toxicity. Candidate drugs must then be evaluated in cellular systems, animal models and clinical trials, with outcomes that include both neurological safety and cancer control. Investigators will also need to determine whether mitochondrial dysfunction is a primary driver of ICANS or one part of a wider network involving cytokines, vascular permeability, coagulation and blood-brain barrier disruption. If the framework withstands those tests, it could help transform ICANS management from a largely reactive effort into an earlier and more targeted intervention. For patients receiving CAR T-cell therapy, that could mean preserving the treatment’s remarkable anticancer potential while reducing one of its most frightening risks.

Subject of Research: Mitochondrial dysfunction and potential mitochondrial-targeting treatments for immune effector cell-associated neurotoxicity syndrome (ICANS) following CAR T-cell therapy.

Article Title: Repurposing mitochondrial-targeting drugs for management of ICANS in CAR T-cell therapy: a novel steroid-sparing approach

News Publication Date: Aug. 18, 2026

Web References: Frontiers in Pharmacology article; UC Irvine Chao Family Comprehensive Cancer Center; UC Irvine News

References: Frontiers in Pharmacology, article published July 27, 2026; “Repurposing mitochondrial-targeting drugs for management of ICANS in CAR T-cell therapy: a novel steroid-sparing approach.”

Keywords: CAR T-cell therapy, cancer immunotherapy, ICANS, neurotoxicity, mitochondrial dysfunction, mitochondria, cytokine release syndrome, brain inflammation, drug repurposing, steroid-sparing treatment, blood cancers, neuro-immuno-oncology