Regulatory T cells are essential guardians against autoimmune disease. They suppress excessive immune reactions and help prevent the body from attacking its own tissues. Inside tumors, however, that same suppressive function can become an advantage for malignant cells. Ti-Treg cells accumulate in the tumor microenvironment and restrain immune activity that might otherwise destroy cancer cells. Their behavior is shaped not only by immune signals but also by the unusual metabolism of tumors, where oxygen can be scarce and nutrients are unevenly distributed. Tumor cells and surrounding stromal cells commonly release large amounts of lactate, a product of glucose metabolism. Rather than serving merely as metabolic waste, lactate can act as a signaling and regulatory molecule. The new findings suggest that Ti-Treg cells exploit this lactate-rich setting to reprogram their own metabolism and acquire the ability to undermine NK-cell function.

The central enzyme identified in the study is glutamate dehydrogenase 1, or GDH1. This enzyme helps regulate the conversion of glutamate into α-ketoglutarate, a metabolite that participates in the tricarboxylic acid cycle and also influences gene regulation. The researchers found that Ti-Treg cells increase GDH1 expression, resulting in higher levels of α-ketoglutarate. That metabolic shift was associated with accelerated tumor progression. α-ketoglutarate is especially important because it can serve as a cofactor for a family of enzymes that chemically modify proteins and nucleic acids. In this case, the metabolite fuels activity linked to ALKBH5, an RNA demethylase. By connecting a change in cellular metabolism to the stability or expression of a specific immune-regulatory gene, the study provides a mechanistic explanation for how the tumor environment can reshape immune-cell behavior from the inside out.

The pathway begins with lactate entering Ti-Treg cells through SLC16A1, a transporter that moves monocarboxylates such as lactate across the cell membrane. Within the lactate-rich tumor microenvironment, the researchers found that GDH1 undergoes lactylation, a chemical modification associated with the presence of lactate. This modification boosts GDH1’s ability to generate α-ketoglutarate. The result is a metabolic circuit in which lactate does not simply provide fuel: it changes the activity of an enzyme, increases a regulatory metabolite and ultimately alters gene expression. The chain can be summarized as lactate uptake, GDH1 lactylation, increased α-ketoglutarate production and enhanced ALKBH5-dependent regulation of Wnt2. Each step offers a possible point of intervention. It also illustrates why cancer metabolism is increasingly viewed as an information system as well as an energy system, capable of transmitting signals between the tumor and immune cells.

The gene Wnt2 encodes a member of the WNT family, a group of secreted signaling proteins involved in communication between cells, tissue development and cancer biology. In the Ti-Treg cells examined in the study, the lactate-driven α-ketoglutarate increase fuels ALKBH5-mediated control of Wnt2 expression. The resulting increase in WNT2 affects neighboring NK cells. NK cells normally recognize and eliminate stressed, infected or transformed cells without requiring the same antigen-specific priming used by conventional T cells. They can release cytotoxic molecules, including perforin and granzymes, that damage target cells. But in the tumor microenvironment, their activity can deteriorate. The study links WNT2 produced under the influence of Ti-Treg metabolism to NK-cell senescence, a state in which cells lose functional capacity and may no longer mount an effective antitumor response.

Senescence is not simply temporary exhaustion. A senescent cell undergoes a durable change in its biological state, often involving altered gene expression, reduced proliferation and changes in the signals it sends to neighboring cells. For NK cells, senescence can mean diminished ability to kill tumor cells and reduced effectiveness after transfer into a patient or experimental host. By inducing this state, Ti-Treg cells can neutralize an immune population that cancer therapies are designed to mobilize. The findings therefore reveal an indirect form of immune suppression: Ti-Treg cells do not merely inhibit NK cells through conventional suppressive signals, but use a metabolic pathway to produce WNT2 and push NK cells toward functional decline. This distinction matters because it suggests that an apparently resistant tumor may not be protecting itself only through cancer-cell mutations or checkpoint signals. It may also be constructing a metabolic environment that ages immune cells before they can attack.

The researchers tested whether interrupting the circuit could restore antitumor immunity. Inhibition of GDH1 reduced the metabolic activity associated with the pathway, while deletion of SLC16A1 specifically in Ti-Treg cells limited lactate uptake. Both interventions reduced NK-cell senescence, according to the study. The results place lactate transport and GDH1 activity upstream of the changes observed in NK cells, strengthening the case that the pathway is causal rather than merely a correlation between tumor metabolism and immune dysfunction. Importantly, interfering with the circuit also improved adoptive NK-cell transfer therapy. In this approach, NK cells are supplied from outside the tumor in an effort to increase the number of cancer-killing immune cells. The study suggests that adding more NK cells may not be enough if Ti-Treg cells continue to expose them to the lactate–α-ketoglutarate–WNT2 circuit. Protecting transferred cells from that environment could substantially improve their therapeutic performance.

The work also highlights the challenge of targeting metabolism without damaging beneficial immune regulation. GDH1 is not unique to Ti-Treg cells, and lactate transporters are used by many normal cells. A broadly acting drug could therefore produce unwanted effects if it disrupts essential metabolic processes in healthy tissues or alters regulatory T-cell activity throughout the body. The most selective strategy suggested by the findings would be to target the pathway within tumor-infiltrating Treg cells, block their access to lactate, or interfere with the GDH1 modification that specifically amplifies α-ketoglutarate production in the tumor setting. Another possibility would be to prevent the downstream WNT2 signal from acting on NK cells. Each approach raises different pharmacological and safety questions. The source study establishes the circuit and identifies intervention points, but translating those findings into treatment will require determining how broadly the mechanism operates across tumor types and how it interacts with existing immunotherapies.

The discovery could be particularly relevant to efforts to improve cell-based cancer treatments, which often fail because transferred immune cells become dysfunctional after entering a tumor. Adoptive NK-cell therapy is attractive because NK cells can recognize malignant stress signals and kill targets without the individualized antigen matching required for some T-cell therapies. Yet their effectiveness depends on surviving and remaining active inside the tumor microenvironment. The new study suggests that Ti-Treg cells may act as metabolic gatekeepers, converting a tumor’s excess lactate into a signal that disables incoming NK cells. Blocking SLC16A1, GDH1 or the downstream WNT2 pathway could therefore be explored as a combination strategy rather than as a standalone treatment. Such combinations might include NK-cell transfer, immune checkpoint blockade or other approaches designed to increase immune-cell infiltration. Whether the mechanism is shared by human tumors remains an important question, as does the possibility that related metabolic circuits suppress other immune-cell types.

At a broader level, the study reframes the relationship between cancer metabolism and immune suppression. Lactate has often been associated with poor immune performance because of its effects on acidity and cellular energy balance. The findings describe a more specific and sophisticated process: lactate chemically modifies GDH1 in Ti-Treg cells, raises α-ketoglutarate, engages an RNA-regulatory enzyme and increases WNT2 production, which then promotes NK-cell senescence. That sequence connects a metabolite, an enzyme modification, epigenetic or RNA regulation and intercellular immune signaling in a single pathway. The researchers’ identification of GDH1 inhibition and Ti-Treg-specific SLC16A1 deletion as ways to reduce NK senescence provides a foundation for therapeutic investigation. If future studies confirm the circuit in human cancers, disrupting this metabolic relay could help turn the tumor microenvironment from a place that exhausts immune cells into one where transferred and naturally occurring NK cells retain their ability to attack malignant tissue.

Cancer-associated fibroblasts, commonly abbreviated as CAFs, are connective-tissue cells that become reprogrammed within tumors. They produce extracellular-matrix proteins, growth factors and signaling molecules that influence blood-vessel formation, tumor-cell behavior and immune-cell movement. CAFs are not a uniform population. Different subsets can have distinct, and sometimes opposing, effects on tumor progression and treatment response. Some may support immune infiltration, while others create barriers that exclude immune cells from malignant tissue. The new study focuses on a CAF population associated with the recruitment and localization of highly suppressive Tregs in lung cancer, revealing that stromal cells can shape immunity through coordinated cellular positioning rather than through generalized immune suppression alone.

Tregs are essential under normal conditions because they prevent excessive immune activation and help maintain tolerance to the body’s own tissues. They are characterized by the transcription factor FOXP3 and frequently express molecules such as CD25, the high-affinity receptor for interleukin-2. In tumors, however, Tregs can become a powerful brake on the immune response. They suppress cytotoxic T cells, natural killer cells and antigen-presenting cells through several mechanisms, including inhibitory receptor signaling, consumption of interleukin-2, secretion of immunoregulatory cytokines and direct cell-to-cell contact. A tumor enriched in Tregs may therefore remain protected from immune attack even when cancer-specific T cells are present. The study’s emphasis on “hyper-suppressive” Tregs points to a further layer of complexity: not every Treg in a tumor has the same capacity to restrain immunity.

The researchers’ central observation is that the newly described CAF population helps bring these potent Tregs into particular regions of lung tumors and supports their retention there. This distinction matters because immune cells do not act in isolation. A Treg positioned next to an activated dendritic cell, a cancer-reactive T cell or a tumor-associated macrophage can exert a very different influence from one located elsewhere in the tissue. By arranging cellular neighborhoods, CAFs may create local immunological “hotspots” where suppression is concentrated. The result is not simply a tumor containing more Tregs, but a tumor in which the most functionally suppressive Tregs are placed where they can most effectively interfere with anti-tumor immune activity.

The findings also underscore the importance of studying tumors in space. Conventional analyses often measure the number of fibroblasts or immune cells in a bulk tissue sample, averaging together cells that may occupy very different microenvironments. Spatial approaches can reveal whether a particular CAF subset lies near blood vessels, tumor nests, lymphoid aggregates or immune-cell interfaces. In this context, the biological message is architectural: the CAF population appears to establish or maintain a local niche that favors Treg recruitment and specialization. Such a niche could involve chemokines that guide Treg migration, adhesion molecules that promote cellular retention, extracellular-matrix structures that define movement routes, or cytokines that reinforce suppressive activity. The precise molecular components remain critical targets for further investigation.

This work may help resolve a longstanding puzzle in lung-cancer immunology. Immune-checkpoint inhibitors can produce striking and durable responses in some patients, yet many tumors either fail to respond or eventually develop resistance. Therapies targeting PD-1, PD-L1 or CTLA-4 are designed to release inhibitory signals on immune cells, but they may be less effective when the tumor microenvironment simultaneously concentrates highly suppressive Tregs around vulnerable immune interactions. A stromal niche that recruits and organizes these cells could therefore contribute to primary resistance, acquired resistance or incomplete responses. The discovery raises the possibility that blocking immune checkpoints may need to be paired with strategies that disrupt the fibroblast-guided organization of suppressive immune cells.

Importantly, the study does not suggest that all CAFs should simply be eliminated. Fibroblasts are involved in wound repair, tissue integrity and normal immune regulation, and broad depletion could damage healthy organs or produce unintended effects. The therapeutic challenge will be to distinguish the disease-associated CAF population from beneficial stromal cells and to interfere with the signals that specifically sustain Treg accumulation or suppressive programming. Potential approaches could include antibodies or small molecules directed against subset-specific surface proteins, inhibitors of chemokine pathways, interventions that remodel abnormal extracellular matrix, or treatments designed to reprogram CAFs into a less immunosuppressive state. Each strategy would require careful testing because stromal cells can change their behavior in response to treatment, inflammation and tumor evolution.

The study also highlights why Treg biology should be evaluated functionally rather than through cell counts alone. A modest population of highly suppressive Tregs may have a greater effect than a larger population with limited activity. Identifying these cells could require a combination of transcriptional profiling, protein analysis, functional suppression assays and spatial mapping. Such measurements may eventually yield biomarkers that predict which lung-cancer patients are most likely to benefit from therapies targeting the CAF–Treg axis. If the relevant fibroblast signature can be detected in biopsies or imaging-linked tissue samples, clinicians might be able to identify tumors whose immune resistance is driven by stromal organization rather than by a lack of tumor-reactive lymphocytes.

As with any study of the tumor microenvironment, the findings will need to be evaluated across diverse patient groups, lung-cancer subtypes and treatment histories. Tumors differ according to their genetic drivers, smoking status, anatomical location and previous exposure to chemotherapy, radiation or immunotherapy. These variables can reshape both fibroblast states and Treg behavior. It will also be important to determine whether the same CAF population operates in other cancers, whether it emerges early or late during tumor development, and whether its activity changes after immune-checkpoint blockade. Nevertheless, the study provides a compelling conceptual advance: lung tumors may exploit a specialized stromal cell population to turn immune suppression into a precisely organized local system. By revealing how fibroblasts recruit and position hyper-suppressive Tregs, the research opens a new route toward therapies that do not merely activate immune cells, but also dismantle the cellular neighborhoods that keep them under control.

Subject of Research: A novel cancer-associated fibroblast population that coordinates the recruitment and localization of highly suppressive regulatory T cells in lung cancer.

Article Title: A novel CAF population coordinates hyper-suppressive regulatory T cell recruitment and localization in lung cancer.

Article References: Ringham, O.R., Rivera, M., Loffredo, L.F. et al. “A novel CAF population coordinates hyper-suppressive regulatory T cell recruitment and localization in lung cancer.” Nature Immunology (2026). https://doi.org/10.1038/s41590-026-02607-2

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41590-026-02607-2

Keywords: lung cancer, cancer-associated fibroblasts, CAFs, regulatory T cells, Tregs, tumor microenvironment, immune suppression, cancer immunology, spatial organization, immunotherapy resistance

Pancreatic cancer’s notorious resistance to treatment has long frustrated oncologists and immunologists alike. Unlike cancers such as melanoma and lung cancer, which respond well to immune checkpoint inhibitors, pancreatic cancer firmly resists these breakthroughs. According to Dr. Katelyn Byrne, the study’s senior author and assistant professor at the OHSU School of Medicine, the underlying culprit is the overwhelming presence of regulatory T cells (Tregs) within the tumor microenvironment. These cells inherently suppress immune activity, effectively disarming the body’s natural tumor-killing cells and rendering conventional immunotherapies ineffective.

Tregs typically serve as guardians against autoimmune diseases by suppressing excessive immune responses. However, in pancreatic tumors, these cells are hijacked to create an immunosuppressive milieu that protects the cancer from immune attacks. Dr. Byrne elaborates that the abundance of Tregs creates a formidable barrier, neutralizing the effectiveness of immune cells that would otherwise identify and eradicate malignant cells. This adaptive immune suppression is a major roadblock, and overcoming it has been a paramount challenge in pancreatic cancer therapy development.

The OHSU team employed an innovative immunotherapy known as agonistic anti-CD40 antibody treatment, which activates immune responses differently from traditional checkpoint blockade. Instead of targeting a singular immune checkpoint, this therapy stimulates dendritic cells and other antigen-presenting cells to amplify a broad immune activation upstream. This approach has shown promise in preclinical models but its effects on Tregs were previously unclear.

Unexpectedly, the study found that agonistic CD40 treatment not only activates tumor-killing effector cells but also reprograms Tregs within the tumor microenvironment. These suppressive cells are converted from immune inhibitors into activated type 1 effectors that support anti-tumor immunity. This phenomenon was surprising, as the treatment does not directly target Tregs but induces secondary effects through the broader immune activation cascade. The ability to flip Tregs from foes to allies represents a paradigm shift in understanding immune regulation in pancreatic cancer.

This dual mechanism—both boosting immune attack and dismantling immune suppression—offers a mechanistic explanation for why many immunotherapies have stalled in pancreatic cancer. It suggests a need to concurrently energize the immune system while overcoming the tumor’s immunosuppressive tactics for effective therapeutic outcomes. Such combination strategies may finally unlock immunotherapy’s potential in a cancer type long deemed refractory to immune modulation.

Importantly, these findings suggest that the transient and suppressive nature of Tregs is not fixed but modifiable. By altering the immune contexture with agonistic CD40 antibodies, the tumor microenvironment transitions from an immune-desert to an immune-active state, paving the way for durable immune responses. This reprogramming may also sensitize tumors to other therapeutic modalities, thereby expanding the armamentarium against pancreatic cancer.

The implications extend beyond immunotherapy alone. Pancreatic tumors frequently harbor genetic mutations, such as those in KRAS, that have been notoriously difficult to target. However, emerging KRAS inhibitors show clinical promise but often require immune system cooperation for sustained efficacy. The ability to reprogram Tregs and activate immune effector cells may synergize with such targeted drugs, creating a multipronged attack against tumor cells. This synergy offers a rational basis for combination clinical trials aiming to improve outcomes.

Personalizing treatment strategies is another critical perspective arising from the research. Pancreatic tumors exhibit heterogeneity in their immune landscapes; some are heavily infiltrated by Tregs, while others lack immune infiltrates altogether. According to Dr. Byrne, profiling patients’ tumors for regulatory T cell content using routine biopsies could guide the selection of therapies most likely to be effective, marking a notable advance in precision oncology for pancreatic cancer.

While the current findings stem from murine models, Dr. Byrne anticipates that clinical trials testing this combination immunotherapy approach in pancreatic cancer patients will commence in the next few years. Her team is actively mapping the complex interplay between immune cells in the tumor microenvironment to understand the long-term durability of the reprogrammed immune cells. Such insights are vital for translating these promising observations into lasting clinical benefits.

The study underscores a fundamental shift in cancer immunotherapy paradigms, demonstrating that the tumor’s immune microenvironment is manipulable rather than static. By strategically converting immune suppressors into effectors, the research opens doors to overcome pancreatic cancer’s entrenched resistance to immune-based treatments. This work heralds a hopeful future in which the immune system’s power can be harnessed against even the most formidable tumors, potentially transforming the prognosis for pancreatic cancer patients worldwide.

Subject of Research: Pancreatic cancer immunotherapy and tumor immune microenvironment
Article Title: Agonistic anti-CD40 antibody treatment converts resident regulatory T cells into activated type 1 effectors within the tumor microenvironment
News Publication Date: Not specified (article DOI 10.1016/j.immuni.2026.03.011)
Web References:

• Study Publication: https://www.sciencedirect.com/science/article/pii/S1074761326001226?via%3Dihub
• DOI link: http://dx.doi.org/10.1016/j.immuni.2026.03.011
  Image Credits: OHSU/Christine Torres Hicks
  Keywords: Pancreatic Cancer, Immunotherapy, Regulatory T cells, Tumor Microenvironment, CD40 Agonist, Immune Reprogramming, Cancer Immunology, KRAS Inhibitors, Combination Therapy, Immune Checkpoint Resistance

Bladder cancer treatment has been revolutionized by the advent of immune checkpoint inhibitors—therapies designed to unleash the immune system’s ability to attack cancer cells. Despite their promise, these treatments yield durable responses in only a subset of patients, leaving many with limited benefit. Previously, elevated blood markers of inflammation, notably C-reactive protein (CRP), have been correlated with poor prognosis, yet the precise connection linking systemic inflammation and tumor immune evasion remained obscure.

The research team, led by Dr. Nina Bhardwaj, Director of Immunotherapy at Mount Sinai, alongside Dr. Matthew Galsky and Dr. Diego Chowell, employed cutting-edge single-cell genomics and RNA sequencing analyses to construct the most comprehensive atlas of bladder tumors reported to date. This atlas enabled unprecedented insight into the cellular and molecular landscape of bladder tumors and their associated immune infiltrates.

Their findings pinpoint a distinct subset of macrophages within the tumor microenvironment characterized by the expression of SPP1, a gene implicated in modulating immune responses. These SPP1-positive macrophages were found to correlate strongly with elevated levels of systemic CRP and interleukin-6 (IL-6), a pro-inflammatory cytokine also detectable in peripheral blood. Importantly, these macrophages exhibited pronounced immunosuppressive properties, actively inhibiting cytotoxic T cell activity essential for anti-tumor immunity.

Mechanistically, the team demonstrated that IL-6 signaling pathways within the tumor microenvironment foster the expansion and activation of these SPP1+ macrophages. The cascade culminates in a potent dampening of T cell-mediated tumor killing, effectively neutralizing the therapeutic actions of checkpoint inhibitors. This phenomenon offers a critical explanation for why some bladder cancers remain refractory to immunotherapy despite systemic treatment.

Contrastingly, the researchers identified a separate subset of macrophages marked by CXCL9 expression, which appear to enhance T cell activation and promote more robust anti-cancer immune responses. This dichotomy highlights the complex balancing act within tumors between immune activation and suppression, governed by the heterogeneous populations of myeloid cells.

This research builds a direct link between systemic inflammatory biomarkers—long used clinically as non-specific indicators—and specific immune processes inside tumors. The implication is profound: routine blood tests assessing CRP and IL-6 levels might soon serve as predictive tools for immunotherapy responsiveness. Patients with heightened systemic inflammation may harbor microenvironments hostile to immune attack, requiring alternative or combination therapeutic strategies.

Dr. Chowell emphasized that this study not only decodes the biological basis of immune dysfunction in bladder cancer but also underscores the broader importance of inflammatory signaling in shaping tumor immunity. The inflammatory milieu serves as a window into the tumor’s immunological status, offering a biomarker-driven framework to guide precision oncology.

The translational potential extends beyond mere diagnostics. By targeting the IL-6–SPP1+ macrophage axis, future therapies may reprogram or inhibit these immunosuppressive cells, restoring T cell function and amplifying the efficacy of existing checkpoint blockade treatments. Novel drug candidates focusing on IL-6 signaling are already in clinical pipeline phases and may benefit from patient stratification rooted in these biomarkers.

Clinically, these insights empower oncologists to stratify patients more effectively, tailoring treatment according to their inflammatory and immunological profiles. Patients with inherent resistance patterns could be offered early intervention through combination therapies or enrolled in clinical trials exploring anti-inflammatory adjuncts to immunotherapy.

The research group continues to delve deeper into the biology of SPP1+ macrophages to unravel the molecular triggers behind their suppressive capabilities and how tumor-intrinsic factors modulate their function. Their ongoing studies aim to unlock therapeutic vulnerabilities and enhance the armamentarium against bladder cancer.

This landmark study was supported by significant funding from the National Institutes of Health, reflective of its innovative nature and clinical relevance. Through the integration of immunology, computational biology, and translational medicine, the team exemplifies the future of cancer research—one that bridges systemic biology with tumor microenvironment intricacies.

In summary, the newly uncovered IL-6–SPP1+ macrophage–CRP axis represents a pivotal checkpoint in bladder cancer immunity. By connecting peripheral inflammation with intra-tumoral immune suppression, this research opens promising pathways to better predict, and ultimately improve, patient responses to immunotherapy, potentially transforming treatment paradigms not only in bladder cancer but also in other inflammation-associated malignancies.

Subject of Research: Cells
Article Title: A tumor-promoting inflammatory SPP1+ macrophage—IL-6—CRP axis drives immune dysfunction in bladder cancer
News Publication Date: 18-Mar-2026
Web References: http://dx.doi.org/10.1158/2159-8290.CD-25-1774
References: Published in Cancer Discovery, DOI: 10.1158/2159-8290.CD-25-1774
Keywords: Cancer immunotherapy, Cancer treatments, Bladder cancer, Immunotherapy resistance, SPP1+ macrophages, IL-6 signaling, C-reactive protein, Tumor microenvironment, Immune suppression, Immune checkpoint inhibitors

Immunotherapy has revolutionized cancer treatment by leveraging the patient’s own immune system to attack malignant cells. Despite its promise, the success of immunotherapies in solid tumors like non-small cell lung cancer (NSCLC) remains limited. A significant hurdle is the infiltration of pro-tumoral macrophages—immune cells that instead of combating cancer, help suppress the antitumor immune response. These macrophages create an immunosuppressive microenvironment, aiding tumor growth and survival. Prior assumptions held that such macrophages adopted their pro-cancer roles only after arriving at the tumor. The new findings overturn this idea by tracing the origin of this immune subversion back to the bone marrow, where macrophage precursors undergo critical changes.

Employing cutting-edge single-cell genomics and lineage-tracing technologies, the researchers mapped the developmental trajectory of bone marrow myeloid progenitor cells, the precursors to macrophages. Their analyses uncovered that tumors broadcast signals that deliver a “first hit” to these progenitor cells in the bone marrow. This initial exposure biases the developing immune cells toward an immunosuppressive phenotype even before they infiltrate the tumor. Later, once in the tumor microenvironment, a “second hit” acts as a catalyst that locks these macrophages into their pro-tumoral functions. This two-step model represents a paradigm shift in our understanding of immune cell education by cancer.

Dr. Samarth Hegde, the study’s lead author, highlights that the temporal aspect of immune suppression had been misunderstood for decades. Observing that immune cells are preconditioned within the bone marrow demands a radical rethink of therapeutic strategies. Traditional approaches focus predominantly on the tumor microenvironment, attempting to re-educate or inhibit macrophages after they have already entrenched themselves among cancer cells. This study suggests that such attempts might be inherently limited. Targeting the progenitor cells prior to their arrival at the tumor could prevent them from becoming immunosuppressive in the first place, thus preserving the immune system’s capacity to mount effective anticancer responses.

One of the most promising molecular candidates identified in this reprogramming process is NRF2, a transcription factor fundamentally involved in cellular stress responses and redox homeostasis. The research team discovered that NRF2 activity is modulated in bone marrow progenitor cells exposed to tumor-derived inflammatory signals, rewiring these cells’ genetic programs. This NRF2-driven reprogramming becomes fully operational when the progenitors differentiate into tumor-infiltrating macrophages, promoting immune suppression and tumor progression in both human patients and mouse models. Crucially, inhibiting NRF2—either through genetic manipulation or experimental pharmacological agents—significantly reduced the formation of suppressive macrophages and revitalized antitumor immunity in preclinical experiments.

Miriam Merad, MD, PhD, senior corresponding author and Chair of Immunology and Immunotherapy at Mount Sinai, emphasizes the translational potential of these findings. By targeting NRF2 signaling in bone marrow progenitors, it might be possible to halt the supply line of immunosuppressive macrophages at its source, essentially cutting off the tumor’s capacity to subvert the immune system. “Current immunotherapies largely address the tumor itself but fail to consider the precursor immune cells’ prior ‘education,’” Dr. Merad notes. “Early intervention at the progenitor stage could dramatically improve the durability of treatment responses and possibly reduce relapse rates.”

Additionally, this newly revealed mechanism of immune cell manipulation by tumors offers a compelling opportunity for diagnostic innovation. Since the reprogrammed myeloid progenitors circulate in the bloodstream before differentiating, blood-based tests could detect these “pre-programmed” immune cells, facilitating earlier diagnosis and enabling timely therapeutic intervention. Such liquid biopsies would mark a significant advance in personalized medicine, allowing clinicians to monitor immune cell states during treatment and remission with unprecedented precision.

The implications of this research extend well beyond lung cancer. The investigators plan to explore whether similar genetic and epigenetic mechanisms govern immune cell progenitor reprogramming in other malignancies and chronic inflammatory diseases such as aging, obesity, and atherosclerosis. These conditions often share dysregulated immune responses, and understanding the underlying molecular controls, including NRF2 signaling, may reveal new treatment opportunities. Moreover, aberrant immune cell proliferation outside of the bone marrow—called extramedullary hematopoiesis—is observed in some cancers, and the team aims to investigate if comparable molecular programs are at play there as well.

A critical future direction involves elucidating how NRF2 and related pathways influence the metabolic reprogramming of immune cells. Tumors are known to manipulate cellular metabolism to evade immunity, and dissecting these interactions at the molecular level may clarify how suppressive macrophages gain their functional phenotype. This could lead to novel metabolic interventions that complement existing immunotherapies, creating multi-pronged strategies to outsmart cancer.

The publication titled “Myeloid Progenitor dysregulation fuels immunosuppressive macrophages in tumors” represents a landmark achievement in cancer immunology. By highlighting how tumors manipulate immune cells from their earliest developmental stages, it provides a blueprint for the next generation of cancer therapies focused on the immune system’s origins rather than its endpoints. This foundational work not only advances scientific understanding but also heralds a promising translational leap toward more effective and durable treatment regimens for patients battling lung cancer and potentially other challenging diseases.

This discovery underscores the critical role of interdisciplinary collaboration and advanced technologies in unraveling the complexity of cancer biology. The team’s integration of genomics, immunology, and translational medicine exemplifies the frontier of precision immunology research, making Mount Sinai a leader in tackling the most stubborn challenges in oncology.

Subject of Research: Cells
Article Title: Myeloid Progenitor dysregulation fuels immunosuppressive macrophages in tumors
News Publication Date: 10-Sep-2025
Web References: https://www.nature.com/articles/s41586-025-09493-y
References: DOI 10.1038/s41586-025-09493-y
Keywords: Cancer immunotherapy