Researchers at Johns Hopkins All Children’s Hospital have made a groundbreaking discovery through a series of experiments conducted on mouse models simulating breast, pancreatic, and muscle cancers. Their work reveals compelling evidence that enhancing the body’s inherent immune mechanisms can effectively prevent cancer recurrence and significantly boost survival probabilities.
This latest study, featured in Nature Immunology and supported by funding from the National Cancer Institute under the National Institutes of Health, concentrated on innovative strategies to empower the immune system in identifying and eliminating tumors that typically manage to dodge detection.
A significant number of aggressive tumors are characterized as immune-suppressive or “immune cold,” meaning the body’s protective mechanisms overlook them as dangers. Individuals suffering from these “cold” tumors frequently exhibit suboptimal responses to conventional therapies and face poorer prognoses. The team from Johns Hopkins aimed to unravel the process of converting these immune-cold tumors into “immune hot” variants, which are far more susceptible to assaults from key immune players like B cells and T cells. Such a transformation holds the potential to dramatically amplify the efficacy of both chemotherapy and immunotherapy approaches.
Expanding upon their earlier investigations into breast cancer, the scientists hypothesized that introducing immune-activating agents into the tumor microenvironment could enhance the robustness and structural integrity of tertiary lymphoid structures (TLSs). These TLSs serve as critical organizational centers where immune cells convene to launch coordinated offensives against cancerous cells.
Tertiary lymphoid structures manifest as clusters of lymphocytes in regions affected by persistent inflammation, such as those found in immune-hot tumors. The existence of these structures is closely associated with superior therapeutic results and extended patient survival, as they facilitate a precise and potent immune counterattack.
In order to validate their hypothesis, the research group replicated the microenvironment typical of tumors rich in TLSs, pinpointing the specific signals responsible for initiating TLS development. Subsequently, they applied these identified signals to tumors in mouse subjects that were devoid of TLSs, employing a pair of immune-stimulating compounds known as agonists. These targeted the STING protein and the lymphotoxin-β receptor (LTβR).
The simultaneous activation of both proteins triggered a rapid and robust immune reaction. Cytotoxic CD8⁺ T cells, often called killer T cells, mobilized aggressively to halt tumor progression. At the same time, novel high endothelial venules—specialized vascular pathways that facilitate immune cell infiltration into tissues—emerged. These venules functioned as entry points, permitting vast influxes of T and B cells into the tumor sites, where they self-organized into nascent TLSs.
Within the confines of these newly formed TLSs, B cells initiated germinal-center responses, maturing into plasma cells that produce antibodies and generating enduring memory cells. The study further detected tumor-specific IgG antibodies alongside long-lived plasma cells residing in the bone marrow, indicating the establishment of a comprehensive, sustained immune protection that could thwart cancer’s return.
The intervention also promoted an increase in helper CD4⁺ T cells and memory CD8⁺ T cells, while harmonizing immune signaling pathways. This bolstered both humoral immunity, which relies on antibodies, and cell-mediated immunity, creating a multifaceted defense strategy.
Collectively, these observations indicate that initiating early, synergistic interventions to elevate T-cell function not only directly eradicates tumor cells but also fosters the maturation of TLSs, thereby perpetuating and intensifying anti-tumor immune activity over time.
“Our research demonstrates the potential to therapeutically generate functional tertiary lymphoid structures within tumors that were previously immune-cold,” stated Masanobu Komatsu, Ph.D., the study’s lead investigator and a senior scientist at the Johns Hopkins All Children’s Cancer & Blood Disorders Institute. “By constructing an optimal immune framework directly within the tumors, we can supercharge the patient’s intrinsic defenses—encompassing both T-cell and B-cell components—to combat cancer proliferation, recurrence, and spread to distant sites.”
Given that the prevalence of TLSs is tied to improved outcomes in a wide array of tumor types, combining these dual protein activators could provide a versatile method to augment current treatments. This includes checkpoint inhibitors, which form the cornerstone of modern immunotherapies, as well as established chemotherapeutic regimens.
Komatsu’s group continues to delve deeper into the precise mechanisms underlying TLS-based therapies and is gearing up for translational efforts toward clinical trials involving both adult and pediatric cancer patients.
The project received backing from National Cancer Institute/NIH R01 grants, the Department of Defense Congressionally Directed Cancer Research Program, and the Florida Department of Health Bankhead Coley Cancer Research Program.
Note that one of the study’s co-authors may have declared potential competing interests.
