Pre-existing TGF-β-specific T-cell immunity in patients with pancreatic cancer predicts survival after checkpoint inhibitors combined with radiotherapy

The antitumor activity of TGFβ-specific T cells is dependent on IL-6 signaling

Although interleukin (IL)-6 is considered immunosuppressive and tumor-promoting, emerging evidence suggests that it may support antitumor immunity. While combining immune checkpoint inhibitors (ICIs) and radiotherapy in patients with pancreatic cancer (PC) has yielded promising clinical results, the addition of an anti-IL-6 receptor (IL-6R) antibody has failed to elicit clinical benefits. Notably, a robust TGFβ-specific immune response at baseline in PC patients treated solely with ICIs and radiotherapy correlated with improved survival. Recent preclinical studies demonstrated the efficacy of a TGFβ-based immune modulatory vaccine in controlling PC tumor growth, underscoring the important role of TGFβ-specific immunity in PC. Here, we explored the importance of IL-6 for TGFβ-specific immunity in PC. In a murine model of PC, coadministration of the TGFβ-based immune modulatory vaccine with an anti-IL-6R antibody rendered the vaccine ineffective. IL-6R blockade hampered the development of vaccine-induced T-cells and tumoral T-cell infiltration. Furthermore, it impaired the myeloid population, resulting in increased tumor-associated macrophage infiltration and an enhanced immunosuppressive phenotype. In PC patients, in contrast to those receiving only ICIs and radiotherapy, robust TGFβ-specific T-cell responses at baseline did not correlate with improved survival in patients receiving ICIs, radiotherapy and IL-6R blockade. Peripheral blood immunophenotyping revealed that IL-6R blockade altered the T-cell and monocytic compartments, which was consistent with the findings in the murine model. Our data suggest that the antitumor efficacy of TGFβ-specific T cells in PC depends on the presence of IL-6 within the tumor. Consequently, caution should be exercised when employing IL-6R blockade in patients receiving cancer immunotherapy.

Radioimmunotherapy: a game-changer for advanced non-small cell lung cancer

Lung cancer, particularly non-small cell lung cancer (NSCLC), remains a leading cause of cancer-related deaths, with conventional treatments offering limited effectiveness in advanced stages, due to distant metastases and treatment resistance. Recent advancements in immunotherapy, specifically immune checkpoint inhibitors (ICIs), have shown promise, but their efficacy as standalone therapies are often insufficient. This has led to increased interest in combining ICIs with radiotherapy, known as radioimmunotherapy (iRT), to enhance treatment outcomes. This review explores the mechanisms that underlie the synergy between radiotherapy and immunotherapy. Radiotherapy can induce the "abscopal effect", eliciting systemic immune responses that reduce tumor burdens outside the treated area. It also increases the expression of major histocompatibility complex class I (MHC-I) on tumor cells, improving immune recognition. Furthermore, radiotherapy can modify the tumor microenvironment by inducing metabolic reprogramming to bolster anti-tumor immunity. We discuss strategies for optimizing iRT, including considerations of radiation doses, fractionation schedules, and treatment site selection, which significantly influence immune responses by enhancing MHC-I expression or promoting T-cell infiltration. Clinical evidence supports the efficacy of iRT in NSCLC and other cancers, though challenges in standardizing treatment protocols and managing side effects persist. Overall, radioimmunotherapy presents a promising approach to improving NSCLC treatment outcomes. Ongoing research into its mechanisms and the refinement of treatment may reshape clinical practice, offering more effective and personalized options for patients with advanced lung cancer. Further studies are essential to validate these findings and optimize therapeutic protocols.

TGFβ in Pancreas and Colorectal Cancer: Opportunities to Overcome Therapeutic Resistance

TGFβ is a pleiotropic signaling pathway that plays a pivotal role in regulating a multitude of cellular functions. TGFβ has a dual role in cell regulation where it induces growth inhibition and cell death; however, it can switch to a growth-promoting state under cancerous conditions. TGFβ is upregulated in colorectal cancer and pancreatic cancer, altering the tumor microenvironment and immune system and promoting a mesenchymal state. The upregulation of TGFβ in certain cancers leads to resistance to immunotherapy, and attempts to inhibit TGFβ expression have led to reduced therapeutic resistance when combined with chemotherapy and immunotherapy. Here, we review the current TGFβ inhibitor drugs in clinical trials for pancreatic and colorectal cancer, with the goal of uncovering advances in improving clinical efficacy for TGFβ combinational treatments in patients. Furthermore, we discuss the relevance of alterations in TGFβ signaling and germline variants in the context of personalizing treatment for patients who show lack of response to current therapeutics.

Promoting Articular Cartilage Regeneration through Microenvironmental Regulation

In recent years, as the aging population continues to grow, osteoarthritis (OA) has emerged as a leading cause of disability, with its incidence rising annually. Current treatments of OA include exercise and medications in the early stages and total joint replacement in the late stages. These approaches only relieve pain and reduce inflammation; however, they have significant side effects and high costs. Therefore, there is an urgent need to identify effective treatment methods that can delay the pathological progression of this condition. The changes in the articular cartilage microenvironment, which are complex and diverse, can aggravate the pathological progression into a vicious cycle, inhibiting the repair and regeneration of articular cartilage. Understanding these intricate changes in the microenvironment is crucial for devising effective treatment modalities. By searching relevant research articles and clinical trials in PubMed according to the keywords of articular cartilage, microenvironment, OA, mechanical force, hypoxia, cytokine, and cell senescence. This study first summarizes the factors affecting articular cartilage regeneration, then proposes corresponding treatment strategies, and finally points out the future research direction. We find that regulating the opening of mechanosensitive ion channels, regulating the expression of HIF-1, delivering growth factors, and clearing senescent cells can promote the formation of articular cartilage regeneration microenvironment. This study provides a new idea for the treatment of OA in the future, which can promote the regeneration of articular cartilage through the regulation of the microenvironment so as to achieve the purpose of treating OA.

Pre-existing cell populations with cytotoxic activity against SARS-CoV-2 in people with HIV and normal CD4/CD8 ratio previously unexposed to the virus

Introduction

HIV-1 infection may produce a detrimental effect on the immune response. Early start of antiretroviral therapy (ART) is recommended to preserve the integrity of the immune system. In fact, people with HIV (PWH) and normal CD4/CD8 ratio appear not to be more susceptible to severe forms of COVID-19 than the general population and they usually present a good seroconversion rate in response to vaccination against SARS-CoV-2. However, few studies have fully characterized the development of cytotoxic immune populations in response to COVID-19 vaccination in these individuals.

Methods

In this study, we recruited PWH with median time of HIV-1 infection of 6 years, median CD4/CD8 ratio of 1.0, good adherence to ART, persistently undetectable viral load, and negative serology against SARS-CoV-2, who then received the complete vaccination schedule against COVID-19. Blood samples were taken before vaccination against COVID-19 and one month after receiving the complete vaccination schedule.

Results

PWH produced high levels of IgG against SARS-CoV-2 in response to vaccination that were comparable to healthy donors, with a significantly higher neutralization capacity. Interestingly, the cytotoxic activity of PBMCs from PWH against SARS-CoV-2-infected cells was higher than healthy donors before receiving the vaccination schedule, pointing out the pre-existence of activated cell populations with likely unspecific antiviral activity. The characterization of these cytotoxic cell populations revealed high levels of Tgd cells with degranulation capacity against SARS-CoV-2-infected cells. In response to vaccination, the degranulation capacity of CD8+ T cells also increased in PWH but not in healthy donors.

Discussion

The full vaccination schedule against COVID-19 did not modify the ability to respond against HIV-1-infected cells in PWH and these individuals did not show more susceptibility to breakthrough infection with SARS-CoV-2 than healthy donors after 12 months of follow-up. These results revealed the development of protective cell populations with broad-spectrum antiviral activity in PWH with normal CD4/CD8 ratio and confirmed the importance of early ART and treatment adherence to avoid immune dysfunctions.

TGFβ-specific T cells induced by a TGFβ-derived immune modulatory vaccine both directly and indirectly modulate the phenotype of tumor-associated macrophages and fibroblasts

The tumor microenvironment (TME) of pancreatic cancer is highly immunosuppressive. We recently developed a transforming growth factor (TGF)β-based immune modulatory vaccine that controlled tumor growth in a murine model of pancreatic cancer by targeting immunosuppression and desmoplasia in the TME. We found that treatment with the TGFβ vaccine not only reduced the percentage of M2-like tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) in the tumor but polarized CAFs away from the myofibroblast-like phenotype. However, whether the immune modulatory properties of the TGFβ vaccine on TAM and CAF phenotypes are a direct consequence of the recognition and subsequent targeting of these subsets by TGFβ-specific T cells or an indirect consequence of the overall modulation induced within the TME remains unknown. Recognition of M2 macrophages and fibroblast by TGFβ-specific T cells was assessed by ELISpot and flow cytometry. The indirect and direct effects of the TGFβ vaccine on these cell subsets were evaluated by culturing M2 macrophages or fibroblasts with tumor-conditioned media or with T cells isolated from the spleen of mice treated with the TGFβ vaccine or a control vaccine, respectively. Changes in phenotype were assessed by flow cytometry and Bio-Plex multiplex system (Luminex). We found that TGFβ-specific T cells induced by the TGFβ vaccine can recognize M2 macrophages and fibroblasts. Furthermore, we demonstrated that the phenotype of M2 macrophages and CAFs can be directly modulated by TGFβ-specific T cells induced by the TGFβ vaccine, as well as indirectly modulated as a result of the immune-modulatory effects of the vaccine within the TME. TAMs tend to have tumor-promoting functions, harbor an immunosuppressive phenotype and are linked to decreased overall survival in pancreatic cancer when they harbor an M2-like phenotype. In addition, myofibroblast-like CAFs create a stiff extracellular matrix that restricts T cell infiltration, impeding the effectiveness of immune therapies in desmoplastic tumors, such as pancreatic ductal adenocarcinoma. Reducing immunosuppression and immune exclusion in pancreatic tumors by targeting TAMs and CAFs with the TGFβ-based immune modulatory vaccine emerges as an innovative strategy for the generation of a more favorable environment for immune-based therapies, such as immune checkpoint inhibitors.

The Role of the Transforming Growth Factor-β Signaling Pathway in Gastrointestinal Cancers

Transforming growth factor-β (TGF-β) has attracted attention as a tumor suppressor because of its potent growth-suppressive effect on epithelial cells. Dysregulation of the TGF-β signaling pathway is considered to be one of the key factors in carcinogenesis, and genetic alterations affecting TGF-β signaling are extraordinarily common in cancers of the gastrointestinal system, such as hereditary nonpolyposis colon cancer and pancreatic cancer. Accumulating evidence suggests that TGF-β is produced from various types of cells in the tumor microenvironment and mediates extracellular matrix deposition, tumor angiogenesis, the formation of CAFs, and suppression of the anti-tumor immune reaction. It is also being considered as a factor that promotes the malignant transformation of cancer, particularly the invasion and metastasis of cancer cells, including epithelial-mesenchymal transition. Therefore, elucidating the role of TGF-β signaling in carcinogenesis, cancer invasion, and metastasis will provide novel basic insight for diagnosis and prognosis and the development of new molecularly targeted therapies for gastrointestinal cancers. In this review, we outline an overview of the complex mechanisms and functions of TGF-β signaling. Furthermore, we discuss the therapeutic potentials of targeting the TGF-β signaling pathway for gastrointestinal cancer treatment and discuss the remaining challenges and future perspectives on targeting this pathway.