Interleukin-15 in cancer immunotherapy: IL-15 receptor complex versus soluble IL-15 in a cancer cell-delivered murine leukemia model

Chemokines and Cytokines in Immunotherapy of Melanoma and Other Tumors: From Biomarkers to Therapeutic Targets

Chemokines and cytokines represent an emerging field of immunotherapy research. They are responsible for the crosstalk and chemoattraction of immune cells and tumor cells. For instance, CXCL9/10/11 chemoattract effector CD8+ T cells to the tumor microenvironment, making an argument for their promising role as biomarkers for a favorable outcome. The cytokine Interleukin-15 (IL-15) can promote the chemokine expression of CXCR3 ligands but also XCL1, contributing to an important DC-T cell interaction. Recruited cytotoxic T cells can be clonally expanded by IL-2. Delivering or inducing these chemokines and cytokines can result in tumor shrinkage and might synergize with immune checkpoint inhibition. In addition, blocking specific chemokine and cytokine receptors such as CCR2, CCR4 or Il-6R can reduce the recruitment of tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs) or regulatory T cells (Tregs). Efforts to target these chemokines and cytokines have the potential to personalize cancer immunotherapy further and address patients that are not yet responsive because of immune cell exclusion. Targeting cytokines such as IL-6 and IL-15 is currently being evaluated in clinical trials in combination with immune checkpoint-blocking antibodies for the treatment of metastatic melanoma. The improved overall survival of melanoma patients might outweigh potential risks such as autoimmunity. However, off-target toxicity needs to be elucidated.

The role of exhausted natural killer cells in the immunopathogenesis and treatment of leukemia

The immune responses to cancer cells involve both innate and acquired immune cells. In the meantime, the most attention has been drawn to the adaptive immune cells, especially T cells, while, it is now well known that the innate immune cells, especially natural killer (NK) cells, play a vital role in defending against malignancies. While the immune cells are trying to eliminate malignant cells, cancer cells try to prevent the function of these cells and suppress immune responses. The suppression of NK cells in various cancers can lead to the induction of an exhausted phenotype in NK cells, which will impair their function. Recent studies have shown that the occurrence of this phenotype in various types of leukemic malignancies can affect the prognosis of the disease, and targeting these cells may be considered a new immunotherapy method in the treatment of leukemia. Therefore, a detailed study of exhausted NK cells in leukemic diseases can help both to understand the mechanisms of leukemia progression and to design new treatment methods by creating a deeper understanding of these cells. Here, we will comprehensively review the immunobiology of exhausted NK cells and their role in various leukemic malignancies. Video Abstract.

Studies on the Role of Compartmentalized Profiles of Cytokines in the Risk of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), the most common form of liver cancer, is frequently diagnosed late due to the absence of symptoms during early disease, thus heavily affecting the overall survival of these patients. Soluble immunological factors persistently produced during cirrhosis have been recognized as promoters of chronic inflammation and neoplastic transformation. The aim of this pilot study was to evaluate the predictive value of the cytokine profiles for HCC development. A Luminex xMAP approach was used for the quantification of 45 proteins in plasma and ascitic fluids of 44 cirrhotic patients without or with HCC of different etiologies. The association with patient survival was also evaluated. Univariate analyses revealed that very low levels of interleukin 5 (IL-5) (<15.86 pg/mL) in ascites and IL-15 (<12.40 pg/mL) in plasma were able to predict HCC onset with an accuracy of 81.8% and a sensitivity of 95.2%. Univariate analyses also showed that HCC, hepatitis B virus/hepatitis C virus infections, low levels of IL-5 and granulocyte-macrophage colony-stimulating factor in ascitic fluids, and high levels of eotaxin-1, hepatocyte growth factor and stromal-cell-derived factor 1α in plasma samples were factors potentially associated with a poor prognosis and decreased survival. Our results suggest a potential protective role of some immune modulators that may act in the peritoneal cavity to counteract disease progression leading to HCC development.

Engineered murine IL-21-secreting leukemia cells induce granzyme B+ T cells and CD4+CD44+CD62L- effector memory cells while suppressing regulatory T cells, leading to long-term survival

We have explored the use of an IL-21 cell-based anti-leukemia treatment in a mouse model of acute lymphoblastic leukemia. 70Z/3 leukemia cells, engineered to secrete IL-21 and injected into the peritoneum of syngeneic mice, induced a strong anti-leukemia response resulting in 100% survival. Mice that mounted an IL-21-induced anti-leukemia immune response were immune to the parent cell line (no IL-21) when rechallenged.Above a certain threshold, IL-21 secretion correlated with improved survival compared to mice injected with parent 70Z/3 cells. IL-21 was detected in serum with peak levels on day 7, correlating with the maximum expansion of IL-21-secreting 70Z/3 cells which subsequently were eliminated. Mice injected with IL-21-secreting leukemia cells had elevated numbers of granzyme B⁺ CD4⁺ and CD8⁺ T cells in the peritoneum, compared to mice injected with the parent cell line. Regulatory T cells, which increased greatly in 70Z/3-injected mice, failed to do so in mice injected with IL-21-secreting cells. Upon rechallenge, IL-21-primed mice went through a secondary immune response, primarily requiring CD4⁺ T cells, triggering a significant increase of CD4⁺CD44⁺CD62L^- effector memory T cells. Adoptive transfer of T cells from IL21-primed/rechallenged hosts into naïve mice was successful, indicating that IL-21-primed antigen-experienced T cells convey immunity to naïve mice.Our study shows that delivery of IL-21 in a cell-based anti-leukemia protocol has the potential to induce a potent immune response leading to cancer elimination and long-term immunity-properties which make IL-21 an attractive candidate for cancer immunotherapy. Protecting against tumor antigens as well as improving cancer immunity is justified, as current strategies are limited.

Exercise-induced IL-15 acted as a positive prognostic implication and tumor-suppressed role in pan-cancer

Objective: Exercise can produce a large number of cytokines that may benefit cancer patients, including Interleukin 15 (IL-15). IL-15 is a cytokine that has multiple functions in regulating the adaptive and innate immune systems and tumorigenesis of lung and breast cancers. However, the roles of IL-15 in other types of cancer remain unknown. In this article, we try to systematically analyze if IL-15 is a potential molecular biomarker for predicting patient prognosis in pan-cancer and its connection with anti-cancer effects of exercise. Methods: The expression of IL-15 was detected by The Cancer Genome Atlas (TCGA) database, Human protein Atlas (HPA), and Genotype Tissue-Expression (GTEX) database. Analysis of IL-15 genomic alterations and protein expression in human organic tissues was analyzed by the cBioPortal database and HPA. The correlations between IL-15 expression and survival outcomes, clinical features, immune-associated cell infiltration, and ferroptosis/cuproptosis were analyzed using the TCGA, ESTIMATE algorithm, and TIMER databases. Gene Set Enrichment Analysis (GSEA) was performed to evaluate the biological functions of IL-15 in pan-cancer. Results: The differential analysis suggested that the level of IL-15 mRNA expression was significantly downregulated in 12 tumor types compared with normal tissues, which is similar to the protein expression in most cancer types. The high expression of IL-15 could predict the positive survival outcome of patients with LUAD (lung adenocarcinoma), COAD (colon adenocarcinoma), COADREAD (colon and rectum adenocarcinoma), ESCA (esophageal carcinoma), SKCM (skin cutaneous melanoma), UCS (uterine carcinosarcoma), and READ (rectum adenocarcinoma). Moreover, amplification was found to be the most frequent mutation type of IL-15 genomic. Furthermore, the expression of IL-15 was correlated to the infiltration levels of various immune-associated cells in pan-cancer assessed by the ESTIMATE algorithm and TIMER database. In addition, IL-15 is positively correlated with ferroptosis/cuproptosis-related genes (ACSL4 and LIPT1) in pan-cancer. Levels of IL-15 were reported to be elevated in humans for 10-120 min following an acute exercise. Therefore, we hypothesized that the better prognosis of pan-cancer patients with regular exercise may be achieved by regulating level of IL-15. Conclusion: Our results demonstrated that IL-15 is a potential molecular biomarker for predicting patient prognosis, immunoreaction, and ferroptosis/cuproptosis in pan-cancer and partly explained the anti-cancer effects of exercise.

ZBTB28 inhibits breast cancer by activating IFNAR and dual blocking CD24 and CD47 to enhance macrophages phagocytosis

Breast cancer is the leading cause of cancer death in female. Until now, advanced breast cancer is still lack effective treatment strategies and reliable prognostic markers. In the present article, we introduced the physiologic and pathologic functions and regulation mechanisms of ZBTB28, a tumor suppressor gene, in breast cancer. ZBTB28 is frequently silenced in breast cancer due to promoter CpG methylation, and its expression is positively correlated with breast cancer patient survival. The antineoplastic effect of ZBTB28 in breast cancer was elucidated through a series of in vitro and in vivo measurements, including cell proliferation, apoptosis, cell cycle, epithelial mesenchymal transition (EMT), and growth of xenografts. Furthermore, ZBTB28 can directly regulate IFNAR to activate interferon-stimulated genes and potentiate macrophage activation. Ectopic ZBTB28 expression in breast cancer cells was sufficient to downregulate CD24 and CD47 to promote phagocytosis of macrophages, demonstrating that ZBTB28 was beneficial for the combination treatment of anti-CD24 and anti-CD47. Collectively, our results reveal a mode of action of ZBTB28 as a tumor suppressor gene and suggest that ZBTB28 is an important regulator of macrophage phagocytosis in breast cancer, holding promise for the development of novel therapy strategies for breast cancer patients.

Cytokines in Liver Transplantation

Cytokines, soluble mediators of the immune system, play a critical role in the pathogenesis of autoimmune, allergic and infectious diseases. They are also implicated in the initiation and development of allograft rejection. During recent years, there have been considerable advances in generating novel anti-cytokine agents with promoted efficacy and safety, which could be administrated for managing dysregulated cytokine secretion; besides, gene therapy for overexpression of immunomodulatory cytokines has shown substantial improvements. Liver transplantation has been established as a life-saving treatment for end-stage hepatic diseases but the growing number of recipients urge for improved post-transplant care including tolerance induction, infection control and resolving immunosuppressant drugs adverse effects. Cytokines with a wide range of proinflammatory and regulatory properties might be considered as potential therapeutic targets for selective suppression or enhancement of the immune responses in recipients. In the present review, we aimed to summarize the positive and negative effects of cytokines on liver allograft in addition to their prognostic and therapeutic values.

Protective and Therapeutic Effects of an IL-15:IL-15Rα-Secreting Cell-Based Cancer Vaccine Using a Baculovirus System

This study reports the use of the BacMam system to deliver and express self-assembling IL-15 and IL-15Rα genes to murine B16F10 melanoma and CT26 colon cancer cells. BacMam-based IL-15 and IL-15Rα were well-expressed and assembled to form the biologically functional IL-15:IL-15Rα complex. Immunization with this IL-15:IL-15Rα cancer vaccine delayed tumor growth in mice by inducing effector memory CD4⁺ and CD8⁺ cells and effector NK cells which are tumor-infiltrating. It caused strong antitumor immune responses of CD8⁺ effector cells in a tumor-antigen specific manner both in vitro and in vivo and significantly attenuated Treg cells which a control virus-infected cancer vaccine could induce. Post-treatment with this cancer vaccine after a live cancer cell injection also prominently delayed the growth of the tumor. Collectively, we demonstrate a vaccine platform consisting of BacMam virus-infected B16F10 or CT26 cancer cells that secrete IL-15:IL-15Rα. This study is the first demonstration of a functionally competent soluble IL-15:IL-15Rα complex-related cancer vaccine using a baculovirus system and advocates that the BacMam system can be used as a secure and rapid method of producing a protective and therapeutic cancer vaccine.

Prognostic Significance of the L3 Skeletal Muscle Index and Advanced Lung Cancer Inflammation Index in Elderly Patients with Esophageal Cancer

Objective

To evaluate the correlation between the advanced lung cancer inflammation index (ALI) and the L3 skeletal muscle index (L3SMI) and their prognostic value in elderly patients with esophageal cancer (EC).

Materials and Methods

The clinical data of 158 elderly patients with EC were collected retrospectively. The L3SMI measures the area of skeletal muscle at the level of the third lumbar (L3) vertebra using computed tomography (CT). A high L3SMI and low L3SMI group were created using sex-based quartiles. The ALI, prognostic nutrition index (PNI), and geriatric nutrition risk index (GNRI) were calculated according to standard laboratory protocols.

Results

The CT diagnostic criteria for senile sarcopenia in South China are height ≤32.96 cm²/m² for females and height ≤35.4 cm²/m² for males. The logistic regression analysis showed that a low L3SMI was significantly associated with a low ALI. Survival analysis revealed EC patients with a low L3SMI and a low ALI had poorer overall survival (OS) than patients with a high L3SMI and a high ALI. Univariate and multivariate Cox analyses showed that the L3SMI and ALI were independent predictors of EC prognosis in elderly individuals.

Conclusion

There was a significant correlation between the PNI, GNRI, ALI, and L3SMI. Overall, our findings show the L3SMI and ALI are clinical indicators that can potentially be used to independently predict the prognosis of elderly EC patients and display good predictive value.

Immunobiology and immunotherapy of COVID-19: A clinically updated overview

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new member of the coronavirus family that can cause coronavirus disease 2019 (COVID-19). COVID-9 has become a global pandemic with severe health issues around the world. Identifying the accurate immunopathogenesis of the COVID-19 and the immune response against SARS-CoV-2 is necessary for the development of therapeutic approaches and rational drug design. This paper aims to overview the updated clinical data on the immunopathogenesis of the COVID-19 and review the innate and adaptive immune response to SARS-CoV-2. Also, challenges of the immune response to SARS-CoV-2 leading to dysfunctional immune response and their contribution to the progression of the disease have been discussed. To achieve a more efficient immune response, multiple methods could be applied, including regulation of the immune response, augmentation of the immune system against the virus, inhibition of the dysfunctional immune checkpoints, and inhibition of the viral replication/infection. Based on the immune response against SARS-CoV-2 and its dysfunction, we introduce potential immunotherapies as well as reviewing recruiting/completed clinical trials of COVID-19.

IL-15/IL-15Rα Heterodimeric Complex as Cancer Immunotherapy in Murine Breast Cancer Models

Interleukin 15 (IL-15) has been evaluated as a potential treatment for solid tumors in clinical trials, but the effectiveness of systemic IL-15 administration as a monotherapy has not been realized. IL-15 receptor alpha (IL-15Rα) can stabilize IL-15 and enhance its bioactivity. The goal of this study was to examine the activity of IL-15/IL-15Rα complex (IL-15cx) to CD8⁺ T cells and evaluate its potential efficacy in murine breast cancer models. The antitumor efficacy was studied in mouse mammary carcinoma models (Her2/neu transgenic and 4T1-luc mammary cancers) treated with systemic recombinant protein with/without the depletion of myeloid-derived suppressor cells or intra-tumoral gene electrotransfer (GET). IL-15cx shows superior in vivo bioactivity to expand CD8 T cells in comparison to an equimolar single chain IL-15. T-bet is partially involved in CD8 T cell expansion ex vivo and in vivo due to IL-15 or IL-15cx. Intraperitoneal administration of IL-15cx results in a moderate inhibition of breast cancer growth that is associated with an increase in the frequency of cytotoxic CD8 T cells and the improvement of their function. The depletion of myeloid-derived suppressor cells (MDSCs) has no impact on mouse breast cancer growth. IL-15cx treatment diminishes MDSCs in murine tumors. However, it also antagonizes the effects of anti-Gr-1 depleting antibodies. Intratumoral GET with plasmid IL-15/IL-15Rα leads to a long-term survival benefit in 4T1 mammary carcinoma model. An early increase of local cytotoxic cells correlates with GET treatment and an increase of long-term memory T cells results from animals with complete tumor regression. Systemic and local administration of IL-15cx shows two distinct therapeutic responses, a moderate tumor growth inhibition or heterogeneous tumor regressions with survival improvement. Further studies are warranted to improve the efficacy of IL-15cx as an immunotherapy for breast cancer.

Biological effects of IL-15 on immune cells and its potential for the treatment of cancer

Interleukin-15 (IL-15) has recently emerged as a novel immunomodulatory cytokine in cancer immunotherapy. IL-15 has the potential to reject and destroy cancer cells in the tumor microenvironment by expanding and activating natural killer (NK), natural killer T (NKT), and memory (m) CD8+T cells. Due to the feasible outcomes obtained from preclinical studies and phase 1/2 clinical trials, IL-15-based therapy, including chimeric antigen receptor (CAR) T cell or CAR NK cell infusion following in vitro expansion in the presence of IL-15, used in combination with checkpoint inhibitors and other therapy may extend to clinical practice in the future. It is also important to understand the biological characteristics of IL-15 to ensure the maximal benefit of therapeutic strategies. Here, we summarize the current development of IL-15 in the following areas: anti-tumor mechanisms in the tumor microenvironment, advances in IL-15-based therapy itself or in combination with other methods, including biological agents, monoclonal antibodies, and adoptive immunotherapy.

Obesity, Sarcopenia, and Outcomes in Non-Small Cell Lung Cancer Patients Treated With Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors

Body composition refers to the proportional content of body fat mass and lean body mass that can lead to a continuum of different phenotypes ranging from cachectic/sarcopenic state to obesity. The heterogenetic phenotypes of body composition can contribute to formation of some cancer types and can sometimes lead to disparate outcomes. Both of these extremes of the spectrum exist in patients with non-small cell lung carcinoma (NSCLC). The discovery of new pathways that drive tumorigenesis contributing to cancer progression and resistance have expanded our understanding of cancer biology leading to development of new targeted therapies including tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (ICI) that have changed the landscape of NSCLC treatment. However, in the new era of precision medicine, the impact of body composition phenotypes on treatment outcomes and survival is now being elucidated. In this review, we will discuss the emerging evidence of a link between body composition and outcomes in patients with NSCLC treated with TKI and ICI. We will also discuss suggested mechanisms by which body composition can impact tumor behavior and anti-tumor immunological response.