GIFT4 fusokine converts leukemic B cells into immune helper cells

Delivery routes matter: Safety and efficacy of intratumoral immunotherapy

Many anticancer immunotherapeutic agents, including the monoclonal immune checkpoint blocking antibodies, toll-like receptor (TLR) agonists, cytokines and immunostimulatory mRNA are commonly administrated by the intravenous route. Unfortunately, this route is prone to inducing, often life-threatening, side effects through accumulation of these immunotherapeutic agents at off-target tissues. Moreover, additional biological barriers need to be overcome before reaching the tumor microenvironment. By contrast, direct intratumoral injection allows for accomplishing local immune activation and multiple (pre)clinical studies have demonstrated decreased systemic toxicity, improved efficacy as well as abscopal effects. The approval of the oncolytic herpes simplex virus type 1 talimogene laherparepvec (T-VEC) as first approved intratumoral oncolytic virotherapy has fueled the interest to study intensively other immunotherapeutic approaches in preclinical models as well as in clinical context. Moreover, it has been shown that intratumoral administration of immunostimulatory agents successfully synergizes with immune checkpoint inhibitor therapy. Here we review the current state of the art in (pre)clinical intratumoral immunotherapy.

Inactivated STAT5 pathway underlies a novel inhibitory role of EBF1 in chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (CLL) is a disease caused by gradual accumulation of functionally incompetent lymphocytes. The majority of CLL cases are accompanied by chemoresistance. Early B cell factor 1 (EBF1) is a crucial contributor to B-cell lymphopoiesis. This study is to explore the effect of EBF1 on CLL cell progression and its involvement in regulating the signal transducers and activators of transcription 5 (STAT5) pathway. We conducted a correlation analysis between EBF1 and the clinical characteristics of CLL patients. Subsequently, EBF1 was overexpressed by transfection with EBF1 overexpression plasmid and the STAT5 pathway was also blocked by treatment with SH-4-54 in isolated CD20⁺ B lymphocytes to investigate their roles in the regulation of cellular functions. STAT5, Janus kinase 2 (JAK2) expression and their phosphorylation levels were determined by quantitative PCR and Western blot analyses. The in vivo effects of EBF1 on tumor growth were evaluated using a xenotransplant model. Downregulation of EBF1 was observed in CD20⁺ B lymphocytes of CLL patients. EBF1 overexpression disrupted the activation of STAT5 pathway, as evidenced by decreased expression and phosphorylation levels of STAT5 and JAK2. Furthermore, overexpression of EBF1 repressed viability and cell cycle entry, and increased apoptosis of CD20⁺ B lymphocytes by inhibiting the STAT5 pathway. Finally, EBF1 exerted antitumor effects in nude mice. Overall, our study elucidates the inhibitory role of EBF1 in CLL through inactivation of the STAT5 pathway, which may provide new targets for CLL treatment.

Clinico-Biological Implications of Modified Levels of Cytokines in Chronic Lymphocytic Leukemia: A Possible Therapeutic Role

B-cell chronic lymphocytic leukemia (B-CLL) is the main cause of mortality among hematologic diseases in Western nations. B-CLL is correlated with an intense alteration of the immune system. The altered functions of innate immune elements and adaptive immune factors are interconnected in B-CLL and are decisive for its onset, evolution, and therapeutic response. Modifications in the cytokine balance could support the growth of the leukemic clone via a modulation of cellular proliferation and apoptosis, as some cytokines have been reported to be able to affect the life of B-CLL cells in vivo. In this review, we will examine the role played by cytokines in the cellular dynamics of B-CLL patients, interpret the contradictions sometimes present in the literature regarding their action, and evaluate the possibility of manipulating their production in order to intervene in the natural history of the disease.

Crim1 suppresses left ventricular hypertrophy

Left ventricular hypertrophy is a leading cause of heart failure and sudden death. Cysteine-rich transmembrane bone morphogenetic protein regulator 1 (Crim1) is expressed at a high level in the heart and has a regulatory role in heart development. The present study aimed to test the hypothesis that Crim1 can have an inhibitory function on ventricular hypertrophy. Rat primary ventricular myocytes were stretched to induce myocyte hypertrophy, and treated with telmisartan or infected with Crim1-expressing recombinant adenovirus (Ad-Crim1). Rat ventricular hypertrophy was induced by abdominal aortic coarctation (AAC), and treated either with telmisartan or myocardial injection of Ad-Crim1 or empty adenovirus vector. The results showed that the expression of Crim1 decreased in the hypertrophic ventricle. The inhibition of angiotensin receptor type 1 (AT1R) by telmisartan in vitro and in vivo significantly increased the expression of Crim1 in the left ventricle. The overexpression of Crim1 by infection with Ad-Crim1 significantly inhibited stretch-induced ventricular myocyte hypertrophy in vitro. The overexpression of Crim1 by gavage with AT1R inhibitor telmisartan or myocardial injection of Ad-Crim1 markedly suppressed AAC-induced left ventricular hypertrophy in vivo. These results suggest that Crim1 has a suppressive function on ventricular hypertrophy and provides a novel therapeutic target for the treatment of cardiac hypertrophy.

Molecular Interactions Between Innate and Adaptive Immune Cells in Chronic Lymphocytic Leukemia and Their Therapeutic Implications

Innate immunity constitutes the first line of host defense against various anomalies in humans, and it also guides the adaptive immune response. The function of innate immune components and adaptive immune components are interlinked in hematological malignancies including chronic lymphocytic leukemia (CLL), and molecular interactions between innate and adaptive immune components are crucial for the development, progression and the therapeutic outcome of CLL. In this leukemia, genetic mutations in B cells and B cell receptors (BCR) are key driving factors along with evasion of cytotoxic T lymphocytes and promotion of regulatory T cells. Similarly, the release of various cytokines from CLL cells triggers the protumor phenotype in macrophages that further edges the CLL cells. Moreover, under the influence of various cytokines, dendritic cells are unable to mature and trigger T cell mediated antitumor response. The phenotypes of these cells are ultimately controlled by respective signaling pathways, the most notables are BCR, Wnt, Notch, and NF-κB, and their activation affects the cytokine profile that controls the pathogenesis of CLL, and challenge its treatment. There are several novel substances for CLL under clinical development, including kinase inhibitors, antibodies, and immune-modulators that offer new hopes. DC-based vaccines and CAR T cell therapy are promising tools; however, further studies are required to precisely dissect the molecular interactions among various molecular entities. In this review, we systematically discuss the involvement, common targets and therapeutic interventions of various cells for the better understanding and therapy of CLL.

Stable incorporation of GM-CSF into dissolvable microneedle patch improves skin vaccination against influenza

The widely used influenza subunit vaccine would benefit from increased protection rates in vulnerable populations. Skin immunization by microneedle (MN) patch can increase vaccine immunogenicity, as well as increase vaccination coverage due to simplified administration. To further increase immunogenicity, we used granulocyte-macrophage colony stimulating factor (GM-CSF), an immunomodulatory cytokine already approved for skin cancer therapy and cancer support treatment. GM-CSF has been shown to be upregulated in skin following MN insertion. The GM-CSF-adjuvanted vaccine induced robust and long-lived antibody responses cross-reactive to homosubtypic and heterosubtypic influenza viruses. Addition of GM-CSF resulted in increased memory B cell persistence relative to groups given influenza vaccine alone and led to rapid lung viral clearance following lethal infection with homologous virus in the mouse model. Here we demonstrate that successful incorporation of the thermolabile cytokine GM-CSF into MN resulted in improved vaccine-induced protective immunity holding promise as a novel approach to improved influenza vaccination. To our knowledge, this is the first successful incorporation of a cytokine adjuvant into dissolvable MNs, thus advancing and diversifying the rapidly developing field of MN vaccination technology.

Evolution of the magic bullet: Single chain antibody fragments for the targeted delivery of immunomodulatory proteins

Immunocytokines are fusion proteins that combine the specific antigen binding capacities of an antibody or derivative thereof and the potent bioactivity of a cytokine partner. These novel biopharmaceuticals have been directed to various targets of oncological as well as non-oncological origin and a handful of promising constructs are currently advancing in the clinical trial pipeline. Several factors such as the choice of a disease specific antigen, the antibody format and the modulatory nature of the payload are crucial, not only for therapeutic efficacy and safety but also for the commercial success of such a product. In this review, we provide an overview of the basic principles and obstacles in immunocytokine design with a specific focus on single chain antibody fragment-based constructs that employ interleukins as the immunoactive component. Impact statement Selective activation of the immune system in a variety of malignancies represents an attractive approach when existing strategies have failed to provide adequate treatment options. Immunocytokines as a novel class of bifunctional protein therapeutics have emerged recently and generated promising results in preclinical and clinical studies. In order to harness their full potential, multiple different aspects have to be taken into consideration. Several key points of these fusion constructs are discussed here and should provide an outline for the development of novel products based on an overview of selected formats.