Targeted Activation of T Cells with IL-2-Coupled Nanoparticles

Construction of rBCG carrying the IL-2-BZLF1 fusion gene and its immunological function

In this research, a recombinant Bacillus Calmette Guerin (rBCG) vector vaccine carrying a human IL-2 and EBV BZLF1 fusion gene (IL-2-BZLF1-rBCG) was constructed. The IL-2-BZLF1-rBCG construct was successfully generated and stably expressed the IL-2 and BZLF1 proteins. IL-2-BZLF1-rBCG activated the immune system and promoted the secretion of IFN-γ and TNF-α by CD4+ and CD8+ T cells. IL-2-BZLF1-rBCG activated lymphocytes to effectively kill EBV-positive NPC cells in vitro. Additionally, IL-2-BZLF1-rBCG stimulated the proliferation of NK cells and lymphocytes in vivo, activated related immune responses, and effectively treated EBV-positive NPC. The immune response to and pharmacological effect of IL-2-BZLF1-rBCG were explored in vitro and in vivo to provide a theoretical and experimental basis for the prevention and treatment of EBV-positive tumors with an rBCG vector vaccine. KEY POINTS: • rBCG with human IL-2 and BZLF1 of EB virus was constructed • The IL-2-BZLF1 fusion gene was stably expressed with rBCG • rBCG with IL-2-BZLF1 has an obvious immune response in vitro and in vivo.

Modulatory effect of interleukin-2 loaded chitosan nano sphere on regulatory T cell activity in streptozotocin-induced diabetic mice

OBJECTIVE

The current study aimed to assess the modulating effect of IL-2 encapsulated chitosan-nanoparticles (CSNPs) on the function of Treg cells through induction of type 1 diabetes (T1D). Treg cell function was monitored by the forkhead box P3 (FoxP3) and transforming growth factor beta (TGFβ) levels, correlating them with blood glucose and serum insulin levels.

MATERIALS AND METHODS

In this case-control study, a low dose of IL-2 (free and chitosan-loaded) was injected into a diabetic mice group. The levels of FoxP3 and TGF-β 1 were assessed using Enzyme-Linked Immunosorbent Assay. In addition, blood glucose and serum insulin levels were determined.

RESULTS

The mean glucose level decreased significantly after free rIL-2 or rIL-2 / CSNPs treatment. Meanwhile, the mean serum insulin level was significantly increased after treatment with free rIL-2 or rIL-2/CSNPs. The mean levels of FoxP3 and TGFβ 1 were significantly increased with either free rIL-2 or rIL-2/CSNPs compared to the T1D untreated group (P < 0.001). In the treated mice group receiving free CSNPs, there was a significant negative correlation between glucose and insulin levels. Moreover, FoxP3 & TGFβ 1 levels had a significant positive correlation. In treated mice groups with free rIL-2 and IL-2 CSNPs, there was a significant positive correlation between FoxP3 and glucose levels. A significant negative correlation was found after conducting a correlation between insulin level and FoxP3 in the T1D/ rIL-2 / CSNPs group.

CONCLUSIONS

Low-dose IL-2 selectively modulates FoxP3 + Tregs, and TGFβ 1 increases their levels. These results demonstrated that IL-2-free and chitosan-loaded nanoparticles can be therapeutic agents in T1D.

Non-clinical safety assessment of novel drug modalities: Genome safety perspectives on viral-, nuclease- and nucleotide-based gene therapies

Gene therapies have emerged as promising treatments for various conditions including inherited diseases as well as cancer. Ensuring their safe clinical application requires the development of appropriate safety testing strategies. Several guidelines have been provided by health authorities to address these concerns. These guidelines state that non-clinical testing should be carried out on a case-by-case basis depending on the modality. This review focuses on the genome safety assessment of frequently used gene therapy modalities, namely Adeno Associated Viruses (AAVs), Lentiviruses, designer nucleases and mRNAs. Important safety considerations for these modalities, amongst others, are vector integrations into the patient genome (insertional mutagenesis) and off-target editing. Taking into account the constraints of in vivo studies, health authorities endorse the development of novel approach methodologies (NAMs), which are innovative in vitro strategies for genotoxicity testing. This review provides an overview of NAMs applied to viral and CRISPR/Cas9 safety, including next generation sequencing-based methods for integration site analysis and off-target editing. Additionally, NAMs to evaluate the oncogenicity risk arising from unwanted genomic modifications are discussed. Thus, a range of promising techniques are available to support the safe development of gene therapies. Thorough validation, comparisons and correlations with clinical outcomes are essential to identify the most reliable safety testing strategies. By providing a comprehensive overview of these NAMs, this review aims to contribute to a better understanding of the genome safety perspectives of gene therapies.

The combination of IL-2 nanoparticles and Palbociclib enhances the anti-tumor immune response for colon cancer therapy

Immunotherapy of tumors plays a pivotal role in the current treatment of cancer. While interleukin 2 (IL-2) demonstrated its efficacy as an immunotherapeutic drug in the early days, its short blood circulation time poses challenges in maintaining effective therapeutic concentrations. Additionally, IL-2's activation of regulatory T cells can counteract its anti-cancer effects. Therefore, the primary goal of this study was to formulate IL-2-carrying nanoparticles via boron-nitrogen coordination between methoxy poly (ethylene glycol) block poly-[(N-2-hydroxyethyl)-aspartamide]phenylboronic acid (mPEG-b-PHEA-PBA, P-PBA) and poly (L-lysine) (PLL). These nanoparticles are intended to be used in combination with CDK4/6 inhibitors to address the short blood circulation time of IL-2, reduce its immunosuppressive effects, and enhance the overall immune response. The envisaged outcome is a sustained and potent therapeutic effect, offering a novel and promising combination therapy strategy for tumor immunotherapy.

Immunoswitch Nanomodulators Enable Active Targeting and Selective Proliferation of Regulatory T Cells for Multiple Sclerosis Therapy

Interleukin-2 (IL-2) used in multiple sclerosis (MS) therapy modulates the balance between regulatory T (Treg) cells and effector T (Teff) cells. However, the off-target activation of Teff cells by IL-2 limits its clinical application. Therefore, a rapidly prepared immunoswitch nanomodulator termed aT-IL2C NPs was developed, which specifically recognized Treg cells with high TIGIT expression thanks to the presence of an anti-TIGIT and an IL-2/JES6-1 complex (IL2C) being delivered to Treg cells but not to Teff cells with low TIGIT expression. Then, IL2C released IL-2 due to the specific expression of the high-affinity IL-2 receptor on Treg cells, thus enabling the active targeting and selective proliferation of Treg cells. Moreover, the anti-TIGIT of aT-IL2C NPs selectively inhibited the proliferation of Teff cells while leaving the proliferation of Treg cells unaffected. In addition, since the IL-2 receptor on Teff cells had medium-affinity, the IL2C hardly released IL-2 to Teff cells, thus enabling the inhibition of Teff cell proliferation. The treatment of experimental autoimmune encephalomyelitis (EAE) mice with aT-IL2C NPs ameliorated the severity of the EAE and restored white matter integrity. Collectively, this work described a potential promising agent for effective MS therapy.

Targeting anticancer immunity in oral cancer: Drugs, products, and nanoparticles

Oral cavity carcinomas are the most frequent malignancies among head and neck malignancies. Oral tumors include not only oral cancer cells with different potency and stemness but also consist of diverse cells, containing anticancer immune cells, stromal and also immunosuppressive cells that influence the immune system reactions. The infiltrated T and natural killer (NK) cells are the substantial tumor-suppressive immune compartments in the tumor. The infiltration of these cells has substantial impacts on the response of tumors to immunotherapy, chemotherapy, and radiotherapy. Nevertheless, cancer cells, stromal cells, and some other compartments like regulatory T cells (Tregs), macrophages, and myeloid-derived suppressor cells (MDSCs) can repress the immune responses against malignant cells. Boosting anticancer immunity by inducing the immune system or repressing the tumor-promoting cells is one of the intriguing approaches for the eradication of malignant cells such as oral cancers. This review aims to concentrate on the secretions and interactions in the oral tumor immune microenvironment. We review targeting tumor stroma, immune system and immunosuppressive interactions in oral tumors. This review will also focus on therapeutic targets and therapeutic agents such as nanoparticles and products with anti-tumor potency that can boost anticancer immunity in oral tumors. We also explain possible future perspectives including delivery of various cells, natural products and drugs by nanoparticles for boosting anticancer immunity in oral tumors.

Critical Role of the Transcription Factor AKNA in T-Cell Activation: An Integrative Bioinformatics Approach

The human akna gene encodes an AT-hook transcription factor, the expression of which is involved in various cellular processes. The goal of this study was to identify potential AKNA binding sites in genes that participate in T-cell activation and validate selected genes. Here we analyzed ChIP-seq and microarray assays to determine AKNA-binding motifs and the cellular process altered by AKNA in T-cell lymphocytes. In addition, we performed a validation analysis by RT-qPCR to assess AKNA's role in promoting IL-2 and CD80 expression. We found five AT-rich motifs that are potential candidates as AKNA response elements. We identified these AT-rich motifs in promoter regions of more than a thousand genes in activated T-cells, and demonstrated that AKNA induces the expression of genes involved in helper T-cell activation, such as IL-2. The genomic enrichment and prediction of AT-rich motif analyses demonstrated that AKNA is a transcription factor that can potentially modulate gene expression by recognizing AT-rich motifs in a plethora of genes that are involved in different molecular pathways and processes. Among the cellular processes activated by AT-rich genes, we found inflammatory pathways potentially regulated by AKNA, suggesting AKNA is acting as a master regulator during T-cell activation.

Crosstalk of Inflammatory Cytokines within the Breast Tumor Microenvironment

Several immune and immunocompetent cells, including dendritic cells, macrophages, adipocytes, natural killer cells, T cells, and B cells, are significantly correlated with the complex discipline of oncology. Cytotoxic innate and adaptive immune cells can block tumor proliferation, and others can prevent the immune system from rejecting malignant cells and provide a favorable environment for tumor progression. These cells communicate with the microenvironment through cytokines, a chemical messenger, in an endocrine, paracrine, or autocrine manner. These cytokines play an important role in health and disease, particularly in host immune responses to infection and inflammation. They include chemokines, interleukins (ILs), adipokines, interferons, colony-stimulating factors (CSFs), and tumor necrosis factor (TNF), which are produced by a wide range of cells, including immune cells, such as macrophages, B-cells, T-cells, and mast cells, as well as endothelial cells, fibroblasts, a variety of stromal cells, and some cancer cells. Cytokines play a crucial role in cancer and cancer-related inflammation, with direct and indirect effects on tumor antagonistic or tumor promoting functions. They have been extensively researched as immunostimulatory mediators to promote the generation, migration and recruitment of immune cells that contribute to an effective antitumor immune response or pro-tumor microenvironment. Thus, in many cancers such as breast cancer, cytokines including leptin, IL-1B, IL-6, IL-8, IL-23, IL-17, and IL-10 stimulate while others including IL-2, IL-12, and IFN-γ, inhibit cancer proliferation and/or invasion and enhance the body's anti-tumor defense. Indeed, the multifactorial functions of cytokines in tumorigenesis will advance our understanding of cytokine crosstalk pathways in the tumor microenvironment, such as JAK/STAT, PI3K, AKT, Rac, MAPK, NF-κB, JunB, cFos, and mTOR, which are involved in angiogenesis, cancer proliferation and metastasis. Accordingly, targeting and blocking tumor-promoting cytokines or activating and amplifying tumor-inhibiting cytokines are considered cancer-directed therapies. Here, we focus on the role of the inflammatory cytokine system in pro- and anti-tumor immune responses, discuss cytokine pathways involved in immune responses to cancer and some anti-cancer therapeutic applications.

Low-dose IL-2 improved clinical symptoms by restoring reduced regulatory T cells in patients with refractory rheumatoid arthritis: A randomized controlled trial

Background

Regulatory T cells (Tregs) have been found to play crucial roles in immune tolerance. However, the status of Tregs in refractory rheumatoid arthritis (RA) is still unclear. Moreover, low-dose interleukin-2 (IL-2) has been reported to selectively promote the expansion of Tregs. This study investigated the status of CD4⁺ Tregs and low-dose IL-2 therapy in patients with refractory RA.

Methods

The absolute number of CD4⁺CD25⁺FOXP3⁺ Treg (CD4 Treg), CD4⁺IL17⁺ T (Th17), and other subsets in peripheral blood (PB) from 41 patients with refractory RA and 40 healthy donors was characterized by flow cytometry combined with an internal microsphere counting standard. Twenty-six patients with refractory RA were treated with daily subcutaneous injections of 0.5 million IU of human IL-2 for five consecutive days. Then, its effects on CD4 Treg and Th17 cells in PB were analyzed.

Results

A decrease in the absolute number of PB CD4 Tregs rather than the increase in the number of Th17 was found to contribute to an imbalance between Th17 and CD4 Tregs in these patients, suggesting an essential role of CD4 Tregs in sustained high disease activity. Low-dose IL-2 selectively increased the number of CD4 Tregs and rebalanced the ratio of Th17 and CD4 Tregs, leading to increased clinical symptom remission without the observed side effects.

Conclusions

An absolute decrease of PB CD4 Tregs in patients with refractory RA was associated with continuing disease activation but not the increase of Th17 cells. Low-dose IL-2, a potential therapeutic candidate, restored decreased CD4 Tregs and promoted the rapid remission of patients with refractory RA without overtreatment and the observed side effects.

Clinical trial registration

http://www.chictr.org.cn/showproj.aspx?proj=13909, identifier ChiCTR-INR-16009546.

Engineered nanomaterials trigger abscopal effect in immunotherapy of metastatic cancers

Despite advances in cancer treatment, metastatic cancer is still the main cause of death in cancer patients. At present, the treatment of metastatic cancer is limited to palliative care. The abscopal effect is a rare phenomenon in which shrinkage of metastatic tumors occurs simultaneously with the shrinkage of a tumor receiving localized treatment, such as local radiotherapy or immunotherapy. Immunotherapy shows promise for cancer treatment, but it also leads to consequences such as low responsiveness and immune-related adverse events. As a promising target-based approach, intravenous or intratumoral injection of nanomaterials provides new opportunities for improving cancer immunotherapy. Chemically modified nanomaterials may be able to trigger the abscopal effect by regulating immune cells. This review discusses the use of nanomaterials in killing metastatic tumor cells through the regulation of immune cells and the prospects of such nanomaterials for clinical use.

Antitumor Immunotherapy of Sialic Acid and/or GM1 Modified Coenzyme Q10 Submicron Emulsion

Immunotherapy is a novel therapeutic approach for controlling and killing tumor cells by stimulating or reconstituting the immune system, among which T cells serve as immune targets. Herein, we used coenzyme Q10 (CoQ10), which has both immune activation and avoids adverse reactions, as a model drug and developed four CoQ10 submicron emulsions modified with sialic acid (SA) and/or monosialotetrahexosyl ganglioside (GM1). On the one hand, SA interacts with L-selectins on the surface of T cells after entering the circulatory system, leading to activation of T cells and enhancement of antitumor immune responses. On the other hand, owing to its immune camouflage, GM1 can prolong the circulation time of the preparation in the body, thereby increasing the accumulation of the drug at the tumor site. In vitro and in vivo experiments showed that SA-modified preparations exhibited stronger immune activation and inhibition of tumor proliferation. Pharmacokinetic experiments showed that GM1-modified preparations have longer circulation times in vivo. However, SA and GM1 co-modification did not produce a synergistic effect on the preparation. In conclusion, the SA-modified CoQ10 submicron emulsion (Q10-SE) showed optimal antitumor efficacy when administered at a medium dose (6 mg CoQ10 kg^-1). In this study, the submicron emulsion model was used as a carrier, and the tumor-bearing mice were used as animal models. In addition, CoQ10 submicron emulsion was modified with SA-CH with active targeting function and/or GM1 with long-circulation function to explore the antitumor effects of different doses of CoQ10 submicron emulsion, and to screen the best tumor immunotherapy formulations of CoQ10.

Controlled release of bioactive IL-2 from visible light photocured biodegradable elastomers for cancer immunotherapy applications

Biodegradable elastomeric controlled-release poly (decane-co-tricarballylate) (PDET) based matrices capable of maintaining the stability and bioactivity of Interleukin-2 (IL-2) through the utilization of visible-light curing and solvent-free loading of the cytokine are reported. The elastomeric devices were fabricated by intimately mixing lyophilized IL-2 powder with the acrylated prepolymer before photocrosslinking. The bioactivity of the released protein was assessed by its ability to stimulate the proliferation of the C57BL/6 mouse cytotoxic T lymphocyte, and its concentration was analysed using ELISA. The influence of changes in the polymer's physicochemical and mechanical properties on IL-2 release kinetics and bioactivity were also studied. The increase in the device's surface area and the incorporation of trehalose in the loaded lyophilized mix increased the IL-2 release rate with drug release proceeding via typical zero-order release kinetics. Moreover, the decrease in the degree of acrylation of the prepared devices increased the IL-2 release rate. The bioactivity assay showed that IL-2 retained over 94% of its initial bioactivity throughout 28 days of the release period. A new protein delivery vehicle composed of biodegradable PDET elastomers was demonstrated to be promising and effective for linear, constant, and sustained osmotic-driven release of bioactive IL-2 and other sensitive proteins and hormones.

Gm40600 promotes CD4+ T-cell responses by interacting with Ahnak

It is important to characterize novel proteins involved in T- and B-cell responses. Our previous study demonstrated that a novel protein, Mus musculus Gm40600, reduced the proliferation of Mus musculus plasmablast (PB)-like SP 2/0 cells and B-cell responses induced in vitro by LPS. In the present study, we revealed that Gm40600 directly promoted CD4+ T-cell responses to indirectly up-regulate B-cell responses. Importantly, we found that CD4+ T-cell responses, including T-cell activation and differentiation and cytokine production, were increased in Gm40600 transgenic (Tg) mice and were reduced in Gm40600 knockout (KO) mice. Finally, we demonstrated that Gm40600 promoted the Ahnak-mediated calcium signalling pathway by interacting with Ahnak to maintain a cytoplasmic lateral location of Ahnak in CD4+ T cells. Collectively, our data suggest that Gm40600 promotes CD4+ T-cell activation to up-regulate the B-cell response via interacting with Ahnak to promote the calcium signalling pathway. The results suggest that targeting Gm40600 may be a means to control CD4+ T-cell-related diseases.

Nanoparticles for generating antigen-specific T cells for immunotherapy

T cell therapy shows promise as an immunotherapy in both immunostimulatory and immunosuppressive applications. However, the forms of T cell-based therapy that are currently in the clinic, such as adoptive cell transfer and vaccines, are limited by cost, time-to-treatment, and patient variability. Nanoparticles offer a modular, universal platform to improve the efficacy of various T cell therapies as nanoparticle properties can be easily modified for enhanced cell targeting, organ targeting, and cell internalization. Nanoparticles can enhance or even replace endogenous cells during each step of generating an antigen-specific T cell response - from antigen presentation and T cell activation to T cell maintenance. In this review, we discuss the unique applications of nanoparticles for antigen-specific T cell therapy, focusing on nanoparticles as vaccines (to activate endogenous antigen presenting cells (APCs)), as artificial Antigen Presenting Cells (aAPCs, to directly activate T cells), and as drug delivery vehicles (to support activated T cells).