Surface engineering for lymphocyte programming

A review of innovative design strategies: Artificial antigen presenting cells in cancer immunotherapy

Developing nanocarriers that can carry medications directly to tumors is an exciting development in cancer nanomedicine. The efficacy of this intriguing therapeutic approach is, however, compromised by intricate and immunosuppressive circumstances that arise concurrently with the onset of cancer. The artificial antigen presenting cell (aAPC), a micro or nanoparticle based device that mimics an antigen presenting cell by providing crucial signal proteins to T lymphocytes to activate them against cancer, is one cutting-edge method for cancer immunotherapy. This review delves into the critical design considerations for aAPCs, particularly focusing on particle size, shape, and the non-uniform distribution of T cell activating proteins on their surfaces. Adequate surface contact between T cells and aAPCs is essential for activation, prompting engineers to develop nano-aAPCs with microscale contact areas through techniques such as shape modification and nanoparticle clustering. Additionally, we explore recommendations for future advancements in this field.

Improvement of Islet Engrafts via Treg Induction Using Immunomodulating Polymeric Tolerogenic Microparticles

Type 1 diabetes (T1D) is a life-threatening condition for which islet transplantation offers a way to extend longevity and vastly improve quality of life, but the degree and duration of success can vary greatly due to the patient's protective immunity against foreign material. The field is in need of cellular engineering modalities to promote a localized, tolerogenic environment to protect transplanted islet tissue. Artificial antigen-presenting cells (aAPCs) can be designed exogenously to mimic immune cells, such as dendritic cells, and administered to patients, allowing greater control over T cell differentiation. As regulatory T cell (Treg) modulation can reduce the activity of cytotoxic T-effector populations, this strategy can be used to promote immune acceptance of both biomaterials and cellular transplants, such as islets. A new class of poly(lactic-co-glycolic acid) (PLGA) and PLGA/PBAE-blend aAPCs containing transforming growth factor beta and conjugated with anti-CD3 and anti-CD28 antibodies, called tolerogenic aAPCs (TolAPCs), are specifically designed to generate a tolerogenic response by inducing Tregs. We characterized TolAPCs' physical and chemical properties via advanced particle imaging and sizing modalities and investigated their impact on the local and systemic immune system across BALB/c and C57BL/6 mouse strains as well as healthy male and female mice via histologic, gene expression, and immunofluorescence staining methods. Strain-specific differences were observed, whereas sex made no difference in the TolAPC response. TolAPCs stimulated the expansion of FOXP3+ Tregs and provided islet cell protection, maintaining improved glucose-stimulated insulin secretion in vitro when co-cultured with cytotoxic CD8+ T cells. We also explored the ability of this TolAPC platform to promote tolerance in a streptozotocin-induced murine T1D C57BL/6 mouse model. We achieved partial islet protection over the first few days following co-injection with PLGA/PBAE TolAPCs; however, grafts failed soon thereafter. Analysis of the local injection site demonstrated that other immune cell types, including APCs and cytotoxic natural killer cells, increased in the islet injection site. While we aimed to promote a localized tolerogenic microenvironment in vivo using biodegradable TolAPCs to induce Tregs and extend islet transplant durability, further TolAPC improvements will be required to both elongate efficacy and control additional immune cell responders.

Integrative Analysis of Bulk RNA-Seq and Single-Cell RNA-Seq Unveils the Characteristics of the Immune Microenvironment and Prognosis Signature in Prostate Cancer

The immune microenvironment is a culmination of the collaborative effort of immune cells and is important in cancer development. The underlying mechanisms of the tumor immune microenvironment in regulating prostate cancer (PRAD) are unclear. In the current study, 144 natural killer cell-related genes were identified using differential expression, single-sample gene set enrichment analysis, and weighted gene coexpression network analysis. Furthermore, VCL, ACTA2, MYL9, MYLK, MYH11, TPM1, ACTG2, TAGLN, and FLNC were selected as hub genes via the protein-protein interaction network. Based on the expression patterns of the hub genes, endothelial, epithelial, and tissue stem cells were identified as key cell subpopulations, which could regulate PRAD via immune response, extracellular signaling, and protein formation. Moreover, 27 genes were identified as prognostic signatures and used to construct the risk score model. Receiver operating characteristic curves revealed the good performance of the risk score model in both the training and testing datasets. Different chemotherapeutic responses were observed between the low- and high-risk groups. Additionally, a nomogram based on the risk score and other clinical features was established to predict the 1-, 3-, and 5-year progression-free interval of patients with PRAD. This study provides novel insights into the molecular mechanisms of the immune microenvironment and its role in the pathogenesis of PARD. The identification of key cell subpopulations has a potential therapeutic and prognostic use in PRAD.

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).

Antibody-drug nanoparticle induces synergistic treatment efficacies in HER2 positive breast cancer cells

Chemotherapeutic drugs suffer from non-specific binding, undesired toxicity, and poor blood circulation which contribute to poor therapeutic efficacy. In this study, antibody–drug nanoparticles (ADNs) are engineered by synthesizing pure anti-cancer drug nanorods (NRs) in the core of nanoparticles with a therapeutic monoclonal antibody, Trastuzumab on the surface of NRs for specific targeting and synergistic treatments of human epidermal growth factor receptor 2 (HER2) positive breast cancer cells. ADNs were designed by first synthesizing ~ 95 nm diameter × ~ 500 nm long paclitaxel (PTX) NRs using the nanoprecipitation method. The surface of PTXNRs was functionalized at 2′ OH nucleophilic site using carbonyldiimidazole and conjugated to TTZ through the lysine residue interaction forming PTXNR-TTZ conjugates (ADNs). The size, shape, and surface charge of ADNs were characterized using scanning electron microscopy (SEM), SEM, and zeta potential, respectively. Using fluorophore labeling and response surface analysis, the percentage conjugation efficiency was found > 95% with a PTX to TTZ mass ratio of 4 (molar ratio ≈ 682). In vitro therapeutic efficiency of PTXNR-TTZ was evaluated in two HER2 positive breast cancer cell lines: BT-474 and SK-BR-3, and a HER2 negative MDA-MB-231 breast cancer cell using MTT assay. PTXNR-TTZ inhibited > 80% of BT-474 and SK-BR-3 cells at a higher efficiency than individual PTX and TTZ treatments alone after 72 h. A combination index analysis indicated a synergistic combination of PTXNR-TTZ compared with the doses of single-drug treatment. Relatively lower cytotoxicity was observed in MCF-10A human breast epithelial cell control. The molecular mechanisms of PTXNR-TTZ were investigated using cell cycle and Western blot analyses. The cell cycle analysis showed PTXNR-TTZ arrested > 80% of BT-474 breast cancer cells in the G2/M phase, while > 70% of untreated cells were found in the G0/G1 phase indicating that G2/M arrest induced apoptosis. A similar percentage of G2/M arrested cells was found to induce caspase-dependent apoptosis in PTXNR-TTZ treated BT-474 cells as revealed using Western blot analysis. PTXNR-TTZ treated BT-474 cells showed ~ 1.3, 1.4, and 1.6-fold higher expressions of cleaved caspase-9, cytochrome C, and cleaved caspase-3, respectively than untreated cells, indicating up-regulation of caspase-dependent activation of apoptotic pathways. The PTXNR-TTZ ADN represents a novel nanoparticle design that holds promise for targeted and efficient anti-cancer therapy by selective targeting and cancer cell death via apoptosis and mitotic cell cycle arrest.

Biodegradable Cationic Polymer Blends for Fabrication of Enhanced Artificial Antigen Presenting Cells to Treat Melanoma

Biomimetic biomaterials are being actively explored in the context of cancer immunotherapy because of their ability to directly engage the immune system to generate antitumor responses. Unlike cellular therapies, biomaterial-based immunotherapies can be precisely engineered to exhibit defined characteristics including biodegradability, physical size, and tuned surface presentation of immunomodulatory signals. In particular, modulating the interface between the biomaterial surface and the target biological cell is key to enabling biological functions. Synthetic artificial antigen presenting cells (aAPCs) are promising as a cancer immunotherapy but are limited in clinical translation by the requirement of ex vivo cell manipulation and adoptive transfer of antigen-specific CD8+ T cells. To move toward acellular aAPC technology for in vivo use, we combine poly(lactic-co-glycolic acid) (PLGA) and cationic poly(beta-amino-ester) (PBAE) to form a biodegradable blend based on the hypothesis that therapeutic aAPCs fabricated from a cationic blend may have improved functions. PLGA/PBAE aAPCs demonstrate enhanced surface interactions with antigen-specific CD8+ T cells that increase T cell activation and expansion ex vivo, associated with significantly increased conjugation efficiency of T cell stimulatory signals to the aAPCs. Critically, these PLGA/PBAE aAPCs also expand antigen-specific cytotoxic CD8+ T cells in vivo without the need of adoptive transfer. Treatment with PLGA/PBAE aAPCs in combination with checkpoint therapy decreases tumor growth and extends survival in a B16-F10 melanoma mouse model. These results demonstrate the potential of PLGA/PBAE aAPCs as a biocompatible, directly injectable acellular therapy for cancer immunotherapy.

Role of Kruppel-like factor 4 in atherosclerosis

Atherosclerosis is one of the chronic progressive diseases, which is caused by vascular injury and promoted by the interaction of various inflammatory factors and inflammatory cells. In recent years, kruppel-like factor 4 (KLF4), a significant transcription factor that participated in cell growth, differentiation and proliferation, has been proved to cause substantial impacts on regulating cardiovascular disease. This paper will give a comprehensive summary to highlight KLF4 as a crucial regulator of foam cell formation, vascular smooth muscle cells (VSMCs) phenotypic transformation, macrophage polarization, endothelial cells inflammation, lymphocyte differentiation and cell proliferation in the process of atherosclerosis. Recent studies show that KLF4 may be an important "molecular switch" in the process of improving vascular injury and inflammation under harmful stimulation, suggesting that KLF4 is a latent disease biomarker for the therapeutic target of atherosclerosis and vascular disease.

3D Bioprinting and Translation of Beta Cell Replacement Therapies for Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disorder in which the body's own immune system selectively attacks beta cells within pancreatic islets resulting in insufficient insulin production and loss of the ability to regulate blood glucose (BG) levels. Currently, the standard of care consists of BG level monitoring and insulin administration, which are essential to avoid the consequences of dysglycemia and long-term complications. Although recent advances in continuous glucose monitoring and automated insulin delivery systems have resulted in improved clinical outcomes for users, nearly 80% of people with T1D fail to achieve their target hemoglobin A1c (HbA1c) levels defined by the American Diabetes Association. Intraportal islet transplantation into immunosuppressed individuals with T1D suffering from impaired awareness of hypoglycemia has resulted in lower HbA1c, elimination of severe hypoglycemic events, and insulin independence, demonstrating the unique potential of beta cell replacement therapy (BCRT) in providing optimal glycemic control and a functional cure for T1D. BCRTs need to maximize cell engraftment, long-term survival, and function in the absence of immunosuppression to provide meaningful clinical outcomes to all people living with T1D. One innovative technology that could enable widespread translation of this approach into the clinic is three-dimensional (3D) bioprinting. Herein, we review how bioprinting could facilitate translation of BCRTs as well as the current and forthcoming techniques used for bioprinting of a BCRT product. We discuss the strengths and weaknesses of 3D bioprinting in this context in addition to the road ahead for the development of BCRTs. Impact statement Significant research developments in beta cell replacement therapies show its promise in providing a functional cure for type 1 diabetes (T1D); yet, their widespread clinical use has been difficult to achieve. This review provides a brief overview of the requirements for a beta cell replacement product followed by a discussion on both the promise and limitations of three-dimensional bioprinting in facilitating the fabrication of such products to enable translation into the clinic. Advancements in this area could be a key component to unlocking the safety and effectiveness of beta cell therapy for T1D.

In situ genetic engineering of tumors for long-lasting and systemic immunotherapy

There is an urgent need for improved cancer immunotherapies. The nanoparticles described here deliver genes to stimulate the immune system to specifically kill tumor cells. This synthetic, biodegradable system avoids the use of common gene delivery materials like viruses that can have safety concerns and manufacturing limitations. Local nanoparticle delivery evades adverse side effects stemming from systemic administration of immune-activating therapeutics. Importantly, this technology causes a tumor-targeting response but does not require prior knowledge of a particular patient’s gene expression profile; thus, it can serve as a platform to combat many different solid cancers. Moreover, local nanoparticle administration causes a systemic cellular immune response, which has the potential to lead to better outcomes in the context of recurrence or metastasis.

Cancer immunotherapy has been the subject of extensive research, but highly effective and broadly applicable methods remain elusive. Moreover, a general approach to engender endogenous patient-specific cellular therapy, without the need for a priori knowledge of tumor antigen, ex vivo cellular manipulation, or cellular manufacture, could dramatically reduce costs and broaden accessibility. Here, we describe a biotechnology based on synthetic, biodegradable nanoparticles that can genetically reprogram cancer cells and their microenvironment in situ so that the cancer cells can act as tumor-associated antigen-presenting cells (tAPCs) by inducing coexpression of a costimulatory molecule (4-1BBL) and immunostimulatory cytokine (IL-12). In B16-F10 melanoma and MC38 colorectal carcinoma mouse models, reprogramming nanoparticles in combination with checkpoint blockade significantly reduced tumor growth over time and, in some cases, cleared the tumor, leading to long-term survivors that were then resistant to the formation of new tumors upon rechallenge at a distant site. In vitro and in vivo analyses confirmed that locally delivered tAPC-reprogramming nanoparticles led to a significant cell-mediated cytotoxic immune response with systemic effects. The systemic tumor-specific and cell-mediated immunotherapy response was achieved without requiring a priori knowledge of tumor-expressed antigens and reflects the translational potential of this nanomedicine.

Overview of Strategies to Improve Therapy against Tumors Using Natural Killer Cell

NK cells are lymphocytes with antitumor properties and can directly lyse tumor cells in a non-MHC-restricted manner. However, the tumor microenvironment affects the immune function of NK cells, which leads to immune evasion. This may be related to the pathogenesis of some diseases. Therefore, great efforts have been made to improve the immunotherapy effect of natural killer cells. NK cells from different sources can meet different clinical needs, in order to minimize the inhibition of NK cells and maximize the response potential of NK cells, for example, modification of NK cells can increase the number of NK cells in tumor target area, change the direction of NK cells, and improve their targeting ability to malignant cells. Checkpoint blocking is also a promising strategy for NK cells to kill tumor cells. Combination therapy is another strategy for improving antitumor ability, especially in combination with oncolytic viruses and nanomaterials. In this paper, the mechanisms affecting the activity of NK cells were reviewed, and the therapeutic potential of different basic NK cell strategies in tumor therapy was focused on. The main strategies for improving the immune function of NK cells were described, and some new strategies were proposed.

Improving cancer immunotherapy through nanotechnology

The 2018 Nobel Prize in Physiology or Medicine was awarded to pioneers in the field of cancer immunotherapy, as the utility of leveraging a patient's coordinated and adaptive immune system to fight the patient's unique tumour has now been validated robustly in the clinic. Still, the proportion of patients who respond to immunotherapy remains modest (~15% objective response rate across indications), as tumours have multiple means of immune evasion. The immune system is spatiotemporally controlled, so therapies that influence the immune system should be spatiotemporally controlled as well, in order to maximize the therapeutic index. Nanoparticles and biomaterials enable one to program the location, pharmacokinetics and co-delivery of immunomodulatory compounds, eliciting responses that cannot be achieved upon administration of such compounds in solution. The convergence of cancer immunotherapy, nanotechnology, bioengineering and drug delivery is opportune, as each of these fields has matured independently to the point that it can now be used to complement the others substantively and rationally, rather than modestly and empirically. As a result, unmet needs increasingly can be addressed with deductive intention. This Review explores how nanotechnology and related approaches are being applied to augmenting both endogenous leukocytes and adoptively transferred ones by informing specificity, influencing localization and improving function.

Imaging: Gear up for mechano-immunology

Immune cells including B and T lymphocytes have a remarkable ability to sense the physical perturbations through their surface expressed receptors. At the advent of modern imaging technologies paired with biophysical methods, we have gained the understanding of mechanical forces exerted by immune cells to perform their functions. This review will go over the imaging techniques already being used to study mechanical forces in immune cells. We will also discuss the dire need for new modern technologies for future work.

Polymeric micro- and nanoparticles for immune modulation

New advances in biomaterial-based approaches to modulate the immune system are being applied to treat cancer, infectious diseases, and autoimmunity. Particulate systems are especially well-suited to deliver immunomodulatory factors to immune cells since their small size allows them to engage cell surface receptors or deliver cargo intracellularly after internalization. Biodegradable polymeric particles are a particularly versatile platform for the delivery of signals to the immune system because they can be easily surface-modified to target specific receptors and engineered to release encapsulated cargo in a precise, sustained manner. Micro- and nanoscale systems have been used to deliver a variety of therapeutic agents including monoclonal antibodies, peptides, and small molecule drugs that function to activate the immune system against cancer or infectious disease, or suppress the immune system to combat autoimmune diseases and transplant rejection. This review provides an overview of recent advances in the development of polymeric micro- and nanoparticulate systems for the presentation and delivery of immunomodulatory agents targeted to a variety of immune cell types including APCs, T cells, B cells, and NK cells.

Facile synthesis of polylactide coarse microspheres as artificial antigen-presenting cells

Magnetic poly(l-lactide) coarse microspheres as artificial antigen-presenting cells were synthesized via simple chemical etching and antibody immobilization.