Macrophage Modification Strategies for Efficient Cell Therapy

Bayesian cell therapy process optimization

Optimizing complex bioprocesses poses a significant challenge in several fields, particularly in cell therapy manufacturing. The development of customized, closed, and automated processes is crucial for their industrial translation and for addressing large patient populations at a sustainable price. Limited understanding of the underlying biological mechanisms, coupled with highly resource-intensive experimentation, are two contributing factors that make the development of these next-generation processes challenging. Bayesian optimization (BO) is an iterative experimental design methodology that addresses these challenges, but has not been extensively tested in situations that require parallel experimentation with significant experimental variability. In this study, we present an evaluation of noisy, parallel BO for increasing noise levels and parallel batch sizes on two in silico bioprocesses, and compare it to the industry state-of-the-art. As an in vitro showcase, we apply the method to the optimization of a monocyte purification unit operation. The in silico results show that BO significantly outperforms the state-of-the-art, requiring approximately 50% fewer experiments on average. This study highlights the potential of noisy, parallel BO as valuable tool for cell therapy process development and optimization.

Superparamagnetic Iron Oxide Nanoparticles Reprogram the Tumor Microenvironment and Reduce Lung Cancer Regrowth after Crizotinib Treatment

ALK-positive NSCLC patients demonstrate initial responses to ALK tyrosine kinase inhibitor (TKI) treatments, but eventually develop resistance, causing rapid tumor relapse and poor survival rates. Growing evidence suggests that the combination of drug and immune therapies greatly improves patient survival; however, due to the low immunogenicity of the tumors, ALK-positive patients do not respond to currently available immunotherapies. Tumor-associated macrophages (TAMs) play a crucial role in facilitating lung cancer growth by suppressing tumoricidal immune activation and absorbing chemotherapeutics. However, they can also be programmed toward a pro-inflammatory tumor suppressive phenotype, which represents a highly active area of therapy development. Iron loading of TAMs can achieve such reprogramming correlating with an improved prognosis in lung cancer patients. We previously showed that superparamagnetic iron oxide nanoparticles containing core-cross-linked polymer micelles (SPION-CCPMs) target macrophages and stimulate pro-inflammatory activation. Here, we show that SPION-CCPMs stimulate TAMs to secrete reactive nitrogen species and cytokines that exert tumoricidal activity. We further show that SPION-CCPMs reshape the immunosuppressive Eml4-Alk lung tumor microenvironment (TME) toward a cytotoxic profile hallmarked by the recruitment of CD8+ T cells, suggesting a multifactorial benefit of SPION-CCPM application. When intratracheally instilled into lung cancer-bearing mice, SPION-CCPMs delay tumor growth and, after first line therapy with a TKI, halt the regrowth of relapsing tumors. These findings identify SPIONs-CCPMs as an adjuvant therapy, which remodels the TME, resulting in a delay in the appearance of resistant tumors.

Leptin signalling regulates transcriptional differences in granulosa cells from genetically obese mice but not the activation of NLRP3 inflammasome

Obesity is associated with increased ovarian inflammation and the establishment of leptin resistance. We presently investigated the role of impaired leptin signalling on transcriptional regulation in granulosa cells (GCs) collected from genetically obese mice. Furthermore, we characterised the association between ovarian leptin signalling, the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome and macrophage infiltration in obese mice. After phenotype characterisation, ovaries were collected from distinct group of animals for protein and mRNA expression analysis: (i) mice subjected to a diet-induced obesity (DIO) protocol, where one group was fed a high-fat diet (HFD) and another a standard chow diet (CD) for durations of 4 or 16 weeks; (ii) mice genetically deficient in the long isoform of the leptin receptor (ObRb; db/db); (iii) mice genetically deficient in leptin (ob/ob); and (iv) mice rendered pharmacologically hyperleptinemic (LEPT). Next, GCs from antral follicles isolated from db/db and ob/ob mice were subjected to transcriptome analysis. Transcriptional analysis revealed opposing profiles in genes associated with steroidogenesis and prostaglandin action between the genetic models, despite the similarities in body weight. Furthermore, we observed no changes in the mRNA and protein levels of NLRP3 inflammasome components in the ovaries of db/db mice or in markers of M1 and M2 macrophage infiltration. This contrasted with the downregulation of NLRP3 inflammasome components and M1 markers in ob/ob and 16-wk HFD-fed mice. We concluded that leptin signalling regulates NLRP3 inflammasome activation and the expression of M1 markers in the ovaries of obese mice in an ObRb-dependent and ObRb-independent manner. Furthermore, we found no changes in the expression of leptin signalling and NLRP3 inflammasome genes in GCs from db/db and ob/ob mice, which was associated with no effects on macrophage infiltration genes, despite the dysregulation of genes associated with steroidogenesis in homozygous obese db/db. Our results suggest that: (i) the crosstalk between leptin signalling, NLRP3 inflammasome and macrophage infiltration takes place in ovarian components other than the GC compartment; and (ii) transcriptional changes in GCs from homozygous obese ob/ob mice suggest structural rearrangement and organisation, whereas in db/db mice the impairment in steroidogenesis and secretory activity.

Macrophage-based therapeutic approaches for cardiovascular diseases

Despite the advances in treatment options, cardiovascular disease (CVDs) remains the leading cause of death over the world. Chronic inflammatory response and irreversible fibrosis are the main underlying pathophysiological causes of progression of CVDs. In recent decades, cardiac macrophages have been recognized as main regulatory players in the development of these complex pathophysiological conditions. Numerous approaches aimed at macrophages have been devised, leading to novel prospects for therapeutic interventions. Our review covers the advancements in macrophage-centric treatment plans for various pathologic conditions and examines the potential consequences and obstacles of employing macrophage-targeted techniques in cardiac diseases.

Accelerative effects of alginate-chitosan/titanium oxide@geraniol nanosphere hydrogels on the healing process of wounds infected with Acinetobacter baumannii and Streptococcus pyogenes bacteria

This study was conducted to evaluate the effects of alginate-chitosan/titanium oxide/geraniol (Alg-Csn/TiO2@GRL nanosphere) nanospheres hydrogels on the healing process of the wounds infected with Acinetobacter baumannii and Streptococcus pyogenes bacteria. The nanospheres were successfully synthesized and their physicochemical properties such as DLS, FTIR, FE-SEM, TEM, XRD and also their safety and in-vitro antibacterial activity were assessed and confirmed. Following induction of the infected wounds, the mice were treated with s base ointment (Control), mupirocin® as standard control group and also hydrogels prepared from Alg-Csn@GRL, Alg-Csn/TiO2 and Alg-Csn/TiO2@GRL. Wound contraction, total bacterial count, expression of bFGF, VEGF, IGF-1, CD68 and COL-1 A, iNOS and eNOS were measured. The results showed the treatment of wounds with Alg-Csn/TiO2@GRL hydrogels significantly accelerated wound contraction, decreased total bacterial count and reduced the expressions of CD68, iNOS and eNOS and increased the expressions of VEGF, bFGF, IGF-1 and COL-1 A compared with other groups. It can be concluded that Alg-Csn/TiO2@GRL hydrogels expedite the wound healing process by their effects on bacteria and subsequently inflammation and increasing the expression of proliferative genes. The Alg-Csn/TiO2@GRL hydrogel can be utilized in combination with other agents for the treatment of infected wounds after future clinical studies.

MicroRNA miR-27a as a possible regulator of anti-inflammatory macrophage phenotype in preeclamptic placenta

INTRODUCTION

The role of the TGFβ signaling pathway, an important cascade responsible for the anti-inflammatory polarization of macrophages, in the development of both early- and late-onset preeclampsia (eoPE and loPE), remains poorly understood. In this study, we examined the components of the TGFβ signaling cascade and macrophage markers within placental tissue in normal pregnancy and in PE.

METHODS

Patients with eoPE, loPE, and normal pregnancy were enrolled in the study (n = 10 in each group). Following techniques were used for the investigation: immunohistochemistry analysis, western blotting, qRT-PCR, isolation of monocytes by magnetic sorting, transfection, microRNA sequencing, and bioinformatic analysis.

RESULTS

We observed a significant decrease in the anti-inflammatory macrophage marker CD206 in the loPE group, alongside with a significant down-regulation of CD206 protein production in both eoPE and loPE groups. The level of CD68-positive cells and relative levels of CD163 and MARCO production were comparable across the groups. However, we identified a significant decrease in the TGFβ receptor 2 production and its gene expression in the PE group. Further analysis revealed a link between TGFBR2 and MRC1 (CD206) genes through a single miRNA, hsa-miR-27a-3p. Transfecting CD14-derived macrophages with the hsa-miR-27a-3p mimic significantly changed TGFBR2 production, indicating the potential role of this miRNA in regulating the TGFβ signaling pathway. We also revealed the up-regulation of hsa-miR-27a-5p and hsa-miR-27a-3p in the trophoblast BeWo b30 cell line under the severe hypoxia condition and the fact that TGFBR2 3' UTR could serve as a potential target for these miRNAs.

DISCUSSION

Our findings uncover a novel potential therapeutic target for managing patients with PE, significantly contributing to a deeper comprehension of the underlying mechanisms involved in the development of this pathology.

Software for evaluation of immune cell activation (Application note)

Biological processes involving immune response exhibit nonlinearity due to complex interactions between different cells. The presented mathematical model considers the temporal development of immune reactions, and corresponding kinetic processes, including the interaction of cells/soluble immune factors in vitro. According to the M1/M2 paradigm of macrophage polarization, unbalanced macrophage activation in the human body can cause an excessive response to an antigen and associated long-term deleterious processes. Therefore, our simulation is based on the evaluation of parameters that describe the interaction of diverse immune factors interconnected within the framework of the M1/M2 paradigm, and taking into account the kinetics of expression of immune factors. A specific program and related web tool to assess the intensity of immune reactions in cell system in vitro were developed. AVAILABILITY: It is accessible through a web-link: https://www.biodevicesystems.com/immunology. CONTACT: Users can get information and apply for the service at info@biodevicesystems.com.

Facile fabrication of carboxymethylcellulose/ZnO/g-C3N4 containing nutmeg extract with photocatalytic performance for infected wound healing

New topical antibacterial agents are required to inhibit and development of bacteria and also promoting the wound healing process. This study was evaluating the healing effect of Myristica fragrans extract coated with carboxymethyl cellulose, zinc oxide and graphite carbon nitride (CMC/ZnO/g-C3N4/MyR) by photocatalytic process on the healing process of full-thickness infectious excision wounds in mice. Nanosheets were prepared and physicochemical properties were evaluated. Safety, in vitro release, antibacterial activities under in vitro and in vivo condition, wound contraction, histopathological properties and the protein expressions of tumor necrosis factor-α (TNF-α), collagen 1A (COL1A) and CD31 were also evaluated. Physicochemical properties confirmed their successful synthesis. Nanosheets exhibited antibacterial activity under in vitro and in vivo conditions. The formulations containing CMC/ZnO/g-C3N4/MyR, significantly (P < 0.05) competed with standard ointment of mupirocin for accelerating the wound healing process due to their effects on bacterial count and the expression of TNF-α and also accelerating the proliferative phase. This structure can be used as a safe structure in combination with other agents for accelerating the wound healing process following future clinical studies.

Molecular and phenotypic distinctions of macrophages in tolerant and susceptible to hypoxia rats

Individual hypoxia tolerance is a major influence on the course and outcome of infectious and inflammatory diseases. Macrophages, which play central roles in systemic inflammatory response and other immunity reactions, are subject to functional activation orchestrated by several transcription factors including hypoxia inducible factors (HIFs). HIF-1 expression levels and the lipopolysaccharide (LPS)-induced systemic inflammatory response severity have been shown to correlate with hypoxia tolerance. Molecular and functional features of macrophages, depending on the organisms resistance to hypoxia, can determine the severity of the course of infectious and inflammatory diseases, including the systemic inflammatory response. The purpose is the comparative molecular and functional characterization of non-activated and LPS-activated bone marrow-derived macrophages under normoxia in rats with different tolerance to oxygen deprivation. Hypoxia resistance was assessed by gasping time measurement in an 11,500 m altitude-equivalent hypobaric decompression chamber. Based on the outcome, the animals were assigned to three groups termed 'tolerant to hypoxia' (n = 12), 'normal', and 'susceptible to hypoxia' (n = 13). The 'normal' group was excluded from subsequent experiments. One month after hypoxia resistance test, the blood was collected from the tail vein to isolate monocytes. Non-activated and LPS-activated macrophage cultures were investigated by PCR, flow cytometry and Western blot methods. Gene expression patterns of non-activated cultured macrophages from tolerant and susceptible to hypoxia animals differed. We observed higher expression of VEGF and CD11b and lower expression of Tnfa, Il1b and Epas1 in non-activated cultures obtained from tolerant to hypoxia animals, whereas HIF-1α mRNA and protein expression levels were similar. LPS-activated macrophage cultures derived from susceptible to hypoxia animals expressed higher levels of Hif1a and CCR7 than the tolerant group; in addition, the activation was associated with increased content of HIF-1α in cell culture medium. The observed differences indicate a specific propensity toward pro-inflammatory macrophage polarization in susceptible to hypoxia rats.

A rapid and high-throughput T cell immunophenotyping assay for cellular therapy bioprocess using the Cellaca® PLX image cytometer

In cellular therapies chimeric antigen receptor (CAR) T or NK cells undergo phenotypic analysis at multiple stages during discovery and development of novel therapies. Patient samples are routinely analyzed via flow cytometry for population identification and distribution of CD3, CD4, and CD8 positive T cells. As an alternative or orthogonal method, image cytometry systems have been used to perform simple cell-based assays in lieu of flow cytometry. Recently, a new image cytometry system, the Cellaca® PLX (Revvity Health Sciences, Inc., Lawrence, MA), was developed for high-throughput cell counting and viability, immunophenotyping, transfection/transduction efficiency, and cell health assays. This novel instrument allows investigators to quickly assess several critical quality attributes (CQAs) such as cell identity, viability, and other relevant biological functions recommended by the International Organization for Standardization using the ISO Cell Characterization documents focused on cellular therapeutic products. In this work, we demonstrate a rapid and high-throughput image cytometry detection method for cellular immunophenotyping and viability using the Cellaca PLX system for samples throughout the cellular therapy workflow. Freshly isolated peripheral blood mononuclear cells (PBMCs) underwent red blood cell (RBC) lysis and CD3 enrichment. Samples were then subsequently stained with Hoechst/CD3/CD4/CD8 or Hoechst/CD3/CD8/RubyDead Dye surface marker kits and measured on the Cellaca PLX and three different flow cytometers for side-by-side comparison and assay validation. Acquisition and analysis of cell viability and cell populations was shown to be faster and more efficient process compared to flow while achieving highly comparable results between the two technology platforms. This data shows that the Cellaca PLX Image Cytometer may provide a rapid alternative or orthogonal method for PBMC immunophenotyping experiments, as well as potentially streamline the workflow to quickly move precious patient samples downstream within the development processes.

Mechanisms and Effects of Macrophage Polarization and Its Specifics in Pulmonary Environment

Macrophages are a specific group of cells found in all body tissues. They have specific characteristics in each of the tissues that correspond to the functional needs of the specific environment. These cells are involved in a wide range of processes, both pro-inflammatory and anti-inflammatory ("wound healing"). This is due to their specific capacity for so-called polarization, a phenotypic change that is, moreover, partially reversible compared to other differentiated cells of the human body. This promises a wide range of possibilities for its influence and thus therapeutic use. In this article, we therefore review the mechanisms that cause polarization, the basic classification of polarized macrophages, their characteristic markers and the effects that accompany these phenotypic changes. Since the study of pulmonary (and among them mainly alveolar) macrophages is currently the focus of scientific interest of many researchers and these macrophages are found in very specific environments, given mainly by the extremely high partial pressure of oxygen compared to other locations, which specifically affects their behavior, we will focus our review on this group.

Macrophage-based therapy for intervertebral disc herniation: preclinical proof-of-concept

Intervertebral disc (IVD) degeneration and herniation is a leading cause of disability globally and a large unmet clinical need. No efficient non-surgical therapy is available, and there is an urgency for minimally invasive therapies capable of restoring tissue function. IVD spontaneous hernia regression following conservative treatment is a clinically relevant phenomenon that has been linked to an inflammatory response. This study establishes the central role of macrophages in IVD spontaneous hernia regression and provides the first preclinical demonstration of a macrophage-based therapy for IVD herniation. A rat model of IVD herniation was used to test complementary experimental setups: (1) macrophage systemic depletion via intravenous administration of clodronate liposomes (Group CLP2w: depletion between 0 and 2 weeks post-lesion; Group CLP6w: depletion between 2 and 6 weeks post-lesion), and (2) administration of bone marrow-derived macrophages into the herniated IVD, 2 weeks post-lesion (Group Mac6w). Herniated animals without treatment were used as controls. The herniated area was quantified by histology in consecutive proteoglycan/collagen IVD sections at 2 and 6 weeks post-lesion. Clodronate-mediated macrophage systemic depletion was confirmed by flow cytometry and resulted in increased hernia sizes. Bone marrow-derived macrophages were successfully administered into rat IVD hernias resulting in a 44% decrease in hernia size. No relevant systemic immune reaction was identified by flow cytometry, cytokine, or proteomic analysis. Furthermore, a possible mechanism for macrophage-induced hernia regression and tissue repair was unveiled through IL4, IL17a, IL18, LIX, and RANTES increase. This study represents the first preclinical proof-of-concept of macrophage-based immunotherapy for IVD herniation.

Biomaterial-Assisted Macrophage Cell Therapy for Regenerative Medicine

Although most tissue types are capable of some form of self-repair and regeneration, injuries that are larger than a critical threshold or those occurring in the setting of certain diseases can lead to impaired healing and ultimately loss of structure and function. The immune system plays an important role in tissue repair and must be considered in the design of therapies in regenerative medicine. In particular, macrophage cell therapy has emerged as a promising strategy that leverages the reparative roles of these cells. Macrophages are critical for successful tissue repair and accomplish diverse functions throughout all phases of the process by dramatically shifting in phenotypes in response to microenvironmental cues. Depending on their response to various stimuli, they may release growth factors, support angiogenesis, and facilitate extracellular matrix remodeling. However, this ability to rapidly shift phenotype is also problematic for macrophage cell therapy strategies, because adoptively transferred macrophages fail to maintain therapeutic phenotypes following their administration to sites of injury or inflammation. Biomaterials are a potential way to control macrophage phenotype in situ while also enhancing their retention at sites of injury. Cell delivery systems incorporated with appropriately designed immunomodulatory signals have potential to achieve tissue regeneration in intractable injuries where traditional therapies have failed. Here we explorecurrent challenges in macrophage cell therapy, especially retention and phenotype control, how biomaterials may overcome them, and opportunities for next generation strategies. Biomaterials will be an essential tool to advance macrophage cell therapy for widespread clinical applications.

Macrophage Reprogramming via the Modulation of Unfolded Protein Response with siRNA-Loaded Magnetic Nanoparticles in a TAM-like Experimental Model

New therapeutic strategies are required in cancer therapy. Considering the prominent role of tumor-associated macrophages (TAMs) in the development and progression of cancer, the re-education of TAMs in the tumor microenvironment (TME) could represent a potential approach for cancer immunotherapy. TAMs display an irregular unfolded protein response (UPR) in their endoplasmic reticulum (ER) to endure environmental stress and ensure anti-cancer immunity. Therefore, nanotechnology could be an attractive tool to modulate the UPR in TAMs, providing an alternative strategy for TAM-targeted repolarization therapy. Herein, we developed and tested polydopamine-coupled magnetite nanoparticles (PDA-MNPs) functionalized with small interfering RNAs (siRNA) to downregulate the protein kinase R (PKR)-like ER kinase (PERK) expression in TAM-like macrophages derived from murine peritoneal exudate (PEMs). After the evaluation of the cytocompatibility, the cellular uptake, and the gene silencing efficiency of PDA-MNPs/siPERK in PEMs, we analyzed their ability to re-polarize in vitro these macrophages from M2 to the M1 inflammatory anti-tumor phenotype. Our results indicate that PDA-MNPs, with their magnetic and immunomodulator features, are cytocompatible and able to re-educate TAMs toward the M1 phenotype by PERK inhibition, a UPR effector contributing to TAM metabolic adaptation. These findings can provide a novel strategy for the development of new tumor immunotherapies in vivo.

Unveiling the Potential of BenzylethyleneAryl-Urea Scaffolds for the Design of New Onco Immunomodulating Agents

This work focuses on the development of thirteen benzylethylenearyl ureas and one carbamate. After the synthesis and purification of the compounds, we studied their antiproliferative action on cell lines, such as HEK-293, and cancer ones, such as HT-29, MCF-7 or A-549, on the immune Jurkat T-cells and endothelial cells HMEC-1. Compounds C.1, C.3, C.12 and C.14 were selected for further biological studies to establish their potential as immunomodulating agents. Some of the derivatives exhibited significant inhibitory effects on both targets: PD-L1 and VEGFR-2 in the HT-29 cell line, showing that urea C.12 is active against both targets. Some compounds could inhibit more than 50% of cancer cell proliferation compared to non-treated ones when assessed in co-cultures using HT-29 and THP-1 cells. In addition, they significantly reduced CD11b expression, which is a promising target for immune modulation in anticancer immunotherapies.

IL-10 in combination with IL-12 and TNF-α attenuates CXCL8/CXCR1 axis in peritoneal macrophages of mice infected with Staphylococcus aureus through the TNFR1-IL-1R-NF-κB pathway

Overexpression of Staphylococcus aureus mediated CXCL8/CXCR1 axis is a major cause of sepsis and severe inflammatory diseases. This chemokine acts conjointly with various pro-inflammatory and anti-inflammatory cytokines that govern the severity of inflammation. The effects of different combinations of exogenous cytokines on CXCR1 expression in macrophages remain undetermined. Exogenous cytokine and anti-inflammatory cytokine therapy had been used to modulate CXCL8 and CXCR1 expression in peritoneal macrophages. Male Swiss albino mice were inoculated with live S. aureus (10⁶ cells/ mouse) for the development of infection. Exogenous cytokines (TNF-α, IL-12, IFN-γ and IL-10) were administered intraperitoneally (single or combination) 24 h post S. aureus infection. The mice were sacrificed and peritoneal macrophages were isolated three days post infection. CXCL8, IL-12, IL-10 secretion, ROS generation and the bacterial phagocytic process had been evaluated. Western blot was used to study the expressions of TNFR1, IL-1R, CXCR1 and NF-κB. TNF-α, IL-12 and IFN-γ treatments aggravated CXCL8 and CXCR1 expression in the macrophages of infected mice. TNF-α + IFN-γ treatment was a major inducer of nitric oxide release and mediated maximum bacterial killing. IL-12 + TNF-α treatment was most potent in increasing ROS, CXCL8/CXCR1 expression through increased levels of TNFR1, IL-1R and NF-κB activation. IL-10 reversed the effects of exogenous cytokines but also impaired the bacterial clearance phenomenon in peritoneal lavage. Treatment with IL-12 + TNF-α + IL-10 was most effective in ameliorating oxidative stress, reduced CXCL8 release and expression levels of TNFR1, IL-1R, and NF-κB. Concludingly, IL-12 + TNF-α + IL-10 treatment mitigated CXCL8/CXCR1 expression and inflammatory signalling via downregulation of TNFR1-IL-1R-NF-κB pathway in peritoneal macrophages and inflammatory sequelae during S. aureus infection.

Exploring BenzylethoxyAryl Urea Scaffolds for Multitarget Immunomodulation Therapies

Thirteen benzylethoxyaryl ureas have been synthesized and biologically evaluated as multitarget inhibitors of VEGFR-2 and PD-L1 proteins to overcome resistance phenomena offered by cancer. The antiproliferative activity of these molecules on several tumor cell lines (HT-29 and A549), on the endothelial cell line HMEC-1, on immune cells (Jurkat T) and on the non-tumor cell line HEK-293 has been determined. Selective indexes (SI) have been also determined and compounds bearing p-substituted phenyl urea unit together with a diaryl carbamate exhibited high SI values. Further studies on these selected compounds to determine their potential as small molecule immune potentiators (SMIPs) and as antitumor agents have been performed. From these studies, we have concluded that the designed ureas have good tumor antiangiogenic properties, exhibit good inhibition of CD11b expression, and regulate pathways involved in CD8 T-cell activity. These properties suggest that these compounds could be potentially useful in the development of new cancer immune treatments.

A systemically administered detoxified TLR4 agonist displays potent antitumor activity and an acceptable tolerance profile in preclinical models

Bacterial lipopolysaccharides (LPS) are potent innate immunostimulants targeting the Toll-like receptor 4 (TLR4), an attractive and validated target for immunostimulation in cancer therapy. Although LPS possess anti-tumor activity, toxicity issues prevent their systemic administration at effective doses in humans. We first demonstrated that LPS formulated in liposomes preserved a potent antitumor activity per se upon systemic administration in syngeneic models, and significantly enhance the antitumor activity of the anti-CD20 antibody rituximab in mice xenografted with the human RL lymphoma model. Liposomal encapsulation also allowed a 2-fold reduction in the induction of pro-inflammatory cytokines by LPS. Mice receiving an intravenous administration demonstrated a significant increase of neutrophils, monocytes and macrophages at the tumor site as well as an increase of macrophages in spleen. Further, we chemically detoxified LPS to obtain MP-LPS that was associated with a 200-fold decrease in the induction of proinflammatory cytokines. When encapsulated in a clinically approved liposomal formulation, toxicity, notably pyrogenicity (10-fold), was limited while the antitumor activity and immunoadjuvant effect were maintained. This improved tolerance profile of liposomal MP-LPS was associated with the preferential activation of the TLR4-TRIF pathway. Finally, in vitro studies demonstrated that stimulation with encapsulated MP-LPS reversed the polarization of M2 macrophages towards an M1 phenotype, and a phase 1 trial in healthy dogs validated its tolerance upon systemic administration up to very high doses (10µg/kg). Altogether, our results demonstrate the strong therapeutic potential of MPLPS formulated in liposomes as a systemically active anticancer agent, supporting its evaluation in patients with cancer.

A multi-targeting bionanomatrix coating to reduce capsular contracture development on silicone implants

BACKGROUND

Capsular contracture is a critical complication of silicone implantation caused by fibrotic tissue formation from excessive foreign body responses. Various approaches have been applied, but targeting the mechanisms of capsule formation has not been completely solved. Myofibroblast differentiation through the transforming growth factor beta (TGF-β)/p-SMADs signaling is one of the key factors for capsular contracture development. In addition, biofilm formation on implants may result chronic inflammation promoting capsular fibrosis formation with subsequent contraction. To date, there have been no approaches targeting multi-facted mechanisms of capsular contracture development.

METHODS

In this study, we developed a multi-targeting nitric oxide (NO) releasing bionanomatrix coating to reduce capsular contracture formation by targeting myofibroblast differentiation, inflammatory responses, and infections. First, we characterized the bionanomatrix coating on silicon implants by conducting rheology test, scanning electron microcsopy analysis, nanoindentation analysis, and NO release kinetics evaluation. In addition, differentiated monocyte adhesion and S. epidermidis biofilm formation on bionanomatrix coated silicone implants were evaluated in vitro. Bionanomatrix coated silicone and uncoated silicone groups were subcutaneously implanted into a mouse model for evaluation of capsular contracture development for a month. Fibrosis formation, capsule thickness, TGF-β/SMAD 2/3 signaling cascade, NO production, and inflammatory cytokine production were evaluated using histology, immunofluorescent imaging analysis, and gene and protein expression assays.

RESULTS

The bionanomatrix coating maintained a uniform and smooth surface on the silicone even after mechanical stress conditions. In addition, the bionanomatrix coating showed sustained NO release for at least one month and reduction of differentiated monocyte adhesion and S. epidermidis biofilm formation on the silicone implants in vitro. In in vivo implantation studies, the bionanomatrix coated groups demonstrated significant reduction of capsule thickness surrounding the implants. This result was due to a decrease of myofibroblast differentiation and fibrous extracellular matrix production through inhibition of the TGF-β/p-SMADs signaling. Also, the bionanomatrix coated groups reduced gene expression of M1 macrophage markers and promoted M2 macrophage markers which indicated the bionanomatrix could reduce inflammation but promote healing process.

CONCLUSIONS

In conclusion, the bionanomatrix coating significantly reduced capsular contracture formation and promoted healing process on silicone implants by reducing myfibroblast differentiation, fibrotic tissue formation, and inflammation. A multi-targeting nitric oxide releasing bionanomatrix coating for silicone implant can reduce capsular contracture and improve healing process. The bionanomatrix coating reduces capsule thickness, α-smooth muscle actin and collagen synthesis, and myofibroblast differentiation through inhibition of TGF-β/SMADs signaling cascades in the subcutaneous mouse models for a month.

Current State of Cold Atmospheric Plasma and Cancer-Immunity Cycle: Therapeutic Relevance and Overcoming Clinical Limitations Using Hydrogels

Cold atmospheric plasma (CAP) is a partially ionized gas that gains attention as a well-tolerated cancer treatment that can enhance anti-tumor immune responses, which are important for durable therapeutic effects. This review offers a comprehensive and critical summary on the current understanding of mechanisms in which CAP can assist anti-tumor immunity: induction of immunogenic cell death, oxidative post-translational modifications of the tumor and its microenvironment, epigenetic regulation of aberrant gene expression, and enhancement of immune cell functions. This should provide a rationale for the effective and meaningful clinical implementation of CAP. As discussed here, despite its potential, CAP faces different clinical limitations associated with the current CAP treatment modalities: direct exposure of cancerous cells to plasma, and indirect treatment through injection of plasma-treated liquids in the tumor. To this end, a novel modality is proposed: plasma-treated hydrogels (PTHs) that can not only help overcome some of the clinical limitations but also offer a convenient platform for combining CAP with existing drugs to improve therapeutic responses and contribute to the clinical translation of CAP. Finally, by integrating expertise in biomaterials and plasma medicine, practical considerations and prospective for the development of PTHs are offered.

Immunotherapy approaches for rare pediatric solid tumors: advances and future directions

PURPOSE OF REVIEW

Immunotherapy for pediatric tumors is rapidly evolving. From major successes in pediatric hematologic malignancies, immunotherapy utility increased in the pediatric solid tumor landscape. Numerous pediatric solid tumors are defined as rare with limitations in diagnosis and treatment. This review will describe four major immunotherapies used in pediatrics and discuss results seen in rare pediatric tumors. We will also briefly review the challenges of immunotherapy in solid tumors and opportunities to drive this therapy forward.

RECENT FINDINGS

Despite rare success employing immunotherapy for pediatric solid tumors, recently there have been several successes in pediatric rare solid tumors. After describing the evolving landscape of rare pediatric tumors, we will demonstrate the successes or disappointments of immunotherapy. We will describe the mechanism of four immunotherapies used in the pediatrics, followed by the published results. Finally, we will discuss the challenges and opportunities for immunotherapies in pediatric rare tumors.

SUMMARY

Pediatric rare tumors are lacking in treatment options. Despite numerous disappointments utilizing immunotherapies in the more common pediatric solid tumors, there have been several successes within the pediatric rare tumor landscape. Much work is still needed to enhance our understanding and knowledge on utilizing these immunotherapies for pediatric rare solid tumors.

Synthesis and Biological Evaluation of Potential Oncoimmunomodulator Agents

Fourteen triazole-scaffold derivatives were synthetized and biologically evaluated as potential oncoimmunomodultator agents by targeting both PD-L1 and c-Myc. First, the antiproliferative activity of these molecules on the monocultures of several tumor cell lines (HT-29, A-549, and MCF-7) and on the non-tumor cell line HEK-293 was studied. Then, the effects on the mentioned biological targets were also evaluated. Finally, the effect on cancer cell viability when the molecules were co-cultured with immune cells (Jurkat T cells or THP-1) was also determined. Compounds bearing a bromoophenyl group were selected because of their excellent results, and their effect on IL-6 secretion was also studied. In conclusion, we found compounds that are capable of downregulating c-Myc, as well as influencing and altering the distribution of PD-L1 in tumor cells; the compounds are thus capable of influencing the behavior of defensive cells towards cancer cells. p-Bromophenyltriazol 3 is the most active of these as a PD-L1 and c-Myc downregulator and as a potential immunomodulator agent. Moreover, it exhibits an interesting action on inflammation-related cytokine IL-6.

Cell Immunotherapy against Melanoma: Clinical Trials Review

Melanoma is one of the most aggressive and therapy-resistant types of cancer, the incidence rate of which grows every year. However, conventional methods of chemo- and radiotherapy do not allow for completely removing neoplasm, resulting in local, regional, and distant relapses. In this case, adjuvant therapy can be used to reduce the risk of recurrence. One of the types of maintenance cancer therapy is cell-based immunotherapy, in which immune cells, such as T-cells, NKT-cells, B cells, NK cells, macrophages, and dendritic cells are used to recognize and mobilize the immune system to kill cancer cells. These cells can be isolated from the patient's peripheral blood or biopsy material and genetically modified, cultured ex vivo, following infusion back into the patient for powerful induction of an anti-tumor immune response. In this review, the advantages and problems of the most relevant methods of cell-based therapy and ongoing clinical trials of adjuvant therapy of melanoma are discussed.

Immunomodulatory activity of manganese dioxide nanoparticles: Promising for novel vaccines and immunotherapeutics

Manganese (Mn), a nutrient inorganic trace element, is necessary for a variety of physiological processes of animal body due to their important roles in oxidative regulation effects and other aspects of activities. Moreover, manganese ion (Mn²⁺) has widely reported to be crucial for the regulations of different immunological responses, thus showing promising application as potential adjuvants and immunotherapeutics. Taking the advantages of Mn-based biological and immunological activities, Manganese dioxide nanoparticles (MnO₂ NPs) are a new type of inorganic nanomaterials with numerous advantages, including simple preparation, low cost, environmental friendliness, low toxicity, biodegradable metabolism and high bioavailability. MnO₂ NPs, as a kind of drug carrier, have also shown the ability to catalyze hydrogen peroxide (H₂O₂) to produce oxygen (O₂) under acidic conditions, which can enhance the efficacy of radiotherapy, chemotherapy and other therapeutics for tumor treatment by remodeling the tumor microenvironment. More importantly, MnO₂ NPs also play important roles in immune regulations both in innate and adaptive immunity. In this review, we summarize the biological activities of Manganese, followed by the introduction for the biological and medical functions and mechanisms of MnO₂ NPs. What's more, we emphatically discussed the immunological regulation effects and mechanisms of MnO₂ NPs, as well as their potentials to serve as adjuvants and immunomodulators, which might benefit the development of novel vaccines and immunotherapies for more effective disease control.

Photon- and Proton-Mediated Biological Effects: What Has Been Learned?

The current understanding of the effects of radiation is gradually becoming broader. However, it still remains unclear why some patients respond to radiation with a pronounced positive response, while in some cases the disease progresses. This is the motivation for studying the effects of radiation therapy not only on tumor cells, but also on the tumor microenvironment, as well as studying the systemic effects of radiation. In this framework, we review the biological effects of two types of radiotherapy: photon and proton irradiations. Photon therapy is a commonly used type of radiation therapy due to its wide availability and long-term history, with understandable and predictable outcomes. Proton therapy is an emerging technology, already regarded as the method of choice for many cancers in adults and children, both dosimetrically and biologically. This review, written after the analysis of more than 100 relevant literary sources, describes the local effects of photon and proton therapy and shows the mechanisms of tumor cell damage, interaction with tumor microenvironment cells and effects on angiogenesis. After systematic analysis of the literature, we can conclude that proton therapy has potentially favorable toxicological profiles compared to photon irradiation, explained mainly by physical but also biological properties of protons. Despite the fact that radiobiological effects of protons and photons are generally similar, protons inflict reduced damage to healthy tissues surrounding the tumor and hence promote fewer adverse events, not only local, but also systemic.

Immune features of the peritumoral stroma in pancreatic ductal adenocarcinoma

Background

The peritumoral stroma is a hallmark of pancreatic ductal adenocarcinoma (PDA) with implications for disease development, progression and therapy resistance. We systematically investigated immune features of the stroma in PDA patients to identify markers of clinical importance and potential therapeutic targets.

Methods

Tissue and blood samples of 51 PDA patients with clinical and follow-up information were included. Laser Capture Microdissection allowed us to analyze the stromal compartment in particular. Systematic immunohistochemistry, followed by software-based image analysis were conducted. Also, multiplex cytokine analyses (including 50 immune-related molecules) were performed. Functional analyses were performed using patient-derived 3D bioprints. Clinical information was used for survival analyses. Intercompartmental IL9 and IL18 gradients were assessed in matched samples of tumor epithelium, stroma, and serum of patients. Serum levels were compared to an age-matched healthy control group.

Results

Stromal IL9 and IL18 are significantly associated with patient survival. While IL9 is a prognostic favorable marker (p=0.041), IL18 associates with poor patient outcomes (p=0.030). IL9 correlates with an anti-tumoral cytokine network which connects regulation of T helper (Th) 9, Th1 and Th17 cells (all: p<0.05 and r>0.5). IL18 correlates with a Th1-type cytokine phenotype and stromal CXCL12 expression (all: p<0.05 and r>0.5). Further, IL18 associates with a higher level of exhausted T cells. Inhibition of IL18 results in diminished Th1- and Th2-type cytokines. Patients with high stromal IL9 expression have a tumor-to-stroma IL9 gradient directed towards the stroma (p=0.019). Low IL18 expression associates with a tumor-to-stroma IL18 gradient away from the stroma (p=0.007). PDA patients showed higher serum levels of IL9 than healthy controls while serum IL18 levels were significantly lower than in healthy individuals. The stromal immune cell composition is distinct from the tumor epithelium. Stromal density of FoxP3⁺ regulatory T cells showed a tendency towards improved patient survival (p=0.071).

Conclusion

An unexpected high expression of the cytokines IL9 and IL18 at different ends is of significance in the stroma of PDA and relates to opposing patient outcomes. Sub-compartmental cytokine analyses highlight the importance of a differentiated gradient assessment. The findings suggest stromal IL9 and/or IL18 as markers for patient stratification and as potential therapeutic targets. Future steps include investigating e. g. the role of local microbiota as both cytokines are also regulated by microbial compositions.

Nanocarriers for effective delivery: modulation of innate immunity for the management of infections and the associated complications

Innate immunity is the first line of defense against invading pathogens. Innate immune cells can recognize invading pathogens through recognizing pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs). The recognition of PAMPs by PRRs triggers immune defense mechanisms and the secretion of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. However, sustained and overwhelming activation of immune system may disrupt immune homeostasis and contribute to inflammatory disorders. Immunomodulators targeting PRRs may be beneficial to treat infectious diseases and their associated complications. However, therapeutic performances of immunomodulators can be negatively affected by (1) high immune-mediated toxicity, (2) poor solubility and (3) bioactivity loss after long circulation. Recently, nanocarriers have emerged as a very promising tool to overcome these obstacles owning to their unique properties such as sustained circulation, desired bio-distribution, and preferred pharmacokinetic and pharmacodynamic profiles. In this review, we aim to provide an up-to-date overview on the strategies and applications of nanocarrier-assisted innate immune modulation for the management of infections and their associated complications. We first summarize examples of important innate immune modulators. The types of nanomaterials available for drug delivery, as well as their applications for the delivery of immunomodulatory drugs and vaccine adjuvants are also discussed.

Phenotypic Alteration of BMDM In Vitro Using Small Interfering RNA

Autologous macrophage transfer is an emerging platform for cell therapy. It is anticipated that conventional macrophage reprogramming based on ex vivo polarization using cytokines and ligands of TLRs may enhance the therapeutic effect. We describe an alternative approach based on small interfering RNA (siRNA) knockdown of selected molecular cues of macrophage polarization, namely EGR2, IRF3, IRF5, and TLR4 in Raw264.7 monocyte/macrophage cell line and mouse-bone-marrow-derived macrophages (BMDMs). The impact of IRF5 knockdown was most pronounced, curtailing the expression of other inflammatory mediators such as IL-6 and NOS2, especially in M1-polarized macrophages. Contrary to IRF5, EGR2 knockdown potentiated M1-associated markers while altogether abolishing M2 marker expression, which is indicative of the principal role of EGR2 in the maintenance of alternative phenotypes. IRF3 knockdown suppressed M1 polarization but upregulated Arg 1, a canonical marker of alternative polarization in M1 macrophages. As anticipated, the knockdown of TLR4 also attenuated the M1 phenotype but, akin to IRF3, significantly induced Arginase 1 in M0 and M1, driving the phenotype towards M2. This study validates RNAi as a viable option for the alteration and maintenance of macrophage phenotypes.

The versatility of macrophage heterogeneity in liver fibrosis

Liver fibrosis is a highly conserved wound healing response to liver injury, characterized by excessive deposition of extracellular matrix (ECM) in the liver which might lead to loss of normal functions. In most cases, many types of insult could damage hepatic parenchymal cells like hepatocytes and/or cholangiocytes, and persistent injury might lead to initiation of fibrosis. This process is accompanied by amplified inflammatory responses, with immune cells especially macrophages recruited to the site of injury and activated, in order to orchestrate the process of wound healing and tissue repair. In the liver, both resident macrophages and recruited macrophages could activate interstitial cells which are responsible for ECM synthesis by producing a variety of cytokines and chemokines, modulate local microenvironment, and participate in the regulation of fibrosis. In this review, we will focus on the main pathological characteristics of liver fibrosis, as well as the heterogeneity on origin, polarization and functions of hepatic macrophages in the setting of liver fibrosis and their underlying mechanisms, which opens new perspectives for the treatment of liver fibrosis.

Macrophages derived from pluripotent stem cells: prospective applications and research gaps

Induced pluripotent stem cells (iPSCs) represent a valuable cell source able to give rise to different cell types of the body. Among the various pathways of iPSC differentiation, the differentiation into macrophages is a recently developed and rapidly growing technique. Macrophages play a key role in the control of host homeostasis. Their dysfunction underlies many diseases, including hereditary, infectious, oncological, metabolic and other disorders. Targeting macrophage activity and developing macrophage-based cell therapy represent promising tools for the treatment of many pathological conditions. Macrophages generated from human iPSCs (iMphs) provide great opportunities in these areas. The generation of iMphs is based on a step-wise differentiation of iPSCs into mesoderm, hematopoietic progenitors, myeloid monocyte-like cells and macrophages. The technique allows to obtain standardizable populations of human macrophages from any individual, scale up macrophage production and introduce genetic modifications, which gives significant advantages over the standard source of human macrophages, monocyte-derived macrophages. The spectrum of iMph applications is rapidly growing. iMphs have been successfully used to model hereditary diseases and macrophage-pathogen interactions, as well as to test drugs. iMph use for cell therapy is another promising and rapidly developing area of research. The principles and the details of iMph generation have recently been reviewed. This review systemizes current and prospective iMph applications and discusses the problem of iMph safety and other issues that need to be explored before iMphs become clinically applicable.

Engineering Human Circulating Monocytes/Macrophages by Systemic Deliverable Gene Editing

Delivery of plasmid DNA to transfect human primary macrophages is extremely difficult, especially for genetic engineering. Engineering macrophages is imperative for the treatment of many diseases including infectious diseases, cancer, neurological diseases, and aging. Unfortunately, plasmid does not cross the nuclear membranes of terminally differentiated macrophages to integrate the plasmid DNA (pDNA) into their genome. To address this issue, we have developed a core-shell nanoparticle (NP) using our newly created cationic lipid to deliver the anti-inflammatory cytokine IL-4 pDNA (IL-4pDNA-NPs). Human blood monocyte-derived macrophages (MDM) were effectively transfected with IL-4pDNA-NPs. IL-4pDNA-NPs were internalized in MDM within 30 minutes and delivered into the nucleus within 2 hours. Exogenous IL-4 expression was detected within 1 - 2 days and continued up to 30 days. Functional IL-4 expression led to M2 macrophage polarization in vitro and in an in vivo mouse model of inflammation. These data suggest that these NPs can protect pDNA from degradation by nucleases once inside the cell, and can transport pDNA into the nucleus to enhance gene delivery in macrophages in vitro and in vivo. In this research, we developed a new method to deliver plasmids into the nucleus of monocytes and macrophages for gene-editing. Introducing IL-4 pDNA into macrophages provides a new gene therapy solution for the treatment of various diseases.

Macrophage polarization in hypoxia and ischemia/reperfusion: Insights into the role of energetic metabolism

Macrophages, the key cells of innate immunity, possess wide phenotypical and functional heterogeneity. In vitro studies showed that microenvironment signals could induce the so-called polarization of macrophages into two phenotypes: classically activated macrophages (M1) or alternatively activated macrophages (M2). Functionally, they are considered as proinflammatory and anti-inflammatory/pro-regenerative, respectively. However, in vivo studies into macrophage states revealed a continuum of phenotypes from M1 to M2 state instead of the clearly distinguished extreme phenotypes. An important role in determining the type of polarization of macrophages is played by energy metabolism, including the activity of oxidative phosphorylation. In this regard, hypoxia and ischemia that affect cellular energetics can modulate macrophage polarization. Here, we overview the data on macrophage polarization during metabolic shift-associated pathologies including ischemia and ischemia/reperfusion in various organs and discuss the role of energy metabolism potentially triggering the macrophage polarization.

Manipulation of the tumor immuno-microenvironment via TAM-targeted expression of transcription factors

An immunosuppressive tumor microenvironment (TME) leads to cancer growth, metastasis, and therapeutic resistance. Immunomodulatory immunotherapy aims to skew the immunosuppressive TME back to an immune active state. Tumor-associated macrophages (TAMs) are a critical component of the TME that are actively involved in tumor-specific inflammation and immunosuppression. TAMs exhibit a diverse range of phenotypes and functions, from pro-tumor to anti-tumor. The plasticity of TAMs makes them a promising target for immunotherapy, and TAM-targeted therapies via different strategies have shown great potential. This review discusses current TAM-specific delivery targets and genes of interest for TAM-reprogramming. As phagocytic cells, TAMs have several receptors that have been used to increase TAM-targeted in vivo delivery. Furthermore, a promising approach for reprogramming TAMs is to activate or suppress specific transcription factors in the signal transducers and activators of transcription (STAT) and interferon regulatory factor (IRF) families. Altering TAM transcription factor expression results in a potent shift in cytokine expression and overall TAM function potentially tipping the balance from an immunosuppressive to an immune active TME.

Macrophage Polarization in Atherosclerosis

The implication of the heterogeneous spectrum of pro- and anti-inflammatory macrophages (Macs) has been an important area of investigation over the last decade. The polarization of Macs alters their functional phenotype in response to their surrounding microenvironment. Macs are the major immune cells implicated in the pathogenesis of atherosclerosis. A hallmark pathology of atherosclerosis is the accumulation of pro-inflammatory M1-like macrophages in coronary arteries induced by pro-atherogenic stimuli; these M1-like pro-inflammatory macrophages are incapable of digesting lipids, thus resulting in foam cell formation in the atherosclerotic plaques. Recent findings suggest that the progression and stability of atherosclerotic plaques are dependent on the quantity of infiltrated Macs, the polarization state of the Macs, and the ratios of different types of Mac populations. The polarization of Macs is defined by signature markers on the cell surface, as well as by factors in intracellular and intranuclear compartments. At the same time, pro- and anti-inflammatory polarized Macs also exhibit different gene expression patterns, with differential cellular characteristics in oxidative phosphorylation and glycolysis. Macs are reflective of different metabolic states and various types of diseases. In this review, we discuss the major differences between M1-like Macs and M2-like Macs, their associated metabolic pathways, and their roles in atherosclerosis.

PET-CT imaging of pulmonary inflammation using [68Ga]Ga-DOTA-TATE

PURPOSE

In the characterization of severe lung diseases, early detection of specific inflammatory cells could help to monitor patients' response to therapy and increase chances of survival. Macrophages contribute to regulating the resolution and termination of inflammation and have increasingly been of interest for targeted therapies. [⁶⁸Ga]Ga-DOTA-TATE is an established clinical radiopharmaceutical targeting somatostatin receptor subtype 2 (SSTR 2). Since activated macrophages (M1) overexpress SSTR 2, the aim of this study was to investigate the applicability of [⁶⁸Ga]Ga-DOTA-TATE for positron emission tomography (PET) imaging of M1 macrophages in pulmonary inflammation.

METHODS

Inflammation in the pig lungs was induced by warm saline lavage followed by injurious ventilation in farm pigs (n = 7). Healthy pigs (n = 3) were used as control. A 60-min dynamic PET scan over the lungs was performed after [⁶⁸Ga]Ga-DOTA-TATE injection and [¹⁸F]FDG scan was executed afterward for comparison. The uptake of both tracers was assessed as mean standardized uptake values (SUV_mean) 30-60-min post-injection. The PET scans were followed by computed tomography (CT) scans, and the Hounsfield units (HU) were quantified of the coronal segments. Basal and apical segments of the lungs were harvested for histology staining. A rat lung inflammation model was also studied for tracer specificity using lipopolysaccharides (LPS) by oropharyngeal aspiration. Organ biodistribution, ex vivo autoradiography (ARG) and histology samples were conducted on LPS treated, octreotide induced blocking and control healthy rats.

RESULTS

The accumulation of [⁶⁸Ga]Ga-DOTA-TATE on pig lavage model was prominent in the more severely injured dorsal segments of the lungs (SUVmean = 0.91 ± 0.56), compared with control animals (SUVmean = 0.27 ± 0.16, p < 0.05). The tracer uptake corresponded to the damaged areas assessed by CT and histology and were in line with HU quantification. The [⁶⁸Ga]Ga-DOTA-TATE uptake in LPS treated rat lungs could be blocked and was significantly higher compared with control group.

CONCLUSION

The feasibility of the noninvasive assessment of tissue macrophages using [⁶⁸Ga]Ga-DOTA-TATE/PET was demonstrated in both porcine and rat lung inflammation models. [⁶⁸Ga]Ga-DOTA-TATE has a great potential to be used to study the role and presence of macrophages in humans in fight against severe lung diseases.

Magnetic resonance imaging of tumor-associated-macrophages (TAMs) with a nanoparticle contrast agent

In the tumor micro-environment, tumor associated macrophages (TAMs) represent a predominant component of the total tumor mass, and TAMs play a complex and diverse role in cancer pathogenesis with potential for either tumor suppressive, or tumor promoting biology. Thus, understanding macrophage localization and function are essential for cancer diagnosis and treatment. Typically, tissue biopsy is used to evaluate the density and polarization of TAMs, but provides a limited "snapshot" in time of a dynamic and potentially heterogeneous tumor immune microenvironment. Imaging has the potential for three-dimensional mapping; however, there is a paucity of macrophage-targeted contrast agents to specifically detect TAM subtypes. We have previously found that sulfated-dextran coated iron oxide nanoparticles (SDIO) can target macrophage scavenger receptor A (SR-A, also known as CD204). Since CD204 (SR-A) is considered a biomarker for the M2 macrophage polarization, these SDIO might provide M2-specific imaging probes for MRI. In this work, we investigate whether SDIO can label M2-polarized cells in vitro. We evaluate the effect of degree of sulfation on uptake by primary cultured bone marrow derived macrophages (BMDM) and found that a higher degree of sulfation led to higher uptake, but there were no differences across the subtypes. Further analysis of the BMDM showed similar SR-A expression across stimulation conditions, suggesting that this classic model for macrophage subtypes may not be ideal for definitive M2 subtype marker expression, especially SR-A. We further examine the localization of SDIO in TAMs in vivo, in the mammary fat pad mouse model of breast cancer. We demonstrate that uptake by TAMs expressing SR-A scales with degree of sulfation, consistent with the in vitro studies. The TAMs demonstrate M2-like function and secrete Arg-1 but not iNOS. Uptake by these M2-like TAMs is validated by immunohistochemistry. SDIO show promise as a valuable addition to the toolkit of imaging probes targeted to different biomarkers for TAMs.

A Perspective on the Roles of Adjuvants in Developing Highly Potent COVID-19 Vaccines

Several countries have made unremitting efforts to develop an optimal vaccine in the fight against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing occurrence of SARS-CoV-2 variants, current vaccines show decreased neutralizing activities, especially towards the Omicron variant. In this context, adding appropriate adjuvants to COVID-19 vaccines can substantially reduce the number of required doses and improve efficacy or cross-neutralizing protection. We mainly focus on research progress and achievements associated with adjuvanted COVID-19 subunit and inactivated vaccines. We further compare the advantages and disadvantages of different adjuvant formulations in order to provide a scientific reference for designing an effective strategy for future vaccine development.

Glial activation positron emission tomography imaging in radiation treatment of breast cancer brain metastases

Brain metastases affect more breast cancer patients than ever before due to increased overall patient survival with improved molecularly targeted treatments. Approximately 25–34% of breast cancer patients develop brain metastases in their lifetime. Due to the blood–brain barrier (BBB), the standard treatment for breast cancer brain metastases (BCBM) is surgery, stereotactic radiosurgery (SRS) and/or whole brain radiation therapy (WBRT). At the cost of cognitive side effects, WBRT has proven efficacy in treating brain metastases when used with local therapies such as SRS and surgery. This review investigated the potential use of glial activation positron emission tomography (PET) imaging for radiation treatment of BCBM. In order to put these studies into context, we provided background on current radiation treatment approaches for BCBM, our current understanding of the brain microenvironment, its interaction with the peripheral immune system, and alterations in the brain microenvironment by BCBM and radiation. We summarized preclinical literature on the interactions between glial activation and cognition and clinical studies using translocator protein (TSPO) PET to image glial activation in the context of neurological diseases. TSPO-PET is not employed clinically in assessing and guiding cancer therapies. However, it has gained traction in preclinical studies where glial activation was investigated from primary brain cancer, metastases and radiation treatments. Novel glial activation PET imaging and its applications in preclinical studies using breast cancer models and glial immunohistochemistry are highlighted. Lastly, we discuss the potential clinical application of glial activation imaging to improve the therapeutic ratio of radiation treatments for BCBM.

Understanding and improving cellular immunotherapies against cancer: From cell-manufacturing to tumor-immune models

The tumor microenvironment (TME) is shaped by dynamic metabolic and immune interactions between precancerous and cancerous tumor cells and stromal cells like epithelial cells, fibroblasts, endothelial cells, and hematopoietically-derived immune cells. The metabolic states of the TME, including the hypoxic and acidic niches, influence the immunosuppressive phenotypes of the stromal and immune cells, which confers resistance to both host-mediated tumor killing and therapeutics. Numerous in vitro TME platforms for studying immunotherapies, including cell therapies, are being developed. However, we do not yet understand which immune and stromal components are most critical and how much model complexity is needed to answer specific questions. In addition, scalable sourcing and quality-control of appropriate TME cells for reproducibly manufacturing these platforms remain challenging. In this regard, lessons from the manufacturing of immunomodulatory cell therapies could provide helpful guidance. Although immune cell therapies have shown unprecedented results in hematological cancers and hold promise in solid tumors, their manufacture poses significant scale, cost, and quality control challenges. This review first provides an overview of the in vivo TME, discussing the most influential cell populations in the tumor-immune landscape. Next, we summarize current approaches for cell therapies against cancers and the relevant manufacturing platforms. We then evaluate current immune-tumor models of the TME and immunotherapies, highlighting the complexity, architecture, function, and cell sources. Finally, we present the technical and fundamental knowledge gaps in both cell manufacturing systems and immune-TME models that must be addressed to elucidate the interactions between endogenous tumor immunity and exogenous engineered immunity.

Whole-Body Imaging to Assess Cell-Based Immunotherapy: Preclinical Studies with an Update on Clinical Translation

In the past decades, immunotherapies against cancers made impressive progress. Immunotherapy includes a broad range of interventions that can be separated into two major groups: cell-based immunotherapies, such as adoptive T cell therapies and stem cell therapies, and immunomodulatory molecular therapies such as checkpoint inhibitors and cytokine therapies. Genetic engineering techniques that transduce T cells with a cancer-antigen-specific T cell receptor or chimeric antigen receptor have expanded to other cell types, and further modulation of the cells to enhance cancer targeting properties has been explored. Because cell-based immunotherapies rely on cells migrating to target organs or tissues, there is a growing interest in imaging technologies that non-invasively monitor transferred cells in vivo. Here, we review whole-body imaging methods to assess cell-based immunotherapy using a variety of examples. Following a review of preclinically used cell tracking technologies, we consider the status of their clinical translation.

Slit2-Mediated Metabolic Reprogramming in Bone Marrow-Derived Macrophages Enhances Antitumor Immunity

Slit2 exerts antitumor effects in various cancers; however, the underlying mechanism, especially its role in regulating the immune, especially in the bone marrow niche, system is still unknown. Elucidating the behavior of macrophages in tumor progression can potentially improve immunotherapy. Using a spontaneous mammary tumor virus promoter-polyoma middle T antigen (PyMT) breast cancer mouse model, we observed that Slit2 increased the abundance of antitumor M1 macrophage in the bone marrow upon differentiation in vitro. Moreover, myeloablated PyMT mice injected with Slit2-treated bone marrow allografts showed a marked reduction in tumor growth, with enhanced recruitment of M1 macrophage in their tumor stroma. Mechanistic studies revealed that Slit2 significantly enhanced glycolysis and reduced fatty acid oxidation in bone marrow-derived macrophages (BMDMs). Slit2 treatment also altered mitochondrial respiration metabolites in macrophages isolated from healthy human blood that were treated with plasma from breast cancer patients. Overall, this study, for the first time, shows that Slit2 increases BMDM polarization toward antitumor phenotype by modulating immune-metabolism. Furthermore, this study provides evidence that soluble Slit2 could be developed as novel therapeutic strategy to enhance antitumor immune response.

Mdivi-1 Modulates Macrophage/Microglial Polarization in Mice with EAE via the Inhibition of the TLR2/4-GSK3β-NF-κB Inflammatory Signaling Axis

Macrophage/microglial modulation plays a critical role in the pathogenesis of multiple sclerosis (MS), which is an inflammatory disorder of the central nervous system. Dynamin-related protein 1 is a cytoplasmic molecule that regulates mitochondrial fission. It has been proven that mitochondrial fission inhibitor 1 (Mdivi-1), a small molecule inhibitor of Drp1, can relieve experimental autoimmune encephalomyelitis (EAE), a preclinical animal model of MS. Whether macrophages/microglia are involved in the pathological process of Mdivi-1-treated EAE remains to be determined. Here, we studied the anti-inflammatory effect of Mdivi-1 on mice with oligodendrocyte glycoprotein peptide_35-55 (MOG_35-55)-induced EAE. We found that Drp1 phosphorylation at serine 616 in macrophages/microglia was decreased with Mdivi-1 treatment, which was accompanied by decreased antigen presentation capacity of the macrophages/microglia in the EAE mouse spinal cord. The Mdivi-1 treatment caused macrophage/microglia to produce low levels of proinflammatory molecules, such as CD16/32, iNOS, and TNF-α, and high levels of anti-inflammatory molecules, such as CD206, IL-10, and Arginase-1, suggesting that Mdivi-1 promoted the macrophage/microglia shift from the inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Moreover, Mdivi-1 was able to downregulate the expression of TRL2, TRL4, GSK-3β, and phosphorylated NF-κB-p65 and prevent NF-κB-mediated IL-1β and IL-6 production. In conclusion, these results indicate that Mdivi-1 significantly alleviates inflammation in mice with EAE by promoting M2 polarization by inhibiting TLR2/4- and GSK3β-mediated NF-κB activation.

Using systems biology approaches to identify signalling pathways activated during chronic wound initiation

Chronic wounds are a significant health problem worldwide. However, nothing is known about how chronic wounds initiate and develop. Here we use a chronic wound model in diabetic mice and a Systems Biology Approach using nanoString nCounter technology and weighted gene correlation network analysis (WGCNA), with tissues collected at 6, 12, 24 and 48 h post-wounding, to identify metabolic signalling pathways involved in initiation of chronicity. Normalized counts obtained from the nanoString nCounter Mouse Metabolic Panel were used for the WGCNA, which groups genes into co-expression modules to visualize the correlation network. Genes with significant module membership and gene trait significance (p < 0.05) were used to identify signalling pathways that are important for the development of chronicity. The pathway analysis using the Reactome database showed stabilization of PTEN, which down-regulates PI3K/AKT1, which in turn down-regulates Nrf2, as shown by ELISA, thus disabling antioxidant production, resulting in high oxidative stress levels. We find that pathways involved in inflammation, including those that generate pro-inflammatory lipids derived from arachidonic acid metabolism, IFNγ and catecholamines, occur. Moreover, HIF3α is over-expressed, potentially blocking Hif1α and preventing activation of growth factors and cytokines that promote granulation tissue formation. We also find that FGF1 is under-expressed, while thrombospondin-1 is over-expressed, resulting in decreased angiogenesis, a process that is critical for healing. Finally, enzymes involved in glycolysis are down-regulated, resulting in decreased production of pyruvate, a molecule critical for ATP production, leading to extensive cell death and wound paralysis. These findings offer new avenues of study that may lead to the development of novel treatments of CW to be administered right after debridement.

Biological fabrication and electrostatic attractions of new layered silver/talc nanocomposite using Lawsonia inermis L. and its chitosan-capped inorganic/organic hybrid: Investigation on acceleration of Staphylococcus aureus and Pseudomonas aeruginosa infected wound healing

In the present study, new-layered inorganic/organic hybrid of silver/talc nanocomposites (Ag/Tlc-NPs) and its chitosan-capped derivative (Ag/Tlc/Csn NCs) were biochemically synthesized utilizing Lawsonia inermis L. extract. The silver nanoparticles (Ag NPs) were synthesized employing green method on the exterior surface layer of talc mineral as a solid substrate. The negatively charged surface layer of talc might function as templates and can attract the chitosan cations from a solution to yield a layered hybrid structure, whose inorganic phase is formed by Si-O-Ag bonds. Our results revealed that Ag NPs were formed on the exterior surface of talc with a diameter with size of 124-215 nm. In addition, cytotoxicity, in vitro antibacterial activity, and clinical effects of wound-healing ointments containing talc were investigated. The results implied the successful synthesis of Ag/Tlc/Csn NCs using the extract. The structures were safe up to 0.50 mg/mL. In vitro studies confirmed antioxidant and antibacterial properties of Ag/Tlc/Csn NCs. In sum, our findings showed that the ointments improve wound healing process by inducing an anti-inflammatory M2 phenotype and bFGF, CD206, collagen1A, and IL-10 production that causes fibroblast migration and wound closure through influencing M2 macrophage. Ag/Tlc/Csn is suggested to be taken into consideration as a medical combination for improving infected wound healing and as a promising agent for clinical administration.

Genetic in situ engineering of myeloid regulatory cells controls inflammation in autoimmunity

The ability of myeloid regulatory cells (MRCs) to control immune responses and to promote tolerance has prompted enormous interest in exploiting them therapeutically to treat inflammation, autoimmunity, or to improve outcomes in transplantation. While immunomodulatory small-molecule compounds and antibodies have provided relief for some patients, the dosing entails high systemic drug exposures and thus increased risk of off-target adverse effects. More recently, MRC-based cell-therapy products have entered clinical testing for tolerance induction. However, the elaborate and expensive protocols currently required to manufacture engineered MRCs ex vivo put this approach beyond the reach of many patients who might benefit. A solution could be to directly program MRCs in vivo. Here we describe a targeted nanocarrier that delivers in vitro-transcribed mRNA encoding a key anti-inflammatory mediator. We demonstrate in models of systemic lupus erythematosus that infusions of nanoparticles formulated with mRNA encoding glucocorticoid-induced leucine zipper (GILZ) effectively control the disease. We further establish that these nanoreagents are safe for repeated dosing. Implemented in the clinic, this new therapy could enable physicians to treat autoimmune disease while avoiding systemic treatments that disrupt immune homeostasis.

Empowering patients from within: Emerging nanomedicines for in vivo immune cell reprogramming

Currently, medicine lacks the ability to reprogram selected immune cells so they possess all the functions which, from a clinical standpoint, physicians might wish them to have. To solve this problem, scientists have been marrying concepts from materials science, immunology, and genetic engineering to develop novel nanotherapeutics that directly genetically reprogram immune cells inside the body. These products could address key limitations of existing ex vivo-engineered cell immunotherapies and substantially enhance patient access and outcomes. This review highlights the latest advances in this rapidly emerging biotech field and discusses challenges in translating these preclinical studies into successful clinical nanomedicines.

Leukocytes in Inflammation, Resolution of Inflammation, Autoimmune Diseases and Cancer

Inflammation is a double-edged sword [...].

The response of two polar monocyte subsets to inflammation

Macrophages are a central component of innate immunity that play an important role in the defense of the organism. Macrophages are highly plastic and are activated by interaction with other cells and environmental factors. In this work, we study the effect of lipopolysaccharide on macrophages derived from the two most polar (CD14+ and CD16+ monocytes) as well as the intermediate subset of blood monocytes from healthy donors and assess what happens to the subset most prone to polarization on the transcriptomic and proteomic level. It has been shown that, according to primary pro-inflammatory polarization markers, their cytokine profile, and their phagocytic activity, macrophages derived from CD14+ monocytes exhibit higher sensitivity to inducers of pro-inflammatory polarization. Flow cytometry analysis revealed increased levels of CD86, while secretome analysis demonstrated significant increase of pro-inflammatory and anti-inflammatory cytokines observed in CD14+-derived macrophages, as compared to CD16+-derived macrophages in conditioned media. Assessment of the transcriptome and proteome of CD14+-derived macrophages with further bioinformatic analysis identified the most significant differences after polarization towards the pro-inflammatory phenotype. Immune-, membrane-, IFN-γ-, cytokine-, and defense-associated pathways were found significantly prevalent, while downregulated pathways were represented by RNA binding-, housekeeping-, exocytosis-, intracellular transport-, peptide and amide metabolic-related signaling. This data could be useful for macrophage-based cell therapeutics of cancer, as it provides additional background for the manipulation of donor monocytes intended for back transplantation.