Innate and adaptive immune response to apoptotic cells

Clones reactive to apoptotic cells and specific chemical adducts are prevalent among human thymic B cells

Introduction

Thymus resident B cells were described more than 40 years ago. In early human life, these cells are found predominantly in the medulla and overwhelmingly display an unswitched IgM+ phenotype. The reactivity of thymic IgM B cells, however, is still unclear.

Methods

Here, we generated 120 IgM-producing B cell clones from 3 separate thymus specimens obtained from infant, adolescent, and adult donors. Using flow cytometry and a unique high-dimensional ELISA platform, we investigated the clones' reactivity to apoptotic cells as well as to common chemical adducts exposed on modified amino acids and other macromolecules.

Results

Regardless of the age, approximately 30-40% of thymic IgM B cells reacted to apoptotic cells. Further, 30-40% displayed reactivity to at least one adduct, including malondialdehyde, Homocysteine, and NEDD 8. Four distinct reactivity patterns were identified through this profiling. Notably, a significant association was observed between reactivity to apoptotic cells, and to one or more adducts, suggesting that the same determinants were recognized in both assays. Additionally, thymic IgM B cells reactive to adducts were more likely to recognize intra-nuclear or intra-cytoplasmic structures in Hep-2 cells as revealed by immunofluorescence staining.

Conclusion/Discussion

Collectively, our findings suggest that thymic IgM B cells actively uptake apoptotic bodies and cellular debris in the medulla by binding specific chemical adducts. This mechanism could underpin their antigen-presenting function and further support their role in T-cell negative selection.

Tailoring of apoptotic bodies for diagnostic and therapeutic applications:advances, challenges, and prospects

Apoptotic bodies (ABs) are extracellular vesicles released during apoptosis and possess diverse biological activities. Initially, ABs were regarded as garbage bags with the main function of apoptotic cell clearance. Recent research has found that ABs carry and deliver various biological agents and are taken by surrounding and distant cells, affecting cell functions and behavior. ABs-mediated intercellular communications are involved in various physiological processes including anti-inflammation and tissue regeneration as well as the pathogenesis of a variety of diseases including cancer, cardiovascular diseases, neurodegeneration, and inflammatory diseases. ABs in biological fluids can be used as a window of altered cellular and tissue states which can be applied in the diagnosis and prognosis of various diseases. The structural and constituent versatility of ABs provides flexibility for tailoring ABs according to disease diagnostic and therapeutic needs. An in-depth understanding of ABs' constituents and biological functions is mandatory for the effective tailoring of ABs including modification of bio membrane and cargo constituents. ABs' tailoring approaches including physical, chemical, biological, and genetic have been proposed for bench-to-bed translation in disease diagnosis, prognosis, and therapy. This review summarizes the updates on ABs tailoring approaches, discusses the existing challenges, and speculates the prospects for effective diagnostic and therapeutic applications.

Kojic acid reverses LPS-induced neuroinflammation and cognitive impairment by regulating the TLR4/NF-κB signaling pathway

Intense neuroinflammation contributes to neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Lipopolysaccharides (LPSs) are an integral part of the cell wall of Gram-negative bacteria that act as pathogen-associated molecular patterns (PAMPs) and potentially activate the central nervous system's (CNS) immune system. Microglial cells are the local macrophages of the CNS and have the potential to induce and control neuroinflammation. This study aims to evaluate the anti-inflammatory and antioxidant effect of kojic acid against the toxic effects of LPSs, such as neuroinflammation-induced neurodegeneration and cognitive decline. The C57BL/6N mice were subjected to LPS injection for 2 weeks on alternate days (each mouse received 0.25 mg/kg/i.p. for a total of seven doses), and kojic acid was administered orally for 3 weeks consecutively (50 mg/kg/mouse, p. o). Bacterial endotoxins, or LPSs, are directly attached to TLR4 surface receptors of microglia and astrocytes and alter the cellular metabolism of immune cells. Intraperitoneal injection of LPS triggers the toll-like receptor 4 (TLR4), phospho-nuclear factor kappa B (p-NFκB), and phospho-c-Jun n-terminal kinase (p-JNK) protein expressions in the LPS-treated group, but these expression levels were significantly downregulated in the LPS + KA-treated mice brains. Prolong neuroinflammation leads to the generation of reactive oxygen species (ROS) followed by a decrease in nuclear factor erythroid-2-related factor 2 (Nrf2) and the enzyme hemeoxygenase 1 (HO-1) expression in LPS-subjected mouse brains. Interestingly, the levels of both Nrf-2 and HO-1 increased in the LPS + KA-treated mice group. In addition, kojic acid inhibited LPS-induced TNF-α and IL-1β production in mouse brains. These results indicated that kojic acid may suppress LPS-induced neuroinflammation and oxidative stress in male wild-type mice brains (in both the cortex and the hippocampus) by regulating the TLR4/NF-κB signaling pathway.

Efferocytosis: Unveiling its potential in autoimmune disease and treatment strategies

Efferocytosis is a crucial process whereby phagocytes engulf and eliminate apoptotic cells (ACs). This intricate process can be categorized into four steps: (1) ACs release "find me" signals to attract phagocytes, (2) phagocytosis is directed by "eat me" signals emitted by ACs, (3) phagocytes engulf and internalize ACs, and (4) degradation of ACs occurs. Maintaining immune homeostasis heavily relies on the efficient clearance of ACs, which eliminates self-antigens and facilitates the generation of anti-inflammatory and immunosuppressive signals that maintain immune tolerance. However, any disruptions occurring at any of the efferocytosis steps during apoptosis can lead to a diminished efficacy in removing apoptotic cells. Factors contributing to this inefficiency encompass dysregulation in the release and recognition of "find me" or "eat me" signals, defects in phagocyte surface receptors, bridging molecules, and other signaling pathways. The inadequate clearance of ACs can result in their rupture and subsequent release of self-antigens, thereby promoting immune responses and precipitating the onset of autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. A comprehensive understanding of the efferocytosis process and its implications can provide valuable insights for developing novel therapeutic strategies that target this process to prevent or treat autoimmune diseases.

Modulating Lipid-Polymer Nanoparticles' Physicochemical Properties to Alter Macrophage Uptake

Macrophage uptake of nanoparticles is highly dependent on the physicochemical characteristics of those nanoparticles. Here, we have created a collection of lipid-polymer nanoparticles (LPNPs) varying in size, stiffness, and lipid makeup to determine the effects of these factors on uptake in murine bone marrow-derived macrophages. The LPNPs varied in diameter from 232 to 812 nm, in storage modulus from 21.2 to 287 kPa, and in phosphatidylserine content from 0 to 20%. Stiff, large nanoparticles with a coating containing phosphatidylserine were taken up by macrophages to a much higher degree than any other formulation (between 9.3× and 166× higher than other LPNPs). LPNPs with phosphatidylserine were taken up most by M2-polarized macrophages, while those without were taken up most by M1-polarized macrophages. Differences in total LPNP uptake were not dependent on endocytosis pathway(s) other than phagocytosis. This work acts as a basis for understanding how the interactions between nanoparticle physicochemical characteristics may act synergistically to facilitate particle uptake.

NADPH oxidase exerts a B cell-intrinsic contribution to lupus risk by modulating endosomal TLR signals

Genome-wide association studies in systemic lupus erythematosus (SLE) have linked loss-of-function mutations in phagocytic NADPH oxidase complex (NOX2) genes, including NCF1 and NCF2, to disease pathogenesis. The prevailing model holds that reduced NOX2 activity promotes SLE via defective efferocytosis, the immunologically silent clearance of apoptotic cells. Here, we describe a parallel B cell-intrinsic mechanism contributing to breaks in tolerance. In keeping with an important role for B cell Toll-like receptor (TLR) pathways in lupus pathogenesis, NOX2-deficient B cells exhibit enhanced signaling downstream of endosomal TLRs, increased humoral responses to nucleic acid-containing antigens, and the propensity toward humoral autoimmunity. Mechanistically, TLR-dependent NOX2 activation promotes LC3-mediated maturation of TLR-containing endosomes, resulting in signal termination. CRISPR-mediated disruption of NCF1 confirmed a direct role for NOX2 in regulating endosomal TLR signaling in primary human B cells. Together, these data highlight a new B cell-specific mechanism contributing to autoimmune risk in NCF1 and NCF2 variant carriers.

Radiotherapy, photodynamic therapy, and cryoablation-induced abscopal effect: Challenges and future prospects

Local therapy modalities such as radiation therapy, photodynamic therapy, photothermal therapy, and cryoablation have been used to treat localized tumors for decades. The discovery of the abscopal effect causes a paradigm shift where local therapy also causes systemic effects and leads to the remission of nonirradiated tumors. The abscopal effect of radiation therapy, alone or in combination with other treatments, has been extensively studied over the last six decades. However, the results are unsatisfactory in producing robust, reproducible, and long-lasting systemic effects. Although immunotherapy and radiation therapy are promising in producing the abscopal effect, the abscopal effect's mechanism is still unclear, owing to various factors such as irradiation type and dose and cancer type. This article reviews the research progress, clinical and preclinical evidence of the abscopal effect by various local therapies alone and in combination with chemotherapy and immunotherapy, case reports, and the current challenges in producing the abscopal effect by various local therapies, focusing on radiotherapy, photodynamic therapy, cryoablation, and the prospects for obtaining a robust, reproducible, and long-lasting abscopal effect.

Kinesin-5 Eg5 is essential for spindle assembly, chromosome stability and organogenesis in development

Chromosome stability relies on bipolar spindle assembly and faithful chromosome segregation during cell division. Kinesin-5 Eg5 is a plus-end-directed kinesin motor protein, which is essential for spindle pole separation and chromosome alignment in mitosis. Heterozygous Eg5 mutations cause autosomal-dominant microcephaly, primary lymphedema, and chorioretinal dysplasia syndrome in humans. However, the developmental roles and cellular mechanisms of Eg5 in organogenesis remain largely unknown. In this study, we have shown that Eg5 inhibition leads to the formation of the monopolar spindle, chromosome misalignment, polyploidy, and subsequent apoptosis. Strikingly, long-term inhibition of Eg5 stimulates the immune responses and the accumulation of lymphocytes in the mouse spleen through the innate and specific immunity pathways. Eg5 inhibition results in metaphase arrest and cell growth inhibition, and suppresses the formation of somite and retinal development in zebrafish embryos. Our data have revealed the essential roles of kinesin-5 Eg5 involved in cell proliferation, chromosome stability, and organogenesis during development. Our findings shed a light on the cellular basis and pathogenesis in microcephaly, primary lymphedema, and chorioretinal dysplasia syndrome of Eg5-mutation-positive patients.

Adipose tissue-derived small extracellular vesicles modulate macrophages to improve the homing of adipocyte precursors and endothelial cells in adipose tissue regeneration

Rapid infiltration of endogenous cells induced by cell-free biomaterials is the first and crucial step in tissue regeneration and macrophage is largely involved. Our previous study reported adipose tissue-derived small extracellular vesicles (sEV-AT) could successfully promote adipose tissue regeneration. However, the role of macrophages in this process was unknown. In this study, we isolated sEV-AT and subcutaneously implanted it into the back of SD rats. The results showed sEV-AT increased macrophage infiltration significantly, which was followed by improving homing of adipocyte precursors (APs) and endothelial cells (ECs). However, when macrophages were depleted by clodronate liposome within 1 week, the homing of APs and ECs, and adipose tissue regeneration were destroyed. In vitro, sEV-AT showed the ability to promote the migration of macrophages directly. Besides, sEV-AT-pretreated macrophages improved the migration of APs and ECs, accompanied by the increase of chemokines (MCP-1, SDF-1, VEGF, and FGF) and the activation of NF-kB signaling pathway. These findings indicated sEV-AT might regulate the secretion of chemokines via activating NF-kB signaling pathway to improve homing of APs and ECs and facilitate adipose tissue regeneration. These findings deepened our understanding of small extracellular vesicle-induced tissue regeneration and laid a theoretical foundation for the clinical application of sEV-AT.

Pathological mechanisms and crosstalk among different forms of cell death in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder characterized by a profound immune dysregulation and the presence of a variety of autoantibodies. Aberrant activation of programmed cell death (PCD) signaling and accelerated cell death is critical in the immunopathogenesis of SLE. Accumulating cellular components from the dead cells and ineffective clearance of the dead cell debris, in particular the nucleic acids and nucleic acids-protein complexes, provide a stable source of self-antigens, which potently activate auto-reactive B cells and promote IFN-I responses in SLE. Different cell types display distinct susceptibility and characteristics to a certain type of cell death, while different PCDs in various cells have mutual and intricate connections to promote immune dysregulation and contribute to the development of SLE. In this review, we discuss the role of various cell death pathways and their interactions in the pathogenesis of SLE. An in depth understanding of the interconnections among various forms cell death in SLE will lead to a better understanding of disease pathogenesis, shedding light on the development of novel therapeutic targets.

Apoptotic body-inspired nanoparticles target macrophages at sites of inflammation to support an anti-inflammatory phenotype shift

Chronic inflammation is a significant pathological process found in a range of disease states. Treatments to reduce inflammation in this family of diseases may improve symptoms and disease progression, but are largely limited by variable response rates, cost, and off-target effects. Macrophages are implicated in many inflammatory diseases for their critical role in the maintenance and resolution of inflammation. Macrophages exhibit significant plasticity to direct the inflammatory response by taking on an array of pro- and anti-inflammatory phenotypes based on extracellular cues. In this work, a nanoparticle has been developed to target sites of inflammation and reduce the inflammatory macrophage phenotype by mimicking the anti-inflammatory effect of apoptotic cell engulfment. The nanoparticle, comprised of a poly(lactide-co-glycolide) core, is coated with phosphatidylserine (PS)-supplemented cell plasma membrane to emulate key characteristics of the apoptotic cell surface. T he particle surface is additionally functionalized with an acid-sensitive sheddable polyethylene glycol (PEG) moiety to increase the delivery of the nanoparticles to low pH environments such as those of chronic inflammation. In a mouse model of lipopolysaccharide-induced inflammation, particles were preferentially taken up by macrophages at the site and promoted an anti-inflammatory phenotype shift. This PEGylated membrane coating increased the delivery of nanoparticles to sites of inflammation and may be used as a tool alone or as a delivery scheme for additional cargo to reduce macrophage-associated inflammatory response.

The Immune-Centric Revolution in the Diabetic Foot: Monocytes and Lymphocytes Role in Wound Healing and Tissue Regeneration-A Narrative Review

Monocytes and lymphocytes play a key role in physiologic wound healing and might be involved in the impaired mechanisms observed in diabetes. Skin wound macrophages are represented by tissue resident macrophages and infiltrating peripheral blood recruited monocytes which play a leading role during the inflammatory phase of wound repair. The impaired transition of diabetic wound macrophages from pro-inflammatory M1 phenotypes to anti-inflammatory pro-regenerative M2 phenotypes might represent a key issue for impaired diabetic wound healing. This review will focus on the role of immune system cells in normal skin and diabetic wound repair. Furthermore, it will give an insight into therapy able to immuno-modulate wound healing processes toward to a regenerative anti-inflammatory fashion. Different approaches, such as cell therapy, exosome, and dermal substitute able to promote the M1 to M2 switch and able to positively influence healing processes in chronic wounds will be discussed.

Truncated PARP1 mediates ADP-ribosylation of RNA polymerase III for apoptosis

Caspase-mediated cleavage of PARP1 is a surrogate marker for apoptosis. However, the biological significance of PARP1 cleavage during apoptosis is still unclear. Here, using unbiased protein affinity purification, we show that truncated PARP1 (tPARP1) recognizes the RNA polymerase III (Pol III) complex in the cytosol. tPARP1 mono-ADP-ribosylates RNA Pol III in vitro and mediates ADP-ribosylation of RNA Pol III during poly(dA-dT)-stimulated apoptosis in cells. tPARP1-mediated activation of RNA Pol III facilitates IFN-β production and apoptosis. In contrast, suppression of PARP1 or expressing the non-cleavable form of PARP1 impairs these molecular events. Taken together, these studies reveal a novel biological role of tPARP1 during cytosolic DNA-induced apoptosis.

Regulatory strategies limiting endosomal Toll-like receptor activation in B cells

The recognition of pathogen-associated nucleic acid (NA) promotes effective immunity against invading pathogens. However, endosomal Toll-like receptor (TLR) activation by self-NA also underlies the pathogenesis of systemic autoimmune diseases, such as systemic lupus erythematosus (SLE). For this reason, the activation thresholds of NA-sensing TLRs must be tightly regulated to balance protective and pathogenic immune responses. In this study, we will provide an overview of the evolutionary mechanisms designed to limit the aberrant activation of endosomal TLRs by self-ligands, focusing on four broad strategies. These include the following: 1) the production of nucleases able to degrade self-DNA and RNA; 2) the cell-specific regulation of endosomal TLR expression; 3) the spatial and temporal control of TLR positioning at a sub-cellular level; and 4) the modulation of downstream TLR signaling cascades. Given the critical role of B cells in lupus pathogenesis, where possible, we will describe evidence for B cell-specific induction of these regulatory mechanisms. We will also highlight our own work showing how modulation of B cell endolysosomal flux tunes NA-sensing TLR activation signals. In the face of inevitable generation of self-NA during normal cellular turnover, these parallel mechanisms are vital to protect against pathogenic inflammation.

Modulation of the Immune System Promotes Tissue Regeneration

The immune system plays an essential role in the angiogenesis, repair, and regeneration of damaged tissues. Therefore, the design of scaffolds that manipulate immune cells and factors in such a way that could accelerate the repair of damaged tissues, following implantation, is one of the main goals of regenerative medicine. However, before manipulating the immune system, the function of the various components of the immune system during the repair process should be well understood and the fabrication conditions of the manipulated scaffolds should be brought closer to the physiological state of the body. In this article, we first review the studies aimed at the role of distinct immune cell populations in angiogenesis and support of damaged tissue repair. In the second part, we discuss the use of strategies that promote tissue regeneration by modulating the immune system. Given that various studies have shown an increase in tissue repair rate with the addition of stem cells and growth factors to the scaffolds, and regarding the limited resources of stem cells, we suggest the design of scaffolds that are capable to develop repair of damaged tissue by manipulating the immune system and create an alternative for repair strategies that use stem cells or growth factors.

miR-200b-3p alleviates TNF-α-induced apoptosis and inflammation of intestinal epithelial cells and ulcerative colitis progression in rats via negatively regulating KHDRBS1

Ulcerative colitis (UC) is difficult to be treated. miRNAs are a group of gene regulators. Study demonstrated that miR-200b-3p is involved in the development of UC, but the specific molecular mechanism is still unclear. A UC model was established by injecting acetic acid into rectum of rats, which were then treated with miR-200b-3p antagonists and agonists. Weight change, fecal viscosity and fecal bleeding were measured to determine disease activity index. The ratio of colon length to weight was measured. Colon lesions were detected by H&E staining. ELISA was used to detect the expression of TGF-β in colon tissues and IL-10/CRP in serum. Intestinal epithelial cells (NCM460) were treated by TNF-α to create an inflammatory environment. MRNA and protein levels of miR-200b-3p, KHDRBS1, IL-10, IL-6, IL-1β, TGF-β, Bcl-2, Bax and C-capase-3 were detected by qRT-PCR and Western blot, respectively. TargetScan database and dual-luciferase reporter assay were conducted to predict the targeting relationship between miR-200b-3p and KHDRBS1. MTT and flow cytometry were respectively performed to detect cell proliferation and apoptosis. MiR-200b-3p expression was inhibited, leading to increased disease activity index and colonic length-weight ratio, and aggravation of lesions of the UC rat model. Up-regulation of miR-200b-3p can relieve inflammation and apoptosis of immune cells in UC rats. MiR-200b-3p targeted KHDRBS1 and inhibited its expression. Moreover, KHDRBS1 reversed the effects of miR-200b-3p on apoptosis, proliferation and inflammation of intestinal epithelial cells. MiR-200b-3p alleviates UC by negatively regulating KHDRBS1.

Cell-Inspired Biomaterials for Modulating Inflammation

Inflammation is a crucial part of wound healing and pathogen clearance. However, it can also play a role in exacerbating chronic diseases and cancer progression when not regulated properly. A subset of current innate immune engineering research is focused on how molecules such as lipids, proteins, and nucleic acids native to a healthy inflammatory response can be harnessed in the context of biomaterial design to promote healing, decrease disease severity, and prolong survival. The engineered biomaterials in this review inhibit inflammation by releasing anti-inflammatory cytokines, sequestering proinflammatory cytokines, and promoting phenotype switching of macrophages in chronic inflammatory disease models. Conversely, other biomaterials discussed here promote inflammation by mimicking pathogen invasion to inhibit tumor growth in cancer models. The form that these biomaterials take spans a spectrum from nanoparticles to large-scale hydrogels to surface coatings on medical devices. Cell-inspired molecules have been incorporated in a variety of creative ways, including loaded into or onto the surface of biomaterials or used as the biomaterials themselves.

Serum antinuclear autoantibodies are associated with measures of oxidative stress and lifestyle factors: analysis of LIPIDOGRAM2015 and LIPIDOGEN2015 studies

Introduction

Oxidative stress is one of many factors suspected to promote antinuclear autoantibody (ANA) formation. Reactive oxygen species can induce changes in the antigenic structure of macromolecules, causing the immune system to treat them as "neo-antigens" and start production of autoantibodies. This study was designed to evaluate the relationship between oxidative stress markers, lifestyle factors and the detection of ANA.

Material and methods

We examined measures of oxidative stress indices of free-radical damage to lipids and proteins, such as total oxidant status (TOS), concentration of protein thiol groups (PSH), and malondialdehyde (MDA), activity of superoxide dismutase (SOD) in 1731 serum samples. The parameters of the non-enzymatic antioxidant system, such as total antioxidant status (TAS) and uric acid (UA) concentration, were also measured and the oxidative stress index (OSI-index) was calculated. All samples were tested for the presence of ANA using an indirect immunofluorescence assay (IIFA).

Results

The presence of ANA in women was associated with lower physical activity (p = 0.036), less frequent smoking (p = 0.007) and drinking of alcohol (p = 0.024) accompanied by significant changes in SOD isoenzymes activity (p < 0.001) and a higher uric acid (UA) concentration (p < 0.001). In ANA positive males we observed lower concentrations of PSH (p = 0.046) and increased concentrations of MDA (p = 0.047).

Conclusions

The results indicate that local oxidative stress may be associated with increased probability of ANA formation in a sex-specific manner.

Thermal ablation in non-small cell lung cancer: a review of treatment modalities and the evidence for combination with immune checkpoint inhibitors

Lung cancer is the leading cause of cancer death worldwide, with approximately 1.6 million cancer related deaths each year. Prognosis is best in patients with early stage disease, though even then five-year survival is only 55% in some groups. Median survival for advanced non-small cell lung cancer (NSCLC) is 8–12 months with conventional treatment. Immune checkpoint inhibitor (ICI) therapy has revolutionised the treatment of NSCLC with significant long-term improvements in survival demonstrated in some patients with advanced NSCLC. However, only a small proportion of patients respond to ICI, suggesting the need for further techniques to harness the potential of ICI therapy. Thermal ablation utilizes the extremes of temperature to cause tumour destruction. Commonly used modalities are radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA). At present thermal ablation is reserved for curative-intent therapy in patients with localized NSCLC who are unable to undergo surgical resection or stereotactic ablative body radiotherapy (SABR). Limited evidence suggests that thermal ablative modalities can upregulate an anticancer immune response in NSCLC. It is postulated that thermal ablation can increase tumour antigen release, which would initiate and upregulated steps in the cancer immunity cycle required to elicit an anticancer immune response. This article will review the current thermal ablative techniques and their ability to modulate an anti-cancer immune response with a view of using thermal ablation in conjunction with ICI therapy.

Non-viral transfection technologies for next-generation therapeutic T cell engineering

Genetically engineered T cells have sparked interest in advanced cancer treatment, reaching a milestone in 2017 with two FDA-approvals for CD19-directed chimeric antigen receptor (CAR) T cell therapeutics. It is becoming clear that the next generation of CAR T cell therapies will demand more complex engineering strategies and combinations thereof, including the use of revolutionary gene editing approaches. To date, manufacturing of CAR T cells mostly relies on γ-retroviral or lentiviral vectors, but their use is associated with several drawbacks, including safety issues, high manufacturing cost and vector capacity constraints. Non-viral approaches, including membrane permeabilization and carrier-based techniques, have therefore gained a lot of interest to replace viral transductions in the manufacturing of T cell therapeutics. This review provides an in-depth discussion on the avid search for alternatives to viral vectors, discusses key considerations for T cell engineering technologies, and provides an overview of the emerging spectrum of non-viral transfection technologies for T cells. Strengths and weaknesses of each technology will be discussed in relation to T cell engineering. Altogether, this work emphasizes the potential of non-viral transfection approaches to advance the next-generation of genetically engineered T cells.

New insight of immuno-engineering in osteoimmunomodulation for bone regeneration

With the continuous development of bone tissue engineering, the importance of immune response in bone tissue regeneration is gradually recognized. The new bone tissue engineering products should possess immunoregulatory functions, harmonizing the interactions between the bone's immune defense and regeneration systems, and promoting tissue regeneration. This article will interpret the relationship between the bone immune system, bone tissue regeneration, as well as the immunoregulatory function of bone biomaterials and seed stem cells in bone tissue engineering. This review locates arears for foucusing efforts at providing novel designs ideas about the development of immune-mediation targeted bone tissue engineering products and the evaluation strategy for the osteoimmunomodulation property of bone biomaterials.

Impact of storage conditions on peripheral leukocytes transcriptome

Leukocytes reflect the physiological and pathological states of each individual, and transcriptomic data of leukocytes have been used to reflect health conditions. Since the overall impact of ex vivo conditions on the leukocyte transcriptome before RNA stabilization remains unclear, we evaluated the influence of temporary storage conditions on the leukocyte transcriptome through RNA sequencing. We collected peripheral blood with EDTA tubes, which were processed immediately or stored either at 4 °C or room temperature (RT, 18-22 °C) for 2 h, 6 h and 24 h. Total cellular RNA was extracted from 42 leukocyte samples after red blood cells lysis for subsequent RNA sequencing. We applied weighted gene co-expression network analysis to construct co-expression networks of mRNA and lncRNA among the samples, and then performed gene ontology (GO) term enrichment to explore possible biological processes affected by storage conditions. Storage conditions change the gene expression of peripheral leukocytes. Comparing with fresh leukocytes, storage for 24 h at 4 °C and RT affected 1515 (1.51%) and 10,823 (10.82%) genes, respectively. Pathway enrichment analysis identified nucleosome assembly enriched in up-regulated genes at both conditions. When blood was stored at RT for 24 h, genes involved in apoptotic signaling pathway, negative regulation of cell cycle and lymphocyte activation were upregulated, while the relative proportion of neutrophils was significantly decreased. Temporary storage conditions profoundly affect the gene expression profiles of leukocytes and might further change cell viability and state. Storage of blood samples at 4 °C within 6 h largely maintains their original transcriptome.

On the Quest for In Vitro Platelet Production by Re-Tailoring the Concepts of Megakaryocyte Differentiation

The demand of platelet transfusions is steadily growing worldwide, inter-donor variation, donor dependency, or storability/viability being the main contributing factors to the current global, donor-dependent platelet concentrate shortage concern. In vitro platelet production has been proposed as a plausible alternative to cover, at least partially, the increasing demand. However, in practice, such a logical production strategy does not lack complexity, and hence, efforts are focused internationally on developing large scale industrial methods and technologies to provide efficient, viable, and functional platelet production. This would allow obtaining not only sufficient numbers of platelets but also functional ones fit for all clinical purposes and civil scenarios. In this review, we cover the evolution around the in vitro culture and differentiation of megakaryocytes into platelets, the progress made thus far to bring the culture concept from basic research towards good manufacturing practices certified production, and subsequent clinical trial studies. However, little is known about how these in vitro products should be stored or whether any safety measure should be implemented (e.g., pathogen reduction technology), as well as their quality assessment (how to isolate platelets from the rest of the culture cells, debris, microvesicles, or what their molecular and functional profile is). Importantly, we highlight how the scientific community has overcome the old dogmas and how the new perspectives influence the future of platelet-based therapy for transfusion purposes.

A 3D-printed biomaterials-based platform to advance established therapy avenues against primary bone cancers

In this study we developed and validated a 3D-printed drug delivery system (3DPDDS) to 1) improve local treatment efficacy of commonly applied chemotherapeutic agents in bone cancers to ultimately decrease their systemic side effects and 2) explore its concomitant diagnostic potential. Thus, we locally applied 3D-printed medical-grade polycaprolactone (mPCL) scaffolds loaded with Doxorubicin (DOX) and measured its effect in a humanized primary bone cancer model. A bioengineered species-sensitive orthotopic humanized bone niche was established at the femur of NOD-SCID IL2Rγ^null (NSG) mice. After 6 weeks of in vivo maturation into a humanized ossicle, Luc-SAOS-2 cells were injected orthotopically to induce local growth of osteosarcoma (OS). After 16 weeks of OS development, a biopsy-like defect was created within the tumor tissue to locally implant the 3DPDDS with 3 different DOX loading doses into the defect zone. Histo- and morphological analysis demonstrated a typical invasive OS growth pattern inside a functionally intact humanized ossicle as well as metastatic spread to the murine lung parenchyma. Analysis of the 3DPDDS revealed the implants' ability to inhibit tumor infiltration and showed local tumor cell death adjacent to the scaffolds without any systemic side effects. Together these results indicate a therapeutic and diagnostic capacity of 3DPDDS in an orthotopic humanized OS tumor model.

The Immune System and Its Contribution to Variability in Regenerative Medicine

The immune system plays a critical role in directing tissue repair and regeneration outcomes. Tissue engineering technologies that are designed to promote new tissue growth will therefore be impacted by immune factors that are present in patients both locally at the site of intervention and systemically. The immune state of patients can be influenced by many factors, including infection, nutrition, and other disease comorbidities. As a result, the immune state is highly variable and may be a source of variability in tissue-engineered products in the clinic, which is not found in preclinical models. In this review, we will summarize key immune cells and evidence of their activity in tissue repair and potential in tissue engineering systems. We also discuss how clinical translation of tissue engineering strategies, in particular stem cells, helped elucidate the importance of the immune system. With increased understanding of the immune system's role in repair and tissue engineering systems, it will likely become a therapeutic target and component of future therapies.

Intracellular Delivery of mRNA in Adherent and Suspension Cells by Vapor Nanobubble Photoporation

Efficient and safe cell engineering by transfection of nucleic acids remains one of the long-standing hurdles for fundamental biomedical research and many new therapeutic applications, such as CAR T cell-based therapies. mRNA has recently gained increasing attention as a more safe and versatile alternative tool over viral- or DNA transposon-based approaches for the generation of adoptive T cells. However, limitations associated with existing nonviral mRNA delivery approaches hamper progress on genetic engineering of these hard-to-transfect immune cells. In this study, we demonstrate that gold nanoparticle-mediated vapor nanobubble (VNB) photoporation is a promising upcoming physical transfection method capable of delivering mRNA in both adherent and suspension cells. Initial transfection experiments on HeLa cells showed the importance of transfection buffer and cargo concentration, while the technology was furthermore shown to be effective for mRNA delivery in Jurkat T cells with transfection efficiencies up to 45%. Importantly, compared to electroporation, which is the reference technology for nonviral transfection of T cells, a fivefold increase in the number of transfected viable Jurkat T cells was observed. Altogether, our results point toward the use of VNB photoporation as a more gentle and efficient technology for intracellular mRNA delivery in adherent and suspension cells, with promising potential for the future engineering of cells in therapeutic and fundamental research applications.

Apoptotic blebs from Leishmania major-infected macrophages as a new approach for cutaneous leishmaniasis vaccination

We focused on apoptotic blebs from Leishmania major-infected macrophages as a vaccine for cutaneous leishmaniasis. Apoptosis was induced in L. major-infected J774A.1 cells in order to prepare apoptotic blebs. Test groups of BALB/c mice were immunized with these at doses of 1 × 10⁶, 5 × 10⁶ or 1 × 10⁷ blebs. An immunization control group received Leishmania lysate antigens. The results showed that as the number of apoptotic bodies increased, the lymphocyte proliferation index increased, and this was proportional to IFN-γ level in the test groups. Additionally, the difference of IFN-γ, IL-4, IFN-γ/IL-4 ratio, or total IgG (p < 0.0001) in all groups was statistically significant compared to the negative control group. The highest IFN-γ (514.0 ± 40.92 pg/mL) and IFN-γ/IL-4 ratio (2.94 ± 0.22) were observed in the group that received 1 × 10⁷ apoptotic blebs. The highest levels of IL-4 (244.6 ± 38.8 pg/mL) and total IgG (5626 ± 377 μg/mL) were observed in the immunization control group. Reflecting these data, no lesions were observed in any of the groups vaccinated with apoptotic blebs after 12 weeks. In summary, the use of apoptotic blebs from L. major-infected macrophages is protective against the challenge with L. major in this animal model.

In vitro platelet production for transfusion purposes: Where are we now?

Over the last decade there has been a worldwide increase in the demand of platelet concentrates (PCs) for transfusion. This is, to a great extent, due to a growing and aging population with the concomitant increase in the incidence of onco-hematological diseases, which require frequent platelet (PLT) transfusions. Currently, PLTs are sourced uniquely from donations, and their storage time is limited only to a few days. The necessity to store PCs at room temperature (to minimize loss of PLT functional integrity), poses a major risk for bacterial contamination. While the implementation of pathogen reduction treatments (PRTs) and new-generation PLT additive solutions have allowed the extension of the shelf life and a safer PLT transfusion product, the concern of PCs shortage still pressures the scientific community to find alternative solutions with the aim of meeting the PLT transfusion increasing demand. In this concise report, we will focus on the efforts made to produce, in in vitro culture, high yields of viable and functional PLTs for transfusion purposes in a cost-effective manner, meeting not only current Good Manufacturing Practices (cGMPs), but also transfusion safety standards.

Systemic lupus erythematosus favors the generation of IL-17 producing double negative T cells

Mature double negative (DN) T cells are a population of αβ T cells that lack CD4 and CD8 coreceptors and contribute to systemic lupus erythematosus (SLE). The splenic marginal zone macrophages (MZMs) are important for establishing immune tolerance, and loss of their number or function contributes to the progression of SLE. Here we show that loss of MZMs impairs the tolerogenic clearance of apoptotic cells and alters the serum cytokine profile, which in turn provokes the generation of DN T cells from self-reactive CD8+ T cells. Increased Ki67 expression, narrowed TCR V-beta repertoire usage and diluted T-cell receptor excision circles confirm that DN T cells from lupus-prone mice and patients with SLE undergo clonal proliferation and expansion in a self-antigen dependent manner, which supports the shared mechanisms for their generation. Collectively, our results provide a link between the loss of MZMs and the expansion of DN T cells, and indicate possible strategies to prevent the development of SLE.

Oral Administration of Alpha Linoleic Acid Rescues Aβ-Induced Glia-Mediated Neuroinflammation and Cognitive Dysfunction in C57BL/6N Mice

In this work, we evaluated the effects of alpha linoleic acid (ALA), an omega-3 polyunsaturated fatty acid, on amyloid-beta-induced glial-cell-mediated neuroinflammation, amyloidogenesis, and cognitive dysfunction in mice. After an infusion of Aβ_1-42 (Aβ_1-42, 5 μL/5 min/mouse, intracerebroventricular injection (i.c.v), and respective treatments of ALA (60 mg/kg per oral for six weeks), neuroinflammation, apoptotic markers, and synaptic markers were evaluated by Western blot and immunofluorescence analyses. According to our findings, the infusion of Aβ_1-42 activated Toll-like receptor 4 (TLR4), glial fibrillary acidic protein (GFAP), and ionized calcium adaptor molecule 1 (Iba-1) in the frontal cortices and hippocampi of the Aβ_1-42-injected mice to a greater extent than the Aβ_1-42 + ALA-cotreated mice. Similarly, there was an elevated expression of phospho-c-Jun-N-terminal kinase (p-JNK), phospho-nuclear factor-kB p65 (p-NF-kB p65 (Ser536)), and tissue necrosis factor (TNF) in the Aβ_1-42 infused mouse brains; interestingly, these markers were significantly reduced in the Aβ + ALA-cotreated group. The elevated expression of pro-apoptotic markers was observed during apoptotic cell death in the Aβ_1-42-treated mouse brains, whereas these markers were markedly reduced in the Aβ + ALA-cotreated group. Moreover, Aβ_1-42 infusion significantly increased amyloidogenesis, as assessed by the enhanced expression of the amyloid precursor proteins (APP) beta-amyloid cleaving enzyme-1 (BACE-1) and amyloid-beta (Aβ_1-42) in the mouse brains, whereas these proteins were markedly reduced in the Aβ + ALA-cotreated group. We also checked the effects of ALA against Aβ-triggered synaptic dysfunction and memory dysfunction, showing that ALA significantly improved memory and synaptic functions in Aβ-treated mouse brains. These results indicated that ALA could be an applicable intervention in neuroinflammation, apoptotic cell loss, amyloidogenesis, and memory dysfunction via the inhibition of TLR4 and its downstream targets in Aβ + ALA-cotreated mouse brains.

Immune Sensing of Cell Death through Recognition of Histone Sequences by C-Type Lectin-Receptor-2d Causes Inflammation and Tissue Injury

The immune system monitors the health of cells and is stimulated by necrosis. Here we examined the receptors and ligands driving this response. In a targeted screen of C-type lectin receptors, a Clec2d reporter responded to lysates from necrotic cells. Biochemical purification identified histones, both free and bound to nucleosomes or neutrophil extracellular traps, as Clec2d ligands. Clec2d recognized poly-basic sequences in histone tails and this recognition was sensitive to post-translational modifications of these sequences. As compared with WT mice, Clec2d^-/- mice exhibited reduced proinflammatory responses to injected histones, and less tissue damage and improved survival in a hepatotoxic injury model. In macrophages, Clec2d localized to the plasma membrane and endosomes. Histone binding to Clec2d did not stimulate kinase activation or cytokine production. Rather, histone-bound DNA stimulated endosomal Tlr9-dependent responses in a Clec2d-dependent manner. Thus, Clec2d binds to histones released upon necrotic cell death, with functional consequences to inflammation and tissue damage.

Cytoreductive treatment strategies for de novo metastatic prostate cancer

In the past decade, a revolution in the treatment of metastatic prostate cancer has occurred with the advent of novel hormonal agents and life-prolonging chemotherapy regimens in combination with standard androgen-deprivation therapy. Notwithstanding, the use of systemic therapy alone can result in a castrate-resistant state; therefore, increasing focus is being placed on the additional survival benefits that could potentially be achieved with local cytoreductive and/or metastasis-directed therapies. Local treatment of the primary tumour with the established modalities of radiotherapy and radical prostatectomy has been explored in this context, and the use of novel minimally invasive ablative therapies has been proposed. In addition, evidence of the potential clinical benefits of metastasis-directed therapy with ionizing radiation (primarily stereotactic ablative radiotherapy) is accumulating. Herein, we summarize the pathobiological rationale for local cytoreduction and the potentially systemic immunological responses to radiotherapy and ablative therapies in patients with metastatic prostate cancer. We also discuss the current evidence base for a cytoreductive strategy, including metastasis-directed therapy, in the current era of sequential multimodal therapy incorporating novel treatments. Finally, we outline further research questions relating to this complex and evolving treatment landscape.

Autoreactive B cells in SLE, villains or innocent bystanders?

The current concepts for development of autoreactive B cells in SLE (systemic lupus erythematosus) focus on extrinsic stimuli and factors that provoke B cells into tolerance loss. Traditionally, major tolerance loss pathways are thought to be regulated by factors outside the B cell including autoantigen engagement of the B-cell receptor (BCR) with simultaneous type I interferon (IFN) produced by dendritic cells, especially plasmacytoid dendritic cells (pDCs). Later, in autoreactive follicles, B-cells encounter T-follicular helper cells (Tfh) that produce interleukin (IL)-21, IL-4 and pathogenic cytokines, IL-17 and IFN gamma (IFNɣ). This review discusses these mechanisms and also highlights recent advances pointing to the peripheral transitional B-cell stage as a major juncture where transient autocrine IFNβ expression by developing B-cells imprints a heightened susceptibility to external factors favoring differentiation into autoantibody-producing plasmablasts. Recent studies highlight transitional B-cell heterogeneity as a determinant of intrinsic resistance or susceptibility to tolerance loss through the shaping of B-cell responsiveness to cytokines and other environment factors.

Intracellular delivery of mRNA to human primary T cells with microfluidic vortex shedding

Intracellular delivery of functional macromolecules, such as DNA and RNA, across the cell membrane and into the cytosol, is a critical process in both biology and medicine. Herein, we develop and use microfluidic chips containing post arrays to induce microfluidic vortex shedding, or μVS, for cell membrane poration that permits delivery of mRNA into primary human T lymphocytes. We demonstrate transfection with μVS by delivery of a 996-nucleotide mRNA construct encoding enhanced green fluorescent protein (EGFP) and assessed transfection efficiencies by quantifying levels of EGFP protein expression. We achieved high transfection efficiency (63.6 ± 3.44% EGFP + viable cells) with high cell viability (77.3 ± 0.58%) and recovery (88.7 ± 3.21%) in CD3 + T cells 19 hrs after μVS processing. Importantly, we show that processing cells via μVS does not negatively affect cell growth rates or alter cell states. We also demonstrate processing speeds of greater than 2.0 × 10⁶ cells s^-1 at volumes ranging from 0.1 to 1.5 milliliters. Altogether, these results highlight the use of μVS as a rapid and gentle delivery method with promising potential to engineer primary human cells for research and clinical applications.

Meta-Analysis for Correlating Structure of Bioactive Peptides in Foods of Animal Origin with Regard to Effect and Stability

Amino acid (AA) sequences of 807 bioactive peptides from foods of animal origin were examined in order to correlate peptide structure with activity (antihypertensive, antioxidative, immunomodulatory, antimicrobial, hypolipidemic, antithrombotic, and opioid) and stability in vivo. Food sources, such as milk, meat, eggs, and marine products, show different frequencies of bioactive peptides exhibiting specific effects. There is a correlation of peptide structure and effect, depending on type and position of AA. Opioid peptides contain a high percentage of aromatic AA residues, while antimicrobial peptides show an excess of positively charged AAs. AA residue position is significant, with those in the first and penultimate positions having the biggest effects on peptide activity. Peptides that have activity in vivo contain a high percentage (67%) of proline residues, but the positions of proline in the sequence depend on the length of the peptide. We also discuss the influence of processing on activity of these peptides, as well as methods for predicting release from the source protein and activity of peptides.

Calcium phosphate altered the cytokine secretion of macrophages and influenced the homing of mesenchymal stem cells

Immune cells such as macrophages play an important role in tissue regeneration. In this study, an in vivo mouse intramuscular implantation model was applied to demonstrate the gradual infiltration of macrophages, followed by homing of mesenchymal stem cells (MSCs) during the early phase of biphasic calcium phosphate (BCP)-induced ectopic bone formation. Then, a novel real-time cell analysis (RTCA) system was used to continuously monitor cell migration in vitro, suggesting the positive roles of BCP-mediated macrophage secretion in MSC recruitment. A Proteome Profiler cytokine array was also applied to investigate the BCP-stimulated secretion pattern of macrophages by simultaneously screening 111 cytokines, indicating that Raw 264.7 macrophages released a pronounced amount of chemokines (CCL2, 3, 4, 5 and CXCL2, 10, 16) and non-chemokine molecules (OPN, VEGF, CD14, Cystatin C and PAI-1), which are involved in cell homing and bone regeneration. Among them, osteoinductive BCP ceramics significantly promoted the secretion of CCL2, 3, 4 and Cystatin C in macrophages, which was consistent with the up-regulated expression of chemokine genes (Ccl2, 3, 4). Considering their previously-reported chemotactic functions, the effects of CCL2/MCP-1 and CCL3/MIP-1α on MSC recruitment were further evaluated by the RTCA system. It was found that exogenous CCL2/MCP-1 and CCL3/MIP-1α dramatically accelerated MSC migration, while their neutralizing antibodies reduced MSC motility. Moreover, BCP-mediated macrophage secretion up-regulated the gene expression of chemokine receptors (Ccr1 and Ccr2) in MSCs, but the blockage of CCR1 and CCR2 exerted inhibitory effects on MSC chemotaxis. RTCA results showed that compared to CCL3/CCR1, the CCL2/CCR2 axis might exert a predominant chemotactic effect for MSC recruitment. These findings indicated that osteoinductive BCP ceramics might regulate macrophage secretion via an ERK signaling pathway, and the increased release of chemokines in macrophages would accelerate MSC homing to facilitate bone formation. These findings might deepen our understanding of biomaterial-mediated immune response and help to design orthopedic implants with desired immunomodulatory abilities to recruit host stem cells endogenously for bone regeneration.

Mer Receptor Tyrosine Kinase Signaling Prevents Self-Ligand Sensing and Aberrant Selection in Germinal Centers

Mer tyrosine kinase (Mer) signaling maintains immune tolerance by clearing apoptotic cells (ACs) and inducing immunoregulatory signals. We previously showed that Mer-deficient mice (Mer-/-) have increased germinal center (GC) responses, T cell activation, and AC accumulation within GCs. Accumulated ACs in GCs can undergo necrosis and release self-ligands, which may influence the outcome of a GC response and selection. In this study, we generated Mer-/- mice with a global MyD88, TLR7, or TLR9 deficiency and cell type-specific MyD88 deficiency to study the functional correlation between Mer and TLRs in the development of GC responses and autoimmunity. We found that GC B cell-intrinsic sensing of self-RNA, but not self-DNA, released from dead cells accumulated in GCs drives enhanced GC responses in Mer-/- mice. Although self-ligands directly affect GC B cell responses, the loss of Mer in dendritic cells promotes enhanced T cell activation and proinflammatory cytokine production. To study the impact of Mer deficiency on the development of autoimmunity, we generated autoimmune-prone B6.Sle1b mice deficient in Mer (Sle1bMer-/-). We observed accelerated autoimmunity development even under conditions where Sle1bMer-/- mice did not exhibit increased AC accumulation in GCs compared with B6.Sle1b mice, indicating that Mer immunoregulatory signaling in APCs regulates B cell selection and autoimmunity. We further found significant expansion, retention, and class-switching of autoreactive B cells in GCs under conditions where ACs accumulated in GCs of Sle1bMer-/- mice. Altogether, both the phagocytic and immunomodulatory functions of Mer regulate GC responses to prevent the development of autoimmunity.

Dendritic cells in the regulation of immunity and inflammation

As potent antigen-presenting cells, dendritic cells (DCs) comprise the most heterogeneous cell population with significant cellular phenotypic and functional plasticity. They form a sentinel network to modulate immune responses, since intrinsic cellular mechanisms and complex external, environmental signals endow DCs with the distinct capacity to induce protective immunity or tolerance to self. Interactions between DCs and other cells of the immune system mediate this response. This interactive response depends on DC maturation status and subtype, as well as the microenvironment of the tissue location and DC-intrinsic regulators. Dysregulated DCs can initiate and perpetuate various immune disorders, which creates attractive therapeutic targets. In this review, we provide a detailed outlook on DC ontogeny and functional specialization. We highlight recent advances on the regulatory role that DCs play in immune responses, the putative molecular regulators that control DC functional responding and the contribution of DCs to inflammatory disease physiopathology.

G Protein-Coupled Receptor Kinases in the Inflammatory Response and Signaling

G protein-coupled receptor kinases (GRKs) are serine/threonine kinases that regulate a large and diverse class of G protein-coupled receptors (GPCRs). Through GRK phosphorylation and β-arrestin recruitment, GPCRs are desensitized and their signal terminated. Recent work on these kinases has expanded their role from canonical GPCR regulation to include noncanonical regulation of non-GPCR and nonreceptor substrates through phosphorylation as well as via scaffolding functions. Owing to these and other regulatory roles, GRKs have been shown to play a critical role in the outcome of a variety of physiological and pathophysiological processes including chemotaxis, signaling, migration, inflammatory gene expression, etc. This diverse set of functions for these proteins makes them popular targets for therapeutics. Role for these kinases in inflammation and inflammatory disease is an evolving area of research currently pursued in many laboratories. In this review, we describe the current state of knowledge on various GRKs pertaining to their role in inflammation and inflammatory diseases.

Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells

Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4-dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair.

Phototherapy-Induced Antitumor Immunity: Long-Term Tumor Suppression Effects via Photoinactivation of Respiratory Chain Oxidase-Triggered Superoxide Anion Burst

AIMS

Our previous studies have demonstrated that as a mitochondria-targeting cancer phototherapy, high-fluence, low-power laser irradiation (HF-LPLI) results in oxidative damage that induces tumor cell apoptosis. In this study, we focused on the immunological effects of HF-LPLI phototherapy and explored its antitumor immune regulatory mechanism.

RESULTS

We found not only that HF-LPLI treatment induced tumor cell apoptosis but also that HF-LPLI-treated apoptotic tumor cells activated macrophages. Due to mitochondrial superoxide anion burst after HF-LPLI treatment, tumor cells displayed a high level of phosphatidylserine oxidation, which mediated the recognition and uptake by macrophages with the subsequent secretion of cytokines and generation of cytotoxic T lymphocytes. In addition, in vivo results showed that HF-LPLI treatment caused leukocyte infiltration into the tumor and efficaciously inhibited tumor growth in an EMT6 tumor model. These phenomena were absent in the respiration-deficient EMT6 tumor model, implying that the HF-LPLI-elicited immunological effects were dependent on the mitochondrial superoxide anion burst.

INNOVATION

In this study, for the first time, we show that HF-LPLI mediates tumor-killing effects via targeting photoinactivation of respiratory chain oxidase to trigger a superoxide anion burst, leading to a high level of oxidatively modified moieties, which contributes to the phenotypic changes in macrophages and mediates the antitumor immune response.

CONCLUSION

Our results suggest that HF-LPLI may be an effective cancer treatment modality that both eradicates the treated primary tumors and induces an antitumor immune response via photoinactivation of respiratory chain oxidase to trigger superoxide anion burst.

Infusion of dendritic cells carrying donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light induces CD19+ IL-10+ regulatory B cells and promotes skin allograft survival

PUVA-SP DCs are immature dendritic cells (imDCs) that have taken up donor splenic lymphocytes treated with 8-methoxypsoralen and ultraviolet A light (PUVA-SPs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation of recipient imDCs, and infusion of PUVA-SP DCs can induce CD4(+)CD25(high)Foxp3(+) regulatory T cells (Treg). However, the regulatory effect of PUVA-SP DCs on B cells is poorly understood. In this study, we compared PUVA-SP DCs with imDCs in terms of lipopolysaccharide (LPS) responsiveness and flow cytometric analysis of interleukin (IL) 10 expression in splenic CD19(+)B cells. Our results demonstrate that PUVA-SP DCs can suppress subsequent LPS-induced DC maturation and that infusion of PUVA-SP DCs, in the absence of an immunosuppressant, significantly promotes skin allograft survival. This effect was associated with up-regulation of circulating regulatory B cells exhibiting preferential IL-10 secretion. Our results suggest that effective treatments involving infusion of PUVA-SP DCs is likely related to the modulation not only of T-cell and Treg functions but also of B-cell and regulatory B-cell (Breg) functions.

Focal cryotherapy of localized prostate cancer: a systematic review of the literature

Radical/whole gland treatment for prostate cancer has significant side-effects. Therefore focal treatments such as cryotherapy have been used to treat localized lesions whilst aiming to provide adequate cancer control with minimal side-effects. We performed a systematic review of Pubmed/Medline and Cochrane databases' to yield 9 papers for primary focal prostate cryotherapy and 2 papers for focal salvage treatment (radio-recurrent). The results of 1582 primary patients showed biochemical disease-free survival between 71-93% at 9-70 months follow-up. Incontinence rates were 0-3.6% and ED 0-42%. Recto-urethral fistula occurred in only 2 patients. Salvage focal cryotherapy had biochemical disease-free survival of 50-68% at 3 years. ED occurred in 60-71%. Focal cryotherapy appears to be an effective treatment for primary localized prostate cancer and compares favorably to radical/whole gland treatments in medium-term oncological outcomes and side-effects. Although more studies are needed it is also effective for radio-recurrent cancer with a low complications rates.

Regulatory dendritic cells in autoimmunity: A comprehensive review

Dendritic cells (DCs) are professional antigen-presenting cells (APC) with significant phenotypic heterogeneity and functional plasticity. DCs play crucial roles in initiating effective adaptive immune responses for elimination of invading pathogens and also in inducing immune tolerance toward harmless components to maintain immune homeostasis. The regulatory capacity of DCs depends on their immature state and distinct subsets, yet not restricted to the immature state and one specialized subset. The tolerogenicity of DC is controlled by a complex network of environmental signals and cellular intrinsic mechanisms. Regulatory DCs play an important role in the maintenance of immunological tolerance via the induction of T cell unresponsiveness or apoptosis, and generation of regulatory T cells. DCs play essential roles in driving autoimmunity via promoting the activation of effector T cells such as T helper 1 and T helper 17 cells, and/or suppressing the generation of regulatory T cells. Besides, a breakdown of DCs-mediated tolerance due to abnormal environmental signals or breakdown of intrinsic regulatory mechanisms is closely linked with the pathogenesis of autoimmune diseases. Novel immunotherapy taking advantage of the tolerogenic potential of regulatory DCs is being developed for treatment of autoimmune diseases. In this review, we will describe the current understanding on the generation of regulatory DC and the role of regulatory DCs in promoting tolerogenic immune responses and suppressing autoimmune responses. The emerging roles of DCs dysfunction in the pathogenesis of autoimmune diseases and the potential application of regulatory DCs in the treatment of autoimmune diseases will also be discussed.

G-protein-coupled receptor kinases in inflammation and disease

G-protein-coupled receptor kinases (GRKs) are serine/threonine protein kinases originally discovered for their role in G-protein-coupled receptor (GPCR) phosphorylation. Recent studies have demonstrated a much broader function for this kinase family including phosphorylation of cytosolic substrates involved in cell signaling pathways stimulated by GPCRs, as well as by non-GPCRs. In addition, GRKs modulate signaling via phosphorylation-independent functions. Because of these various biochemical functions, GRKs have been shown to affect critical physiological and pathophysiological processes, and thus are considered as drug targets in diseases such as heart failure. Role of GRKs in inflammation and inflammatory diseases is an evolving area of research and several studies including work from our lab in the recent years have demonstrated critical role of GRKs in the immune system. In this review, we discuss the classical and the newly emerging functions of GRKs in the immune system and their role in inflammation and disease processes.

Primary biliary cirrhosis: Clinical and laboratory criteria for its diagnosis

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic granulomatous, and destructive inflammatory lesion of small intralobular and septal bile ducts, which is likely to be caused by an autoimmune mechanism with a the presence of serum antimitochondrial antibodies and a potential tendency to progress to cirrhosis. Despite the fact that the etiology of this disease has been unknown so far, there has been a considerable body of scientific evidence that can reveal the clinical and laboratory signs of PBC and the individual components of its pathogenesis and elaborate diagnostic criteria for the disease and its symptomatic therapy. Deficiencies in autoimmune tolerance are critical factors for the initiation and perpetuation of the disease. The purpose of this review is to summarize the data available in the literature and the author's findings on clinical and laboratory criteria for the diagnosis of PBC. This review describes the major clinical manifestations of the disease and the mechanisms of its development. It presents the immunological, biochemical, and morphological signs of PBC and their significance for its diagnosis. A great deal of novel scientific evidence for the problem of PBC has been accumulated. However, the inadequate efficiency of therapy for the disease lends impetus to the quest for its etiological factors and to further investigations of its pathogenetic mechanisms and, on this basis, to searches for new methods for its early diagnosis.

Deletion of WASp and N-WASp in B cells cripples the germinal center response and results in production of IgM autoantibodies

Humoral immunodeficiency caused by mutations in the Wiskott-Aldrich syndrome protein (WASp) is associated with failure to respond to common pathogens and high frequency of autoimmunity. Here we addressed the question how deficiency in WASp and the homologous protein N-WASp skews the immune response towards autoreactivity. Mice devoid of WASp or both WASp and N-WASp in B cells formed germinal center to increased load of apoptotic cells as a source of autoantigens. However, the germinal centers showed abolished polarity and B cells retained longer and proliferated less in the germinal centers. While WASp-deficient mice had high titers of autoreactive IgG, B cells devoid of both WASp and N-WASp produced mainly IgM autoantibodies with broad reactivity to autoantigens. Moreover, B cells lacking both WASp and N-WASp induced somatic hypermutation at reduced frequency. Despite this, IgG1-expressing B cells devoid of WASp and N-WASp acquired a specific high affinity mutation, implying an increased BCR signaling threshold for selection in germinal centers. Our data provides evidence for that N-WASp expression alone drives WASp-deficient B cells towards autoimmunity.