Extracorporeal Photochemotherapy: Mechanistic Insights Driving Recent Advances and Future Directions.

Dendritic cells (DCs) are professional antigen-presenting cells, necessary for the initiation and maintenance of antigen-specific immunity and tolerance. Decades of research have been driven by hopes to harness the immunological capabilities of DCs and achieve physiological partnership with the immune system for therapeutic ends. Potential applications for DC-based immunotherapy include treatments for cancer, autoimmune disorders, and infectious diseases. However, DCs have poor availability in peripheral and lymphoid tissues and have poor survivability in culture, leading to the development of multiple strategies to generate and manipulate large numbers of DCs ex vivo. Among these is Extracorporeal Photopheresis (ECP), a widely used cancer immunotherapy. Recent advancements have uncovered that stimulation of monocyte-to-DC maturation via physiologic inflammatory signaling lies at the mechanistic core of ECP. Here, we describe the landscape of DC-based immunotherapy, the historical context of ECP, the current mechanistic understanding of ex vivo monocyte-to-DC maturation in ECP, and the implications of this understanding on making scientifically driven improvements to modern ECP protocols and devices.

American council on ECP (ACE): Why now?

Stimulated by the scientific progress in deciphering the principal elements contributing to the clinical efficacy of extracorporeal photochemotherapy (ECP), the American Council on ECP (ACE) was formed, under the auspices of the American Society for Apheresis (ASFA), to develop a field-guiding Consensus Report. ACE is composed of thirty nationally recognized ECP experts, clinically spanning cancer, transplantation, and autoimmunity and scientifically bridging immunology, bioengineering, and hematology. The two-day meeting took place in Manhattan, April 13-14, 2017, and unanimous consensus on nine pivotal points is herein reported. (1) ECP's clinical evolution must now enter a scientifically driven phase. (2) ECP is currently a bidirectional therapy, both immunizing and tolerizing simultaneously, via a single one-size-fits-all inflexible medical device. (3) To preclude inadvertent tolerization in the cancer setting, or immunization in the transplant rejection setting, polarization of ECP to either immunization or tolerization mode to match the clinical need is now possible and necessary. (4) Cutaneous T cell lymphoma (CTCL) is a genetically driven cancer, whose response to ECP is due to enhanced anti-cancer immunity. (5) ECP is a dendritic antigen-presenting cell (DC) based therapy. (6) ECP's efficacy can now be tested in a broad array of cancers. (7) ECP's capacity to tolerize to allotransplants via processing of donor leukocytes merits expedited human investigation. (8) UVA-8-MOP-impacted ECP-induced DC are potent antigen-specific tolerizing agents, while UVA-8-MOP(8-Methoxypsoralen)-spared ECP-induced DC are potent antigen-specific immunizing agents. (9) Six pilot clinical trial areas (CTCL, graft-vs.-host disease, ovarian carcinoma, anti-graft cytotoxic antibodies, pemphigus vulgaris, and haplotype mismatched stem cell transplants) are advised. ACE will be an ongoing advisory group for the field, with the goal of overseeing coordinated clinical and fundamental research efforts.

Configuration-dependent Presentation of Multivalent IL-15:IL-15Rα Enhances the Antigen-specific T Cell Response and Anti-tumor Immunity.

Here we report a "configuration-dependent" mechanism of action for IL-15:IL-15Rα (heterodimeric IL-15 or hetIL-15) where the manner by which IL-15:IL-15Rα molecules are presented to target cells significantly affects its function as a vaccine adjuvant. Although the cellular mechanism of IL-15 trans-presentation via IL-15Rα and its importance for IL-15 function have been described, the full effect of the IL-15:IL-15Rα configuration on responding cells is not yet known. We found that trans-presenting IL-15:IL-15Rα in a multivalent fashion on the surface of antigen-encapsulating nanoparticles enhanced the ability of nanoparticle-treated dendritic cells (DCs) to stimulate antigen-specific CD8(+) T cell responses. Localization of multivalent IL-15:IL-15Rα and encapsulated antigen to the same DC led to maximal T cell responses. Strikingly, DCs incubated with IL-15:IL-15Rα-coated nanoparticles displayed higher levels of functional IL-15 on the cell surface, implicating a mechanism for nanoparticle-mediated transfer of IL-15 to the DC surface. Using artificial antigen-presenting cells to highlight the effect of IL-15 configuration on DCs, we showed that artificial antigen-presenting cells presenting IL-15:IL-15Rα increased the sensitivity and magnitude of the T cell response, whereas IL-2 enhanced the T cell response only when delivered in a paracrine fashion. Therefore, the mode of cytokine presentation (configuration) is important for optimal immune responses. We tested the effect of configuration dependence in an aggressive model of murine melanoma and demonstrated significantly delayed tumor progression induced by IL-15:IL-15Rα-coated nanoparticles in comparison with monovalent IL-15:IL-15Rα. The novel mechanism of IL-15 transfer to the surface of antigen-processing DCs may explain the enhanced potency of IL-15:IL-15Rα-coated nanoparticles for antigen delivery.

Quantifying in vivo murine antigen-specific T cell responses without requirement for prior knowledge of antigen identity.

Extracorporeal Photochemotherapy (ECP) is a widely applied anti-cancer immunotherapy for patients with cutaneous T cell lymphoma (CTCL). By using apoptotic malignant cells as a source of patient-specific tumor antigen, it enables clinically relevant and curative anti-CTCL immunity, with potential efficacy in other tumors. Currentmethods to track patient-specific responses are tedious, and new methods are needed to assess putative global immunity. We developed a clinically practical method to assess antigen-specific T cell activation that does not rely on knowledge of the particular antigen, thereby eliminating the requirement for patient-specific reagents. In the OT-I transgenic murine system, we quantified calcium flux to reveal early T cell engagement by antigen presenting cells constitutively displaying a model antigenic peptide, ovalbumin (OVA)-derived SIINFEKL. We detected calcium flux in OVA-specific T cells, triggered by specific T cell receptor engagement by SIINFEKL peptide-loaded DC. This approach led to sensitive detection of antigen-specific calcium flux (ACF) down to a peptide-loading concentration of ∼10-3uM and at a frequency of ∼0.1% OT-I cells among wild-type (WT), non-responding cells. Antigen-specific T cells were detected in spleen, lymph nodes, and peripheral blood after adoptive transfer into control recipient mice. Methods like this for assessing therapeutic response are lacking in patients currently on immune-based therapies, such as ECP, where assessment of clinical response is made by delayed measurement of the size of the malignant clone. These findings suggest an early, practical way to measure therapeutically-induced anti-tumor responses in ECP-treated patients that have been immunized against their malignant cells.

Cutaneous T-cell lymphoma (CTCL): Current practices in blood assessment and the utility of T-cell receptor (TCR)-Vß chain restriction.

BACKGROUND: Accurate quantification of malignant cells in the peripheral blood of patients with cutaneous T-cell lymphoma is important for early detection, prognosis, and monitoring disease burden. OBJECTIVE: We sought to determine the spectrum of current clinical practices; critically evaluate elements of current International Society for Cutaneous Lymphomas (ISCL) B1 and B2 staging criteria; and assess the potential role of T-cell receptor-Vß analysis by flow cytometry. METHODS: We assessed current clinical practices by survey, and performed a retrospective analysis of 161 patients evaluated at Yale (2011-2014) to compare the sensitivity, specificity, positive predictive value, and negative predictive value of parameters for ISCL B2 staging. RESULTS: There was heterogeneity in clinical practices among institutions. ISCL B1 criteria did not capture 5 Yale cohort cases with immunophenotypic abnormalities that later progressed. T-cell receptor-Vß testing was more specific than polymerase chain reaction and aided diagnosis in detecting clonality, but was of limited benefit in quantification of tumor burden. LIMITATIONS: Because of limited follow-up involving a single center, further investigation will be necessary to conclude whether our proposed diagnostic algorithm is of general clinical benefit. CONCLUSION: We propose further study of modified B1 criteria: CD4/CD8 ratio 5 or greater, %CD4(+) CD26(-) 20% or greater, or %CD4(+) CD7(-) 20% or greater, with evidence of clonality. T-cell receptor-Vß testing should be considered in future diagnostic and staging algorithms.

Mechanistic insights into extracorporeal photochemotherapy: efficient induction of monocyte-to-dendritic cell maturation.

Extracorporeal photochemotherapy (ECP) is a widely used immunotherapy for cutaneous T cell lymphoma, as well as immunomodulation of graft-versus-host disease (GVHD) and transplanted organ rejection. ECP's mechanism encompasses large-scale physiologic platelet induction of dendritic cells (DCs). The normal bidirectional immunologic talents of DCs likely contribute heavily to ECP's capacity to immunize against tumor antigens, while also suppressing transplant immunopathology. Our understanding of how ECP physiologically induces monocyte-to-DC maturation can enhance the treatment's potency, potentially broaden its use to other cancers and autoimmune disorders and tailor its application to individual patients' diseases. ECP's next decade is filled with promise.

Induction of monocyte-to-dendritic cell maturation by extracorporeal photochemotherapy: initiation via direct platelet signaling.

Extracorporeal Photochemotherapy (ECP) is a widely used therapy for cutaneous T cell lymphoma (CTCL). Although the mechanism of clinical action of ECP is not precisely established, previous studies have shown evidence of induction of dendritic cells (DCs). Here we show that, under flow conditions similar to those in post-capillary venules, ECP promotes platelet immobilization and activation, initiating stepwise receptor-ligand interactions with monocytes, which then differentiate into DC. These findings clarify how ECP directly stimulates DC maturation; suggest a new clinically applicable approach to the obtainment of DC; and identify a novel mechanism that may reflect physiological induction of DC.

Activation of GILZ gene by photoactivated 8-methoxypsoralen: potential role of immunoregulatory dendritic cells in extracorporeal photochemotherapy.

Extracorporeal photochemotherapy (ECP) is a widely used method for either immunization against cutaneous T cell lymphoma or immunosuppression of graft-versus-host disease and organ transplant rejection (OTR). Leukapheresed blood is routed through a chamber, in which 8-methoxypsoralen is activated by ultraviolet energy (PUVA), thereby causing DNA crosslinks in processed leukocytes. Return of ECP-processed mononuclear leukocytes to the patient then modulates aberrant T cell immunity. Since interaction with the ECP flow chamber induces monocyte-to-dendritic antigen presenting cell (DC) maturation, we examined the possibility that PUVA may direct the most heavily exposed monocytes to differentiate into tolerogenic DC, while the least exposed DC might remain immunogenic. Expression of the glucocorticoid-induced leucine zipper (GILZ) gene is a distinguishing marker of tolerogenic DC. We report that PUVA directly stimulates GILZ expression. PUVA-exposed DC up-regulated GILZ, down-regulated costimulatory CD80 and CD86, became resistant to Toll-like receptor-induced maturation, increased IL-10 production and decreased IL-12p70 production, all features of immunosuppressive DC. Knockdown of GILZ with siRNA reduced IL-10 and increased IL-12p70 production, demonstrating that GILZ is critical for this profile. PUVA-induction of GILZ expression by DC may help explain how ECP suppresses GVHD and OTR. Conversely, those ECP-processed monocytes minimally exposed to PUVA may mediate ECP's immunogenic effects.

Rapid generation of maturationally synchronized human dendritic cells: contribution to the clinical efficacy of extracorporeal photochemotherapy.

Extracorporeal photochemotherapy (ECP) is widely used to treat cutaneous T-cell lymphoma, graft-versus-host disease, and allografted organ rejection. Its clinical and experimental efficacy in cancer immunotherapy and autoreactive disorders suggests a novel mechanism. This study reveals that ECP induces a high percentage of processed monocytes to enter the antigen-presenting dendritic cell (DC) differentiation pathway, within a single day, without added cytokines, as determined by enhanced expression of relevant genes. The resulting DCs are capable of processing and presentation of exogenous and endogenous antigen and are largely maturationally synchronized, as assessed by the level of expression of costimulatory surface molecules. Principal component analysis of the ECP-induced monocyte transcriptome reveals that activation or suppression of more than 1100 genes produces a reproducible distinctive molecular signature, common to ECP-processed monocytes from normal subjects, and those from patients. Because ECP induces normal monocytes to enter the DC differentiation pathway, this phenomenon is independent of disease state. The efficiency with which ECP stimulates new functional DCs supports the possibility that these cells participate prominently in the clinical successes of the treatment. Appropriately modified by future advances, ECP may potentially offer a general source of therapeutic DCs.

Optimization of stability, encapsulation, release, and cross-priming of tumor antigen-containing PLGA nanoparticles.

PURPOSE: In order to investigate Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP) as potential vehicles for efficient tumor antigen (TA) delivery to dendritic cells (DC), this study aimed to optimize encapsulation/release kinetics before determining immunogenicity of antigen-containing NP. METHODS: Various techniques were used to liberate TA from cell lines. Single (gp100) and multiple (B16-tumor lysate containing gp100) antigens were encapsulated within differing molecular weight PLGA co-polymers. Differences in morphology, encapsulation/release and biologic potency were studied. Findings were adopted to encapsulate fresh tumor lysate from patients with advanced tumors and compare stimulation of tumor infiltrating lymphocytes (TIL) against that achieved by soluble lysate. RESULTS: Four cycles of freeze-thaw + 15 s sonication resulted in antigen-rich lysates without the need for toxic detergents or protease inhibitors. The 80 KDa polymer resulted in maximal release of payload and favorable production of immunostimulatory IL-2 and IFN-γ. NP-mediated antigen delivery led to increased IFN-γ and decreased immunoinhibitory IL-10 synthesis when compared to soluble lysate. CONCLUSIONS: Four cycles of freeze-thaw followed by 15 s sonication is the ideal technique to obtain complex TA for encapsulation. The 80 KDa polymer has the most promising combination of release kinetics and biologic potency. Encapsulated antigens are immunogenic and evoke favorable TIL-mediated anti-tumor responses.

Rapid Screen for Antiviral T-Cell Immunity with Nanowire Electrochemical Biosensors.

The ability to rapidly assess and monitor patient immune responses is critical for clinical diagnostics, vaccine design, and fundamental investigations into the presence or generation of protective immunity against infectious diseases. Recently, findings on the limits of antibody-based protection provided by B-cells have highlighted the importance of engaging pathogen-specific T-cells for long-lasting and broad protection against viruses and their emergent variants such as in SARS-CoV-2. However, low-cost and point-of-care tools for detecting engagement of T-cell immunity in patients are conspicuously lacking in ongoing efforts to assess and control population-wide disease risk. Currently available tools for human T-cell analysis are time and resource-intensive. Using multichannel silicon-nanowire field-effect transistors compatible with complementary metal-oxide-semiconductor, a device designed for rapid and label-free detection of human T-cell immune responses is developed. The generalizability of this approach is demonstrated by measuring T-cell responses against melanoma antigen MART1, common and seasonal viruses CMV, EBV, flu, as well as emergent pandemic coronavirus, SARS-CoV-2. Further, this device provides a modular and translational platform for optimizing vaccine formulations and combinations, offering quick and quantitative readouts for acquisition and persistence of T-cell immunity against variant-driven pathogens such as flu and pandemic SARS-CoV-2.

Pre-transplant infusion of donor leukocytes treated with extracorporeal photochemotherapy induces immune hypo-responsiveness and long-term allograft survival in murine models.

Recipients of solid organ transplantation (SOT) rely on life-long immunosuppression (IS), which is associated with significant side effects. Extracorporeal photochemotherapy (ECP) is a safe, existing cellular therapy used to treat transplant rejection by modulating the recipient's own blood cells. We sought to induce donor-specific hypo-responsiveness of SOT recipients by infusing ECP-treated donor leukocytes prior to transplant. To this end, we utilized major histocompatibility complex mismatched rodent models of allogeneic cardiac, liver, and kidney transplantation to test this novel strategy. Leukocytes isolated from donor-matched spleens for ECP treatment (ECP-DL) were infused into transplant recipients seven days prior to SOT. Pre-transplant infusion of ECP-DL without additional IS was associated with prolonged graft survival in all models. This innovative approach promoted the production of tolerogenic dendritic cells and regulatory T-cells with subsequent inhibition of T-cell priming and differentiation, along with a significant reduction of donor-specific T-cells in the spleen and grafts of treated animals. This new application of donor-type ECP-treated leukocytes provides insight into the mechanisms behind ECP-induced immunoregulation and holds significant promise in the prevention of graft rejection and reduction in need of global immune suppressive therapy in patients following SOT.

Polymer nanoparticles containing tumor lysates as antigen delivery vehicles for dendritic cell-based antitumor immunotherapy.

Encapsulation of tumor-associated antigens in polymer nanoparticles (NP) is a promising approach to enhance efficiency of antigen delivery for anti-tumor vaccines. Head and neck squamous carcinoma (HNSCC) cell lines were initially used to generate tumor-associated antigens (TAA)-containing poly (lactic-co-glycolic acid) (PLGA) NP; encapsulation efficiency and release kinetics were profiled. Findings were adopted to entrap fresh tumor lysate from five patients with advanced HNSCC. To test the hypothesis that NP enhance antigen presentation, dendritic cell (DC) produced from patient blood monocyte precursors were loaded with either the un-encapsulated or NP-encapsulated versions of tumor lysates. These were used to stimulate freshly-isolated autologous CD8+ T cells. In four of five patients, anti-tumor CD8+ T cells showed significantly increased immunostimulatory IFN-γ (p=0.071) or decreased immmunoinhibitory IL-10 production (p=0.0004) associated with NP-mediated antigen delivery. The observations represent an enabling step in the production of clinically-translatable, inexpensive, highly-efficient, and personalized polymer-based immunotherapy for solid organ malignancies. FROM THE CLINICAL EDITOR: Enhancing the antigen presentation may be a viable approach to increase the efficiency of tumor cell directed cytotoxicity via immune mechanisms. This study presents an example for this using head and neck cancer cell lines and nanotechnology-based encapsulated antigen presentation to dendritic cells. The observed CD8+ T-cell response was significantly enhanced. This method may pave the way to a highly efficient cancer cell elimination method with minimal to no toxicity.

Detection of Immunogenic Cell Death in Tumor Vaccination Mouse Model.

Immunogenic cell death (ICD) is a form of regulated cell death that is capable of eliciting an immune response. In cancer, tumor cells undergoing ICD are known to emit damage associated molecular patterns (DAMPs) that are capable of recruiting and activating antigen presenting cells (APCs), which ultimately lead to the activation of an antitumor immune response. Surface translocation of intracellular chaperones such as calreticulin, release of TLR agonists such as high mobility box 1, and the secretion of type I IFN are some of the hallmark features seen in tumors succumbing to ICD. While detection of these molecules is suggestive of ICD induction, which alone does not certify that the treatment is an ICD inducer, an in vivo vaccination assay using injured tumor cells remains to be the gold standard method to functionally verify ICD. This chapter will discuss the necessary steps required to conduct an in vivo vaccination assay, focusing on the preparation of vaccine using treated tumor cells, and how these cells are then utilized in the animal model.

Platelet P-selectin initiates cross-presentation and dendritic cell differentiation in blood monocytes.

Dendritic cells (DCs) are adept at cross-presentation and initiation of antigen-specific immunity. Clinically, however, DCs produced by in vitro differentiation of monocytes in the presence of exogenous cytokines have been met with limited success. We hypothesized that DCs produced in a physiological manner may be more effective and found that platelets activate a cross-presentation program in peripheral blood monocytes with rapid (18 hours) maturation into physiological DCs (phDCs). Differentiation of monocytes into phDCs was concomitant with the formation of an "adhesion synapse," a biophysical junction enriched with platelet P-selectin and monocyte P-selectin glycoprotein ligand 1, followed by intracellular calcium fluxing and nuclear localization of nuclear factor κB. phDCs were more efficient than cytokine-derived DCs in generating tumor-specific T cell immunity. Our findings demonstrate that platelets mediate a cytokine-independent, physiologic maturation of DC and suggest a novel strategy for DC-based immunotherapies.

Rapid Production of Physiologic Dendritic Cells (phDC) for Immunotherapy.

Generation of large numbers of dendritic cells (DC) for research or immunotherapeutic purposes typically involves in vitro conversion of murine bone marrow precursors or human blood monocytes to DC via cultivation with supraphysiologic concentrations of cytokines such as GM-CSF and IL-4 for up to 7 days. Alternatively, our group has recently established a new approach, based on the underlying mechanism of action of a widely used cancer immunotherapy termed Extracorporeal Photochemotherapy (ECP). Our method of rapid and cytokine-free production of therapeutically relevant DC populations, leveraging the innate physiologic programs likely responsible for DC differentiation from blood monocytes in vivo, potentially offers a novel, inexpensive, and easily accessible source of DC for clinical and research uses. This approach involves ex vivo physiologic reprogramming of blood monocytes to immunologically tunable dendritic antigen-presenting cells, which we term "phDC," for physiological DC. To facilitate access and utilization of these new DC populations by the research community, in this chapter, we describe the use of a scaled-down version of the clinical ECP leukocyte-treatment device termed the Transimmunization (TI) chamber or plate, suitable for processing both mouse and human samples. We highlight the methodological sequences necessary to isolate mouse or human peripheral blood mononuclear cell (PBMC) from whole blood, and to expose those PBMC to the TI chamber for facilitating monocyte activation and conversion to physiological DC (phDC) through interaction with blood proteins and activated platelets under controlled flow conditions. We then provide sample protocols for potential applications of the generated DC, including their use as vaccinating antigen-presenting cells (APC) in murine in vivo antitumor models, and in human ex vivo T-cell stimulation and antigen cross-presentation assays which mimic clinical vaccination. We additionally highlight the technical aspects of loading mouse or human phDC with tumor-associated antigens (TAA) in the form of peptides or apoptotic tumor cells. We provide a simple and clinically relevant means to reprogram blood monocytes into functional APC, potentially replacing the comparatively expensive and clinically disappointing cytokine-derived DC which have previously dominated the dendritic cell landscape.

Transimmunization restores immune surveillance and prevents recurrence in a syngeneic mouse model of ovarian cancer.

Ovarian cancer accounts for most deaths from gynecologic malignancies. Although more than 80% of patients respond to first-line standard of care, most of these responders present with recurrence and eventually succumb to carcinomatosis and chemotherapy-resistant disease. To improve patient survival, new modalities must, therefore, target or prevent recurrent disease. Here we describe for the first time a novel syngeneic mouse model of recurrent high-grade serous ovarian cancer (HGSOC), which allows immunotherapeutic interventions in a time course relevant to human carcinomatosis and disease course. Using this model, we demonstrate the efficacy of Transimmunization (TI), a dendritic cell (DC) vaccination strategy that uses autologous and physiologically derived DC loaded with autologous whole tumor antigens. TI has been proven successful in the treatment of human cutaneous T cell lymphoma and we report for the first time its in vivo efficacy against an intra-peritoneal solid tumor. Given as a single therapy, TI is able to elicit an effective anti-tumor immune response and inhibit immune-suppressive crosstalks with sufficient power to curtail tumor progression and establishment of carcinomatosis and recurrent disease. Specifically, TI is able to inhibit the expansion of tumor-associated macrophages as well as myeloid-derived suppressive cells consequently restoring T cell immune-surveillance. These results demonstrate the possible value of TI in the management of ovarian cancer and other intra-peritoneal tumors.

Preliminary Results From a US Clinical Trial of a Novel Synthetic Polymer Meniscal Implant.

BACKGROUND: At least 760,000 outpatient meniscectomies are performed in the United States each year, making this the most common musculoskeletal procedure. However, meniscal resection can alter the joint biomechanics and overload the articular cartilage, which may contribute to degenerative changes and the need for knee replacement. Avoiding or delaying knee replacement is particularly important in younger or more active patients. Synthetic meniscal implants have been developed in an attempt to restore the natural joint biomechanics, alleviate pain and disability, and potentially minimize degenerative changes in patients who require meniscectomy. PURPOSE: To evaluate the preliminary results from 2 ongoing trials that are evaluating the safety and effectiveness of a synthetic polymer meniscal implant (NUsurface; Active Implants, LLC). STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: This was a preliminary analysis of the first 100 patients enrolled across 2 studies for 12 months: a single-arm, intervention-only study and a randomized controlled trial comparing the investigational meniscal implant with nonsurgical therapy. There were 65 patients in the implant group (30 randomized) and 35 in the control group. Outcomes included Knee injury and Osteoarthritis Outcome Score (KOOS) and adverse events (AEs) collected at baseline and follow-up visits of 6 weeks, 6 months, and 12 months. RESULTS: No statistically significant differences were found in baseline characteristics between the implant and control groups. At 12 months, follow-up KOOS data were available for 87% of the 100 included patients. Significantly greater improvements from baseline were observed in the implant group compared with controls in all KOOS subcomponents, except for symptoms (119%-177% greater improvement at 12 months). AEs were reported at similar rates between the 2 groups, with 12 AEs among 11 patients in the implant group (16.9%) versus 5 AEs among 5 patients (14.3%) in the control group (P = .99). CONCLUSION: These preliminary results suggest significant improvements in pain and function scores with the implant over nonsurgical therapy and a similar adverse event rate.

Consensus guidelines for the definition, detection and interpretation of immunogenic cell death.

Cells succumbing to stress via regulated cell death (RCD) can initiate an adaptive immune response associated with immunological memory, provided they display sufficient antigenicity and adjuvanticity. Moreover, multiple intracellular and microenvironmental features determine the propensity of RCD to drive adaptive immunity. Here, we provide an updated operational definition of immunogenic cell death (ICD), discuss the key factors that dictate the ability of dying cells to drive an adaptive immune response, summarize experimental assays that are currently available for the assessment of ICD in vitro and in vivo, and formulate guidelines for their interpretation.

Ex vivo dendritic cell generation-A critical comparison of current approaches.

Dendritic cells (DCs) are professional antigen-presenting cells, required for the initiation of naïve and memory T cell responses and regulation of adaptive immunity. The discovery of DCs in 1973, which culminated in the Nobel Prize in Physiology or Medicine in 2011 for Ralph Steinman and colleagues, initially focused on the identification of adherent mononuclear cell fractions with uniquely stellate dendritic morphology, followed by key discoveries of their critical immunologic role in initiating and maintaining antigen-specific immunity and tolerance. The medical promise of marshaling these key capabilities of DCs for therapeutic modulation of antigen-specific immune responses has guided decades of research in hopes to achieve genuine physiologic partnership with the immune system. The potential uses of DCs in immunotherapeutic applications include cancer, infectious diseases, and autoimmune disorders; thus, methods for rapid and reliable large-scale production of DCs have been of great academic and clinical interest. However, difficulties in obtaining DCs from lymphoid and peripheral tissues, low numbers and poor survival in culture, have led to advancements in ex vivo production of DCs, both for probing molecular details of DC function as well as for experimenting with their clinical utility. Here, we review the development of a diverse array of DC production methodologies, ranging from cytokine-based strategies to genetic engineering tools devised for enhancing DC-specific immunologic functions. Further, we explore the current state of DC therapies in clinic, as well as emerging insights into physiologic production of DCs inspired by existing therapies.