Accum™ Technology: A Novel Conjugable Primer for Onco-Immunotherapy.

Compromised activity is a common impediment for biologics requiring endosome trafficking into target cells. In cancer cells, antibody-drug conjugates (ADCs) are trapped in endosomes or subsequently pumped extracellularly, leading to a reduction in intracellular accumulation. In subsets of dendritic cells (DCs), endosome-engulfed antigens face non-specific proteolysis and collateral damage to epitope immunogenicity before proteasomal processing and subsequent surface presentation. To bypass these shortcomings, we devised Accum™, a conjugable biotechnology harboring cholic acid (ChAc) and a nuclear localization signal (NLS) sequence for endosome escape and prompt nuclear targeting. Combined, these mechanisms culminate in enhanced intracellular accumulation and functionalization of coupled biologics. As proof-of-principle, we have biochemically characterized Accum, demonstrating its adaptability to ADCs or antigens in different cancer settings. Additionally, we have validated that endosome escape and nuclear routing are indispensable for effective intracellular accumulation and guaranteed target cell selectivity. Importantly, we have demonstrated that the unique mechanism of action of Accum translates into enhanced tumor cytotoxicity when coupled to ADCs, and durable therapeutic and prophylactic anti-cancer immunogenicity when coupled to tumor antigens. As more pre-clinical evidence accumulates, the adaptability, unique mechanism of action, and high therapeutic potency of Accum signal a promising transition into clinical investigations in the context of onco-immunotherapy.

Bone marrow aspirate concentrate versus platelet-rich plasma for treating knee osteoarthritis: a one-year non-randomized retrospective comparative study.

BACKGROUND: Knee osteoarthritis (OA) is a debilitating condition affecting human body biomechanics and quality of life. Current standard care for knee OA leads to trivial improvement and entails multiple adverse effects or complications. Recently, investigational cell therapies injected intra-articularly, such as bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP), have shown safety and therapeutic potency providing patients with pain relief. In the current retrospective comparative study, we investigated the differences in pain and functional improvements in patients with symptomatic knee OA receiving intra-articular injections of BMAC vs PRP. METHODS: Pain and functionality scores were measured at baseline and at different time points post-injection over 12 months, using 3 self-administered, clinically validated questionnaires: the visual analogue scale (VAS) for assessing pain intensity, the knee injury and osteoarthritis outcome score (KOOS) for evaluating functionality and knee-related quality of life, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for evaluating physical function. The repeated-measures general linear model with Sidak test for pairwise comparisons was used to investigate the influence of the treatment on the score evolution within groups (between baseline and each time point) and between groups (overall). RESULTS: The BMAC group (n = 26 knees) significantly improved in VAS, KOOS, and WOMAC scores between baseline and 12 months (57.4, 75.88, and 73.95% mean score improvement, respectively). In contrast, the PRP group (n = 13 knees) witnessed nonsignificant improvement in all scores. BMAC, in comparison to PRP, induced significant improvement in outcomes by 29.38% on the VAS scale, 53.89% on the KOOS scale, and 51.71% on the WOMAC scale (P < .002, P < .01, P < .011, respectively). CONCLUSIONS: Intra-articular autologous BMAC injections are safe, effective in treating pain, and ameliorate functionality in patients with symptomatic knee OA to a greater extent than PRP injections. Intra-articular autologous BMAC therapy is safe and provides more relief to patients with symptomatic knee osteoarthritis compared to PRP therapy.

Cell Therapy: Types, Regulation, and Clinical Benefits.

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

Autologous BMAC Therapy Improves Spinal Degenerative Joint Disease in Lower Back Pain Patients.

Spinal degenerative joint disease (DJD) is associated with lower back pain (LBP) arising from the degeneration of intervertebral discs (IVD), facet joints, intertransversarii muscles, and interspinous ligaments among other anatomical structures. To circumvent the socioeconomic burdens and often-problematic surgical options imposed by DJD therapy, cell-based biologic modalities like bone marrow aspirate concentrate (BMAC) have been investigated in pre-clinical and clinical settings, mostly for IVD degeneration (IDD), with encouraging outcomes. In this study, we evaluated the differences in therapeutic benefits of BMAC between IVD- and facet joint-originating chronic LBP. Eighteen patients diagnosed with chronic LBP met the selection criteria. Following discography and provocation testing, 13 patients tested positive and were assigned into IDD-associated LBP (1st arm), while the remaining 5 tested negative and were assigned into facetogenic LBP (2nd arm). Autologous BMAC was injected intradiscally in the 1st arm, while the 2nd arm received posterior spinal chain injections. No procedure-related serious events ensued. Clinical improvement was evaluated over 12 months based on pain and functionality questionnaires (VAS, BPI, RAND-36), opioid use, and changes in disc parameters assessed by magnetic resonance imaging (MRI). Ameliorated VAS and BPI scores differed significantly between both arms in favor of IDD patients who also took significantly less opioids. Average RAND-36 scores showed no significant difference between groups albeit a trend suggesting improvement was observed in IDD patients. MRI scans conducted on IDD patients demonstrated marked elevation in disc height and spinal canal space size without worsening disc quality. Overall, this is the first study investigating the potency of BMAC as an IDD treatment in Canada and the first globally for addressing facetogenic pain using cellular therapy.

The Role of the Proteasome in Platelet Function.

Platelets are megakaryocyte-derived acellular fragments prepped to maintain primary hemostasis and thrombosis by preserving vascular integrity. Although they lack nuclei, platelets harbor functional genomic mediators that bolster platelet activity in a signal-specific manner by performing limited de novo protein synthesis. Furthermore, despite their limited protein synthesis, platelets are equipped with multiple protein degradation mechanisms, such as the proteasome. In nucleated cells, the functions of the proteasome are well established and primarily include proteostasis among a myriad of other signaling processes. However, the role of proteasome-mediated protein degradation in platelets remains elusive. In this review article, we recapitulate the developing literature on the functions of the proteasome in platelets, discussing its emerging regulatory role in platelet viability and function and highlighting how its functional coupling with the transcription factor NF-κB constitutes a novel potential therapeutic target in atherothrombotic diseases.

TACIMA-218: A Novel Pro-Oxidant Agent Exhibiting Selective Antitumoral Activity.

We report the discovery, via a unique high-throughput screening strategy, of a novel bioactive anticancer compound: Thiol Alkylating Compound Inducing Massive Apoptosis (TACIMA)-218. We demonstrate that this molecule engenders apoptotic cell death in genetically diverse murine and human cancer cell lines, irrespective of their p53 status, while sparing normal cells. TACIMA-218 causes oxidative stress in the absence of protective antioxidants normally induced by Nuclear factor erythroid 2-related factor 2 activation. As such, TACIMA-218 represses RNA translation and triggers cell signaling cascade alterations in AKT, p38, and JNK pathways. In addition, TACIMA-218 manifests thiol-alkylating properties resulting in the disruption of redox homeostasis along with key metabolic pathways. When administered to immunocompetent animals as a monotherapy, TACIMA-218 has no apparent toxicity and induces complete regression of pre-established lymphoma and melanoma tumors. In sum, TACIMA-218 is a potent oxidative stress inducer capable of selective cancer cell targeting.

Engineering immunoproteasome-expressing mesenchymal stromal cells: A potent cellular vaccine for lymphoma and melanoma in mice.

Dendritic cells (DCs) excel at cross-presenting antigens, but their effectiveness as cancer vaccine is limited. Here, we describe a vaccination approach using mesenchymal stromal cells (MSCs) engineered to express the immunoproteasome complex (MSC-IPr). Such modification instills efficient antigen cross-presentation abilities associated with enhanced major histocompatibility complex class I and CD80 expression, de novo production of interleukin-12, and higher chemokine secretion. This cross-presentation capacity of MSC-IPr is highly dependent on their metabolic activity. Compared with DCs, MSC-IPr hold the ability to cross-present a vastly different epitope repertoire, which translates into potent re-activation of T cell immunity against EL4 and A20 lymphomas and B16 melanoma tumors. Moreover, therapeutic vaccination of mice with pre-established tumors efficiently controls cancer growth, an effect further enhanced when combined with antibodies targeting PD-1, CTLA4, LAG3, or 4-1BB under both autologous and allogeneic settings. Therefore, MSC-IPr constitute a promising subset of non-hematopoietic antigen-presenting cells suitable for designing universal cell-based cancer vaccines.

A Novel Sulfonyl-Based Small Molecule Exhibiting Anti-cancer Properties.

Phenotypic screening is an ideal strategy for the discovery of novel bioactive molecules. Using a customized high-throughput screening (HTS) assay employing primary T lymphocytes, we screened a small library of 4,398 compounds with unknown biological function/target to identify compounds eliciting immunomodulatory properties and discovered a sulfonyl-containing hit, we named InhiTinib. This compound inhibited interferon (IFN)-gamma production and proliferation of primary CD3+ T cells without inducing cell death. In contrast, InhiTinib triggered apoptosis in several murine and human cancer cell lines. Besides, the compound was well tolerated by immunocompetent mice, triggered tumor regression in animals with pre-established EL4 T-cell lymphomas, and prolonged the overall survival of mice harboring advanced tumors. Altogether, our data demonstrate the anti-cancer properties of InhiTinib, which can henceforth bridge to wider-scale biochemical and clinical tests following further in-depth pharmacodynamic studies.

Mesenchymal Stem Cells Beyond Regenerative Medicine.

Mesenchymal stem cells (MSCs) are competent suitors of cellular therapy due to their therapeutic impact on tissue degeneration and immune-based pathologies. Additionally, their homing and immunomodulatory properties can be exploited in cancer malignancies to transport pharmacological entities, produce anti-neoplastic agents, or induce anti-tumor immunity. Herein, we create a portfolio for MSC properties, showcasing their distinct multiple therapeutic utilities and successes/challenges thereof in both animal studies and clinical trials. We further highlight the promising potential of MSCs not only in cancer management but also in instigating tumor-specific immunity - i.e., cancer vaccination. Finally, we reflect on the possible reasons impeding the clinical advancement of MSC-based cancer vaccines to assist in contriving novel methodologies from which a therapeutic milestone might emanate.

Aspirin Reduces the Potentiating Effect of CD40L on Platelet Aggregation via Inhibition of Myosin Light Chain.

Background Antiplatelet therapy with aspirin (acetylsalicylic acid [ASA]) is less efficient in some coronary patients, which increases their risk of developing thrombosis. Elevated blood levels of thromboinflammatory mediators, like soluble CD40L (sCD40L), may explain such variabilities. We hypothesized that in the presence of elevated levels of sCD40L, the efficacy of ASA may vary and aimed to determine the effects of ASA on CD40L signaling and aggregation of platelets. Methods and Results The effects of ASA on CD40L-treated human platelets, in response to suboptimal concentrations of collagen or thrombin, were assessed at levels of aggregation, thromboxane A2 secretion, and phosphorylation of p38 mitogen-activated protein kinase, nuclear factor kappa B, transforming growth factor-ß-activated kinase 1, and myosin light chain. sCD40L significantly elevated thromboxane A2 secretion in platelets in response to suboptimal doses of collagen and thrombin, which was reversed by ASA. ASA did not inhibit the phosphorylation of p38 mitogen-activated protein kinase, nuclear factor kappa B, and transforming growth factor-ß-activated kinase 1, with sCD40L stimulation alone or with platelet agonists. sCD40L potentiated platelet aggregation, an effect completely reversed and partially reduced by ASA in response to a suboptimal dose of collagen and thrombin, respectively. The effects of ASA in sCD40L-treated platelets with collagen were related to inhibition of platelet shape change and myosin light chain phosphorylation. Conclusions ASA does not affect platelet sCD40L signaling but prevents its effect on thromboxane A2 secretion and platelet aggregation in response to collagen, via a mechanism implying inhibition of myosin light chain. Targeting the sCD40L axis in platelets may have a therapeutic potential in patients with elevated levels of sCD40L and who are nonresponsive or less responsive to ASA.

Thymoproteasome-Expressing Mesenchymal Stromal Cells Confer Protective Anti-Tumor Immunity via Cross-Priming of Endogenous Dendritic Cells.

Proteasomes are complex macromolecular structures existing in various forms to regulate a myriad of cellular processes. Besides degrading unwanted or misfolded proteins (proteostasis), distinct immune functions were ascribed for the immunoproteasome and thymoproteasome (TPr) complexes. For instance, antigen degradation during ongoing immune responses mainly relies on immunoproteasome activity, whereas intrathymic CD8 T-cell development requires peptide generation by the TPr complex. Despite these substantial differences, the functional contribution of the TPr to peripheral T-cell immunity remains ill-defined. We herein explored whether the use of mesenchymal stromal cells (MSCs) engineered to exhibit altered proteasomal activity through de novo expression of the TPr complex can be exploited as a novel anti-cancer vaccine capable of triggering potent CD8 T-cell activation. Phenotypic and molecular characterization of MSC-TPr revealed a substantial decrease in MHCI (H2-Kb and H2-Dd) expression along with elevated secretion of various chemokines (CCL2, CCL9, CXCL1, LIX, and CX3CL1). In parallel, transcriptomic analysis pinpointed the limited ability of MSC-TPr to present endogenous antigens, which is consistent with their low expression levels of the peptide-loading proteins TAP, CALR, and PDAI3. Nevertheless, MSC-TPr cross-presented peptides derived from captured soluble proteins. When tested for their protective capacity, MSC-TPr triggered modest anti-tumoral responses despite efficient generation of effector memory CD4 and CD8 T cells. In contrast, clodronate administration prior to vaccination dramatically enhanced the MSC-TPr-induced anti-tumoral immunity clearly highlighting a refractory role mediated by phagocytic cells. Thus, our data elute to a DC cross-priming-dependant pathway in mediating the therapeutic effect of MSC-TPr.

Role of NF-κB in Platelet Function.

Platelets are megakaryocyte-derived fragments lacking nuclei and prepped to maintain primary hemostasis by initiating blood clots on injured vascular endothelia. Pathologically, platelets undergo the same physiological processes of activation, secretion, and aggregation yet with such pronouncedness that they orchestrate and make headway the progression of atherothrombotic diseases not only through clot formation but also via forcing a pro-inflammatory state. Indeed, nuclear factor-κB (NF-κB) is largely implicated in atherosclerosis and its pathological complication in atherothrombotic diseases due to its transcriptional role in maintaining pro-survival and pro-inflammatory states in vascular and blood cells. On the other hand, we know little on the functions of platelet NF-κB, which seems to function in other non-genomic ways to modulate atherothrombosis. Therein, this review will resemble a rich portfolio for NF-κB in platelets, specifically showing its implications at the levels of platelet survival and function. We will also share the knowledge thus far on the effects of active ingredients on NF-κB in general, as an extrapolative method to highlight the potential therapeutic targeting of NF-κB in coronary diseases. Finally, we will unzip a new horizon on a possible extra-platelet role of platelet NF-κB, which will better expand our knowledge on the etiology and pathophysiology of atherothrombosis.

Restoring thymic function: Then and now.

Thymic vulnerability, a leading cause of defective immunity, was discovered decades ago. To date, several strategies have been investigated to unveil any immunorestorative capacities they might confer. Studies exploiting castration, transplantation, adoptive cell therapies, hormones/growth factors, and cytokines have demonstrated enhanced in vitro and in vivo thymopoiesis, albeit with clinical restrictions. In this review, we will dissect the thymus on a physiological and pathological level and discuss the pros and cons of several strategies esteemed thymotrophic from a pre-clinical perspective. Finally, we will shed light on interleukin (IL)-21, a pharmacologically-promising cytokine with a significant thymotrophic nature, and elaborate on its potential clinical efficacy and safety in immune-deficient subjects.