Hematopoietic Stem Cell Therapy Research Articles

Care of patients with inborn errors of immunity in thirty J Project countries between 2004 and 2021.

The J Project (JP) physician education and clinical research collaboration program was started in 2004 and includes by now 32 countries mostly in Eastern and Central Europe (ECE). Until the end of 2021, 344 inborn errors of immunity (IEI)-focused meetings were organized by the JP to raise awareness and facilitate the diagnosis and treatment of patients with IEI. In this study, meeting profiles and major diagnostic and treatment parameters were studied. JP center leaders reported patients' data from 30 countries representing a total population of 506 567 565. Two countries reported patients from JP centers (Konya, Turkey and Cairo University, Egypt). Diagnostic criteria were based on the 2020 update of classification by the IUIS Expert Committee on IEI. The number of JP meetings increased from 6 per year in 2004 and 2005 to 44 and 63 in 2020 and 2021, respectively. The cumulative number of meetings per country varied from 1 to 59 in various countries reflecting partly but not entirely the population of the respective countries. Altogether, 24,879 patients were reported giving an average prevalence of 4.9. Most of the patients had predominantly antibody deficiency (46,32%) followed by patients with combined immunodeficiencies (14.3%). The percentages of patients with bone marrow failure and phenocopies of IEI were less than 1 each. The number of patients was remarkably higher that those reported to the ESID Registry in 13 countries. Immunoglobulin (IgG) substitution was provided to 7,572 patients (5,693 intravenously) and 1,480 patients received hematopoietic stem cell therapy (HSCT). Searching for basic diagnostic parameters revealed the availability of immunochemistry and flow cytometry in 27 and 28 countries, respectively, and targeted gene sequencing and new generation sequencing was available in 21 and 18 countries. The number of IEI centers and experts in the field were 260 and 690, respectively. We found high correlation between the number of IEI centers and patients treated with intravenous IgG (IVIG) (correlation coefficient, cc, 0,916) and with those who were treated with HSCT (cc, 0,905). Similar correlation was found when the number of experts was compared with those treated with HSCT. However, the number of patients treated with subcutaneous Ig (SCIG) only slightly correlated with the number of experts (cc, 0,489) and no correlation was found between the number of centers and patients on SCIG (cc, 0,174). 1) this is the first study describing major diagnostic and treatment parameters of IEI care in countries of the JP; 2) the data suggest that the JP had tremendous impact on the development of IEI care in ECE; 3) our data help to define major future targets of JP activity in various countries; 4) we suggest that the number of IEI centers and IEI experts closely correlate to the most important treatment parameters; 5) we propose that specialist education among medical professionals plays pivotal role in increasing levels of diagnostics and adequate care of this vulnerable and still highly neglected patient population; 6) this study also provides the basis for further analysis of more specific aspects of IEI care including genetic diagnostics, disease specific prevalence, newborn screening and professional collaboration in JP countries.

Autologous hematopoietic stem cell transplantation improves long-term survival—data from a national registry

BackgroundCurrent recommendations on the management of systemic sclerosis (SSc) suggest that autologous hematopoietic stem cell therapy (HSCT) can be a rescue therapy for patients with rapidly progressive SSc.ObjectivesTo assess the safety and efficacy of HSCT for patients with SSc and to compare these with non-HSCT patients in a control cohort with adjusted risk factors.MethodsA retrospective analysis of data from the multicentric German network for systemic scleroderma (DNSS) with 5000 patients with SSc. Control groups consisted of all patients with diffuse cutaneous (dc)-SSc (group A) and an adjusted high-risk cohort of male patients with Scl70-positive dc-SSc (group B).ResultsEighty SSc patients received an HSCT 4.1 ± 4.8 years after SSc diagnosis. Among them, 86.3% had dc-SSc, 43.5% were males, and 71.3% were positive for Scl70 antibodies. The control group A (n=1513) showed a significant underrepresentation of these risk factors for mortality. When the survival of the control group B (n=240) was compared with the HSCT group, a lower mortality of the latter was observed instead. Within 5 years after HSCT, we observed an improvement of the mRSS from 17.6 ± 11.5 to 11.0 ± 8.5 (p=0.001) and a stabilization of the DLCO. We did not see differences in transplant-related mortality between patients who received HSCT within 3 years after SSc diagnosis or later.ConclusionOur analysis of real-life data show that the distribution of risk factors for mortality is critical when HSCT cohorts are compared with non-HSCT control groups.

Repair of Limb Ischemia Is Dependent on Hematopoietic Stem Cell Specific-SHP-1 Regulation of TGF-β1.

Hematopoietic stem cell (HSC) therapy has shown promise for tissue regeneration after ischemia. Therefore, there is a need to understand mechanisms underlying endogenous HSCs activation in response to ischemic stress and coordination of angiogenesis and repair. SHP-1 plays important roles in HSC quiescence and differentiation by regulation of TGF-β1 signaling. TGF-β1 promotes angiogenesis by stimulating stem cells to secrete growth factors to initiate the formation of blood vessels and later aid in their maturation. We propose that SHP-1 responds to ischemia stress in HSC and progenitor cells (HSPC) via regulation of TGF-β1. A mouse hind limb ischemia model was used. Local blood perfusion in the limbs was determined using laser doppler perfusion imaging. The number of positive blood vessels per square millimeter, as well as blood vessel diameter (μm) and area (μm2), were calculated. Hematopoietic cells were analyzed using flow cytometry. The bone marrow transplantation assay was performed to measure HSC reconstitution. After femoral artery ligation, TGF-β1 was initially decreased in the bone marrow by day 3 of ischemia, followed by an increase on day 7. This pattern was opposite to that in the peripheral blood, which is concordant with the response of HSC to ischemic stress. In contrast, SHP-1 deficiency in HSC is associated with irreversible activation of HSPCs in the bone marrow and increased circulating HSPCs in peripheral blood following limb ischemia. In addition, there was augmented auto-induction of TGF-β1 and sustained inactivation of SHP-1-Smad2 signaling, which impacted TGF-β1 expression in HSPCs in circulation. Importantly, restoration of normal T GF-β1 oscillations helped in the recovery of limb repair and function. HSPC-SHP-1-mediated regulation of TGF-β1 in both bone marrow and peripheral blood is required for a normal response to ischemic stress.

Non-Genotoxic Conditioning Approach for Autologous Hematopoietic Stem Cell Therapies through Transient mRNA Engineering Using Vector-Free Microfluidic Cell Squeeze® Technology

Non-Genotoxic Conditioning Approach for Autologous Hematopoietic Stem Cell Therapies through Transient mRNA Engineering Using Vector-Free Microfluidic Cell Squeeze® Technology

Engineered Stem Cell Antibody Paired Evasion-2 (ESCAPE-2): Paired HSC Epitope Engineering and Direct Editing of Sickle Allele for Antibody-Mediated Autologous Hematopoietic Stem Cell Therapy Conditioning for the Treatment of Sickle Cell Disease

Introduction of the naturally-occurring Hb G-Makassar variation in the human betaglobin gene (HBB) through base editing to eliminate the polymerizing sickle protein, HbS, the major molecular driver for sickle cell disease (SCD), represents a promising new paradigm for the potential treatment of individuals with this disease. While several ex vivo delivery of gene editing technologies for SCD are advancing in the clinic, several challenges remain for this potentially transformative cell therapy, namely the requirement of myeloablative conditioning necessary for autologous hematopoietic stem cell transplant (HSCT) to be fully effective. Aiming to address this, we have developed a strategy whereby a monoclonal antibody (mAb) that binds to CD117, a critical receptor on HSPCs essential for viability, is coupled with multiplexed engineered HSCs (eHSCs). Our eHSCs are designed to both evade mAb binding and harbor the Makassar therapeutic edit. Our engineered stem cell antibody paired evasion (ESCAPE) strategy is designed to provide a non-genotoxic alternative to current conditioning regimens and a potential curative therapy for the treatment of SCD. In our ESCAPE-1 approach, we demonstrated that we could successfully engineer epitopes of the stem cell marker and receptor, CD117, by introducing missense mutations in the ligand binding domain that preserved normal CD117 function and prevented the binding of a high affinity antibody against wildtype (WT) CD117. We leveraged this selective advantage and screened guides that could install missense mutations that covered the entirety of the CD117 ectodomain and were compatible in a multiplexed edited HSC with a next-generation adenine base editor that could install the therapeutic Hb G-Makassar edit. We generated a library of CD117 variants via highly-efficient base editing of the CD117 gene, in mobilized peripheral blood CD34+ HSPCs and then counter-screened these variants against a library of mAbs that bound to wild-type CD117. We identified an antagonist mAb that interacts in the ligand binding domain of CD117, blocking normal SCF ligand binding to the WT receptor, but was unable to bind eHSCs. In vitro biological de-risking of this engineered epitope showed no significant changes in receptor function in response to SCF, or during in vitro differentiation and colony forming unit (CFU) assays when compared to WT CD117. Furthermore, we could demonstrate that this engineered epitope allowed for evasion of cytotoxicity in vitro when edited HSCs were exposed to increasing concentrations of the mAb. We next optimized the multiplex editing conditions in HSCs and achieved outcomes where all cells harboring a CD117 edit, also included at least one Makassar edit. We previously demonstrated that sickle cells harboring even a single Makassar edit exhibited reduced sickling when exposed to hypoxia in vitro. Subsequent Fc receptor silencing modifications were also optimized to reduce any mast cell degranulation that could be the result of antibody-based binding to Fc-receptor on mast cells. Altogether, our ESCAPE-2 strategy is compatible with the installation of the therapeutic Makassar edit that, when combined with a mAb as a conditioning agent, represents a promising potential alternative to busulfan-based myeloablative regimens in an autologous HSCT setting for the treatment of SCD.

CRISPR/Cas9 Genome-Edited Autologous Hematopoietic Stem Cell Transplantation Therapies for Sickle Cell Disease

Hematopoietic stem cell transplantation is the only curative option for sickle cell disease (SCD), a life-threatening genetic disorder that impacts millions worldwide, yet the majority of patients do not have a suitable donor for an allogeneic transplantation. Increased levels of fetal hemoglobin (HbF) are protective against complications of SCD. BCL11A is a transcription factor that binds to the y-globin promoter and controls fetal-to-adult hemoglobin switching. Reducing BCL11A expression or inhibiting its activity can induce expression of HbF in adult red blood cells. We have developed 2 genome editing strategies targeting BCL11A for the induction of HbF levels and report the preclinical development of two potentially curative CRISPR/Cas9 ex-vivo genome-edited autologous hematopoietic stem cell therapies: HIX763 and OTQ923. HIX763 is an investigational cell therapy product harboring a genome modification in the erythroid-specific enhancer region of the BCL11A gene on chromosome 2 resulting in reduced BCL11A expression only in erythroid cells. OTQ923 is an investigational cell therapy product generated by targeted disruption of the γ-globin gene promoter on chromosome 11 to presumably delete BCL11A binding regions in the targeted region. Both HIX763 and OTQ923 are intended to durably increase HbF to therapeutically effective levels to ameliorate complications of SCD. Both products showed editing-dependent upregulation of γ-globin, HbF expression and number of F-cells upon erythroid differentiation of edited hematopoietic stem cells from healthy donors and SCD patients. No off-target editing was identified for both HIX763 and OTQ923 through a complementary suite of genome-wide biochemical and cell-based assays including in silico off-target prediction, SITE-Seq, PanHeme analysis of known oncogenes and tumor suppressors, karyotyping, UnIT evaluation of chromosomal rearrangements, and on-target long-range sequencing analysis. A six-month tumorigenicity study revealed no tumor formation or clonal outgrowth upon transplantation of full human doses of HIX763 and OTQ923 into immunocompromised NOD scid gamma mouse (NSG) mice. Finally, a comparability assessment of OTQ923 produced using the research process and the clinical manufacturing process showed comparability in the quality of cells, as measured by off-target editing, genomic rearrangement, cell viability, editing efficiency, HbF induction, and in vivo engraftment. Together these studies demonstrate that the preclinical data adequately reflects the behavior of the cells intended for clinical use and supports advancing these drug products into clinical trials for the treatment of sickle cell disease.

Engineered Stem Cell Antibody Paired Evasion 1 (ESCAPE-1): Paired HSC Epitope Engineering and Upregulation of Fetal Hemoglobin for Antibody-Mediated Autologous Hematopoietic Stem Cell Therapy Conditioning for the Treatment of Hemoglobinopathies

Engineered Stem Cell Antibody Paired Evasion 1 (ESCAPE-1): Paired HSC Epitope Engineering and Upregulation of Fetal Hemoglobin for Antibody-Mediated Autologous Hematopoietic Stem Cell Therapy Conditioning for the Treatment of Hemoglobinopathies

IMMU-42. ADOPTIVE HEMATOPOIETIC STEM CELL AND APD1 THERAPY CONVERGE IN THE THYMUS TO PROMOTE ANTI-GLIOBLASTOMA IMMUNITY

Abstract Our lab previously published that adoptive hematopoietic stem cell (HSC) therapy administered in conjunction with aPD1 increases median survival in multiple models of CNS malignancies. Tumor-infiltrating lymphocytes (TIL) abundance is independently associated with better outcomes in many cancers. Impressively, approximately 25% of TILs are HSC-derived in early disease. Importantly, we show HSC therapy generates de novo TILs in a thymus-dependent fashion and offer evidence of altered central tolerance following aPD1 therapy, which may permit immune activation against a larger pool of tumor-associated antigens. Therapeutic HSCs were prepared from constitutive GFP-expressing (CD45.2+) and PD1KO (CD45.2+) mice and transferred into CD45.1+ hosts. Sublethal 5Gy total body irradiation was administered day 5 post-intracranial tumor implantation. The next day, 1E6 HSCs from a 1:1 – GFP:PD1KO cocktail were injected intravenously. Descriptive statistics are reported as mean ± SD. Transferred HSCs engraft, expand, differentiate, and migrate to form approximately 25% of the TIL compartment in only 15 days. We found that, 56.2% ± 20.3 of CD3+ TILs display a thymocyte-like CD4+CD8+ (DP) phenotype in early disease, and 43.8% ± 17.4 of these DP-TILs are HSC-derived. Interestingly, DP-TILs were virtually absent in advanced disease 29 days after treatment. At this stage, HSC-derived TILs most commonly fell within the single-positive (SP) TIL subsets, comprising 9.8% ± 5.6 of SP-CD8+ TILs. Notably, HSCPD1KO-derived cells were 4x more abundant amongst SP-CD8 TILs when compared to HSCGFP-derived cells (6.5% vs 1.6%, p < 0.05). SP-CD8 thymocytes were similarly enriched for HSCPD1KO progeny (41.1% vs 24.7%, p < 0.05) which may suggest PD-1 blockade directly promotes thymopoiesis. The privileged maturation of PD1-deficient HSCs is intriguingly reversed when GFP:PD1KO HSCs are co-transferred into non-tumor-bearing mice. Thus, we show the thymus is an active site where PD-1-blocking agents function, and that HSC + aPD1 therapy is uniquely positioned to leverage thymus-dependent anti-tumor immunity.

Nanoparticles targeting hematopoietic stem and progenitor cells: Multimodal carriers for the treatment of hematological diseases.

Modern-day hematopoietic stem cell (HSC) therapies, such as gene therapy, modify autologous HSCs prior to re-infusion into myelo-conditioned patients and hold great promise for treatment of hematological disorders. While this approach has been successful in numerous clinical trials, it relies on transplantation of ex vivo modified patient HSCs, which presents several limitations. It is a costly and time-consuming procedure, which includes only few patients so far, and ex vivo culturing negatively impacts on the viability and stem cell-properties of HSCs. If viral vectors are used, this carries the additional risk of insertional mutagenesis. A therapy delivered to HSCs in vivo, with minimal disturbance of the HSC niche, could offer great opportunities for novel treatments that aim to reverse disease symptoms for hematopoietic disorders and could bring safe, effective and affordable genetic therapies to all parts of the world. However, substantial unmet needs exist with respect to the in vivo delivery of therapeutics to HSCs. In the last decade, in particular with the development of gene editing technologies such as CRISPR/Cas9, nanoparticles (NPs) have become an emerging platform to facilitate the manipulation of cells and organs. By employing surface modification strategies, different types of NPs can be designed to target specific tissues and cell types in vivo. HSCs are particularly difficult to target due to the lack of unique cell surface markers that can be utilized for cell-specific delivery of therapeutics, and their shielded localization in the bone marrow (BM). Recent advances in NP technology and genetic engineering have resulted in the development of advanced nanocarriers that can deliver therapeutics and imaging agents to hematopoietic stem- and progenitor cells (HSPCs) in the BM niche. In this review we provide a comprehensive overview of NP-based approaches targeting HSPCs to control and monitor HSPC activity in vitro and in vivo, and we discuss the potential of NPs for the treatment of malignant and non-malignant hematological disorders, with a specific focus on the delivery of gene editing tools.

Phenytoin as seizure prophylaxis in hematopoietic stem cell transplantation with busulfan conditioning.

BackgroundPhenytoin is widely used as primary seizure prophylaxis in hematopoietic stem cell transplantation in patients undergoing myeloablative conditioning with busulfan. Because of the negative side effects of phenytoin, we abandoned phenytoin use in these patients. To assess the effect of this change, we performed a retrospective cohort study on all patients receiving busulfan.MethodsWe included 139 patients who underwent conditioning with busulfan for hematopoietic stem cell therapy. We registered the use of phenytoin, as well as the occurrence of seizures, until 7 days after busulfan administration. We compared seizure incidence between patients who received phenytoin and those who did not.ResultsOf the 43 patients who received phenytoin prophylaxis, four patients (9.3%) had a seizure during the conditioning regimen, of which two patients had cerebral non-Hodgkin lymphoma. Furthermore, all these 4 patients had very high levels of phenytoin (intoxication). Of the 96 patients that did not receive phenytoin prophylaxis, three patients (3.1%) had a seizure, and one of these patients had an undefined cerebral lesion. Phenytoin did not relate to seizure prevention in a logistic regression analysis.ConclusionWe conclude that phenytoin prophylaxis in patients treated with busulfan is obsolete and possibly harmful, as phenytoin intoxication can occur. We recommend discontinuing the use of phenytoin as primary seizure prophylaxis in these patients.

Regulatory learnings for the next wave of cellular immuno-oncology agents

Dr Pietrusko currently serves as Chief Regulatory and Quality Officer at Vor Biopharma in Cambridge, MA and leads the Regulatory strategy for engineered hematopoietic stem cell therapy for hematologic malignancies including AML. He has directed the worldwide approval of more than 30 new products in multiple therapeutic areas. As an early team member at Voyager Therapeutics, Dr Pietrusko pioneered regulatory strategies to translate gene therapies from research into the clinic. Prior to Voyager, he was Vice President of Global Regulatory Affairs & Quality and Executive Officer at ViroPharma, Inc. He also served as Senior Vice President of Regulatory Affairs at Millennium Pharmaceuticals, spearheading the accelerated approval of Velcade® in the US and in more than 90 countries worldwide. Earlier in his career, he was Vice President of Regulatory Affairs at SmithKline Beecham (now GSK). He has played a key role in shaping US regulatory policy for cutting edge medicines, such as recently pioneering the concept of an expedited pathway to approval for cell and gene therapies that led to the Regenerative Medicine Advanced Therapy (RMAT) designation process that was included in the United States 21st Century Cures Act. He currently serves as Chair of the Regulatory Affairs Committee of the Alliance for Regenerative Medicine (ARM) and is an appointed member of the Regulatory Affairs Committee of the American Society of Gene and Cell Therapies (ASGCT). Dr Pietrusko holds a Bachelor of Science degree in biology, a Bachelor of Pharmacy degree from Rutgers University, and a Doctor of Pharmacy degree from the Philadelphia College of Pharmacy and Science. He completed his residency training in hospital pharmacy at Thomas Jefferson University Hospital and is the author or co-author of over 50 scientific publications.

Stem Cell-Based Therapies for Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic, relapsing disease that severely affects patients’ quality of life. The exact cause of IBD is uncertain, but current studies suggest that abnormal activation of the immune system, genetic susceptibility, and altered intestinal flora due to mucosal barrier defects may play an essential role in the pathogenesis of IBD. Unfortunately, IBD is currently difficult to be wholly cured. Thus, more treatment options are needed for different patients. Stem cell therapy, mainly including hematopoietic stem cell therapy and mesenchymal stem cell therapy, has shown the potential to improve the clinical disease activity of patients when conventional treatments are not effective. Stem cell therapy, an emerging therapy for IBD, can alleviate mucosal inflammation through mechanisms such as immunomodulation and colonization repair. Clinical studies have confirmed the effectiveness of stem cell transplantation in refractory IBD and the ability to maintain long-term remission in some patients. However, stem cell therapy is still in the research stage, and its safety and long-term efficacy remain to be further evaluated. This article reviews the upcoming stem cell transplantation methods for clinical application and the results of ongoing clinical trials to provide ideas for the clinical use of stem cell transplantation as a potential treatment for IBD.

Dominant-acting CSF1R variants cause microglial depletion and altered astrocytic phenotype in zebrafish and adult-onset leukodystrophy

Tissue-resident macrophages of the brain, including microglia, are implicated in the pathogenesis of various CNS disorders and are possible therapeutic targets by their chemical depletion or replenishment by hematopoietic stem cell therapy. Nevertheless, a comprehensive understanding of microglial function and the consequences of microglial depletion in the human brain is lacking. In human disease, heterozygous variants in CSF1R, encoding the Colony-stimulating factor 1 receptor, can lead to adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) possibly caused by microglial depletion. Here, we investigate the effects of ALSP-causing CSF1R variants on microglia and explore the consequences of microglial depletion in the brain. In intermediate- and late-stage ALSP post-mortem brain, we establish that there is an overall loss of homeostatic microglia and that this is predominantly seen in the white matter. By introducing ALSP-causing missense variants into the zebrafish genomic csf1ra locus, we show that these variants act dominant negatively on the number of microglia in vertebrate brain development. Transcriptomics and proteomics on relatively spared ALSP brain tissue validated a downregulation of microglia-associated genes and revealed elevated astrocytic proteins, possibly suggesting involvement of astrocytes in early pathogenesis. Indeed, neuropathological analysis and in vivo imaging of csf1r zebrafish models showed an astrocytic phenotype associated with enhanced, possibly compensatory, endocytosis. Together, our findings indicate that microglial depletion in zebrafish and human disease, likely as a consequence of dominant-acting pathogenic CSF1R variants, correlates with altered astrocytes. These findings underscore the unique opportunity CSF1R variants provide to gain insight into the roles of microglia in the human brain, and the need to further investigate how microglia, astrocytes, and their interactions contribute to white matter homeostasis.

Brain Magnetic Resonance Imaging Findings of Pediatric Hemophagocytic Lymphohistiocytosis Could Be Diagnostic and Life-Saving

BackgroundHemophagocytic lymphohistiocytosis (HLH) is a rare and fatal disease and may also present with central nervous system findings at the beginning without specific diagnostic criteria. Brain magnetic resonance imaging (MRI) findings are diverse and can also be diagnostic. We aimed to emphasize the importance of brain MRI findings in the early diagnosis of this fatal disease. MethodsMRI findings, clinical presentations, treatment response, and prognosis of seven patients with HLH were described. ResultsThere were seven pediatric patients who were initially diagnosed with HLH with neurological findings without systemic signs of HLH: four as primary, two as secondary, and one as possible primary HLH. All patients had contrast-enhancing diffuse cerebellar and brainstem lesions; patchy periventricular and callosal cerebral lesions were observed. Thalamus involvement was found in three (42.8%), corpus callosum involvement in six (85.7%), and cervical spinal involvement in one (14.2%). Patients were followed up with these MRI findings, with prediagnoses of toxic, metabolic, infectious, vascular, and demyelinating diseases. Not all patients met the HLH diagnostic criteria due to incomplete systemic/laboratory findings; therefore, only two were immediately directed for hematopoietic stem cell therapy. Four died shortly after admission, one patient could not be followed up after HLH treatment, and two patients who fulfilled the HLH diagnostic criteria underwent hematopoietic stem cell transplantation and survived. ConclusionsBrain MRI findings, especially in the presence of neurological findings, allow for early diagnosis, which can be life-saving. These common features in brain MRI findings should be evaluated with this suspicion and included in HLH diagnostic criteria.

Rational Design of Bisphosphonate Lipid-like Materials for mRNA Delivery to the Bone Microenvironment

The development of lipid nanoparticle (LNP) formulations for targeting the bone microenvironment holds significant potential for nucleic acid therapeutic applications including bone regeneration, cancer, and hematopoietic stem cell therapies. However, therapeutic delivery to bone remains a significant challenge due to several biological barriers, such as low blood flow in bone, blood-bone marrow barriers, and low affinity between drugs and bone minerals, which leads to unfavorable therapeutic dosages in the bone microenvironment. Here, we construct a series of bisphosphonate (BP) lipid-like materials possessing a high affinity for bone minerals, as a means to overcome biological barriers to deliver mRNA therapeutics efficiently to the bone microenvironment in vivo. Following in vitro screening of BP lipid-like materials formulated into LNPs, we identified a lead BP-LNP formulation, 490BP-C14, with enhanced mRNA expression and localization in the bone microenvironment of mice in vivo compared to 490-C14 LNPs in the absence of BPs. Moreover, BP-LNPs enhanced mRNA delivery and secretion of therapeutic bone morphogenetic protein-2 from the bone microenvironment upon intravenous administration. These results demonstrate the potential of BP-LNPs for delivery to the bone microenvironment, which could potentially be utilized for a range of mRNA therapeutic applications including regenerative medicine, protein replacement, and gene editing therapies.

β adrenergic signaling regulates hematopoietic stem and progenitor cell commitment and therapy sensitivity in multiple myeloma.

Not available.

Pre-operative Considerations in Adult Mucopolysaccharidosis Patients Planned for Cardiac Intervention.

Mucopolysaccharidoses (MPS) are rare lysosomal storage diseases characterized by multiorgan involvement and shortened longevity. Due to advances in therapies such as enzyme replacement therapy and haematopoietic stem cell therapy, life expectancy has increased posing newer challenges to patients and health professionals. One such challenge is cardiovascular manifestations of MPS, which can be life limiting and cause reduction in quality of life. Any cardiovascular intervention mandates comprehensive, multi-systemic work-up by specialist teams to optimize outcome. We highlight the importance of multidisciplinary evaluation of adult MPS patients requiring cardiovascular intervention. Clinical assessments and investigations are discussed, with a focus on the cardiac, anesthetic, airway, respiratory, radiological and psychosocial factors.

New Applications of JAK/STAT Inhibitors in Pediatrics: Current Use of Ruxolitinib.

Janus kinases (JAK) are a family of tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) that transduce cytokine-mediated signals through the JAK–STAT metabolic pathway. These kinases act by regulating the transcription of specific genes capable of inducing biological responses in several immune cell subsets. Inhibition of Janus kinases interferes with the JAK–STAT signaling pathway. Besides being used in the treatment of cancer and inflammatory diseases, in recent years, they have also been used to treat inflammatory conditions, such as graft-versus-host disease (GVHD) and cytokine release syndrome as complications of allogeneic hematopoietic stem cell transplantation and cell therapy. Recently, the FDA approved the use of ruxolitinib, a JAK1/2 inhibitor, in the treatment of acute steroid-refractory GVHD (SR-aGVHD), highlighting the role of JAK inhibition in this immune deregulation. Ruxolitinib was initially used to treat myelofibrosis and true polycythemia in a high-dose treatment and caused hematological toxicity. Since a lower dosage often could not be effective, the use of ruxolitinib was suspended. Subsequently, ruxolitinib was evaluated in adult patients with SR-aGVHD and was found to achieve a rapid and effective response. In addition, its early low-dose use in pediatric patients affected by GVHD has proved effective, safe, and reasonably preventive. The review aims to describe the potential properties of ruxolitinib to identify new therapeutic strategies.

Preventive Effects of a Human Hematopoietic Mesenchymal Stem Cell (hHMSC) Therapy in Ovalbumin-Induced Food Allergy.

No effective therapeutic strategies have been developed against food allergies. Immunomodulation during early infant period could prevent the development of food allergies. We investigated the preventive effects of human hematopoietic mesenchymal stem cells (hHMSCs) in mice with ovalbumin (OVA)-induced food allergy. BALB/c mice with OVA-induced food allergy were divided into 3 groups, and each group was treated with hHMSCs or hHMSC culture medium (hHMSC-CM) or saline. Ear thickness, allergy score, rectal temperature, and diarrhea occurrence were checked. Total IgE, OVA-specific IgE, and mucosal mast cell protease-1 (mMCP-1) were measured by ELISA. Other allergic parameters were analyzed using histology specimens, RT-PCR, and flow cytometry. Treatment with hHMSCs or hHMSC-CM significantly suppressed the frequency of anaphylactic response and rectal temperature decline, reduced diarrhea, total IgE, OVA-specific IgE, and mMCP-1. While the treatment decreased the level of Th2 cytokines, it enhanced IL-10 and TGF-β1 mRNA. Exposure to hHMSC or hHMSC-CM did not generate regulatory T cells, but reduced mast cells. The immunomodulatory effect on the Th2 cytokines was greater in hHMSC-CM than in hHMSCs. hHMSC treatment may be a promising preventive intervention against food allergy. Further studies are needed to elucidate the key substances released from hHMSC to induce immune tolerance.

Gene Therapy: Recent Advancement and Challenges

Background: Gene therapy involves delivering therapeutic genomic material to a target tissue to modify expression of a protein or induce other characteristic changes. Recent advancements in the field, including FDA-approval of numerous gene therapies, are paving the way for future technological progress. While gene therapy can be either somatic or germline, most research and drug development has focused on somatic cells. In this article, we discuss the recent advancements and challenges associated with gene therapy.
 Main Text: There are multiple types of gene therapies, including hematopoietic stem cell therapy, CAR-T cell therapy, and Crispr/Cas9 gene therapy. Rare diseases and cancers are being researched to determine methods of treatment using gene therapy, and several clinical trials have been performed within the last decade to test the efficacy of new therapeutic drugs, many of them at least somewhat successful. However, gene therapy does pose some challenges, including large-scale manufacturing of vectors, precision of gene delivery to target tissue, and, most importantly, the immune responses of patients.
 Conclusions: The near future is an exciting time for new gene therapy technologies and strategies. Researchers and patients can look forward to new advancements in base editing, prime editing, and RNA-targeted editing technologies. Furthermore, future research can focus on new genetic targets, such as genes whose functions may still be unknown and epigenomic elements.