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Delayed hematopoietic recovery is a major drawback of umbilical cord blood (UCB) transplantation. Transplantation of ex vivo-expanded UCB shortens time to hematopoietic recovery, but long-term, robust engraftment by the expanded unit has yet to be demonstrated. We tested the hypothesis that a UCB-derived cell product consisting of stem cells expanded for 21 days in the presence of nicotinamide and a noncultured T cell fraction (NiCord) can accelerate hematopoietic recovery and provide long-term engraftment. In a phase I trial, 11 adults with hematologic malignancies received myeloablative bone marrow conditioning followed by transplantation with NiCord and a second unmanipulated UCB unit. Safety, hematopoietic recovery, and donor engraftment were assessed and compared with historical controls. No adverse events were attributable to the infusion of NiCord. Complete or partial neutrophil and T cell engraftment derived from NiCord was observed in 8 patients, and NiCord engraftment remained stable in all patients, with a median follow-up of 21 months. Two patients achieved long-term engraftment with the unmanipulated unit. Patients transplanted with NiCord achieved earlier median neutrophil recovery (13 vs. 25 days, P < 0.001) compared with that seen in historical controls. The 1-year overall and progression-free survival rates were 82% and 73%, respectively. UCB-derived hematopoietic stem and progenitor cells expanded in the presence of nicotinamide and transplanted with a T cell-containing fraction contain both short-term and long-term repopulating cells. The results justify further study of NiCord transplantation as a single UCB graft. If long-term safety is confirmed, NiCord has the potential to broaden accessibility and reduce the toxicity of UCB transplantation. Clinicaltrials.gov NCT01221857. Gamida Cell Ltd.

ObjectivesThere is a need for effective and safe treatment during pregnancy in women with chronic inflammatory diseases. This study evaluated placental transfer of certolizumab pegol (CZP), an Fc-free anti-tumour necrosis factor drug, from CZP-treated pregnant women to their infants.MethodsCRIB was a pharmacokinetic (PK) study of women ≥30 weeks pregnant receiving commercial CZP for a locally approved indication (last dose ≤35 days prior to delivery). Blood samples were collected from mothers, umbilical cords and infants at delivery, and infants again at weeks 4 and 8 post-delivery. CZP plasma concentrations were measured with a highly sensitive and CZP-specific electrochemiluminescence immunoassay (lower limit of quantification 0.032 μg/mL).ResultsSixteen women entered and completed the study. Maternal CZP plasma levels at delivery were within the expected therapeutic range (median [range] 24.4 [5.0–49.4] μg/mL). Of the 16 infants, 2 were excluded from the per-protocol set: 1 due to missing data at birth and 1 due to implausible PK data. Of the remaining 14 infants, 13 had no quantifiable CZP levels at birth (<0.032 μg/mL), and 1 had a minimal CZP level of 0.042 μg/mL (infant/mother plasma ratio 0.0009); no infants had quantifiable CZP levels at weeks 4 and 8. Of 16 umbilical cord samples, 1 was excluded due to missing data; 3/15 had quantifiable CZP levels (maximum 0.048 μg/mL).ConclusionsThere was no to minimal placental transfer of CZP from mothers to infants, suggesting lack of in utero foetal exposure during the third trimester. These results support continuation of CZP treatment during pregnancy, when considered necessary.Trial registration number NCT02019602; Results.

Cord blood (CB) cells that express CD34 have extensive hematopoietic capacity and rapidly divide ex vivo in the presence of cytokine combinations; however, many of these CB CD34+ cells lose their marrow-repopulating potential. To overcome this decline in function, we treated dividing CB CD34+ cells ex vivo with several histone deacetylase inhibitors (HDACIs). Treatment of CB CD34+ cells with the most active HDACI, valproic acid (VPA), following an initial 16-hour cytokine priming, increased the number of multipotent cells (CD34+CD90+) generated; however, the degree of expansion was substantially greater in the presence of both VPA and cytokines for a full 7 days. Treated CD34+ cells were characterized based on the upregulation of pluripotency genes, increased aldehyde dehydrogenase activity, and enhanced expression of CD90, c-Kit (CD117), integrin α6 (CD49f), and CXCR4 (CD184). Furthermore, siRNA-mediated inhibition of pluripotency gene expression reduced the generation of CD34+CD90+ cells by 89%. Compared with CB CD34+ cells, VPA-treated CD34+ cells produced a greater number of SCID-repopulating cells and established multilineage hematopoiesis in primary and secondary immune-deficient recipient mice. These data indicate that dividing CB CD34+ cells can be epigenetically reprogrammed by treatment with VPA so as to generate greater numbers of functional CB stem cells for use as transplantation grafts.

Haematopoietic stem cells (HSCs) are a rare cell type that reconstitute the entire blood and immune systems after transplantation and can be used as a curative cell therapy for a variety of haematological diseases 1 , 2 . However, the low number of HSCs in the body makes both biological analyses and clinical application difficult, and the limited extent to which human HSCs can be expanded ex vivo remains a substantial barrier to the wider and safer therapeutic use of HSC transplantation 3 . Although various reagents have been tested in attempts to stimulate the expansion of human HSCs, cytokines have long been thought to be essential for supporting HSCs ex vivo 4 . Here we report the establishment of a culture system that allows the long-term ex vivo expansion of human HSCs, achieved through the complete replacement of exogenous cytokines and albumin with chemical agonists and a caprolactam-based polymer. A phosphoinositide 3-kinase activator, in combination with a thrombopoietin-receptor agonist and the pyrimidoindole derivative UM171, were sufficient to stimulate the expansion of umbilical cord blood HSCs that are capable of serial engraftment in xenotransplantation assays. Ex vivo HSC expansion was further supported by split-clone transplantation assays and single-cell RNA-sequencing analysis. Our chemically defined expansion culture system will help to advance clinical HSC therapies. A culture system allows the long-term expansion of human haematopoietic stem cells (HSCs) in vivo without the use of recombinant cytokines or albumin, with potential applications for clinical therapies involving HSCs.

The ability to expand hematopoietic stem and progenitor cells (HSPCs) ex vivo is critical to fully realize the potential of HSPC-based therapies. In particular, the application of clinically effective therapies, such as cord blood transplantation, has been impeded because of limited HSPC availability. Here, using 3D culture of human HSPCs in a degradable zwitterionic hydrogel, we achieved substantial expansion of phenotypically primitive CD34+ cord blood and bone-marrow-derived HSPCs. This culture system led to a 73-fold increase in long-term hematopoietic stem cell (LT-HSC) frequency, as demonstrated by limiting dilution assays, and the expanded HSPCs were capable of hematopoietic reconstitution for at least 24 weeks in immunocompromised mice. Both the zwitterionic characteristics of the hydrogel and the 3D format were important for HSPC self-renewal. Mechanistically, the impact of 3D zwitterionic hydrogel culture on mitigating HSPC differentiation and promoting self-renewal might result from an inhibition of excessive reactive oxygen species (ROS) production via suppression of O2-related metabolism. HSPC expansion using zwitterionic hydrogels has the potential to facilitate the clinical application of hematopoietic-stem-cell therapies.

Umbilical cord blood (UCB) plays substantial roles in hematopoietic stem cell (HSC) transplantation and regenerative medicine. UCB is usually cryopreserved for years before use. It remains unclear whether and how cryopreservation affects UCB function. We constructed a single-cell transcriptomics profile of CD34+ hematopoietic stem and progenitor cells (HSPCs) and mononuclear cells (MNCs) from fresh and cryopreserved UCB stored for 1, 5, 10, and 19 years. Compared with fresh UCB, cryopreserved HSCs and multipotent progenitors (MPPs) exhibited more active cell-cycle and lower expression levels of HSC and multipotent progenitor signature genes. Hematopoietic reconstitution of cryopreserved HSPCs gradually decreased during the first 5 years but stabilized thereafter, aligning with the negative correlation between clinical neutrophil engraftment and cryopreservation duration of UCB. Cryopreserved HSPCs also showed reduced megakaryocyte generation. In contrast, cryopreserved NK cells and T cells maintained a capacity for cytokine production and cytotoxicity comparable to that of fresh cells. Mechanistically, cryopreserved HSPCs exhibited elevated ROS, reduced ATP synthesis, and abnormal mitochondrial distribution, which collectively led to attenuated hematopoietic reconstitution. These effects could be ameliorated by sulforaphane (SF). Together, we elucidate the negative effect of cryopreservation on UCB HSPCs and identify SF as a mitigation strategy, broadening the temporal window and scope for clinical applications of cryopreserved UCB.

The human genome contains approximately 20 thousand protein-coding genes 1 , but the size of the collection of antigen receptors of the adaptive immune system that is generated by the recombination of gene segments with non-templated junctional additions (on B cells) is unknown—although it is certainly orders of magnitude larger. It has not been established whether individuals possess unique (or private) repertoires or substantial components of shared (or public) repertoires. Here we sequence recombined and expressed B cell receptor genes in several individuals to determine the size of their B cell receptor repertoires, and the extent to which these are shared between individuals. Our experiments revealed that the circulating repertoire of each individual contained between 9 and 17 million B cell clonotypes. The three individuals that we studied shared many clonotypes, including between 1 and 6% of B cell heavy-chain clonotypes shared between two subjects (0.3% of clonotypes shared by all three) and 20 to 34% of λ or κ light chains shared between two subjects (16 or 22% of λ or κ light chains, respectively, were shared by all three). Some of the B cell clonotypes had thousands of clones, or somatic variants, within the clonotype lineage. Although some of these shared lineages might be driven by exposure to common antigens, previous exposure to foreign antigens was not the only force that shaped the shared repertoires, as we also identified shared clonotypes in umbilical cord blood samples and all adult repertoires. The unexpectedly high prevalence of shared clonotypes in B cell repertoires, and identification of the sequences of these shared clonotypes, should enable better understanding of the role of B cell immune repertoires in health and disease. Many clonotypes in human B cell repertoires are shared, including between adult and umbilical cord blood repertoires, which indicates that this similarity is not driven only by exposure to common antigens.

Enhancement of hematopoietic stem cell (HSC) homing and engraftment is clinically critical, especially for cord blood (CB) hematopoietic cell transplantation. Here we report that specific HDAC5 inhibition highly upregulates CXCR4 surface expression in human CB HSCs and progenitor cells (HPCs). This results in enhanced SDF-1/CXCR4-mediated chemotaxis and increased homing to the bone marrow environment, with elevated SCID-repopulating cell (SRC) frequency and enhanced long-term and secondary engraftment in NSG mice. HDAC5 inhibition increases acetylated p65 levels in the nucleus, which is important for CXCR4 transcription. Inhibition of nuclear factor-κB (NF-κB) signaling suppresses HDAC5-mediated CXCR4 upregulation, enhanced HSC homing, and engraftment. Furthermore, activation of the NF-κB signaling pathway via TNFα also results in significantly increased CXCR4 surface expression, enhanced HSC homing, and engraftment. These results demonstrate a previously unknown negative epigenetic regulation of HSC homing and engraftment by HDAC5, and allow for a new and simple translational strategy to enhance HSC transplantation. Enhancement of haematopoietic stem cell (HSC) homing and engraftment is critical for haematopoietic cell transplantation. Here, the authors find that HDAC5 inhibition enhances HSC homing and engraftment by increasing p65 acetylation and enhancing NF-kB mediated CXCR4 transcription.

Worldwide vitamin D insufficiency is remarkably prevalent in both children and adults, including pregnant women. The total amount of the vitamin is best measured by 25-hydroxy-vitamin D (25(OH)D), which is a measurement of total serum cholecalciferol 25(OH)D3 and ergocalciferol 25(OH)D2. There is a known correlation between maternal and umbilical cord blood (UCB) 25(OH)D; however, whether specific maternal demographics or comorbidities influence the correlation remains uncertain. This prospective observational study was designed to study if maternal 25(OH)D levels, maternal age and BMI, amount of supplementation, mode of delivery, diabetes, hypertension/preeclampsia, or sunlight exposure had an impact on the correlation. Women were enrolled in the study at admission to the labor ward. If they agreed to participate, venous blood was directly collected and analyzed for 25(OH)D. The UCB was sampled after delivery from the unclamped cord and immediately analyzed for 25(OH)D. ANOVA, Fisher’s exact test, Pearson’s correlation, and test of the differences between correlations using Fisher’s z-transformation with Bonferroni correction were used accordingly. Of the 298 women enrolled, blood from both the mother and umbilical cord was analyzed successfully for 25(OH)D in 235 cases. The crude correlation between maternal and UCB 25(OH)D was very strong over all values of 25(OH)D (r = 0.905, R 2 = 0.821, p <0,001) and remained strong independently of maternal demographics or co-morbidities (r ≥ 0.803, R 2 ≥ 0.644, p <0.001). For women who delivered by caesarean section in second stage the correlation was strong (r ≥ 0.633, R 2 ≥ 0.4, p <0.037). Test of differences between correlations showed significant stronger correlation in women with unknown 25(OH)D3 supplementation compared to women receiving 10.000 IU/week ( p = 0.02) and 20.000IU/week ( p = 0.01) and that the correlation was significantly stronger for women with a BMI of 25–29.9 compared to women with a BMI of <24.9 ( p = 0.004) and 30–34.9 ( p = 0.002). 213 (91%) women had lower 25(OH)D compared to the neonate, with a mean difference of -13.7nmol/L (SD = 15.6). In summary, the correlation between maternal and UCB 25(OH)D is very strong throughout low to high maternal levels of 25(OH)D with lower levels in maternal blood. Typical maternal demographics and comorbidities did not affect the transition.

Gestational diabetes mellitus (GDM) is a growing global health concern, driving the need for novel diagnostic and prognostic approaches. The aim of this study was to analyze the amino acid profile in the mother–fetus system (maternal venous blood, umbilical cord blood, and amniotic fluid) and to identify specific biological markers of GDM and macrosomia. Using HPLC-MS/MS, we analyzed serum from maternal venous and umbilical cord blood, along with amniotic fluid, across 94 mother–fetus pairs (53 GDM, 41 controls). Machine learning and metabolic pathway analysis revealed significant alterations in 19 amino acids. In GDM, maternal serum showed elevated 5-OH-lysine and homocitrulline, while cord blood had higher isoleucine, serine, and threonine. Amniotic fluid exhibited increased leucine, isoleucine, threonine, serine, arginine, and ornithine. Conversely, histidine, glutamine, alanine, asparagine, β-/γ-aminobutyric acids, phenylalanine, ornithine, and citrulline were reduced. Histidine, glutamine, and asparagine inversely correlated with blood glucose (r = −0.26, r = −0.33, r = −0.30) and were lower in GDM. These findings highlight three key metabolic loci in GDM pathogenesis, with glutamine, histidine, and asparagine emerging as potential maternal blood biomarkers for early macrosomia prediction. However, given confounding factors in metabolomic studies, further large-scale validation is essential.