CAR-T manufactured from frozen PBMC yield efficient function with prolonged in vitro production.

Chimeric antigen receptor (CAR)-T cells are engineered to identify and eliminate cells expressing a target antigen. Current manufacturing protocols vary between commercial CAR-T cell products warranting an assessment of these methods to determine which approach optimally balances successful manufacturing capacity and product efficacy. One difference between commercial product manufacturing methods is whether T cell engineering begins with fresh (unfrozen) patient cells or cells that have been cryopreserved prior to manufacture. Starting with frozen PBMC material allows for greater manufacturing flexibility, and the possibility of collecting and storing blood from patients prior to multiple lines of therapy. We prospectively analyzed if second generation anti-CD19 CAR-T cells with either CD28 or 4-1BB co-stimulatory domains have different phenotype or function when prepared side-by-side using fresh or cryopreserved PBMCs. We found that cryopreserved PBMC starting material is associated with slower CAR-T cell expansion during manufacture but does not affect phenotype. We also demonstrate that CAR-T cell activation, cytokine production and in vitro anti-tumor cytotoxicity were not different when CAR-T cells were manufactured from fresh or cryopreserved PBMC. As CAR-T cell therapy expands globally, the need for greater flexibility around the timing of manufacture will continue to grow. This study helps support the concept that cryopreservation of PBMCs could be the solution to these issues without compromising the quality of the final CAR-T product.

Functional studies on the role of Notch signaling in Hydractinia development.

The function of Notch signaling was previously studied in two cnidarians, Hydra and Nematostella, representing the lineages Hydrozoa and Anthozoa, respectively. Using pharmacological inhibition in Hydra and a combination of pharmacological and genetic approaches in Nematostella, it was shown in both animals that Notch is required for tentacle morphogenesis and for late stages of stinging cell maturation. Surprisingly, a role for Notch in neural development, which is well documented in bilaterians, was evident in embryonic Nematostella but not in adult Hydra. Adult neurogenesis in the latter seemed to be unaffected by DAPT, a drug that inhibits Notch signaling. To address this apparent discrepancy, we studied the role of Notch in Hydractinia echinata, an additional hydrozoan, in all life stages. Using CRISPR-Cas9 mediated mutagenesis, transgenesis, and pharmacological interference we show that Notch is dispensable for Hydractinia normal neurogenesis in all life stages but is required for the maturation of stinging cells and for tentacle morphogenesis. Our results are consistent with a conserved role for Notch in morphogenesis and nematogenesis across Cnidaria, and a lineage-specific loss of Notch dependence in neurogenesis in hydrozoans.

Glucose deprivation elicits phenotypic plasticity via ZEB1-mediated expression of NNMT.

Glucose is considered the primary energy source for all cells, and some cancers are addicted to glucose. Here, we investigated the functional consequences of chronic glucose deprivation in serous ovarian cancer cells. We found that cells resistant to glucose starvation (glucose-restricted cells) demonstrated increased metabolic plasticity that was dependent on NNMT (Nicotinamide N-methyltransferase) expression. We further show that ZEB1 induced NNMT, rendered cells resistant to glucose deprivation and recapitulated metabolic adaptations and mesenchymal gene expression observed in glucose-restricted cells. NNMT depletion reversed metabolic plasticity in glucose-restricted cells and prevented de novo formation of glucose-restricted colonies. In addition to its role in glucose independence, we found that NNMT was required for other ZEB1-induced phenotypes, such as increased migration. NNMT protein levels were also elevated in metastatic and recurrent tumors compared to matched primary carcinomas, while normal ovary and fallopian tube tissue had no detectable NNMT expression. Our studies define a novel ZEB1/NNMT signaling axis, which elicits mesenchymal gene expression, as well as phenotypic and metabolic plasticity in ovarian cancer cells upon chronic glucose starvation. Understanding the causes of cancer cell plasticity is crucial for the development of therapeutic strategies to counter intratumoral heterogeneity, acquired drug resistance and recurrence in high-grade serous ovarian cancer (HGSC).

New roles for Nanos in neural cell fate determination revealed by studies in a cnidarian.

Nanos is a pan-metazoan germline marker, important for germ cell development and maintenance. In flies, Nanos also acts in posterior and neural development, but these functions have not been demonstrated experimentally in other animals. Using the cnidarian Hydractinia we have uncovered novel roles for Nanos in neural cell fate determination. Ectopic expression of Nanos2 increased the numbers of embryonic stinging cell progenitors, but decreased the numbers of neurons. Downregulation of Nanos2 had the opposite effect. Furthermore, Nanos2 blocked maturation of committed, post-mitotic nematoblasts. Hence, Nanos2 acts as a switch between two differentiation pathways, increasing the numbers of nematoblasts at the expense of neuroblasts, but preventing nematocyte maturation. Nanos2 ectopic expression also caused patterning defects, but these were not associated with deregulation of Wnt signaling, showing that the basic anterior-posterior polarity remained intact, and suggesting that numerical imbalance between nematocytes and neurons might have caused these defects, affecting axial patterning only indirectly. We propose that the functions of Nanos in germ cells and in neural development are evolutionarily conserved, but its role in posterior patterning is an insect or arthropod innovation.

Induced stem cell neoplasia in a cnidarian by ectopic expression of a POU domain transcription factor.

The evolutionary origin of stem cell pluripotency is an unresolved question. In mammals, pluripotency is limited to early embryos and is induced and maintained by a small number of key transcription factors, of which the POU domain protein Oct4 is considered central. Clonal invertebrates, by contrast, possess pluripotent stem cells throughout their life, but the molecular mechanisms that control their pluripotency are poorly defined. To address this problem, we analyzed the expression pattern and function of Polynem (Pln), a POU domain gene from the marine cnidarian Hydractinia echinata. We show that Pln is expressed in the embryo and adult stem cells of the animal and that ectopic expression in epithelial cells induces stem cell neoplasms and loss of epithelial tissue. Neoplasm cells downregulated the transgene but expressed the endogenous Pln gene and also Nanos, Vasa, Piwi and Myc, which are all known cnidarian stem cell markers. Retinoic acid treatment caused downregulation of Pln and the differentiation of neoplasm cells to neurosensory and epithelial cells. Pln downregulation by RNAi led to differentiation. Collectively, our results suggest an ancient role of POU proteins as key regulators of animal stem cells.

An acidic glycoconjugate from Lythrum salicaria L. with controversial effects on haemostasis.

AIM OF THE STUDY: Lythrum salicaria L. belongs to the small Lythraceae family of 22 genera, which range in habit from herbs to shrubs and trees found with worldwide distribution (Heywood, 1993). The generic name of Lythrum derived from Greek "luthron"--blood, possibly referring to the color of the flowers or to the one of its herbal use as an astringent to stop bleeding (Thompson et al., 1987; Mountain, 1994; Pawlaczyk and Pacula, 2002). The flowering parts and the flowering branch tips are used in traditional medicine and pharmaceuticals internally in a form of decoctions or as extracts for treatment of diarrhea, chronic intestinal catarrhs, hemorrhoids and eczema, or externally to treat varicose veins, venous insufficiency and gums (Mantle et al., 2000; Rauha et al., 2000). The aim of this study was to isolate the plant glycoconjugate from flowering parts of Lythrum salicaria, and to verify its influence on blood coagulation process. MATERIALS AND METHODS: From the air-dried flowering parts of this plant a water-soluble glycoconjugate has been isolated by hot alkaline extraction followed by neutralization and purification by multi-steps extraction with organic solvents, dialysis and concentration. The plant isolate was tested in vitro on anticoagulant activity on human plasma, and on Wistar rats blood system in vivo as well as ex vivo. RESULTS: A dark brown isolate was obtained in the yield of 8% of starting material (w/w) as a macromolecular compound with M(w) approximately 12,500. Chemical analysis revealed the presence of carbohydrates (30%), phenolics (1g contained 1.2mM of gallic acid equivalent) and proteins (0.8%). The result of compositional analyses of carbohydrate part revealed the predominance of uronic acids (approximately 66%), galactose (approximately 12%), rhamnose (approximately 10%) and arabinose (approximately 9%) residues indicating thus the presence of pectic type of polymers, i.e. galacturonan and/or rhamnogalacturonan associated with arabinogalactan in Lythrum glycoconjugate. In vitro and ex vivo experiments showed complete inhibition of plasma clot formation, however, the application of Lythrum glycoconjugate in vivo showed controversial effect on animal blood system in comparison with in vitro ones, i.e. pro-coagulant activity. CONCLUSION: The in vivo results give a scientific explanation for the traditional use of Lythrum salicaria as a styptic agent. It seems that pro-coagulant activity of this complex could be probably connected with the other factors in blood circulation system, like platelets.