NK cells: An attractive candidate for cancer therapy

Natural killer (NK) cells have significant capability in tumor immune-surveillance. The ability of lyse transformed cells immediately in an antigen-independent manner make them an attractive candidate for cancer cell therapy. Despite employment of NK cells in cancer immunotherapy, clinical trials are faced with serious limitations such as trouble with the penetration of NK cells in tumor sites, limited in vivo persistence, and tumor microenvironment interference. Taken together, the NK-cell cancer therapy is still infant scenario that has a long way to be translated in clinic. Current article first reviews characteristic features of NK lymphocytes. Then, it discusses about important disruptive barriers and motivator in the developmental stages of NK cells like as tumor microenvironment. Finally, some revolutionary approaches are highlighted utilizing of NK cells in cancer therapy.     

Hepatocyte differentiation of human induced pluripotent stem cells is modulated by stearoyl‐CoA desaturase 1 activity

Stearoyl‐CoA desaturase 1 (SCD1) plays important roles in organ development, glucose tolerance, insulin sensitivity, and cancer. Here, we examined the role of SCD1 for the differentiation of human induced pluripotent stem (hiPS) cells to liver cells by using drug inhibition and biochemical experiments. hiPS cells cultured in a pro‐hepatic medium were exposed to an SCD1 inhibitor at various stages throughout differentiation. Liver‐specific markers, specifically α‐fetoprotein, albumin and urea in conditioned medium, and hepatocyte nuclear factor 4α (HNF4α) and cytochrome P450 7A1 (CYP7A1) gene expressions and triglyceride in cellular extracts were analyzed at various development stages. Measures of hepatocyte‐specific function and triglyceride accumulation in later stages were strongly inhibited a minimum of −29% (P < 0.05) by SCD1 inhibitor in the early stage of hepatic differentiation and effectively reversed (>30%, P < 0.01) by the addition of oleate. The results were also reproducible with human primary mononuclear cells (hPMN). SCD1 inhibitor had no significant effect on liver‐specific markers when it was added in the hepatic maturation stage. However, it strikingly led to higher albumin (1.6‐fold, P = 0.03) and urea (1.9‐fold, P = 0.02) production, and HNF4α (1.9‐fold, P = 0.02) and CYP7A1 (1.3‐fold, P = 0.03) expression upon incubation during the lineage‐commitment stage. Hepatic differentiation from cultured hiPS cells is sensitive to SCD1 inhibition and this sensitivity is affected by the stage of cellular differentiation. Notably, findings also indicate that this notion can be extended to hPMN. The requirement for SCD1 activity in functional differentiation of hepatocytes may have relevance for human liver disease and metabolic dysregulation.     

Morphine Inhibited the Rat Neural Stem Cell Proliferation Rate by Increasing Neuro Steroid Genesis

Up to present, a large number of reports unveiled exacerbating effects of both long- and short-term administration of morphine, as a potent analgesic agent, on opium-addicted individuals and a plethora of cell kinetics, although contradictory effect of morphine on different cells have been introduced until yet. To address the potent modulatory effect of morphine on neural multipotent precursors with emphasis on endogenous sex-related neurosteroids biosynthesis, we primed the rat neural stem cells isolated from embryonic rat telencephalon to various concentrations of morphine including 10, 20, 50 and 100 µM alone or in combination with naloxone (100 µM) over period of 72 h. Flow cytometric Ki-67 expression and Annexin-V/PI based necrosis and apoptosis of exposed cells were evaluated. The total content of dihydrotestosterone and estradiol in cell supernatant was measured by ELISA. According on obtained data, both concentration- and time-dependent decrement of cell viability were orchestrated thorough down-regulation of ki-67 and simultaneous up-regulation of Annexin-V. On the other hand, the addition of naloxone (100 µM), as Mu opiate receptor antagonist, could blunt the morphine-induced adverse effects. It also well established that time-course exposure of rat neural stem cells with morphine potently could accelerate the endogenous dihydrotestosterone and estradiol biosynthesis. Interestingly, naloxone could consequently attenuate the enhanced neurosteroidogenesis time-dependently. It seems that our results discover a biochemical linkage between an accelerated synthesis of sex-related steroids and rat neural stem cells viability.

     

IL-8 induces imbalances between nitric oxide and endothelin-1, and also between plasminogen activator inhibitor-1 and tissue-type plasminogen activator in cultured endothelial cells

Interleukin-8 (IL-8), a member of the CXC chemokine family, plays an important role in the modulation of multiple biological functions in endothelial cells containing the receptors CXCR1 and CXCR2. It has previously been shown that IL-8 directly enhances endothelial cell survival, and stimulates the production of matrix metalloproteinases, which in turn regulates angiogenesis. However, its role in the regulation of the production of vasoactive substances in endothelial cells is less well defined. In this study, we investigate the effects of IL-8 on the proliferation of human umbilical vein endothelial cells (HUVECs). In addition, we also study the effects of IL-8 on the production of vasodilator, vasoconstrictor and fibrinolytic factors in these cells. The results show that recombinant IL-8 (50-200ng/ml) induces neither HUVEC proliferation nor nitric oxide (NO) release. However, it significantly increases the production of endothelin-1 (ET-1) in a concentration-dependent manner. Furthermore, incubation of endothelial cells with IL-8 (200ng/ml) up-regulates the plasminogen activator inhibitor-1 (PAI-1) in HUVECs, while it down-regulates the tissue plasminogen activator (t-PA). These findings suggest that IL-8 offsets the balance between endothelial vasoconstrictors and vasodilators. Furthermore, IL-8 also leads to an imbalance between PAI-1 and t-PA, which causes the ECs to become procoagulative and hypofibrinolytic.     

Quantity of HLA-C surface expression and licensing of KIR2DL+ natural killer cells

Natural killer (NK) cells require interaction of inhibitory surface receptors with human leukocyte antigen (HLA) ligands during development to acquire functional competence in a process termed "licensing." The quantity of HLA required for this process is unknown. Two polymorphisms affecting HLA-C surface expression (rs9264942 and rs67384697) have recently been identified, and shown to influence progression of HIV infection. We typed a cohort of healthy donors for the two HLA-C-related polymorphisms, KIR2DL1 and KIR2DL3, and their respective HLA-C ligands and analyzed how HLA ligands influenced licensing status of killer cell immunoglobulin-like receptor (KIR)+ NK cells in terms of degranulation and cytokine production in response to HLA-deficient target cells. The presence of respective HLA class I ligands increased the function of KIR2DL1+ and KIR2DL3+ NK cells in a dose-dependent manner. In contrast, neither of the HLA-C-related polymorphisms nor the quantity of cell surface HLA-C had any significant effect on NK cell function. Interestingly, HLA-Cw7-an HLA-C allele with low surface expression-licensed KIR2DL3+ NK cells more strongly than any other KIR2DL3 ligand. The quantity of cell surface HLA-C does not appear to influence licensing of NK cells, and the HLA-C-related polymorphisms presumably influence HIV progression through factors unrelated to NK cell education.     

Performance evaluation of a novel conceptual bioprocess for clinically-required mass production of hematopoietic cells

Objective

The novel engineered bioprocess, which was designed and modeled to provide the clinically relevant cell numbers for different therapies in our previous work (Kaleybar et al. Food Bioprod Process 122:254–268, https://doi.org/10.1016/j.fbp.2020.04.012, 2020), was evaluated by using U937 as hematopoietic model cells.

Results

The culture system showed a 30-fold expansion of U937 cells in one-step during a 10-day culture period. The cell growth profile, the substrate and oxygen consumptions, and byproduct formations were all in agreement with the model predications during 7 days. The cell proliferation decrease after 7 days was attributed to optional oxygen limiting condition in the last days of culture. The bioreactor culture system revealed also a slight enhancement of lactate dehydrogenase (LDH) production as compared to the 2D conventional culture system, indicating the low impact of shear stress on cellular damage in the dynamic system.

Conclusions

The results demonstrated that the conceptual bioprocess for suspended stem cell production has a great potential in practice although additional experiments are required to improve the system.

     

Investigation of intermolecular hydrogen bond interactions in crystalline l-Cysteine by DFT calculations of the oxygen-17, nitrogen-14, and hydrogen-2 EFG tensors and AIM analysis

A systematic computational study is carried out to investigate hydrogen bond (HB) interactions in the real crystalline structures of l-Cysteine at 30 and 298 K by density functional theory (DFT) calculations of electric field gradient (EFG) tensors at the sites of O-17, N-14, and H-2 nuclei. One-molecule (monomer) and nine-molecule (cluster) models of l-Cysteine are created by available crystal coordinates at both temperatures and the EFG tensors are calculated for both models to indicate the effect of HB interactions on the tensors. The calculated EFG tensors at the level of B3LYP and B3PW91 DFT methods and 6-311++G?? and cc-pVTZ basis sets are converted to those experimentally measurable nuclear quadrupole resonance (NQR) parameters i.e. quadrupole coupling constants (qcc) and asymmetry parameters (η_Q). The evaluated NQR parameters reveal that the EFG tensors of ¹⁷O, ¹⁴N, and ²H are influenced and show particular trends from monomer to the target molecule in the cluster due to the contribution of target molecule to classic N–H…O, and non-classic S–H…O and S–H…S types of HB interactions. On the other hand, atoms in molecules (AIM) analyses confirm the presence of HB interactions and rationalize the observed EFG trends. The results indicate different contribution of various nuclei to HB interactions in the cluster where O2 and N1 have major contributions. The EFG tensors as well as AIM analysis at the H6 site show that the N1-H6…O2 HB undergoes a significant change from 30 to 298 K where changes in other N–H…O interactions are almost negligible. There is a good agreement between the calculated ¹⁴N NQR parameters and reported experimental data.