Activation of NLRP3 Inflammasome Complexes by Beta-Tricalcium Phosphate Particles and Stimulation of Immune Cell Migration in vivo.

Beta-tricalcium phosphate (ß-TCP) serves as a bone substitute in clinical practice because it is resorbable, biocompatible, osteointegrative, and osteoconductive. Particles of ß-TCP are also inflammatory mediators although the mechanism of this function has not been fully elucidated. Regardless, the ability of ß-TCP to stimulate the immune system might be useful for immunomodulation. The present study aimed to determine the effects of ß-TCP particles on NLR family pyrin domain containing 3 (NLRP3) inflammasome complexes. We found that ß-TCP activates NLRP3 inflammasomes, and increases interleukin (IL)-1ß production in primary cultured mouse dendritic cells (DCs) and macrophages, and human THP-1 cells in caspase-1 dependent manner. In THP-1 cells, ß-TCP increased also IL-18 production, and NLRP3 inflammasome activation by ß-TCP depended on phagocytosis, potassium efflux, and reactive oxygen species (ROS) generation. We also investigated the effects of ß-TCP in wild-type and NLRP3-deficient mice in vivo. Immune cell migration around subcutaneously injected ß-TCP particles was reduced in NLRP3-deficient mice. These findings suggest that the effects of ß-TCP particles in vivo are at least partly mediated by NLRP3 inflammasome complexes.

Development of an optimized closed and semi-automatic protocol for Good Manufacturing Practice manufacturing of tumor-infiltrating lymphocytes in a hospital environment.

BACKGROUND AIMS: Several studies report on Good Manufacturing Process (GMP)-compliant manufacturing protocols for the ex vivo expansion of tumor-infiltrating lymphocytes (TILs) for the treatment of patients with refractory melanoma and other solid malignancies. Further opportunities for improvements in terms of ergonomy and operating time have been identified. METHODS: To enable GMP-compliant TILs production for adoptive cell therapy needs, a simple automated and reproducible protocol for TILs manufacturing with the use of a closed system was developed and implemented at the authors' institution. RESULTS: This protocol enabled significant operating time reduction during TILs expansion while allowing the generation of high-quality TILs products. CONCLUSIONS: A simplified and efficient method of TILs expansion will enable the broadening of individualized tumor therapy and will increase patients' access to state-of-the-art TILs adoptive cell therapy treatment.

A new anti-mesothelin antibody targets selectively the membrane-associated form.

Mesothelin is a glycosylphosphatidylinositol (GPI)-anchored membrane protein that shows promise as a target for antibody-directed cancer therapy. High levels of soluble forms of the antigen represent a barrier to directing therapy to cellular targets. The ability to develop antibodies that can selectively discriminate between membrane-bound and soluble conformations of a specific protein, and thus target only the membrane-associated antigen, is a substantive issue. We show that use of a tolerance protocol provides a route to such discrimination. Mice were tolerized with soluble mesothelin and a second round of immunizations was performed using mesothelin transfected P815 cells. RNA extracted from splenocytes was used in phage display to obtain mesothelin-specific antigen-binding fragments (Fabs) that were subsequently screened by flow cytometry and ELISA. This approach generated 147 different Fabs in 34 VH-CDR3 families. Utilizing competition assays with soluble protein and mesothelin-containing serum obtained from metastatic cancer patients, 10 of these 34 VH-CDR3 families were found to bind exclusively to the membrane-associated form of mesothelin. Epitope mapping performed for the 1H7 clone showed that it does not recognize GPI anchor. VH-CDR3 sequence analysis of all Fabs showed significant differences between Fabs selective for the membrane-associated form of the antigen and those that recognize both membrane bound and soluble forms. This work demonstrates the potential to generate an antibody specific to the membrane-bound form of mesothelin. 1H7 offers potential for therapeutic application against mesothelin-bearing tumors, which would be largely unaffected by the presence of the soluble antigen.

Effects of beta-tricalcium phosphate particles on primary cultured murine dendritic cells and macrophages.

Beta-tricalcium phosphate (ß-TCP) is widely used for bone substitution in clinical practice. Particles of calcium phosphate ceramics including ß-TCP act as an inflammation mediators, which is an unfavorable characteristic for a bone substituent or a prosthetic coating material. It is thought that the stimulatory effect of ß-TCP on the immune system could be utilized as an immunomodulator. Here, in vitro effects of ß-TCP on primary cultured murine dendritic cells (DCs) and macrophages were investigated. ß-TCP particles enhanced expression of costimulatory surface molecules, including CD86, CD80, and CD40 in DCs, CD86 in macrophages, and MHC class II and class I molecules in DCs. DEC205 and CCR7 were up-regulated in ß-TCP-treated DCs. Production of cytokines and chemokines, including CCL2, CCL3, CXCL2, and M-CSF, significantly increased in DCs; CCL2, CCL3, CCL4, CCL5, CXCL2, and IL-11ra were up-regulated in macrophages. The results of the functional assays revealed that ß-TCP caused a prominent reduction in antigen uptake by DCs, and that conditioned medium from DCs treated with ß-TCP facilitated the migration of splenocytes in the transwell migration assay. Thus, ß-TCP induced phenotypical and functional maturation/activation of DCs and macrophages; these stimulating effects may contribute to the observed in vivo effect where ß-TCP induced extensive migration of immune cells. When compared to lipopolysaccharide (LPS), an authentic TLR ligand, the stimulatory effect of ß-TCP on the immune systems is mild to moderate; however, it may have some advantages as a novel immunomodulator. This is the first report on the direct in vitro effects of ß-TCP against bone marrow-derived DCs and macrophages.

Identification of metabolic signatures associated with erlotinib resistance of non-small cell lung cancer cells.

BACKGROUND/AIM: The acquisition of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) remains a major challenge in lung cancer medicine. We sought to identify biomarkers for the early detection of resistance to TKIs. MATERIALS AND METHODS: Capillary electrophoresis time-of-flight mass spectrometry analysis was performed to identify the metabolic signatures associated with erlotinib resistance in erlotinib-resistant PC-9ER NSCLC cells established from the EGFR-mutant NSCLC cell line PC-9. RESULTS: PC-9ER cells showed metabolic signatures indicative of enhanced glutamine metabolism. Copy number gains in v-myc avian myelocytomatosis viral oncogene homolog (MYC), glutathione-S-transferase theta 2 (GSTT2), gamma-glutamyltransferase 1 (GGT1), and GGT5 were also detected, suggesting that amplification of these genes confers glutamine addiction in PC-9ER cells. CONCLUSION: Enhanced glutamine metabolism may be a surrogate marker that can be used to predict the likelihood of patients to respond to EGFR-TKIs.

Impact of 2-deoxy-D-glucose on the target metabolome profile of a human endometrial cancer cell line.

2-deoxy-D-glucose (2DG) has been clinically evaluated for its potential use as an anticancer drug. Although 2DG is generally thought to inhibit the glycolytic pathway through accumulation of 2-deoxy-D-glucose-6-phosphate (2DG6P), it may also interfere with various other biological processes. Here, to further understand the role of 2DG as an inhibitor of tumor progression, we assessed the metabolism of 2DG in a human endometrial cancer cell line using capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS). A total of 113 target metabolite peaks were identified and 90 metabolites of them were quantified. Furthermore, we present a new methodology which uses CE-TOFMS metabolome profiling following introduction of an artificial metabolite to evaluate tumor-specific metabolite traces. Aside from 2DG6P, we detected the presence of unique 2DG-derived deoxy metabolites in 2DG-treated cells. These metabolites may be responsible for the alteration of global metabolism in cells and act as various biological effectors.

Fragrant environment with α-pinene decreases tumor growth in mice.

Stress is believed to be harmful to not only mental but also physical health. However, proving a link between stress and disease is difficult. A recent study reported that an environmental enrichment reduced cancer growth via the hypothalamic-pituitary-adrenal axis and leptin. Here, we report that mice kept in a fragrant environment enriched with α-pinene show reduced melanoma growth. Tumor volume of mice under the α-pinene environment was about 40% smaller than that in the control mice. α-Pinene had no inhibitory effect on melanoma cell proliferation in vitro, suggesting that this effect was not a direct effect of α-pinene. These results suggest that the provision of a fragrant environment may be an important factor in the therapeutic approach to cancer.

Quantitative metabolome profiling of Illicium anisatum by capillary electrophoresis time-of-flight mass spectrometry.

We used capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) to characterize the metabolic profiles of the seed, pulp, stem and leaf of Illicium anisatum. CE-TOFMS detected more than 1000 polar metabolites within 40 min, of which 58 were annotated and quantified. Seed had higher levels of glycolytic metabolites than pulp, stem and leaf, while leaf had higher levels of TCA cycle and nucleoside metabolites. Among amino acid metabolites, levels of Gln, Glu, and Asp were higher in almost every organ. Levels of shikimic acid, the source compound for Tamiflu, were high in all organs, ranging from 6.84% to 28.82%. These results indicate that CETOFMS-based metabolomics offers an efficient, convenient method for comprehensive metabolite profiling, and may be a powerful tool for the screening of drug discovery.

Human cord blood-derived hematopoietic and neural-like stem/progenitor cells are attracted by the neurotransmitter GABA.

Migration of stem/progenitor cells is a crucial event for homing toward tissue where cells need to be renewed. The neurotransmitter gamma-aminobutyric acid (GABA) has been shown to have a crucial role in migration of neuronal stem/progenitor cells. Since human umbilical cord blood (HUCB) contains stem/progenitor cells able to generate either neuronal or hematopoietic cells, we evaluated the effect of GABA on this type of cells. While whole fraction of mononuclear cells expressed GABA(A) and GABA(B) receptor subunits (GABA-R), only GABA(B)R subunits were found to be expressed on immature CD133+ cells. Functional experiments revealed that both cell fractions of HUCB were attracted by a gradient of GABA concentration and furthermore were blocked by specific antagonists of GABA(A)R and GABA(B)R bicuculline and saclofen, respectively. Moreover, through GABA(B)R activation the migrating fraction was highly enriched by both hematopoietic progenitors and cells able to generate neuron- like cells in culture. Therefore, GABA is a potent chemoattractant of HUCB stem/progenitor cells specifically through GABA(B)R activation.

Cord blood-derived neurons are originated from CD133+/CD34 stem/progenitor cells in a cell-to-cell contact dependent manner.

Previous studies described that neurons could be generated in vitro from human umbilical cord blood cells. However, there are few data concerning their origin. Notably, cells generating neurons are not well characterized. The present study deals with the origin of cord blood cells generating neurons and mechanisms allowing the neuronal differentiation. We studied neuronal markers of both total fractions of cord blood and stem/progenitor cord blood cells before and after selections and cultures. We also compared neuronal commitment of cord blood cells to that observed for the neuronal cell line SK-N-BE(2). Before cultures, neuronal markers are found within the total fraction of cord blood cells. In CD133+ stem/progenitor cell fraction only immature neuronal markers are detected. However, CD133+ cells are unable to give rise to neurons in cultures, whereas this is achieved when total fraction of cord blood cells is used. In fact, mature functional neurons can be generated from CD133+ cells only in cell-to-cell close contact with either CD133- fraction or a neurogenic epithelium. Furthermore, since CD133+ fraction is heterogenous, we used several selections to precisely identify the phenotype of cord blood-derived neuronal stem/progenitor cells. Results reveal that only CD34- cells from CD133+ fraction possess neuronal potential. These data show the phenotype of cord blood neuronal stem/progenitor cells and the crucial role of direct cell-to-cell contact to achieve their commitment. Identifying the neuron supporting factors may be beneficial to the use of cord blood neuronal stem/progenitor cells for regenerative medicine.