Targeting osteosarcoma with canine B7-H3 CAR T cells and impact of CXCR2 Co-expression on functional activity

The use of large animal spontaneous models of solid cancers, such as dogs with osteosarcoma (OS), can help develop new cancer immunotherapy approaches, including chimeric antigen receptor (CAR) T cells. The goal of the present study was to generate canine CAR T cells targeting the B7-H3 (CD276) co-stimulatory molecule overexpressed by several solid cancers, including OS in both humans and dogs, and to assess their ability to recognize B7-H3 expressed by canine OS cell lines or by canine tumors in xenograft models. A second objective was to determine whether a novel dual CAR that expressed a chemokine receptor together with the B7-H3 CAR improved the activity of the canine CAR T cells. Therefore, in the studies reported here we examined B7-H3 expression by canine OS tumors, evaluated target engagement by canine B7-H3 CAR T cells in vitro, and compared the relative effectiveness of B7-H3 CAR T cells versus B7-H3-CXCR2 dual CAR T cells in canine xenograft models. We found that most canine OS tumors expressed B7-H3; whereas, levels were undetectable on normal dog tissues. Both B7-H3 CAR T cells demonstrated activation and OS-specific target killing in vitro, but there was significantly greater cytokine production by B7-H3-CXCR2 CAR T cells. In canine OS xenograft models, little anti-tumor activity was generated by B7-H3 CAR T cells; whereas, B7-H3-CXCR2 CAR T cells significantly inhibited tumor growth, inducing complete tumor elimination in most treated mice. These findings indicated therefore that addition of a chemokine receptor could significantly improve the anti-tumor activity of canine B7-H3 CAR T cells, and that evaluation of this new dual CAR construct in dogs with primary or metastatic OS is warranted since such studies could provide a critical and realistic validation of the chemokine receptor concept.

Expanding the scope of WT1- and cyclin A1-specific TCR gene therapy for AML and other cancers

TCR gene therapy hastens the reproducible generation of tumor-specific T cells from patients, creating a promising avenue for treating hematological and solid tumors. Several hurdles remain to making this a broadly effective modality, including variable target antigen expression, risk of tumor antigenic escape, and current therapies limited almost exclusively to HLA-A0201+ patients. We previously characterized WT1 and cyclin A1 as favorable T cell immunotherapy targets, based on high expression in malignant versus normal cells and roles in oncogenesis, reducing likelihood of loss variants. We currently have a high-affinity HLA-A0201/WT1-specific TCR in Phase I trials for the treatment of AML and NSCLC, and are now focused on developing WT1- and cyclin A1-specific TCRs for ~7 common HLA types, aiming to cover >90% of patients. T cell lines were generated by stimulating donor PBMC with overlapping peptide libraries to identify new reactive epitopes, and the highest affinity T cell clones for each HLA/antigen combination identified by tetramer binding strength. TCRs were then cloned into lentiviral vectors for expression in CD8 T cells. We are currently in the process of selecting the best HLA-A0201/cyclin A1-specific TCR with which to proceed to clinical development. We are also continuing to optimize our epitope discovery protocol for the improved selection of TCRs for other HLA alleles. Safety and efficacy of selected TCRs are rigorously tested using bioinformatic screens, in vitro assays, and humanized MHC-I mouse models. Our goal is to create a molecular toolbox of off-the-shelf TCR reagents to facilitate rapid treatment of patients, using T cell immunotherapies targeted to their particular tumor antigenic profile and HLA type.

Seebeck rectification enabled by intrinsic thermoelectrical coupling in magnetic tunneling junctions

An intrinsic thermoelectric coupling effect in the linear response regime of magnetic tunneling junctions (MTJ) is reported. In the dc response, it leads to a nonlinear correction to Ohm's law. Dynamically, it enables a novel Seebeck rectification and second harmonic generation, which apply for a broad frequency range and can be magnetically controlled. A phenomenological model on the footing of the Onsager reciprocal relation and the principle of energy conservation explains very well the experimental results obtained from both dc and frequency-dependent transport measurements performed up to GHz frequencies. Our work refines previous understanding of magnetotransport and microwave rectification in MTJs. It forms a new foundation for utilizing spin caloritronics in high-frequency applications.

Effects of berberine on intracellular free calcium in smooth muscle cells of Guinea pig colon

AIM

To investigate the effects and mechanism of berberine (Ber) on the intracellular free calcium concentration ([Ca(2+)](i)) in the smooth muscle cells of guinea pig colon.

METHODS

The changes of [Ca(2+)](i) were assayed by the biwavelength spectrophotometry with Fura 2-AM in the cell suspension of the smooth muscle cells, which were freshly isolated from guinea pig colon.

RESULTS

In the resting state, [Ca(2+)](i) in the HEPES-Ringer solution (CaCl(2) 1.5 mmol.l(-1)) was (108 +/- 9.4) nmol.l(-1) (n = 7). Ber had no significant effects on the resting [Ca(2+)](i), but markedly inhibited the increase in [Ca(2+)](i )induced by 60 mmol.l(-1) KCl in a concentration-dependent manner. The value of IC(50 )was 34.09 micromol.l(-1). 30 and 100 micromol.l(-1) Ber also inhibited the elevation of [Ca(2+)](i) evoked by 10 micromol.l(-1) Ach in a dose-dependent fashion in the presence or absence of extracellular Ca(2+). In addition, Ber inhibited the elevation of [Ca(2+)](i) stimulated by cyclopiazonic acid (CPA) in a dose-dependent manner. This effect was more potent in the HEPES-Ringer solution (IC(50) = 37.79 micromol.l(-1)) than Ca(2+)-free medium (IC(50) = 49.70 micromol.l(-1)).

CONCLUSIONS

Ber possessed an inhibitory effect on the influx of extracellular Ca(2+) and Ca(2+)-release from intracellular stores in the smooth muscle cells of colon. That is to say Ber may be a blocker of Ca(2+) channels.

[Effects of berberine on intracellular calcium concentration in smooth muscle cells of guinea pig colon]

The purpose of the present investigation is to study how berberine (Ber) affect the intracellular free calcium concentration ( Ca(2+) (i)) of the smooth muscle cells of guinea pig colon by means of biwavelength spectrophotometry with Fura 2 AM in a cell suspension specimen. In the resting state, Ca(2+) (i) in HEPES Ringer solution (CaCl2 1.5 mmol/L) was 108 9.4 nmol/L (n=7), which was not significantly affected by Ber. On the other hand, Ber inhibited the increased Ca(2+) (i) induced by 60 mmol/L KCl in a dose dependent manner, with a value of IC(50) being 34.09 micromol/L. 30, 100 micromol/L Ber also inhibited 10 micromol/L ACh evoked Ca(2+) (i) elevation in a dose dependent manner either in the presence or absence of extracellular Ca(2+). In addition, Ber inhibited cyclopiazonic acid (CPA) stimulated Ca(2+) (i) elevation dose dependently. This effect was more potent in HEPES Ringer solution (IC(50)=37.79 micromol/L) than in Ca(2+) free medium (IC(50)=49.70 micromol/L). The above results suggest that Ber exerts an inhibitory effect on the extracellular Ca(2+) influx and the Ca(2+) release from intracellular stores.

Evaluation of medical cost lost due to smoking in Chinese cities

Smoking induces substantial diseases on both individual and the whole society. To identify the true smoking-attributable economic loss, we introduce medical cost accounting as a means to calculate disease-specific medical cost, including inpatient and outpatient cost of those diseases caused by smoking. Medical cost is defined as health resource consumption in terms of money. Cost is allocated to department and services according to coefficient of benefit and operation time. The study in 1988 indicates that total smoking-attributable medical cost is 2.32 billion RMB Yuan in China, 1.70 billion RMB Yuan for outpatient, 0.62 billion RMB Yuan for inpatient. If indirect cost is included, the cost will be greater. Chronic obstructive emphysema has the highest proportion (55.41%) in smoking attributable medical cost.

[Isolation and fermentation conditions of polyvinyl alcohol-degrading enzyme producing strain]

A bacterium D8 strain which high efficiently degrading PVA was isolated from waste water of factory. The strain possesses the abilities of completely degrading 0.5 per cent of PVA (500, 1700) included in the culture medium for four days. It was identified Pseudomonas pseudoalcaligenes. Fermentation conditions of the strain have been investigated. The suitable medium consisted of PVA 1.5% (NH4)2SO40.1%, K2HPO4 0.24%, KH2PO4 0.04%, MgSO4.7H2O 0.035%, NaCl 0.01%, FeSO4 0.001%, yeast extract 0.15%, pH 7.5. The optimal condition for enzyme production are as follows: 250 ml shake filled with 30 ml medium, 30 degrees C, 160n/min incubation period 72 h. Under such conditions enzyme activity is highest.