Characterization of brain tumor initiating cells isolated from an animal model of CNS primitive neuroectodermal tumors.

CNS Primitive Neuroectodermal tumors (CNS-PNETs) are members of the embryonal family of malignant childhood brain tumors, which remain refractory to current therapeutic treatments. Current paradigm of brain tumorigenesis implicates brain tumor-initiating cells (BTIC) in the onset of tumorigenesis and tumor maintenance. However, despite their significance, there is currently no comprehensive characterization of CNS-PNETs BTICs. Recently, we described an animal model of CNS-PNET generated by orthotopic transplantation of human Radial Glial (RG) cells - the progenitor cells for adult neural stem cells (NSC) - into NOD-SCID mice brain and proposed that BTICs may play a role in the maintenance of these tumors. Here we report the characterization of BTIC lines derived from this CNS-PNET animal model. BTIC's orthotopic transplantation generated highly aggressive tumors also characterized as CNS-PNETs. The BTICs have the hallmarks of NSCs as they demonstrate self-renewing capacity and have the ability to differentiate into astrocytes and early migrating neurons. Moreover, the cells demonstrate aberrant accumulation of wild type tumor-suppressor protein p53, indicating its functional inactivation, highly up-regulated levels of onco-protein cMYC and the BTIC marker OCT3/4, along with metabolic switch to glycolysis - suggesting that these changes occurred in the early stages of tumorigenesis. Furthermore, based on RNA- and DNA-seq data, the BTICs did not acquire any transcriptome-changing genomic alterations indicating that the onset of tumorigenesis may be epigenetically driven. The study of these BTIC self-renewing cells in our model may enable uncovering the molecular alterations that are responsible for the onset and maintenance of the malignant PNET phenotype.

Peptide amphiphile micelles self-adjuvant group A streptococcal vaccination.

Delivery system design and adjuvant development are crucially important areas of research for improving vaccines. Peptide amphiphile micelles are a class of biomaterials that have the unique potential to function as both vaccine delivery vehicles and self-adjuvants. In this study, peptide amphiphiles comprised of a group A streptococcus B cell antigen (J8) and a dialkyl hydrophobic moiety (diC16) were synthesized and organized into self-assembled micelles, driven by hydrophobic interactions among the alkyl tails. J8-diC16 formed cylindrical micelles with highly α-helical peptide presented on their surfaces. Both the micelle length and secondary structure were shown to be enhanced by annealing. When injected into mice, J8-diC16 micelles induced a strong IgG1 antibody response that was comparable to soluble J8 peptide supplemented with two classical adjuvants. It was discovered that micelle adjuvanticity requires the antigen be a part of the micelle since separation of J8 and the micelle was insufficient to induce an immune response. Additionally, the diC16 tail appears to be non-immunogenic since it does not stimulate a pathogen recognition receptor whose agonist (Pam3Cys) possesses a very similar chemical structure. The research presented in this paper demonstrates the promise peptide amphiphile micelles have in improving the field of vaccine engineering.

Development of an ELISA microarray assay for the sensitive and simultaneous detection of ten biodefense toxins.

Plant and microbial toxins are considered bioterrorism threat agents because of their extreme toxicity and/or ease of availability. Additionally, some of these toxins are increasingly responsible for accidental food poisonings. The current study utilized an ELISA-based protein antibody microarray for the multiplexed detection of ten biothreat toxins, botulinum neurotoxins (BoNT) A, B, C, D, E, F, ricin, shiga toxins 1 and 2 (Stx), and staphylococcus enterotoxin B (SEB), in buffer and complex biological matrices. The multiplexed assay displayed a sensitivity of 1.3 pg mL(-1) (BoNT/A, BoNT/B, SEB, Stx-1 and Stx-2), 3.3 pg mL(-1) (BoNT/C, BoNT/E, BoNT/F) and 8.2 pg mL(-1) (BoNT/D, ricin). All assays demonstrated high accuracy (75-120 percent recovery) and reproducibility (most coefficients of variation <20%). Quantification curves for the ten toxins were also evaluated in clinical samples (serum, plasma, nasal fluid, saliva, stool, and urine) and environmental samples (apple juice, milk and baby food) with overall minimal matrix effects. The multiplex assays were highly specific, with little cross-reactivity observed between the selected toxin antibodies. The results demonstrate a multiplex microarray that improves current immunoassay sensitivity for biological warfare agents in buffer, clinical, and environmental samples.

Synthesis of substituted 2-arylindanes from E-(2-stilbenyl)methanols via Lewis acid-mediated cyclization and nucleophililc transfer from trialkylsilyl reagents.

A preparative method for the synthesis of functionalized 2-arylindanes has been developed via the Lewis acid-mediated ring closure of stilbenyl methanols followed by nucleophilic transfer from trialkylsilyl reagents. The reactions gave the corresponding products in moderate to high yields and diastereoselectivity. The solvent as well as the nucleophile played an important role in determining the type(s) of product arising either from nucleophilic addition (indanes) or loss of a proton ß to the indanyl-type carbocations (indenes). Electron-donating groups on the fused aromatic ring (Y and Z = OMe) or the presence of electron-withdrawing groups (NO2) on the nonfused Ar ring facilitate the cyclization. In contrast, the presence of electron-donating groups (OMe) on the nonfused Ar ring impedes the process. In the case of Cl on the nonfused Ar ring, temperature modulates the resonance versus inductive field effects on the overall reaction pathways involving cyclization to form the indanyl-type cation. Quantum chemical calculations supported the intermediacy of the carbocation species and the transfer of hydride from triethylsilane (Nu = H) to the indanyl-type cations to form the trans-1,2-disubstituted indane as the single diastereomer product.