TCF-1 is a key transcription factor in progenitor exhausted CD8 T cells (Tex). Moreover, this Tex cell subset mediates responses to PD-1 checkpoint pathway blockade. However, the role of the transcription factor TCF-1 in early fate decisions and initial generation of Tex cells is unclear. Single-cell RNA sequencing (scRNA-seq) and lineage tracing identified a TCF-1 + Ly108 + PD-1 + CD8 T cell population that seeds development of mature Tex cells early during chronic infection. TCF-1 mediated the bifurcation between divergent fates, repressing development of terminal KLRG1 Hi effectors while fostering KLRG1 Lo Tex precursor cells, and PD-1 stabilized this TCF-1 + Tex precursor cell pool. TCF-1 mediated a T-bet-to-Eomes transcription factor transition in Tex precursors by promoting Eomes expression and drove c-Myb expression that controlled Bcl-2 and survival. These data define a role for TCF-1 in early-fate-bifurcationdriving Tex precursor cells and also identify PD-1 as a protector of this early TCF-1 subset.

Collisions of 0-4 eV electrons with thin DNA films are shown to produce single strand breaks. The yield is sharply structured as a function of electron energy and indicates the involvement of pi* shape resonances in the bond breaking process. The cross sections are comparable in magnitude to those observed in other compounds in the gas phase in which pi* electrons are transferred through the molecule to break a remote bond. The results therefore support aspects of a theoretical study by Barrios et al. [J. Phys. B 106, 7991 (2002)]] indicating that such a mechanism could produce strand breaks in DNA.

To better understand the cause of the diversity in reported values of the electron affinities (EAs) for DNA bases, we performed a series of DFT (B3LYP functional) calculations at different basis set sizes. Through investigation of (1) trends in the values of EAs, (2) the excess electron spin distribution of the anion radical dependence on basis set size, (3) effect of the excess electron on ZPEs, we are able to identify the features of a basis set that allows for dipole-bound and continuum states to compete with molecular states for the electron. Smaller basis sets that confine the excess electron to the molecule allow for reasonable estimates of relative valence electron affinities excluding dipole-bound states and suggest the order of adiabatic valence electron affinities to be U ≈ T > C ≈ I (hypoxanthine) > A > G with G nearly 1 eV less electron affinic than U. Combining the best estimates from theory and experiment we place the adiabatic valence electron affinities of the pyrimidines as zero to +0.2 eV, whereas the purines A and G are predicted to be clearly negative with electron affinities of ca. -0.35 and -0.75 eV, respectively. The virtual states (i.e., negative electron affinities) for A and G in the gas-phase become relevant to biology when their energies are lowered to bound states in solvated systems. Indeed, our calculations performed including the effect of solvation (PCM model) show that all EAs for the DNA bases are positive and have the same relative order as found with the compact basis sets in the gas-phase calculations.

Proton-transfer reactions in two DNA base pair anion and cation radicals are treated by density functional theory to aid our understanding of the possible contributions of these reactions to electron and hole transfer in DNA. The proton-transfer transition structures for both the GC and IC anion and cation radicals are found. For both anion and cation radicals, it is the proton at the N1 guanine (G) site, or hypoxanthine (I) site, that transfers to cytosine. The forward and reverse activation energies as well as reaction enthalpies and free energy changes are calculated. These calculations show that small activation energies of 1 and 3 kcal/mol are present for the GC anion and cation, respectively. The predicted free energy change for the proton transfer is favorable for GC anion radical (-3 kcal/mol) but is slightly unfavorable for the GC cation radical (1.4 kcal/mol). Both of these values compare well with experimental estimates. Remarkably, the IC anion radical system shows no activation energy toward proton transfer and a large free energy change favoring the proton transferred state (-7 kcal). Electron affinities (EA) and ionization potentials (IP) of the two base pairs are also calculated and reported.

Gold nanoparticle (AuNP) radiosensitization represents a novel approach to enhance the effectiveness of ionizing radiation. Its efficiency varies widely with photon source energy and AuNP size, concentration, and intracellular localization. In this Monte Carlo study we explored the effects of those parameters to define the optimal clinical use of AuNPs. Photon sources included (103)Pd and (125)I brachytherapy seeds; (169)Yb, (192)Ir high dose rate sources, and external beam sources 300 kVp and 6 MV. AuNP sizes were 1.9, 5, 30, and 100 nm. We observed a 10(3) increase in the rate of photoelectric absorption using (125)I compared to 6 MV. For a (125)I source, to double the dose requires concentrations of 5.33-6.26 mg g(-1) of Au or 7.10 × 10(4) 30 nm AuNPs per tumor cell. For 6 MV, concentrations of 1560-1760 mg g(-1) or 2.17 × 10(7) 30 nm AuNPs per cell are needed, which is not clinically achievable. Examining the proportion of energy transferred to escaping particles or internally absorbed in the nanoparticle suggests two clinical strategies: the first uses photon energies below the k-edge and takes advantage of the extremely localized Auger cascade. It requires small AuNPs conjugated to tumor targeted moieties and nuclear localizing sequences. The second, using photon sources above the k-edge, requires a higher gold concentration in the tumor region. In this approach, energy deposited by photoelectrons is the main contribution to radiosensitization; AuNP size and cellular localization are less relevant.

Graphene-based mixed-dimensional materials hybridization is important for a myriad of applications. However, conventional manufacturing techniques face critical challenges in producing arbitrary geometries with programmable features, continuous interior networks, and multimaterials homogeneity. Here we propose a generalized three-dimensional (3D) printing methodology for graphene aerogels and graphene-based mixed-dimensional (2D + nD, where n is 0, 1, or 2) hybrid aerogels with complex architectures, by the development of hybrid inks and printing schemes to enable mix-dimensional hybrids printability, overcoming the limitations of multicomponents inhomogeneity and harsh post-treatments for additives removal. Importantly, nonplanar designed geometries are also demonstrated by shape-conformable printing on curved surfaces. We further demonstrate the 3D-printed hybrid aerogels as ultrathick electrodes in a symmetric compression tolerant microsupercapacitor, exhibiting quasi-proportionally enhanced areal capacitances at high levels of mass loading. The excellent performance is attributed to the sufficient ion- and electron-transport paths provided by the 3D-printed highly interconnected networks. The encouraging finding indicates tremendous potentials for practical energy storage applications. As a proof of concept, this general strategy provides avenues for various next-generation complex-shaped hybrid architectures from microscale to macroscale, for example, seawater desalination devices, electromagnetic shielding systems, and so forth.

The cytotoxicity and tumor-targeting properties of the anti-HER2/neu monoclonal antibody trastuzumab modified with peptides (CGYGPKKKRKVGG) harboring the nuclear localization sequence ([NLS] italicized) of simian virus 40 large T-antigen and radiolabeled with 111 In were evaluated. Methods: Trastuzumab was derivatized with sulfosuccinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (sulfo-SMCC) for reaction with NLSpeptides and labeled with 111 In using diethylenetriaminepentaacetic acid (DTPA). The immunoreactivity of 111 In-NLS-trastuzumab was determined by its ability to displace the binding of trastuzumab to SK-BR-3 human breast cancer (BC) cells. Cellular uptake and nuclear localization were evaluated in SK-BR-3, MDA-MB-361, and MDA-MB-231 BC cells, expressing high, intermediate, or very low levels of HER2/neu, respectively, by cell fractionation and confocal microscopy. Biodistribution and nuclear uptake were compared in athymic mice bearing MDA-MB-361 xenografts. The cytotoxicity of 111 In-trastuzumab and 111 In-NLS-trastuzumab was studied by clonogenic assays, and DNA damage was assessed by probing for phosphorylated histone H2AX (gH2AX) foci. Results: The dissociation constant for binding of 111 In-NLS-trastuzumab to SK-BR-3 cells was reduced ,3-fold compared with that of 111 In-trastuzumab, demonstrating relatively preserved receptorbinding affinity. The receptor-mediated internalization of 111 Intrastuzumab in SK-BR-3, MDA-MB-361, and MDA-MB-231 cells increased significantly from 7.2% 6 0.9%, 1.3% 6 0.1%, and 0.2% 6 0.05% to 14.4% 6 1.8%, 6.3% 6 0.2%, and 0.9% 6 0.2% for 111 In-NLS-trastuzumab harboring 6 NLS-peptides, respectively. NLS-trastuzumab localized in the nuclei of BC cells, whereas unmodified trastuzumab remained surface-bound. Conjugation of 111 In-trastuzumab to NLS-peptides did not affect its tissue biodistribution but promoted specific nuclear uptake in MDA-MB-361 xenografts (2.4-2.9 %ID/g [percentage injected dose per gram] for 111 In-NLS-trastuzumab and 1.1 %ID/g for 111 In-trastuzumab). 111 In-NLS-trastuzumab was 5-and 2-fold more potent at killing SK-BR-3 and MDA-MB-361 cells than 111 In-trastuzumab, respectively, whereas toxicity toward MDA-MB-231 cells was minimal. 111 In-NLS-trastuzumab was 6-fold more effective at killing SK-BR-3 cells than unlabeled trastuzumab. The development of recombinant antibodies for cancer therapy has emerged as one of the most promising areas in oncology (1). Trastuzumab (Herceptin; Hoffmann-La Roche), in particular, is a humanized monoclonal antibody (mAb) directed against the human epidermal growth factor receptor-2 (HER2/neu), a transmembrane receptor tyrosine kinase that is overexpressed in 25%-30% of breast cancers (BCs) and distant metastases (2). Trastuzumab shows clinical activity in women with HER2/neu-overexpressing metastatic BC and exhibits synergistic antitumor effects when combined with paclitaxel or anthracyclines, achieving overall response rates of 40%-60% (2). Despite its effectiveness in combination regimens, the response rate...

An investigation of electron transfer in DNA at low temperatures in an aqueous glassy medium is reported for a system in which electrons are generated by radiation and trapped on DNA. The transfer of the electron from the DNA anion radical to randomly interspaced intercalators is followed by electron spin resonance spectroscopic observation of the buildup in the intercalator electron adduct electron spin resonance (ESR) signal and the loss of the DNA anion signal with time at 77 K. The intercalators investigated, mitoxantrone, ethidium bromide, 1,10-phenanthroline, and 5-nitro-1,10-phenanthroline, test the effect of charge and electron affinity. The time frame of the experiment, minutes to weeks, allowed the use of large intercalator spacings (low loadings) at which random intercalation is most likely. The fraction of the electron captured by the intercalator was found to increase with ln(t) as expected for a single-step tunneling process. Fits of results to expressions for electron capture by intercalators based on a random distribution suggest that the random model is appropriate up to loadings of about 1 per 10−20 DNA base pairs depending on the intercalator. The distances of electron-transfer range from 4 base pairs (ethidium) to 10 base pairs (mitoxantrone) after 1 min at 77 K. The low temperatures employed allow for the observation of single-step tunneling free from competing mechanisms such as hopping. The values of the tunneling constant β found, 0.8−1.2 Å-1, do not suggest that tunneling through the DNA base stack provides a particularly facile route for transfer of excess electrons through DNA. We find that the transfer distances and rates correlate with intercalator electron affinities calculated by density functional theory.