BackgroundClinical success with chimeric antigen receptor (CAR)- based immunotherapy for leukemia has been accompanied by the associated finding that antigen-escape variants of the disease are responsible for relapse. To target hematologic malignancies with a chimeric antigen receptor (CAR) that targets two antigens with a single vector, and thus potentially lessen the chance of leukemic escape mutations, a tandem-CAR approach was investigated.MethodsAntigen binding domains from the FMC63 (anti-CD19) and Leu16 (anti-CD20) antibodies were linked in differing configurations to transmembrane and T cell signaling domains to create tandem-CARs. Expression on the surface of primary human T cells was induced by transduction with a single lentiviral vector (LV) encoding the tandem-CAR. Tandem-CARs were compared to single antigen targeting CARs in vitro and in vivo, and to an admixture of transduced cells expressing each CAR in vivo in immunodeficient (NSG) disease-bearing mice.ResultsTandem constructs efficient killed the Raji leukemia cell line both in vitro and in vivo. Tandem CARs generated less cytokine than the CD20 CAR, but similar to CD19 CARs, on their own. In co-culture experiments at low effector to target ratios with both single- and tandem- CAR-T cells, a rapid down-modulation of full-length CD19 expression was seen on leukemia targets. There also was a partial down-modulation of CD22, and to a lesser degree, of CD20. Our data also highlight the extreme sensitivity of the NALM-6 cell line to general lymphocyte-mediated cytotoxicity. While single and tandem constructs were effective in vivo in a standard setting, in a high-disease burden setting, the tandem CAR proved both effective and less toxic than an admixture of transduced T cell populations expressing single CARs.ConclusionTandem CARs are equally effective in standard disease models to single antigen specificity CARs, and may be both more effective and less toxic in a higher disease burden setting. This may be due to optimized cell killing with more moderate cytokine production. The rapid co-modulation of CD19, CD20, and CD22 may account for the ability to rapidly evolve escape mutants by selecting for leukemic clones that not require these target antigens for continued expansion.Electronic supplementary materialThe online version of this article (doi:10.1186/s40425-017-0246-1) contains supplementary material, which is available to authorized users.

Elective esophageal variceal ligation (EVL) is performed to decrease the risk of variceal hemorrhage. Side effects of EVL include hemorrhage, chest pain, dysphagia, and odynophagia. Because gastric acid may exacerbate postbanding ulcers and delay healing, proton pump inhibition may decrease side effects associated with EVL. The aim of this study was to assess the efficacy of pantoprazole, a proton pump inhibitor, as an adjunct to elective EVL. We performed a double-blinded, randomized, placebo-controlled trial of pantoprazole after elective EVL. Subjects in the pantoprazole arm received 40 mg pantoprazole intravenously after EVL followed by 40 mg oral pantoprazole for 9 days. Control subjects received intravenous and oral placebo. Subjects underwent upper endoscopy 10 to 14 days after banding. Primary outcomes included the size and number of ulcers and the subjects' reports of dysphagia, chest pain, and heartburn. Forty-four subjects were randomized: 42 completed the protocol. At follow-up endoscopy, the mean number of ulcers was similar in the two groups. However, the ulcers in the pantoprazole group were on average half as large as in the placebo group (37 mm 2 vs. 82 mm 2 , P < .01). Chest pain, dysphagia, and heartburn scores were not significantly different. Four subjects, all in the placebo group, had adverse outcomes, including 3 who bled from postbanding ulcers and 1 with sepsis. In conclusion, subjects receiving pantoprazole after elective EVL had significantly smaller postbanding ulcers on follow-up endoscopy than subjects receiving placebo. However, the total ulcer number and patient symptoms were not different between the groups. (HEPATOLOGY 2005;41: 588-594.)

Insulin-like growth factor 1 (IGF-1) enhances thymopoiesis but given the broad distribution of IGF-1 receptors (IGF-1Rs), its mechanism of action has remained unclear. To identify points of thymic regulation by IGF-1, we examined its effects on T-cell precursors, thymocytes, and thymic epithelial cells (TECs) in normal and genetically altered mice. In thymusintact but not thymectomized mice, IGF-1 administration increased peripheral naive and recent thymic emigrant (RTE) populations, demonstrating its effect on T-cell production, not peripheral expansion. IGF-1 administration increased bone marrow LSK (lineage ؊ , Sca-1 ؉ , c-kit ؉ ) precursor proliferation and peripheral LSK populations, increased thymocyte populations in a sequential wave of expansion, and proportionately expanded TEC subpopulations and enhanced their chemokine expression. To separate IGF-1's effects on thymocytes and TECs, we generated mice lacking IGF-1R on thymocytes and T cells. Thymocyte and RTE numbers were decreased in these mice, but IGF-1 treatment produced comparable thymocyte numbers to similarly treated wild-type mice. We additionally separated thymic-from LSK-specific effects by demonstrating that IGF-1 increased thymocyte numbers despite impaired early thymic progenitor ( IntroductionThymic function after lymphodepletion as seen in hematopoietic stem cell transplantation (HSCT), HIV infection, and aging is critical for maintaining a broad repertoire of T-cell responses. Impaired thymic function results in not only increased susceptibility to opportunistic infections but also increased risk of tumor relapse due to impaired tumor surveillance. 1 Moreover, given the critical role of the thymus in negative selection and the generation of regulatory T cells, impaired thymic function may be a significant contributory factor in the development of graft-versus-host disease and autoimmunity. 2,3 Strategies to preserve and/or enhance thymic function therefore may overcome these important clinical barriers.Thymic regulation can occur at multiple levels. The thymus requires continuous replenishment of bone marrow-derived progenitors to maintain T-cell production. Thereafter, T-cell development occurs in an ordered temporal-spatial sequence within distinct developmental niches defined by interactions between thymocytes and thymic epithelial cells (TECs). TECs define overall thymic function by modulating thymocyte survival, proliferation, trafficking, and positive and negative selection. 4 Consequently, increasing the number of available T-cell precursors for importation into the thymus, 5,6 expanding developmental niches within the thymus by expanding of TEC populations, 7,8 and manipulating interactions between TECs and thymocytes to increase thymopoietic throughput have all been implicated as potential points of thymic function regulation. Nevertheless, their relative importance in the regulation of overall thymic regulation remains unknown. In this regard, the actions of thymic regulators, which presumably act by one or more of these mech...

The reported risk of adenocarcinoma in subjects with BE is low and not significantly decreased by a surgical antireflux procedure. Antireflux surgery in the setting of BE should not be recommended as an antineoplastic measure.

Complete dissolution is needed for the separation, characterization, or homogeneous labeling of whole starch molecules. A method is presented to quantify the extent of starch dissolution in DMSO for the first time; it is validated on a commercial rice starch. It is used directly on starch dispersions containing possible undissolved or co-dissolved species. High-amylose maize starches, known to be digested slowly in vivo, only quantitatively dissolve in the presence of high concentrations of an H-bond disrupter, LiBr, although they form clear dispersions at low LiBr concentrations. Starch quantitatively dissolves from waxy rice flours; non-starch components partially co-dissolve but do not interfere with the dissolution quantification.

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Hydrophilic polymers with so-called LCST behavior are soluble within a certain temperature range but undergo phase separation or a change in volume above a critical temperature value, the lower critical solution temperature (LCST). [1] These phenomena can also be observed when other parameters are changed such as pH value, [2] electric field, and ionic strength.[3] For example, poly(N-isopropylacrylamide) shows a LCST at 34 8C in pure aqueous solution. This means that the polymer is soluble in water below 34 8C and precipitates simply when the solution is heated above that critical temperature.[4] The LCST value can be influenced, for example, by copolymerization of N-isopropylacrylamide or by chemical modification of the acrylamide polymer itself. The slightly cross-linked LCST polymers, so-called hydrogels, find potential application in the medical and biochemical fields, for controlled drug delivery [5] and as materials for bioreactors.[6] Although this LCST behavior of polymers cannot yet be explained, many studies have focused on this topic. One general explanation of the LCST effect is that strong hydrogen bonds exist between water molecules and the hydrophilic groups of the polymer at low temperature.[7] With increasing temperature, intramolecular interactions between hydrophobic chain components of the polymer increase. Reaching the LCST, polymer aggregation takes place, and the solubility in water decreases suddenly. We report here on a similar LCST-type solubility effect based on the reversible complexation of suitable polymers with b-cyclodextrin. Although the formation of complexes of hydrophobic polymers with cyclodextrins (CDs) has already been reported, [8] a characteristic LCST-type behavior has not yet been observed.A functionalized polymer suitable for complexation with b-CD was prepared by the synthesis and radical polymerization of monomer 5 according to Scheme 1. Intermediate 3 was obtained from the reaction of 1 and 2 (Scheme 1).[9] The esterification of 3 with 4 led to formation of methacrylamide monomer 5, which contains a bulky group suitable for complexation with CD and a bromine atom, which opens up the possibility of further modification by atom-transfer radical polymerization (ATRP).

Special-purpose classical force fields (FFs) provide good accuracy at very low computational cost, but their application is limited to systems for which potential energy functions are available. This excludes most metal-containing proteins or those containing cofactors. In contrast, the GFN2-xTB semiempirical quantum chemical method is parametrized for almost the entire periodic table. The accuracy of GFN2-xTB is assessed for protein structures with respect to experimental X-ray data. Furthermore, the results are compared with those of two special-purpose FFs, HF-3c, PM6-D3H4X, and PM7. The test sets include proteins without any prosthetic groups as well as metalloproteins. Crystal packing effects are examined for a set of smaller proteins to validate the molecular approach. For the proteins without prosthetic groups, the special purpose FF OPLS-2005 yields the smallest overall RMSD to the X-ray data but GFN2-xTB provides similarly good structures with even better bond-length distributions. For the metalloproteins with up to 5000 atoms, a good overall structural agreement is obtained with GFN2-xTB. The full geometry optimizations of protein structures with on average 1000 atoms in wall-times below 1 day establishes the GFN2-xTB method as a versatile tool for the computational treatment of various biomolecules with a good accuracy/computational cost ratio.