Materials can be transformed from one crystalline phase to another by using an electric field to control ion transfer, in a process that can be harnessed in applications such as batteries, smart windows and fuel cells. Increasing the number of transferrable ion species and of accessible crystalline phases could in principle greatly enrich material functionality. However, studies have so far focused mainly on the evolution and control of single ionic species (for example, oxygen, hydrogen or lithium ions). Here we describe the reversible and non-volatile electric-field control of dual-ion (oxygen and hydrogen) phase transformations, with associated electrochromic and magnetoelectric effects. We show that controlling the insertion and extraction of oxygen and hydrogen ions independently of each other can direct reversible phase transformations among three different material phases: the perovskite SrCoO (ref. 12), the brownmillerite SrCoO (ref. 13), and a hitherto-unexplored phase, HSrCoO. By analysing the distinct optical absorption properties of these phases, we demonstrate selective manipulation of spectral transparency in the visible-light and infrared regions, revealing a dual-band electrochromic effect that could see application in smart windows. Moreover, the starkly different magnetic and electric properties of the three phases-HSrCoO is a weakly ferromagnetic insulator, SrCoO is a ferromagnetic metal, and SrCoO is an antiferromagnetic insulator-enable an unusual form of magnetoelectric coupling, allowing electric-field control of three different magnetic ground states. These findings open up opportunities for the electric-field control of multistate phase transformations with rich functionalities.

Purpose Multiple myeloma (MM) is a usually incurable malignancy of plasma cells. New therapies are urgently needed for MM. Adoptive transfer of chimeric antigen receptor (CAR)-expressing T cells is a promising new therapy for hematologic malignancies, but an ideal target antigen for CAR-expressing T cell therapies of MM has not been identified. B-cell maturation antigen (BCMA) is a protein that has been reported to be selectively expressed by B-lineage cells including MM cells. Our goal was to determine if BCMA is a suitable target for CAR-expressing T cells. Experimental Design We conducted an assessment of BCMA expression in normal human tissues and MM cells by flow cytometry, quantitative PCR, and immunohistochemistry. We designed and tested novel anti-BCMA CARs. Results BCMA had a restricted RNA expression pattern. Except for expression on plasma cells, BCMA protein was not detected in normal human tissues. BCMA was not detected on primary human CD34+ hematopoietic cells. We detected uniform BCMA cell-surface expression on primary MM cells from 5 of 5 patients. We designed the first anti-BCMA CARs to be reported, and we transduced T cells with lentiviral vectors encoding these CARs. The CARs gave T cells the ability to specifically recognize BCMA. The anti-BCMA-CAR-transduced T cells exhibited BCMA-specific functions including cytokine production, proliferation, cytotoxicity, and in vivo tumor eradication. Importantly, anti-BCMA-CAR-transduced T cells recognized and killed primary MM cells. Conclusions BCMA is a suitable target for CAR-expressing T cells, and adoptive transfer of anti-BCMA-CAR-expressing T cells is a promising new strategy for treating MM.

Cluster of differentiation (CD)8 ؉ T cells exist as naive, central memory, and effector memory subsets, and any of these populations can be genetically engineered into tumor-reactive effector cells for adoptive immunotherapy. However, the optimal subset from which to derive effector CD8 ؉ T cells for patient treatments is controversial and understudied. We investigated human CD8 ؉ T cells and found that naive cells were not only the most abundant subset but also the population most capable of in vitro expansion and T-cell receptor transgene expression. Despite increased expansion, naive-derived cells displayed minimal effector differentiation, a quality associated with greater efficacy after cell infusion. Similarly, the markers of terminal differentiation, killer cell lectin-like receptor G1 and CD57, were expressed at lower levels in cells of naive origin. Finally, naive-derived effector cells expressed higher CD27 and retained longer telomeres, characteristics that suggest greater proliferative potential and that have been linked to greater efficacy in clinical trials. Thus, these data suggest that naive cells resist terminal differentiation, or "exhaustion," maintain high replicative potential, and therefore may be the superior subset for use in adoptive immunotherapy. (Blood. 2011;117(3):808-814) IntroductionIt is now possible to genetically engineer human T lymphocytes to express virtually any known gene, including genes encoding T-cell receptors (TCRs) or chimeric antigen receptors (CARs), to provide the desired T-cell specificity. These gene-engineered lymphocytes hold the promise to treat infectious diseases and cancer, 1-10 but the appropriate substrate cells to use is understudied, and most current protocols simply transfer genes into "bulk" peripheral blood mononuclear cells (PBMCs). Varieties of data indicate that T cells, and in particular CD8 ϩ T cells, are worthy substrates for gene engineering. However, CD8 ϩ T cells in peripheral blood are themselves a complex mixture, composed of at least 3 major subsets-naive (T N ), central memory (T CM ), and effector memory (T EM )-each having different functional qualities.The optimal subset to engineer for adoptive immunotherapy is controversial. 8,[11][12][13][14] Memory CD8 ϩ T-cell subsets are more studied than naive cells, because antigen-specific clones can be found at increased frequencies. In a landmark paper, Berger et al 13 have shown in macaques that effector cells derived from T CM rather than T EM possess greater ability to survive and establish immunologic memory after infusion. This finding is consistent with data comparing memory subsets in mice. 15 However, T N cells were not explicitly analyzed in these reports, 12 an omission that might be important given recent findings in mice that naive T cells convey more antitumor activity than memory cells. 12 Short of conducting a series of clinical trials, the decision of which CD8 ϩ T-cell subset to use for clinical protocols will depend on the cell phenotypes that result from transduction of T...

To generate chimeric Ag receptors (CARs) for the adoptive immunotherapy of cancer patients with ErbB2-expressing tumors, a single-chain Ab derived from the humanized mAb 4D5 Herceptin (trastuzumab) was initially linked to T cell signaling domains derived from CD28 and the CD3ζ to generate a CAR against ErbB2. Human PBLs expressing the 4D5 CAR demonstrated Ag-specific activities against ErbB2+ tumors. However, a gradual loss of transgene expression was noted for PBLs transduced with this 4D5 CAR. When the CD3ζ signaling domain of the CAR was truncated or mutated, loss of CAR expression was not observed, suggesting that the CD3ζ signaling caused the transgene decrease, which was supported by the finding that T cells expressing 4D5 CARs with CD3ζ ITAM mutations were less prone to apoptosis. By adding 4–1BB cytoplasmic domains to the CD28-CD3ζ signaling moieties, we found increased transgene persistence in 4D5 CAR-transduced PBLs. Furthermore, constructs with 4–1BB sequences demonstrated increased cytokine secretion and lytic activity in 4D5 CAR-transduced T cells. More importantly, PBLs expressing this new version of the 4D5 CAR could not only efficiently lyse the autologous fresh tumor digests, but they could strongly suppress tumor growth in a xenogenic mouse model.

Anti-CD19 chimeric antigen receptor (CAR) T cells have caused remissions of B cell malignancies, but problems including cytokine-mediated toxicity and short persistence of CAR T cells in vivo might limit the effectiveness of anti-CD19 CAR T cells. Anti-CD19 CARs that have been tested clinically had single-chain variable fragments (scFvs) derived from murine antibodies. We have designed and constructed novel anti-CD19 CARs containing a scFv with fully human variable regions. T cells expressing these CARs specifically recognized CD19 target cells and carried out functions including degranulation, cytokine release, and proliferation. We compared CARs with CD28 costimulatory moieties along with hinge and transmembrane domains from either the human CD28 molecule or the human CD8α molecule. Compared with T cells expressing CARs with CD28 hinge and transmembrane domains, T cells expressing CARs with CD8α hinge and transmembrane domains produced lower levels of cytokines and exhibited lower levels of activation-induced cell death (AICD). Importantly, CARs with hinge and transmembrane regions from either CD8α or CD28 had similar abilities to eliminate established tumors in mice. In anti-CD19 CARs with CD28 costimulatory moieties, lower levels of inflammatory cytokine production and AICD are potential clinical advantages of CD8α hinge and transmembrane domains over CD28 hinge and transmembrane domains.

Interleukin-12 (IL-12) is an important immunostimulatory cytokine, yet its clinical application has been limited by the systemic toxicity associated with its administration. In this work, we developed a strategy to selectively deliver IL-12 to the tumor environment using genetically engineered lymphocytes. However, peripheral blood lymphocytes (PBLs) transduced with a γ-retroviral vector, which constitutively expressed IL-12, failed to expand in culture due to apoptosis. To circumvent this problem, a vector was designed where IL-12 expression was directed by a composite promoter-containing binding motifs for nuclear factor of activated T-cells (NFAT.hIL12.PA2). The NFAT-responsive promoter was activated to drive IL-12 expression upon the recognition of tumor-specific antigen mediated by a T cell receptor (TCR) that was engineered into the same lymphocytes. We tested the efficacy of the inducible IL-12 vector in vivo in a murine melanoma model. Adoptive transfer of pmel-1 T cells genetically engineered with NFAT-murineIL12 (NFAT.mIL12.PA2) significantly enhanced regression of large established B16 melanoma. Notably, this targeted and controlled IL-12 treatment was without toxicity. Taken together, our results suggest that using the NFAT.hIL12.PA2 vector might be a promising approach to enhance adoptive cancer immunotherapy.

In human gene therapy applications, lentiviral vectors may have advantages over g-retroviral vectors in several areas, including the ability to transduce nondividing cells, resistance to gene silencing and a potentially safer integration site profile. However, unlike g-retroviral vectors it has been problematic to drive the expression of multiple genes efficiently and coordinately with approaches such as internal ribosome entry sites or dual promoters. Using different 2A peptides, lentiviral vectors expressing two-gene T-cell receptors directed against the melanoma differentiation antigens gp100 and MART-1 were constructed. We demonstrated that addition of amino-acid spacer sequences (GSG or SGSG) before the 2A sequence is a prerequisite for efficient synthesis of biologically active T-cell receptors and that addition of a furin cleavage site followed by a V5 peptide tag yielded optimal T-cell receptor gene expression. Furthermore, we determined that the furin cleavage site was recognized in lymphocytes and accounted for removal of residual 2A peptides at the post-translational level with an efficiency of 20-30%, which could not be increased by addition of multiple furin cleavage sites. The novel bicistronic lentiviral vector developed herein afforded robust antimelanoma activities to engineered peripheral blood lymphocytes, including cytokine secretion, cell proliferation and lytic activity. Such optimal vectors may have immediate applications in cancer gene therapy.

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