bluuebunny/crossref_metadata_2025_split huggingface dataset:
Notch Signaling Augments T Cell Responsiveness by Enhancing CD25 Expression
Authors: Adler Scott H. , Chiffoleau Elise , Xu Lanwei , Dalton Nicole M. , Burg Jennifer M. , Wells Andrew D. , Wolfe Michael S. , Turka Laurence A. , Pear Warren S. 
Published: April 2014

Abstract
Notch receptors signal through a highly conserved pathway to influence cell fate decisions. Notch1 is required for T lineage commitment; however, a role for Notch signaling has not been clearly defined for the peripheral T cell response. Notch gene expression is induced, and Notch1 is activated in primary CD4+ T cells following specific peptide-Ag stimulation. Notch activity contributes to the peripheral T cell response, as inhibition of endogenous Notch activation decreases the proliferation of activated T cells in a manner associated with the diminished production of IL-2 and the expression of the high affinity IL-2R (CD25). Conversely, forced expression of a constitutively active Notch1 in primary T cells results in increased surface expression of CD25, and renders these cells more sensitive to both cognate Ag and IL-2, as measured by cell division. These data suggest an important role for Notch signaling during CD4+ T cell responses, which operates through augmenting a positive feedback loop involving IL-2 and its high affinity receptor.
Phenotypic and Functional Characterization of Long-Term Cultured Rhesus Macaque Spleen-Derived NKT Cells
Authors: Gansuvd Balgansuren , Hubbard William J. , Hutchings Anne , Thomas Francis T. , Goodwin Jeanine , Wilson S. Brian , Exley Mark A. , Thomas Judith M. 
Published: April 2014

Abstract
Natural killer T cells are immunoregulatory cells, which have important roles in tolerance and autoimmunity, as demonstrated primarily in mice and humans. In this study, we define the phenotype and function of Vα24+ T cells derived from the spleens of rhesus macaques, a species increasingly used in models of immune tolerance. Vα24+ cells were isolated and expanded with monocyte-derived immature dendritic cells in the presence of α-galactosylceramide, IL-2, and IL-15. Rhesus NKT cells were stained with mAbs against both Vα24 and the invariant complementarity-determining region 3 epitope of the human Vα24/JαQ TCR. The cells were CD4, CD8 double negative and expressed CD56. Rhesus NKT cells also exhibited moderate to high expression of CD95, CD45RO, CD11a, and β7 integrin, but did not express CD45 RA, CD62L, CCR7, CD28, and other activation, costimulatory molecules (CD69 and CD40L). By intracellular staining, &gt;90% of unstimulated rhesus NKT cells expressed IL-10, but not IFN-γ. However, the latter was strongly expressed after stimulation. Rhesus NKT secreted large amounts of TGF-β, IL-13, and IL-6, and modest levels of IFN-γ, whereas IL-10 secretion was negligible and no detectable IL-4 was observed either intracellularly or in culture supernatants. Functionally, the NKT cells and their supernatants suppressed T cell proliferation in allogeneic MLR. We conclude that long-term cultured rhesus macaque spleen-derived Vα24+ T cells are semi-invariant double-negative cells with effector memory phenotype. These cells are semianergic, polarized to a uniquely Th3 &gt; T regulatory-1 regulatory cell phenotype, and have regulatory/suppressive function in vitro.
In Vitro Generation and Life Span Extension of Human Papillomavirus Type 16-Specific, Healthy Donor-Derived CTL Clones
Authors: Schreurs Marco W. J. , Scholten Kirsten B. J. , Kueter Esther W. M. , Ruizendaal Janneke J. , Meijer Chris J. L. M. , Hooijberg Erik 
Published: April 2014

Abstract
Human papillomavirus (HPV) type 16 infection is strongly associated with the development of cervical carcinoma (CxCa) in women. The HPV16-derived oncoproteins E6 and E7, responsible for both onset and maintenance of malignant transformation, are expressed constitutively in CxCa cells and represent tumor-associated Ags. As a result, E6 and E7 constitute potential targets for adoptive CTL-mediated immunotherapy of CxCa. However, the availability to date of well-characterized HPV16-specific, CxCa-reactive human CTLs is extremely limited. The current study describes the in vitro generation and isolation of HPV16 E7-specific, CxCa-reactive human CTL clones from low-frequency healthy donor-derived CD8β-positive precursors. For this purpose, an in vitro CTL induction protocol was used involving mature monocyte-derived dendritic cells as stimulator cells loaded with an HLA-A2.1-restricted, E711–20-derived high-affinity altered peptide ligand. A double tetramer-guided isolation procedure and subsequent limiting-dilution cloning resulted in Ag-specific CTL clones. Stringent CTL characterization clearly indicated Ag-specific, HLA-A2.1-restricted reactivity against different HPV16-transformed CxCa cell lines. To allow expansion of E711–20-specific CTL clones to numbers required for prolonged in vitro as well as in vivo application, their life span was significantly extended by ectopic expression of human telomerase reverse transcriptase. Collectively, our results show that optimized CTL induction and stringent CTL selection procedures, followed by human telomerase reverse transcriptase-mediated life span extension will allow continued availability of low-frequency HPV16-specific, CxCa-reactive human CTL clones. This may enhance the prospects of HPV16-specific adoptive CTL immunotherapy in CxCa patients.
Recombinant CD63/ME491/Neuroglandular/NKI/C-3 Antigen Inhibits Growth of Established Tumors in Transgenic Mice
Authors: Li Jian , Li Weiping , Liang Shaohong , Cai Dewei , Kieny Marie Paule , Jacob Lutz , Linnenbach Alban , Abramczuk Jan W. , Bender Hans , Sproesser Katrin , Swoboda Rolf , Somasundaram Rajasekharan , Guerry DuPont , Herlyn Dorothee 
Published: April 2014

AbstractAttempts to vaccinate against tumors can be hindered by the induction of immunological tolerance to the target Ag as a result of Ag expression on normal tissues. In this study, we find that transgenic mice expressing the melanoma-associated Ag CD63/ME491/neuroglandular/NKI/C-3 on their normal tissues do, in fact, exhibit immunological tolerance to the Ag, recapitulating the conditions in cancer patients. In these mice, growth of murine melanoma cells expressing the Ag after gene transfer was inhibited by immunization with Ag-expressing recombinant vaccinia virus combined with IL-2, but not by immunization with the protein alone, anti-idiotypic Abs, or irradiated tumor cells. The effect of the recombinant virus was demonstrated both for nonestablished and established tumors. Infiltration with both CD4+ and CD8+ T lymphocytes was significantly more extensive in tumors from experimental mice than in tumors from control mice. MHC class I-positive, but not class I-negative, tumors were inhibited by the vaccine, suggesting that MHC class I-restricted T lymphocytes play a role in the antitumor effects. Abs did not appear to be involved in the vaccine effects. CD63 was immunogenic in 2 of 13 melanoma patients, pointing to the potential of this Ag, combined with IL-2, as a vaccine for melanoma patients.
An IL-2-Dependent Switch Between CD95 Signaling Pathways Sensitizes Primary Human T Cells Toward CD95-Mediated Activation-Induced Cell Death
Authors: Schmitz Ingo , Krueger Andreas , Baumann Sven , Schulze-Bergkamen Henning , Krammer Peter H. , Kirchhoff Sabine 
Published: April 2014

Abstract
The CD95 (APO-1/Fas) system plays a critical role in activation-induced cell death (AICD) of T cells. We previously described two distinct CD95 (APO-1/Fas) signaling pathways: 1) type I cells show strong death-inducing signaling complex (DISC) formation and mitochondria-independent apoptosis and 2) DISC formation is reduced in type II cells, leading to mitochondria-dependent apoptosis. To investigate the relevance of these pathways, we set up an in vitro model that mimics the initiation and the down phase of an immune response, respectively. Freshly activated human T cells (initiation) are resistant toward CD95-mediated AICD despite high expression of CD95. We previously reported that these T cells show reduced DISC formation. In this study, we show that freshly activated T cells are CD95-type II cells that show high expression levels of Bcl-xL and display a block in the mitochondrial apoptosis pathway. Furthermore, we show that, upon prolonged culture (down phase), human T cells undergo a switch from type II to type I cells that renders T cells sensitive to CD95-mediated AICD. Finally, we demonstrate that this switch is dependent on the presence of IL-2. Our observations reveal for the first time that the existence of coexisting CD95 signaling pathways is of physiological relevance.
Assessment of Requirements for IL-15 and IFN Regulatory Factors in Uterine NK Cell Differentiation and Function During Pregnancy
Authors: Ashkar Ali A. , Black Gordon P. , Wei Qingxia , He Hong , Liang Luchuan , Head Judith R. , Croy B. Anne 
Published: April 2014

Abstract
In mouse and human, precursors of NK cell lineage home to decidualizing uteri. To assess the requirement for IL-15, an essential cytokine for NK differentiation in lymphoid tissue, on uterine NK (uNK) cell differentiation, implantation sites from IL-15−/− mice were analyzed histologically. IL-15−/− implantation sites had no uNK cells, no spiral-artery modification, and lacked the decidual integrity found in normal mice. IL-15−/− recipients of C57BL/6 marrow displayed similar pathology. However, implantation sites from recombination-activating gene-2−/−γc−/− (alymphoid) recipients of IL-15−/− marrow showed normal uNK cells, modified spiral arteries, and well-developed decidua basalis. Deletion of the IFN-regulatory factor (IRF)-1, but not IRF-2 (factors important in peripheral NK cell differentiation) limited but did not prevent uNK cell development. In situ hybridization localized IRF-1 largely to placental trophoblast cells. IRF-1−/− marrow transplanted into recombination-activating gene-2−/−γc−/− displayed competence for full uNK cell differentiation. IL-15 mRNA expression at implantation sites of IRF-1−/− and C57BL/6 was similar, suggesting that, unlike in bone marrow and spleen, IRF-1 does not regulate IL-15 in the pregnant uterus. Terminal differentiation of uNK cells was not promoted in pregnant IRF-1−/− mice by 5-day infusion of murine rIL-15, suggesting that IRF-1 deficiency rather than IL-15 deficiency limits uNK cell differentiation in these mice. Further, IRF-1 regulates placental growth, birth weight, and postnatal growth of offspring. These studies indicate that uNK cell development and maturation share some aspects with NK cell development in other tissues, but also display distinctive tissue-specific regulation.
Alterations in the Expression of MHC Class I Glycoproteins by B16BL6 Melanoma Cells Modulate Insulin Receptor-Regulated Signal Transduction and Augments Resistance to Apoptosis
Authors: Assa-Kunik Efrat , Fishman Daniel , Kellman-Pressman Sigal , Tsory Sylvia , Elhyany Shira , Baharir Ofer , Segal Shraga 
Published: April 2014

Abstract
In a variety of malignancies, the immune-escape phenotype is associated, in part, with the inability of tumor cells to properly present their Ags to CTLs due to a deranged expression of MHC class I glycoproteins. However, these molecules were found to possess broader nonimmune functions, including participation in signal transduction and regulation of proliferation, differentiation, and sensitivity to apoptosis-inducing factors; processes, which are characteristically impaired during malignant transformation. We investigated whether the deranged expression of MHC class I expression by tumor cells could affect proper receptor-mediated signal transduction and accentuate their malignant phenotype. The malignant and H-2K murine MHC class I-deficient B16BL6 melanoma cells were characterized by an attenuated capacity to bind insulin due to the retention of corresponding receptor in intracellular stores. The restoration of H-2K expression in these cells, which abrogated their capacity to form tumors in mice, enhanced membrane translocation of the receptor, presumably, by modulating its glycosylation. The addition of insulin to H-2K-expressing melanoma cells cultured in serum-free conditions precluded apoptotic death by up-regulating the activity of protein kinase B (PKB)/Akt. In contrast, the deficiency for H-2K characteristic to the malignant clones was associated with a constitutive high activity of PKB/Akt, which rendered them resistant to apoptosis, induced by deprivation of serum-derived growth factors. The possibility to correct the regulation of PKB/Akt activity by restoration of H-2K expression in B16BL6 melanoma cells may be considered as an attractive approach for cancer therapy, since an aberrant activation of this enzyme is characteristic to resistant malignancies.
In Vivo Antitumor Activity of NKT Cells Activated by the Combination of IL-12 and IL-18
Authors: Baxevanis Constantin N. , Gritzapis Angelos D. , Papamichail Michael 
Published: April 2014

AbstractInterleukin-12 and IL-18 have been demonstrated to potentiate innate immunity in a variety of experimental tumor models, but the functional roles of NK and/or NKT cells and their mechanism of action in these models have not been fully addressed. Through adoptive transfer of NKT cells activated in vitro with a combination of IL-12 plus IL-18 (IL-12/IL-18 NKT) into syngeneic animals, we demonstrate in this study that IL-12/IL-18 NKT cells are essential and collaborate with the host’s own NK cells in natural host immunity against the growth of ALC and MC57X syngeneic tumors. The relative roles of the adoptively transferred IL-12/IL-18 NKT cells and endogenous NK cells in host protection were first shown in normal C57BL/6 (B6) mice treated with anti-asialo GM1 Ab that selectively depletes NK cells; second, in B6.TCRJα281−/− mice specifically deficient for NKT cells; and third, in B6.scid mice that also lack NKT cells. Furthermore, by injecting normal B6 mice with anti-IL-2 and/or anti-IFN-γ mAb, we could demonstrate that effective innate immunity against both types of syngeneic tumors was dependent on the production of IL-2 and IFN-γ by the adoptively transferred NKT cells. In vitro studies confirmed both the secretion of IL-2 and IFN-γ by the IL-12/IL-18-activated NKT cells and their collaborative role with NK cells for lysis of ALC and MC57X syngeneic tumor targets. This is the first description of an antitumor function of IL-12/IL-18 NKT cells adoptively transferred into syngeneic hosts that provides the basis for a new modality in the cellular immunotherapy of cancer.
Differential Chemokine Responses and Homing Patterns of Murine TCRαβ NKT Cell Subsets
Authors: Johnston Brent , Kim Chang H. , Soler Dulce , Emoto Masashi , Butcher Eugene C. 
Published: April 2014

AbstractNKT cells play important roles in the regulation of diverse immune responses. Therefore, chemokine receptor expression and chemotactic responses of murine TCRαβ NKT cells were examined to define their homing potential. Most NKT cells stained for the chemokine receptor CXCR3, while &gt;90% of Vα14i-positive and ∼50% of Vα14i-negative NKT cells expressed CXCR6 via an enhanced green fluorescent protein reporter construct. CXCR4 expression was higher on Vα14i-negative than Vα14i-positive NKT cells. In spleen only, subsets of Vα14i-positive and -negative NKT cells also expressed CXCR5. NKT cell subsets migrated in response to ligands for the inflammatory chemokine receptors CXCR3 (monokine induced by IFN-γ/CXC ligand (CXCL)9) and CXCR6 (CXCL16), and regulatory chemokine receptors CCR7 (secondary lymphoid-tissue chemokine (SLC)/CC ligand (CCL)21), CXCR4 (stromal cell-derived factor-1/CXCL12), and CXCR5 (B cell-attracting chemokine-1/CXCL13); but not to ligands for other chemokine receptors. Two NKT cell subsets migrated in response to the lymphoid homing chemokine SLC/CCL21: CD4− Vα14i-negative NKT cells that were L-selectinhigh and enriched for expression of Ly49G2 (consistent with the phenotype of most NKT cells found in peripheral lymph nodes); and immature Vα14i-positive cells lacking NK1.1 and L-selectin. Mature NK1.1+ Vα14i-positive NKT cells did not migrate to SLC/CCL21. BCA-1/CXCL13, which mediates homing to B cell zones, elicited migration of Vα14i-positive and -negative NKT cells in the spleen. These cells were primarily CD4+ or CD4−CD8− and were enriched for Ly49C/I, but not Ly49G2. Low levels of chemotaxis to CXCL16 were only detected in Vα14i-positive NKT cell subsets. Our results identify subsets of NKT cells with distinct homing and localization patterns, suggesting that these populations play specialized roles in immunological processes in vivo.
Enhancing DNA Vaccine Potency by Combining a Strategy to Prolong Dendritic Cell Life with Intracellular Targeting Strategies
Authors: Kim Tae Woo , Hung Chien-Fu , Boyd David , Juang Jeremy , He Liangmei , Kim Jeong Won , Hardwick J. Marie , Wu T.-C. 
Published: April 2014

Abstract
We have recently shown that intradermal coadministration of DNA encoding Ag with DNA encoding inhibitors of apoptosis, including Bcl-xL, prolongs dendritic cell (DC) life and thereby enhances the potency of DNA vaccines in vivo. We have also demonstrated that DNA vaccines targeting Ag to subcellular compartments, using proteins such as Mycobacterium tuberculosis heat shock protein 70, calreticulin, or the sorting signal of the lysosome-associated membrane protein type 1 (LAMP-1), enhanced DNA vaccine potency. In this study, we reasoned that the combination of a strategy to prolong DC life with intracellular targeting strategies might produce a more effective DNA vaccine against human papillomavirus E7. We showed that coadministration of DNA encoding Bcl-xL with DNA encoding E7/heat shock protein 70, calreticulin/E7, or Sig/E7/LAMP-1 resulted in further enhancement of the E7-specific CD8+ T cell response for all three constructs. Of these strategies, mice vaccinated with Sig/E7/LAMP-1 DNA mixed with Bcl-xL DNA showed the greatest increase in E7-specific CD8+ T cells (∼13-fold increase). This combination of strategies resulted in increased CD8+ T cell functional avidity, an increased E7-specific CD4+ Th1 cell response, enhanced tumor treatment ability, and stronger long-term tumor protection when compared with mice vaccinated without Bcl-xL DNA. Therefore, DNA vaccines that combine strategies to enhance intracellular Ag processing and prolong DC life have potential clinical implications for control of viral infection and neoplasia.
Identification of a Novel Subpopulation of Human Cord Blood CD34−CD133−CD7−CD45+Lineage− Cells Capable of Lymphoid/NK Cell Differentiation After In Vitro Exposure to IL-15
Authors: Rutella Sergio , Bonanno Giuseppina , Marone Maria , de Ritis Daniela , Mariotti Andrea , Voso Maria Teresa , Scambia Giovanni , Mancuso Salvatore , Leone Giuseppe , Pierelli Luca 
Published: April 2014

Abstract
The hemopoietic stem cell (HSC) compartment encompasses cell subsets with heterogeneous proliferative and developmental potential. Numerous CD34− cell subsets that might reside at an earlier stage of differentiation than CD34+ HSCs have been described and characterized within human umbilical cord blood (UCB). We identified a novel subpopulation of CD34−CD133−CD7−CD45dimlineage (lin)− HSCs contained within human UCB that were endowed with low but measurable extended long-term culture-initiating cell activity. Exposure of CD34−CD133−CD7−CD45dimlin− HSCs to stem cell factor preserved cell viability and was associated with the following: 1) concordant expression of the stem cell-associated Ags CD34 and CD133, 2) generation of CFU-granulocyte-macrophage, burst-forming unit erythroid, and megakaryocytic aggregates, 3) significant extended long-term culture-initiating cell activity, and 4) up-regulation of mRNA signals for myeloperoxidase. At variance with CD34+lin− cells, CD34−CD133−CD7−CD45dimlin− HSCs maintained with IL-15, but not with IL-2 or IL-7, proliferated vigorously and differentiated into a homogeneous population of CD7+CD45brightCD25+CD44+ lymphoid progenitors with high expression of the T cell-associated transcription factor GATA-3. Although they harbored nonclonally rearranged TCRγ genes, IL-15-primed CD34−CD133−CD7−CD45dimlin− HSCs failed to achieve full maturation, as manifested in their CD3−TCRαβ−γδ− phenotype. Conversely, culture on stromal cells supplemented with IL-15 was associated with the acquisition of phenotypic and functional features of NK cells. Collectively, CD34−CD133−CD7−CD45dimlin− HSCs from human UCB displayed an exquisite sensitivity to IL-15 and differentiated into lymphoid/NK cells. Whether the transplantation of CD34−lin− HSCs possessing T/NK cell differentiation potential may impact on immunological reconstitution and control of minimal residual disease after HSC transplantation for autoimmune or malignant diseases remains to be determined.
The WD Motif-Containing Protein RACK-1 Functions as a Scaffold Protein Within the Type I IFN Receptor-Signaling Complex
Authors: Usacheva Anna , Tian Xinyong , Sandoval Raudel , Salvi Debra , Levy David , Colamonici Oscar R. 
Published: April 2014

Abstract
The WD repeat-containing protein receptor for activated protein kinase C (RACK)-1 has been linked to a variety of signaling systems including protein kinase C, growth factors, and IFNs. In the IFN system, RACK-1 functions as an adaptor recruiting the transcription factor STAT1 to the receptor complex. However, RACK-1 should play a broader role in type I IFN signaling because mutation of the RACK-1 binding site in the IFN-α receptor 2/β subunit of the type I IFN receptor abrogates not only STAT1, but also STAT2, activation. In this study, we demonstrate that RACK-1 serves as a scaffold protein for a multiprotein complex that includes the IFN-α receptor 2/β-chain of the receptor, STAT1, Janus kinase 1, and tyrosine kinase 2. In vitro data further suggest that within this complex tyrosine kinase 2 is the tyrosine kinase responsible for the phosphorylation of STAT1. Finally, we provide evidence that RACK-1 may also serve as a scaffold protein in other cytokine systems such as IL-2, IL-4, and erythropoietin.
In Vivo Impact of CpG1826 Oligodeoxynucleotide on CD8 T Cell Primary Responses and Survival
Authors: Beloeil Laurent , Tomkowiak Martine , Angelov Georgi , Walzer Thierry , Dubois Patrice , Marvel Jacqueline 
Published: April 2014

Abstract
CpG oligodeoxynucleotide (ODN) promotes maturation of APCs in vivo and induces strong type 1 T cell responses in mice. In this study, we have investigated the ability of CpG1826 to modulate peptide-specific CD8 T cell responses in a context where CD4 T cells are likely to play a minor role. The effects of CpG1826 were evaluated in a system where a population of NP68-specific F5 TCR transgenic CD8 T cells is diluted into a polyclonal host following adoptive transfer into C57BL/10 syngeneic recipients. Using this approach, we found that CpG1826 enhanced the ability of F5 CD8 T cells to undergo multiple divisions in vivo, to express IFN-γ ex vivo, and to up-regulate memory-associated cell surface markers such as CD122 (IL-2Rβ) and Ly-6C. Moreover, CpG1826 greatly increased in vivo cytotoxic activity. Using tetramer detection, we found that CpG1826 promoted long-term survival of Ag-specific CD8 T cells after immunization while no NP68-specific cells were detected when the cognate peptide was injected alone. These results indicate that CpG1826 acts as an adjuvant which increases CD8 T cell effector responses and promotes long-term survival of NP68 peptide-specific cells in vivo. They also suggest that this adjuvant can modulate CD8 T cell responses in a system which is likely to be independent of CD4 T cell help.