bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissociation of NKT Stimulation, Cytokine Induction, and NK Activation In Vivo by the Use of Distinct TCR-Binding Ceramides
Authors: Ortaldo John R. , Young Howard A. , Winkler-Pickett Robin T. , Bere Earl W. , Murphy William J. , Wiltrout Robert H. 
Published: April 2014

Abstract
NKT and NK cells are important immune regulatory cells. The only efficient means to selectively stimulate NKT cells in vivo is α-galactosylceramide (αGalCer). However, αGalCer effectively stimulates and then diminishes the number of detectable NKT cells. It also exhibits a potent, indirect ability to activate NK cells. We have now discovered another ceramide compound, β-galactosylceramide (βGalCer) (C12), that efficiently diminishes the number of detectable mouse NKT cells in vivo without inducing significant cytokine expression or activation of NK cells. Binding studies using CD1d tetramers loaded with βGalCer (C12) demonstrated significant but lower intensity binding to NKT cells when compared with αGalCer, but both ceramides were equally efficient in reducing the number of NKT cells. However, βGalCer (C12), in contrast to αGalCer, failed to increase NK cell size, number, and cytolytic activity. Also in contrast to αGalCer, βGalCer (C12) is a poor inducer of IFN-γ, TNF-α, GM-CSF, and IL-4 gene expression. These qualitative differences in NKT perturbation/NK activation have important implications for delineating the unique in vivo roles of NKT vs NK cells. Thus, αGalCer (which triggers NKT cells and activates NK cells) efficiently increases the resistance to allogeneic bone marrow transplantation while βGalCer (C12) (which triggers NKT cells but does not activate NK cells) fails to enhance bone marrow graft rejection. Our results show βGalCer (C12) can effectively discriminate between NKT- and NK-mediated responses in vivo. These results indicate the use of different TCR-binding ceramides can provide a unique approach for understanding the intricate immunoregulatory contributions of these two cell types.
The Cell Surface-Localized Heat Shock Protein 70 Epitope TKD Induces Migration and Cytolytic Activity Selectively in Human NK Cells
Authors: Gastpar Robert , Gross Catharina , Rossbacher Lydia , Ellwart Joachim , Riegger Julia , Multhoff Gabriele 
Published: April 2014

Abstract
Profiling of surface-bound proteins uncovers a tumor-selective heat shock protein 70 (Hsp70) membrane expression that provides a target structure for human NK cells. Hsp70 peptide TKD (TKDNNLLGRFELSG; aa 450–463) was found to enhance the cytolytic activity of NK cells. In this study, we demonstrate that TKD-activated CD3−CD56+CD94+ NK cells are selectively attracted by Hsp70 membrane-positive tumor cells, and supernatants derived thereof. Hsp70 membrane-negative tumors failed to attract these NK cells. The capacity to migrate was associated with a substantial lytic activity against Hsp70-positive tumor cells. Because NK cell migration was independent of cell-to-cell contact, the involvement of a soluble factor was assumed. Interestingly, synthetic Hsp70 protein and Hsp70 peptide TKD, mimicking surface-bound Hsp70, initiates migration of NK cells in a concentration-dependent (1–5 μg/ml), highly selective, and chemokine-independent manner. In summary, our results indicate that Hsp70 peptide TKD not only stimulates cytolysis but also chemotaxis in CD3−CD56+CD94+ NK cells.
Mechanistic Insights into Impaired Dendritic Cell Function by Rapamycin: Inhibition of Jak2/Stat4 Signaling Pathway
Authors: Chiang Po-Hui , Wang Lianfu , Bonham C. Andrew , Liang Xiaoyan , Fung John J. , Lu Lina , Qian Shiguang 
Published: April 2014

AbstractThe suppressive effect of rapamycin on T cells has been extensively studied, but its influence on the function of APC is less clear. The data in this study demonstrated that immunostimulatory activity of B10 (H2b) dendritic cells (DC) exposed to rapamycin (rapa-DC) was markedly suppressed as evidenced by the induction of low proliferative responses and specific CTL activity in allogeneic (C3H, H2k) T cells. Administration of rapa-DC significantly prolonged survival of B10 cardiac allografts in C3H recipients. Treatment with rapamycin did not affect DC expression of MHC class II and costimulatory molecules or IL-12 production. Rapamycin did not inhibit DC NF-κB pathway, however, IL-12 signaling through Janus kinase 2/Stat4 activation was markedly suppressed. Indeed, Stat4−/− DC similarly displayed poor allostimulatory activity. The Stat4 downstream product, IFN-γ, was also inhibited by rapamycin, but DC dysfunction could not solely be attributed to low IFN-γ production as DC deficient in IFN-γ still exhibited vigorous allostimulatory activity. Rapamycin did not affect DC IL-12R expression, but markedly suppressed IL-18Rα and β expression, which may in turn down-regulate DC IL-12 autocrine activation.
Tolerance Induction by Intrathymic Expression of P0
Authors: Visan Lucian , Visan Ioana A. , Weishaupt Andreas , Hofstetter Harald H. , Toyka Klaus V. , Hünig Thomas , Gold Ralf 
Published: April 2014

Abstract
Genetic deficiency or instability of myelin protein zero (P0) results in hereditary motor sensory neuropathy. In view of recent advances in gene therapy, substitution of the molecular defect may become realistic in the near future. Here we investigate the impact of genetic deficiency of P0 on selection of the autoreactive T cell repertoire in the corresponding mouse model. We show that P0 mRNA transcripts are expressed in thymic stroma, similar to other myelin proteins and that expression of intact P0 protein can be detected by Western blot. Using a library of overlapping 20mer peptides spanning the entire length of P0 and applying the ELISPOT technique, we detected a strong immune response toward P0 extracellular domain peptide aa 41–60 in P0−/− knockout mice, but not in heterozygous P0+/− or wild-type (wt) mice. In addition, one cryptic epitope and two subdominant epitopes of P0 were identified. Using P0−/− into wt bone marrow (BM) chimeras we found that P0 expression in the host suffices for full tolerance induction, which is in line with its presence in thymic stroma. However, repopulation of P0−/− mice with wt BM led to partial induction of tolerance, suggesting that BM derived cells can also express this protein. Our findings may have implications for secondary autoimmunity developing after gene therapy in hereditary neuropathies and other diseases with genetically determined protein deficiency, because the repaired protein will then represent a foreign, nontolerized Ag.
Cellular Maturation Defects in Bruton’s Tyrosine Kinase-Deficient Immature B Cells Are Amplified by Premature B Cell Receptor Expression and Reduced by Receptor Editing
Authors: Middendorp Sabine , Hendriks Rudolf W. 
Published: April 2014

AbstractIn the mouse, Bruton’s tyrosine kinase (Btk) is essential for efficient developmental progression of CD43+CD2− large cycling into CD43−CD2+ small resting pre-B cells in the bone marrow and of IgMhigh transitional type 2 B cells into IgMlow mature B cells in the spleen. In this study, we show that the impaired induction of cell surface changes in Btk-deficient pre-B cells was still noticeable in κ+ immature B cells, but was largely corrected in λ+ immature B cells. As λ gene rearrangements are programmed to follow κ rearrangements and λ expression is associated with receptor editing, we hypothesized that the transit time through the pre-B cell compartment or receptor editing may affect the extent of the cellular maturation defects in Btk-deficient B cells. To address this issue, we used 3-83μδ transgenic mice, which prematurely express a complete B cell receptor and therefore manifest accelerated B cell development. In Btk-deficient 3-83μδ mice, the IgM+ B cells in the bone marrow exhibited a very immature phenotype (pre-BCR+CD43+CD2−) and were arrested at the transitional type 1 B cell stage upon arrival in the spleen. However, these cellular maturation defects were largely restored when Btk-deficient 3-83μδ B cells were on a centrally deleting background and therefore targeted for receptor editing. Providing an extended time window for developing B cells by enforced expression of the antiapoptotic gene Bcl-2 did not alter the Btk dependence of their cellular maturation. We conclude that premature B cell receptor expression amplifies the cellular maturation defects in Btk-deficient B cells, while extensive receptor editing reduces these defects.
IL-11 Protects Human Microvascular Endothelium from Alloinjury In Vivo by Induction of Survivin Expression
Authors: Kirkiles-Smith Nancy C. , Mahboubi Keyvan , Plescia Janet , McNiff Jennifer M. , Karras James , Schechner Jeffrey S. , Altieri Dario C. , Pober Jordan S. 
Published: April 2014

AbstractIL-11 can reduce tissue injury in animal models of inflammation but the mechanism(s) is unknown. When C.B-17 SCID/beige mice bearing human skin grafts are injected i.p. with human PBMC allogeneic to the donor skin, infiltrating T cells destroy human microvessels by day 21. Intradermal injection of human IL-11 (500 ng/day) delays the time course of graft microvessel loss without reducing the extent of T cell infiltration. Protective actions of IL-11 are most pronounced on day 15. IL-11 has no effect on T cell activation marker, effector molecule, cytokine expression, or endothelial ICAM-1 expression. IL-11 up-regulates the expression of survivin, a cytoprotective protein, in graft keratinocytes and endothelial cells. Topical application of survivin antisense oligonucleotide down-regulates survivin expression in both cell types and largely abrogates the protective effect of IL-11. We conclude that in this human transplant model, IL-11 exerts a cytoprotective rather than anti-inflammatory or immunomodulatory effect mediated through induction of survivin.
Independent Control ofLy49gAlleles: Implications for NK Cell Repertoire Selection and Tumor Cell Killing
Authors: Makrigiannis Andrew P. , Rousselle Etienne , Anderson Stephen K. 
Published: April 2014

AbstractA novel murine NK cell-reactive mAb, AT8, was generated. AT8 recognizes Ly49G from 129/J, BALB/c, and related mouse strains, but does not bind to Ly49GB6. Costaining with AT8 and a Ly49GB6-restricted Ab (Cwy-3) provides the first direct evidence that Ly49G protein is expressed from both alleles on a significant proportion of NK cells from four different types of F1 hybrid mice. The observed level of biallelic Ly49G expression reproducibly followed the product rule in both freshly isolated and cultured NK cells. Surprisingly, the percentage of NK cells expressing both Ly49G alleles could be dramatically increased in vitro and in vivo through IL-2R- and IFN receptor-dependent signaling pathways, respectively. Unexpectedly, Ly49GB6+ NK cells in an H-2d, but not H-2b, background were more likely to lyse Dd+ and Chinese hamster ovary tumor cells than Ly49GBALB/129+ NK cells. Furthermore, Ly49GB6+ NK cells also proliferated to a higher degree in response to poly(I:C) than NK cells expressing a non-Ly49GB6 allele in an H-2d, but not H-2b, background. These results suggest that Ly49GB6 has a lower affinity for H-2Dd than Ly49GBALB/129, and the genetic background calibrates the responsiveness of NK cells bearing self-specific Ly49. Other H-2Dd receptors on the different Ly49G+ NK cell subsets were unequally coexpressed, possibly explaining the disparate responses of Ly49GB6+ NK cells in different hybrid mice. These data indicate that the stochastic mono- and biallelic expression of divergent Ly49G alleles increases the range of MHC affinities and the functional potential in the total NK cell population of heterozygous mice.
Estrogen Preferentially Promotes the Differentiation of CD11c+ CD11bintermediate Dendritic Cells from Bone Marrow Precursors
Authors: Paharkova-Vatchkova Vladislava , Maldonado Ruben , Kovats Susan 
Published: April 2014

AbstractSex biases in autoimmunity and infection suggest that steroid sex hormones directly modulate immune cells. We show in this study that 17-β-estradiol (E2) promotes the differentiation of functional dendritic cells (DC) from murine bone marrow precursor cells. Remarkably, ex vivo DC differentiation was inhibited in steroid hormone-deficient medium, and was restored by addition of physiological amounts of E2, but not dihydrotestosterone. DC differentiation was inhibited by the estrogen receptor (ER) antagonists ICI 182,780 and tamoxifen, and from ERα−/− bone marrow cells, indicating that E2 acted via ERs. E2 addition was most effective in promoting DC differentiation immediately ex vivo, but did not increase DC proliferation. E2 treatment specifically promoted differentiation of a CD11c+ CD11bint DC population that displayed high levels of cell surface MHC class II and CD86, suggesting that E2 could augment numbers of potent APC. DC that differentiated in E2-supplemented medium were fully functional in their capability to mediate presentation of self and foreign Ags and stimulate the proliferation of naive CD4+ T cells. The requirement for estrogen during DC differentiation suggests a mechanism by which E2 levels in peripheral tissues might modulate both the number and functional capabilities of DC in vivo, thereby influencing immune responses.
Production of Donor T Cells Is Critical for Induction of Donor-Specific Tolerance and Maintenance of Chimerism
Authors: Xu Hong , Chilton Paula M. , Huang Yiming , Schanie Carrie L. , Ildstad Suzanne T. 
Published: April 2014

AbstractNonmyeloablative conditioning has significantly reduced the morbidity associated with bone marrow transplantation. The donor hemopoietic cell lineage(s) responsible for the induction and maintenance of tolerance in nonmyeloablatively conditioned recipients is not defined. In the present studies we evaluated which hemopoietic stem cell-derived components are critical to the induction of tolerance in a total body irradiation-based model. Recipient B10 mice were pretreated with mAbs and transplanted with allogeneic B10.BR bone marrow after conditioning with 100–300 cGy total body irradiation. The proportion of recipients engrafting increased in a dose-dependent fashion. All chimeric recipients exhibited multilineage donor cell production. However, induction of tolerance correlated strictly with early production of donor T cells. The chimeras without donor T cells rejected donor skin grafts and demonstrated strong antidonor reactivity in vitro, while possessing high levels of donor chimerism. These animals lost chimerism within 8 mo. Differentiation into T cells was aborted at a prethymic stage in recipients that did not produce donor T cells. Moreover, donor Ag-driven clonal deletion of recipient T cells occurred only in chimeras with donor T cells. These results demonstrate that donor T cell production is critical in the induction of transplantation tolerance and the maintenance of durable chimerism. In addition, donor T cell production directly correlates with the deletion of potentially alloreactive cells.
ζ-Associated Protein of 70 kDa (ZAP-70), but Not Syk, Tyrosine Kinase Can Mediate Apoptosis of T Cells through the Fas/Fas Ligand, Caspase-8 and Caspase-3 Pathways
Authors: Zhong Lingwen , Wu Chun-Hua , Lee Wen-Hui , Liu Chih-Pin 
Published: April 2014

AbstractThe TCR ζ-chain-associated protein of 70 kDA (ZAP-70) and Syk tyrosine kinases play critical roles in regulating TCR-mediated signal transduction. They not only share some overlapped functions but also may play unique roles in regulating the function and development of T cells. However, it is not known whether they have different effects on the activation and activation-induced cell death of T cells. To address this question, we generated cDNAs encoding chimeric molecules that a tailless TCR ζ-chain was directly linked to truncated ZAP-70 (Z/ZAP) or Syk (Z/Syk) molecules lacking the two Src homology 2 domains. Transfection of these molecules into ζ-chain-deficient cells restored their TCR expression. In addition, Z/ZAP and Z/Syk transfectants but not control cells demonstrated kinase activities in phosphorylating an exogenous substrate specific for ZAP-70 and Syk kinases. Z/ZAP transfectants activated through TCRs underwent a faster time course of apoptosis and had a greater percentage of apoptotic cells than that of Z/Syk and control cells. Activated Z/ZAP transfectants increased Fas and Fas ligand (FasL) expression 3- and 40-fold, respectively. Blocking of the Fas/FasL interaction could inhibit the apoptosis of Z/ZAP transfectants. In contrast, although activated Z/Syk transfectants could increase FasL expression, their Fas expression actually decreased and the percentage of apoptotic cells did not increase. Further studies of the mechanisms revealed that activation of Z/ZAP but not Z/Syk transfectants resulted in rapid activation of caspase-3 and caspase-8 that could also be inhibited by blocking Fas/FasL interaction. These results demonstrated that ZAP-70 and Syk play distinct roles in T cell activation and activation-induced cell death.
Early Adenoviral Gene Expression Mediates Immunosuppression by Transduced Dendritic Cell (DC): Implications for Immunotherapy Using Genetically Modified DC
Authors: Tuettenberg Andrea , Jonuleit Helmut , Tüting Thomas , Brück Jürgen , Biermann Volker , Kochanek Stefan , Knop Jürgen , Enk Alexander H. 
Published: April 2014

Abstract
Long-lasting, high-level gene expression in the absence of a toxic or inflammatory response to viral Ags is necessary for the successful application of genetically modified dendritic cell (DC). We previously demonstrated that efficient transduction of mature DC using ΔE1ΔE3 adenoviruses suppressed their stimulatory capacity for T cells. The current study was designed to investigate in more detail the suppressive effect of Ad-DC. We demonstrate that immunosuppression is not mediated by alterations in the T cell phenotype or cytokine profiles released by stimulated T cells. Also DC phenotypes are not affected. However, we demonstrate a cell cycle arrest of the T cell population stimulated by adenovirally transduced DC. Surprisingly, only freshly transduced DC are perturbed in their stimulatory capacity. Experiments using cycloheximide to block early intracellular viral gene expression showed that viral genes expressed in DC are responsible for this transient immunosuppression. In agreement with these findings, high-capacity (gutless) Ad-vectors that differ in viral gene expression from conventional ΔE1ΔE3 adenovirus are suitable for an efficient transduction of human DC. DC transduced with gutless Ad-vectors showed a high allostimulatory capacity for CD4+ and CD8+ T cells. Thus, the immunosuppressive effect of ΔE1ΔE3 Ad-transduced mature DC seems to be the result of early viral gene expression in DC that can be prevented using gutless Ad-vectors for transduction. These results have important implications for the use of genetically modified DC for therapeutic application.
CD4+ and CD8+ Regulatory T Cells Generated Ex Vivo with IL-2 and TGF-β Suppress a Stimulatory Graft-versus-Host Disease with a Lupus-Like Syndrome
Authors: Zheng Song Guo , Wang Ju Hua , Koss Michael N. , Quismorio Francisco , Gray J. Dixon , Horwitz David Allen 
Published: April 2014

AbstractRegulatory T cells generated ex vivo from conventional mouse T cells have been used to prevent and alter the course of a stimulatory graft-vs-host disease with a lupus-like syndrome. DBA/2 mouse T cells induce this syndrome when injected into (DBA/2 × C57BL/6) F1 mice. Stimulating DBA/2 T cells with irradiated C57BL/6 in the presence of IL-2 and TGF-β induced both CD4+ and CD8+ cells to develop potent suppressive activity and enhanced their survival. The IL-2 and TGF-β-treated T cells lost their ability to induce graft-vs-host disease and, instead, prevented other parental T cells from inducing lymphoid hyperplasia, B cell activation, and an immune complex glomerulonephritis. Moreover, a single transfer of TGF-β-conditioned T cells to animals that had already developed anti-dsDNA Abs decreased the titer, suppressed proteinuria, and doubled survival. This study raises the possibility that autologous regulatory T cells generated ex vivo have the potential to be used as an adoptive immunotherapy to induce allograft tolerance and to control autoimmunity.
IL-21 Induces Tumor Rejection by Specific CTL and IFN-γ-Dependent CXC Chemokines in Syngeneic Mice
Authors: Di Carlo Emma , Comes Alberto , Orengo Anna Maria , Rosso Ombretta , Meazza Raffaella , Musiani Piero , Colombo Mario P. , Ferrini Silvano 
Published: April 2014

Abstract
IL-21 is an immune-stimulatory four α helix cytokine produced by activated T cells. To study the in vivo antitumor activities of IL-21, TS/A murine mammary adenocarcinoma cells were genetically modified to secrete IL-21 (TS/A-IL-21). These cells developed small tumors that were subsequently rejected by 90% of s.c. injected syngeneic mice. Five days after injection, TS/A-IL-21 tumors showed numerous infiltrating granulocytes, NK cells, and to a lesser extent CD8+ T cells, along with the expression of TNF-α, IFN-γ, and endothelial adhesion molecules ICAM-1 and VCAM-1. At day 7, CD8+ and CD4+ T cells increased together with IFN-γ, and the CXC chemokines IFN-γ-inducible protein 10, monokine induced by IFN-γ, and IFN-inducible T cell α-chemoattractant. The TS/A-IL-21 tumor displayed a disrupted vascular network with abortive sprouting and signs of endothelial cell damage. In vivo depletion experiments by specific Abs showed that rejection of TS/A-IL-21 cells required CD8+ T lymphocytes and granulocytes. When injected in IFN-γ-deficient mice, TS/A-IL-21 cells formed tumors that regressed in only 29% of animals, indicating a role for IFN-γ in IL-21-mediated antitumor response, but also the existence of IFN-γ-independent effects. Most immunocompetent mice rejecting TS/A-IL-21 cells developed protective immunity against TS/A-pc (75%) and against the antigenically related C26 colon carcinoma cells (61%), as indicated by rechallenge experiments. A specific CTL response against the gp70-env protein of an endogenous murine retrovirus coexpressed by TS/A and C26 cells was detected in mice rejecting TS/A-IL-21 cells. These data suggest that IL-21 represents a suitable adjuvant in inducing specific CTL responses.
Autoreactive B Cells in Lupus-Prone New Zealand Black Mice Exhibit Aberrant Survival and Proliferation in the Presence of Self-Antigen In Vivo
Authors: Chang Nan-Hua , MacLeod Ralph , Wither Joan E. 
Published: April 2014

AbstractTo identify defects in B cell tolerance that may contribute to the production of autoantibodies in New Zealand Black (NZB) mice, we crossed soluble hen egg white lysozyme (sHEL) and anti-HEL Ig transgenes (Ig Tg) onto the NZB background. In this study, we have examined one of the first checkpoints involved in maintenance of peripheral B cell tolerance, follicular exclusion and elimination of self-reactive B cells in the absence of T cell help. Freshly isolated anti-HEL Ig Tg B cells were labeled with CFSE, adoptively transferred into sHEL recipients, and the fate of self-reactive anti-HEL Ig Tg B cells was followed using flow cytometry and immunofluorescence microscopy. Although anti-HEL Ig Tg B cells from NZB mice are appropriately excluded from B cell follicles in NZB sHEL recipient mice, they demonstrate aberrant survival, proliferation, and generation of anti-HEL Ab-producing cells. This abnormal response results from an intrinsic defect in NZB B cells, requires the presence of CD4+ T cells, and is facilitated by the splenic environment in NZB mice. Thus, NZB mice have immune defects that interact synergistically to allow autoreactive B cells to become activated despite the presence of tolerizing autoantigens.