bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct T Cell Developmental Consequences in Humans and Mice Expressing Identical Mutations in the DLAARN Motif of ZAP-70
Authors: Elder Melissa E. , Skoda-Smith Suzanne , Kadlecek Theresa A. , Wang Fengling , Wu Jun , Weiss Arthur 
Published: April 2014

AbstractThe protein tyrosine kinase, ZAP-70, is pivotally involved in transduction of Ag-binding signals from the TCR required for T cell activation and development. Defects in ZAP-70 result in SCID in humans and mice. We describe an infant with SCID due to a novel ZAP-70 mutation, comparable with that which arose spontaneously in an inbred mouse colony. The patient inherited a homozygous missense mutation within the highly conserved DLAARN motif in the ZAP-70 kinase domain. Although the mutation only modestly affected protein stability, catalytic function was absent. Despite identical changes in the amino acid sequence of ZAP-70, the peripheral T cell phenotypes of our patient and affected mice are distinct. ZAP-70 deficiency in this patient, as in other humans, is characterized by abundant nonfunctional CD4+ T cells and absent CD8+ T cells. In contrast, ZAP-70-deficient mice lack both major T cell subsets. Although levels of the ZAP-70-related protein tyrosine kinase, Syk, may be sufficiently increased in human thymocytes to rescue CD4 development, survival of ZAP-70-deficient T cells in the periphery does not appear to be dependent on persistent up-regulation of Syk expression.
Costimulation-Dependent Modulation of Experimental Autoimmune Encephalomyelitis by Ligand Stimulation of Vα14 NK T Cells
Authors: Pál Endre , Tabira Takeshi , Kawano Tetsu , Taniguchi Masaru , Miyake Sachiko , Yamamura Takashi 
Published: April 2014

Abstract
Experimental autoimmune encephalomyelitis (EAE) is a Th1 cell-mediated autoimmune disease that can be protected against by stimulating regulatory cells. Here we examined whether EAE can be purposefully modulated by stimulating Vα14 NK T cells with the CD1d-restricted ligand α-galactosylceramide (α-GC). EAE induced in wild-type C57BL/6 (B6) mice was not appreciably altered by injection of α-GC. However, EAE induced in IL-4 knockout mice and IFN-γ knockout mice was enhanced or suppressed by α-GC, respectively. This indicates that the IL-4 and IFN-γ triggered by α-GC may play an inhibitory or enhancing role in the regulation of EAE. We next studied whether NK T cells of wild-type mice may switch their Th0-like phenotype toward Th1 or Th2. Notably, in the presence of blocking B7.2 (CD86) mAb, α-GC stimulation could bias the cytokine profile of NK T cells toward Th2, whereas presentation of α-GC by CD40-activated APC induced a Th1 shift of NK T cells. Furthermore, transfer of the α-GC-pulsed APC preparations suppressed or enhanced EAE according to their ability to polarize NK T cells toward Th2 or Th1 in vitro. These results have important implications for understanding the role of NK T cells in autoimmunity and for designing a therapeutic strategy targeting NK T cells.
Increased Production of Immature Myeloid Cells in Cancer Patients: A Mechanism of Immunosuppression in Cancer
Authors: Almand Bond , Clark Joseph I. , Nikitina Ekaterina , van Beynen James , English Nicholas R. , Knight Stella C. , Carbone David P. , Gabrilovich Dmitry I. 
Published: April 2014

AbstractDefective dendritic cell (DC) function caused by abnormal differentiation of these cells is an important mechanism of tumor escape from immune system control. Previously, we have demonstrated that the number and function of DC were dramatically reduced in cancer patients. This effect was closely associated with accumulation of immature cells (ImC) in peripheral blood. In this study, we investigated the nature and functional role of those ImC. Using flow cytometry, electron microscopy, colony formation assays, and cell differentiation in the presence of different cell growth factors, we have determined that the population of ImC is composed of a small percentage (&lt;2%) of hemopoietic progenitor cells, with all other cells being represented by MHC class I-positive myeloid cells. About one-third of ImC were immature macrophages and DC, and the remaining cells were immature myeloid cells at earlier stages of differentiation. These cells were differentiated into mature DC in the presence of 1 μM all-trans-retinoic acid. Removal of ImC from DC fractions completely restored the ability of the DC to stimulate allogeneic T cells. In two different experimental systems ImC inhibited Ag-specific T cell responses. Thus, immature myeloid cells generated in large numbers in cancer patients are able to directly inhibit Ag-specific T cell responses. This may represent a new mechanism of immune suppression in cancer and may suggest a new approach to cancer treatment.
Gangliosides GD1b, GT1b, and GQ1b Enhance IL-2 and IFN-γ Production and Suppress IL-4 and IL-5 Production in Phytohemagglutinin-Stimulated Human T Cells
Authors: Kanda Naoko , Watanabe Shinichi 
Published: April 2014

AbstractGangliosides are sialic acid-containing glycolipids. We studied the in vitro effects of gangliosides on Th1 and Th2 cytokine production in PHA-stimulated human T cells. Gangliosides GD1b, GT1b, and GQ1b (each 100 nM) enhanced PHA-induced IL-2 secretion of peripheral blood T cells ∼4-fold and enhanced that of IFN-γ 3- to 4-fold compared with controls. These gangliosides decreased PHA-induced IL-4 secretion by 50–53% and that of IL-5 by 53–63% compared with controls, respectively. The other gangliosides did not alter the secretion of Th1 or Th2 cytokines. RT-PCR showed that GD1b, GT1b, and GQ1b enhanced PHA-induced IL-2 and IFN-γ transcription and suppressed that of IL-4 and IL-5. Transient transfection assays of Jurkat T cells showed that GD1b, GT1b, and GQ1b enhanced PHA-induced IL-2 and IFN-γ promoter activities but suppressed those of IL-4 and IL-5. The cAMP analogue dibutyryl cAMP and the cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine each reversed GD1b-, GT1b-, and GQ1b-induced stimulation of IL-2 and IFN-γ production and inhibition of IL-4 and IL-5 production at the levels of proteins, transcription, and promoter activities. GD1b, GT1b, and GQ1b suppressed PHA-induced increase in cAMP level in T cells. These gangliosides suppressed PHA-stimulated adenylate cyclase activity in T cells. These results suggest that GD1b, GT1b, and GQ1b may enhance Th1 cytokine production while suppressing Th2 production by inhibiting adenylate cyclase activity.
Anti-CD40 Antibody Induces Antitumor and Antimetastatic Effects: The Role of NK Cells
Authors: Turner Joel G. , Rakhmilevich Alexander L. , Burdelya Lyudmila , Neal Zane , Imboden Michael , Sondel Paul M. , Yu Hua 
Published: April 2014

AbstractWe assessed the effect of the stimulatory anti-CD40 Ab on NK cell activation in vivo and the therapeutic potential of activated NK cells in tumor-bearing mice. Single-dose i.p. injection of the anti-CD40 Ab resulted in production of IL-12 and IFN-γ in vivo, followed by a dramatic increase in NK cell cytolytic activity in PBLs. NK cell activation by anti-CD40 Ab was also observed in CD40 ligand knockout mice. Because NK cells express CD40 ligand but not CD40, our results suggest that NK activation is mediated by increased cytokine production upon CD40 ligation of APCs. Treatment of tumor-bearing mice with anti-CD40 Ab resulted in substantial antitumor and antimetastatic effects in three tumor models. Depletion of NK cells with anti-asialo GM1 Ab reduced or abrogated the observed antitumor effects in all the tested models. These results indicate that a stimulatory CD40 Ab indirectly activates NK cells, which can produce significant antitumor and antimetastatic effects.
CD44-Deficient Mice Exhibit Enhanced Hepatitis After Concanavalin A Injection: Evidence for Involvement of CD44 in Activation-Induced Cell Death
Authors: Chen Dawei , McKallip Robert J. , Zeytun Ahmet , Do Yoonkyung , Lombard Catherine , Robertson John L. , Mak Tak W. , Nagarkatti Prakash S. , Nagarkatti Mitzi 
Published: April 2014

AbstractAdministration of Con A induces severe injury to hepatocytes in mice and is considered to be a model for human hepatitis. In the current study, we investigated the role of CD44 in Con A-induced hepatitis. Intravenous administration of Con A (20 mg/kg) caused 100% mortality in C57BL/6 CD44-knockout (KO) mice, although it was not lethal in C57BL/6 CD44 wild-type (WT) mice. Administration of lower doses of Con A (12 mg/kg body weight) into CD44 WT mice induced hepatitis as evident from increased plasma aspartate aminotransferase levels accompanied by active infiltration of mononuclear cells and neutrophils, and significant induction of apoptosis in the liver. Interestingly, CD44 KO mice injected with similar doses of Con A exhibited more severe acute suppurative hepatitis. Transfer of spleen cells from Con A-injected CD44 KO mice into CD44 WT mice induced higher levels of hepatitis when compared with transfer of similar cells from CD44 WT mice into CD44 WT mice. The increased hepatitis seen in CD44 KO mice was accompanied by increased production of cytokines such as TNF-α, IL-2 and IFN-γ, but not Fas or Fas ligand. The increased susceptibility of CD44 KO mice to hepatitis correlated with the observation that T cells from CD44 KO mice were more resistant to activation-induced cell death when compared with the CD44 WT mice. Together, these data demonstrate that activated T cells use CD44 to undergo apoptosis, and dysregulation in this pathway could lead to increased pathogenesis in a number of diseases, including hepatitis.
Distinct Mechanisms Contribute to Generate and Change the CD4:CD8 Cell Ratio During Thymus Development: A Role for the Notch Ligand, Jagged1
Authors: Jiménez Eva , Vicente Angeles , Sacedón Rosa , Muñoz Juan J. , Weinmaster Gerry , Zapata Agustín G. , Varas Alberto 
Published: April 2014

AbstractIn adult life, the high CD4:CD8 cell ratio observed in peripheral lymphoid organs originates in the thymus. Our results show that the low peripheral CD4:CD8 cell ratio seen during fetal life also has an intrathymic origin. This distinct production of CD4+CD8− and CD4−CD8+ thymocytes is regulated by the developmental age of the thymic stroma. The differential expression of Notch receptors and their ligands, especially Jagged1, throughout thymus development plays a key role in the generation of the different CD4:CD8 cell ratios. We also show that the intrathymic CD4:CD8 cell ratio sharply changes from fetal to adult values around birth. Differences in the proliferation and emigration rates of the mature thymocyte subsets contribute to this change.
Definition of a Novel Cellular Constituent of the Bone Marrow That Regulates the Response of Immature B Cells to B Cell Antigen Receptor Engagement
Authors: Sandel Peter C. , Gendelman Mariya , Kelsoe Garnett , Monroe John G. 
Published: April 2014

AbstractPreviously we defined a Thy1dull bone marrow-derived cell population that regulated fate decisions by immature B cells after Ag receptor signaling. The microenvironmental signals provided by this cell population were shown to redirect the B cell Ag receptor -induced apoptotic response of immature B cells toward continued recombination-activating gene (RAG) expression and secondary light chain recombination (receptor editing). Neither the identity of the cell responsible for this activity nor its role in immature B cell development in vivo were addressed by these previous studies. Here we show that this protective microenvironmental niche is defined by the presence of a novel Thy1dull, DX5pos cell that can be found in close association with immature B cells in vivo. Depletion of this cell eliminates the anti-apoptotic effect of bone marrow in vitro and leads to a significant decrease in the number and frequency of bone marrow immature B cells in vivo. We propose that, just as the bone marrow environment is essential for the survival and progression of pro-B and pre-B cells through their respective developmental checkpoints, this cellular niche regulates the progression of immature stage B cells through negative selection.
Protein Kinase C-θ Mediates a Selective T Cell Survival Signal Via Phosphorylation of BAD
Authors: Villalba Martin , Bushway Paul , Altman Amnon 
Published: April 2014

AbstractProtein kinase C (PKC)-activating phorbol esters protect T cells from Fas-induced apoptosis. However, the mechanism of this protective effect and the identity of the relevant PKC isoform(s) are poorly understood. Here, we show that PKCθ plays a selective and important role in this protection. Fas triggering led to a selective caspase-3-dependent cleavage of the enzyme and proteasome-mediated degradation and inactivation of its catalytic fragment. These events preceded the onset of apoptosis. Pharmacological inhibition of PKCθ promoted Fas-mediated apoptosis in three different types of T cells. Conversely, constitutively active PKCθ (and, to a lesser degree, PKCε) selectively protected T cells from Fas-induced apoptosis. We provide evidence that the distant Bcl-2 family member, BAD, is a PKCθ substrate, is phosphorylated by TCR stimulation, and can mediate at least in part the anti-apoptotic effect of PKCθ.
Generation of Macrophages from Early T Progenitors In Vitro
Authors: Lee Chong-Kil , Kim Jeong Ki , Kim Youngsoo , Lee Myung-Koo , Kim Kyungjae , Kang Jong-Koo , Hofmeister Robert , Durum Scott K. , Han Seong Sun 
Published: April 2014

AbstractEarly T progenitors in the thymus have been reported to have the capacity to develop into B cells, thymic dendritic cells, and NK cells. Here we describe conditions that induce early T progenitors to develop into macrophages. Initially, we observed that early T progenitors could be induced to develop into macrophages by cytokines produced from a thymic stromal cell line, TFGD, and later we found that the cytokine mixture of M-CSF plus IL-6 plus IL-7 also induced macrophage differentiation from pro-T cells. M-CSF by itself was unable to induce macrophage differentiation from early T progenitors. To correlate this observation with the developmental potential of early T progenitors, mouse embryonic thymocytes were sorted into four populations, pro-T1 to pro-T4, based on the expression of CD44 and CD25, and then cultured with TFGD culture supernatant. We found that pro-T1 and pro-T2 cells, but not pro-T3 and pro-T4 cells, generate macrophages. Limiting dilution analysis of the differentiation capability of sorted pro-T2 cells also confirmed that pro-T2 cells could generate macrophages. These results suggest that T cells and thymic macrophages could originate from a common intrathymic precursor.
Early Intestinal Th1 Inflammation and Mucosal T Cell Recruitment During Acute Graft-Versus-Host Reaction
Authors: Snider Denis , Liang Hong 
Published: April 2014

AbstractLittle is understood about the earliest cytokine responses and the role(s) of donor CD4 T cells in the intestine during the induced graft-vs-host reaction (GVHR). We investigated the activation and mucosal homing phenotype of the donor CD4 cells and the kinetics of cytokine responses within the intestine and associated lymphoid tissues during early GVHR. Significant frequencies of donor CD4 cells accumulated within recipient Peyer’s patches (PP), mesenteric lymph nodes (MLN), lamina propria (LP), and spleen (SP), during the first 9 days of GVHR. Many donor CD4 cells in SP, MLN, and LP expressed CD44 and also expressed de novo the mucosal homing integrin α4β7 (LPAM-1). A large IFN-γ response occurred by day 3 in cells from PP and MLN, but much later (day 9) in SP and LP cells. IL-10 production by SP and MLN cells was elevated initially but declined substantially by day 9. IL-4 production by SP, MLN, and PP cells was low on day 3 and showed gradual decline in LP by day 9. IL-5 production by LP cells gradually increased in direct contrast to IL-5 production by MLN cells. The MLN CD4 cells showed the most dynamic changes, with high numbers of activated/effector donor CD4 cells and altered cytokine production consistent with a developing Th1 response. The IFN-γ responses in PP and MLN preceded that of the SP, suggesting an intestinal origin for some Th1 effector cells in GVHR. Donor CD4 T cells apparently acquire the ability to home to the LP during early GVHR.
An IFN-γ-Dependent Pathway Controls Stimulation of Memory Phenotype CD8+ T Cell Turnover In Vivo by IL-12, IL-18, and IFN-γ
Authors: Tough David F. , Zhang Xiaohong , Sprent Jonathan 
Published: April 2014

Abstract
Unlike naive T cells, memory phenotype (CD44high) T cells exhibit a high background rate of turnover in vivo. Previous studies showed that the turnover of memory phenotype CD8+ (but not CD4+) cells in vivo can be considerably enhanced by products of infectious agents such as LPS. Such stimulation is TCR independent and hinges on the release of type I IFNs (IFN-I) which leads to the production of an effector cytokine, probably IL-15. In this study, we describe a second pathway of CD44high CD8+ stimulation in vivo. This pathway is IFN-γ rather than IFN-I dependent and is mediated by at least three cytokines, IL-12, IL-18, and IFN-γ. As for IFN-I, these three cytokines are nonstimulatory for purified T cells and under in vivo conditions probably act via production of IL-15.
Involvement of Bik, a Proapoptotic Member of the Bcl-2 Family, in Surface IgM-Mediated B Cell Apoptosis
Authors: Jiang Aimin , Clark Edward A. 
Published: April 2014

AbstractApoptosis plays a central role in shaping the repertoire of circulating mature B lymphocytes, but the underlying molecular mechanisms regulating B cell fate are not well understood. Human B104 B lymphoma cells undergo apoptosis after surface Ig (sIg)M, but not sIgD, ligation; sIgM-mediated apoptosis of B104 cells apparently requires new gene transcription because actinomycin D can inhibit the apoptotic response. Here we report that expression of Bik, a proapoptotic member of the Bcl-2 family, is greatly increased after sIgM ligation. Bik expression was tightly controlled at both transcriptional and post-transcriptional levels. Whereas a calcineurin-dependent pathway was essential for Bik mRNA induction, both the phosphatidylinositol 3-kinase (PI3K)- and the calcineurin-dependent pathways were required for the sustained production of Bik protein. Consistent with these findings, sIgD ligation, which leads to the similar calcium mobilization and increases in Bik mRNA, induced only a transient activation of PI3K and did not lead to sustained Bik protein expression. Furthermore, sustained Bik protein expression correlated with B cell apoptosis, as treatment with either a calcineurin inhibitor or PI3K inhibitors blocked both sIgM-mediated sustained Bik protein induction and apoptosis. In addition, sIgM ligation strongly increased the amount of Bik associated with endogenous Bcl-x, but sIgD ligation did not. Studies with caspase inhibitors also revealed that Bik and Bcl-x interacted upstream of caspases in the B cell apoptosis cascade. Thus, Bik protein induction and, subsequently, sequestering of antiapoptotic Bcl-x by Bik may play an important role in regulating B cell apoptosis.
CD45 Tyrosine Phosphatase Controls Common γ-Chain Cytokine-Mediated STAT and Extracellular Signal-Related Kinase Phosphorylation in Activated Human Lymphoblasts: Inhibition of Proliferation Without Induction of Apoptosis
Authors: Blank Norbert , Kriegel Martin , Hieronymus Thomas , Geiler Thomas , Winkler Silke , Kalden Joachim R. , Lorenz Hanns-Martin 
Published: April 2014

AbstractThe objective of this study was to test whether CD45 signals can influence signaling processes in activated human lymphoblasts. To this end, we generated lymphoblasts which proliferate in response to common γ-chain cytokines, but readily undergo apoptosis after cytokine withdrawal. In experiments with the CD45R0 mAb UCHL-1, but not control CD45 mAbs, we found significant inhibition of proliferation. Interestingly, the pan-CD45 mAb GAP8.3, which is most effective in inhibition of OKT-3-mediated proliferation in quiescent lymphocytes, was ineffective in lymphoblasts. Addition of CD3 mAb OKT-3 had no influence on IL-2-mediated proliferation (with or without UCHL-1). In contrast, after addition of OKT-3 to IL-4- and IL-7-stimulated proliferation assays, UCHL-1 signals could not significantly alter cellular proliferation. We did not find induction of apoptosis following CD45R0 signaling. In Western blots using mAbs detecting phosphorylated STAT-3, STAT-5, STAT-6, or extracellular signal-related kinase 1/2, we found that CD45R0 signaling could effectively diminish phosphorylation of these intracellular signaling components. Using RT-PCR, we found that CD45R0 signaling inhibited IL-2 mRNA production without major influence on IL-13, IL-5, or IFN-γ mRNA levels. Costimulation with OKT-3 and IL-2 optimally induced secretion of IFN-γ, TNF-α, and IL-5, which was not decreased by CD45 signals. In conclusion, we illustrate that CD45R0 signals control early cytokine receptor-associated signaling processes and mRNA and DNA synthesis in activated human lymphoblasts. Furthermore, we show the existence of CD45 epitopes (GAP8.3), which are active and critical for signaling in quiescent lymphocytes, but are nonfunctional in activated human lymphoblasts.
Recombinant Allergens with Reduced Allergenicity but Retaining Immunogenicity of the Natural Allergens: Hybrids of Yellow Jacket and Paper Wasp Venom Allergen Antigen 5s
Authors: King Te Piao , Jim Sui Y. , Monsalve Rafael I. , Kagey-Sobotka Anne , Lichtenstein Lawrence M. , Spangfort Michael D. 
Published: April 2014

AbstractThe homologous venom allergen Ag 5s from the yellow jacket (Vespula vulgaris) and paper wasp (Polistes annularis) have 59% sequence identity of their respective 204 and 205 amino acid residues, and they have low degrees of antigenic cross-reactivity in insect allergic patients and in animal models. Hybrids containing different segments of these two vespid Ag 5s were expressed in yeast. Circular dichroism spectroscopy suggests the hybrids to have the secondary structure of natural Ag 5. Inhibition ELISA with human and murine Abs suggests the hybrids to have the discontinuous B cell epitopes of the natural Ag 5 but with an altered epitope density. The hybrids were immunogenic in mice for B and T cell responses to both Ag 5s. The N-terminal region of Ag 5 was found to contain its dominant B cell epitope(s). Hybrids containing 10–49 residues of yellow jacket Ag 5 showed 100- to 3000-fold reduction in allergenicity when tested by histamine release assay with basophils of yellow jacket-sensitive patients. Our findings suggest that hybrids represent a useful approach to map the discontinuous B cell epitope-containing regions of proteins. They also suggest that Ag 5 hybrids may be useful immunotherapeutic reagents in man.