bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental Switch of the Expression of Ion Channels in Human Dendritic Cells
Authors: Zsiros Emese , Kis-Toth Katalin , Hajdu Peter , Gaspar Rezso , Bielanska Joanna , Felipe Antonio , Rajnavolgyi Eva , Panyi Gyorgy 
Published: September 2009

Abstract
Modulation of the expression and activity of plasma membrane ion channels is one of the mechanisms by which immune cells can regulate their intracellular Ca2+ signaling pathways required for proliferation and/or differentiation. Voltage-gated K+ channels, inwardly rectifying K+ channels, and Ca2+-activated K+ channels have been described to play a major role in controlling the membrane potential in lymphocytes and professional APCs, such as monocytes, macrophages, and dendritic cells (DCs). Our study aimed at the characterization and identification of ion channels expressed in the course of human DC differentiation from monocytes. We report in this study for the first time that immature monocyte-derived DCs express voltage-gated Na+ channels in their plasma membrane. The analysis of the biophysical and pharmacological properties of the current and PCR-based cloning revealed the presence of Nav1.7 channels in immature DCs. Transition from the immature to a mature differentiation state, however, was accompanied by the down-regulation of Nav1.7 expression concomitant with the up-regulation of voltage-gated Kv1.3 K+ channel expression. The presence of Kv1.3 channels seems to be common for immune cells; hence, selective Kv1.3 blockers may emerge as candidates for inhibiting various functions of mature DCs that involve their migratory, cytokine-secreting, and T cell-activating potential.
Impaired Mast Cell Activation in Gene-Targeted Mice Lacking the Serum- and Glucocorticoid-Inducible Kinase SGK1
Authors: Sobiesiak Malgorzata , Shumilina Ekaterina , Lam Rebecca S. , Wölbing Florian , Matzner Nicole , Kaesler Susanne , Zemtsova Irina M. , Lupescu Adrian , Zahir Naima , Kuhl Dietmar , Schaller Martin , Biedermann Tilo , Lang Florian 
Published: September 2009

AbstractThe PI3K pathway plays a pivotal role in the stimulation of mast cells. PI3K-dependent kinases include the serum- and glucocorticoid-inducible kinase 1 (SGK1). The present study explored the role of SGK1 in mast cell function. Mast cells were isolated from bone marrow (BMMC) of SGK1 knockout mice (sgk1−/−) and their wild-type littermates (sgk1+/+). The BMMC number as well as CD117, CD34, and FcεRI expression in BMCCs were similar in both genotypes. Upon Ag stimulation of the FcεRI receptor, Ca2+ entry but not Ca2+ release from intracellular stores was markedly impaired in sgk1−/− BMMCs. The currents through Ca2+-activated K+ channels induced by Ag were significantly higher in sgk1+/+ BMMCs than in sgk1−/− BMMCs. Treatment with the Ca2+ ionophore ionomycin (1 μM) led to activation of the K+ channels in both genotypes, indicating that the Ca2+-activated K+ channels are similarly expressed and sensitive to activation by Ca2+ in sgk1+/+ and sgk1−/− BMMCs, and that blunted stimulation of Ca2+-activated K+ channels was secondary to decreased Ca2+ entry. Ag-IgE-induced degranulation and early IL-6 secretion were also significantly blunted in sgk1−/− BMMCs. The decrease in body temperature following Ag treatment, which reflects an anaphylactic reaction, was substantially reduced in sgk1−/− mice, pointing to impaired mast cell function in vivo. Serum histamine levels measured 30 min after induction of an anaphylactic reaction were significantly lower in sgk1−/− than in sgk1+/+mice. The observations reveal a critical role for SGK1 in ion channel regulation and the function of mast cells, and thus disclose a completely novel player in the regulation of allergic reaction.
Killer Ig-Like Receptor Ligand Mismatch Directs NK Cell Expansion In Vitro
Authors: Rose Mingus J. J. , Brooks Andrew G. , Stewart Lisbeth A. , Nguyen Thi H. , Schwarer Anthony P. 
Published: September 2009

Abstract
NK cell alloreactivity is governed largely through failure to detect self-HLA class I ligands by the clonally distributed inhibitory killer Ig-like receptors (KIR) expressed on the NK cell surface. In this study, we investigated the extent to which HLA class I-KIR interactions influence human NK cell proliferation in the allogeneic setting. NK cells were cultured with feeder cells either matched or mismatched for inhibitory KIR ligands, the latter lacking one or more ligands present in the NK cell donor. In postculture cytotoxicity assays, the ability of polyclonal NK cells to kill KIR ligand-mismatched targets was enhanced by exposure to appropriately mismatched feeder cells in prior culture. This corresponded with an increased frequency of postculture donor NK cells expressing a given inhibitory KIR if the allogeneic feeder cells used in the culture lacked its ligand. Similar skewing of KIR distribution was seen in clonally expanded NK cells. Finally, a flow cytometry-based proliferation assay was used to show KIR-specific NK cell division in response to missing self. The findings demonstrate that KIR distribution among a population of alloresponding peripheral blood NK cells is shaped by the HLA class I environment.
IL-27 Regulates IL-10 and IL-17 from CD4+ Cells in Nonhealing Leishmania major Infection
Authors: Anderson Charles F. , Stumhofer Jason S. , Hunter Christopher A. , Sacks David 
Published: September 2009

Abstract
Control of infection caused by Leishmania major requires the development of IFN-γ+CD4+ lymphocytes for the induction of microbicidal activity in host macrophages. We recently reported on the inability of conventionally resistant C57BL/6 mice to successfully resolve infection by an isolate of L. major, despite a strong IFN-γ response by the host. Susceptibility was caused by Ag-specific IL-10 from CD4+ cells that were also producing IFN-γ. In the present studies, we have explored the role for IL-27 in the regulation of IL-10 from Th1 cells in leishmaniasis. Cytokine analysis of CD4+ cells in the lesions and draining lymph nodes of infected IL-27R-deficient (WSX-1−/−) mice revealed diminished IL-10 from IFN-γ+ CD4+ cells, which was accompanied by a reduction in total IFN-γ+CD4+ cells and an increase in IL-4. Despite the inhibition of IL-10 from CD4+ cells, no significant change in parasite numbers was observed, due both to the shift in the Th1/Th2 balance and to residual levels of IL-10. Strikingly, infected WSX-1−/− mice developed more severe lesions that were associated with the appearance of IL-17+ CD4+ cells, demonstrating a function for IL-27 in blocking the development of inappropriate Th17 cells during L. major infection. The results demonstrate the pleiotropic effects that IL-27 has on L. major-driven Th1, Th2, and Th17 development, and reinforce its function as a key regulatory cytokine that controls the balance between immunity and pathology.
Extracellular ATP Acting at the P2X7 Receptor Inhibits Secretion of Soluble HLA-G from Human Monocytes
Authors: Rizzo Roberta , Ferrari Davide , Melchiorri Loredana , Stignani Marina , Gulinelli Sara , Baricordi Olavio R. , Di Virgilio Francesco 
Published: September 2009

Abstract
Bacterial LPS induces the release of ATP from immune cells. Accruing evidence suggests that extracellular ATP participates in the inflammatory response as a proinflammatory mediator by activating the inflammasome complex, inducing secretion of cytokines (IL-1, IL-18) and cell damaging agents such as oxygen radicals, cationic proteins, and metalloproteases. It is not known whether ATP can also act as a proinflammatory mediator by inhibiting production of molecules down-modulating the immune response. Here, we show that extracellular ATP impairs in an IL-10-dependent fashion the expression of the tolerogenic soluble and membrane-bound HLA-G Ag in human monocytes. The effect of ATP was mimicked by BzATP (3′-O-(4-benzoyl)benzoyl-ATP) and greatly reduced by pretreatment with oATP (periodate-oxidized ATP), KN-62 (1-[N,O-bis(5-isoquinoline-sulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine), and an anti-P2X7 mAb, thus pointing to a specific role of the P2X7 receptor. The effect of ATP was time- and dose-dependent and was not due to a decrease in expression of IL-10 receptor. Inhibition by ATP was reverted by supplementation of culture medium with exogenous IL-10. Due to the well-known immunosuppressive activity of IL-10 and soluble HLA-G, this novel effect of ATP might be relevant for the pathophysiology and therapy of inflammatory disorders.
TLR3 Ligand Polyinosinic:Polycytidylic Acid Induces IL-17A and IL-21 Synthesis in Human Th Cells
Authors: Holm Christian K. , Petersen Charlotte C. , Hvid Malene , Petersen Line , Paludan Søren R. , Deleuran Bent , Hokland Marianne 
Published: September 2009

Abstract
TLR3 and TLR9 recognize the pathogen-associated microbial patterns dsRNA and unmethylated DNA, respectively. The recent discovery that these receptors also recognize endogenous ligands from necrotic material has drawn increased attention to their involvement in autoimmunity. Th cell cytokines IL-17A and IL-21 have been assigned with pivotal roles in the regulation of such autoimmune diseases. IL-17A is the hallmark cytokine of the recently discovered proinflammatory Th cell subset TH17. By contrast, the expression of IL-21 does not seem to be limited to a single distinct Th cell subset. We investigated the expression of IL-17A and IL-21 in human CD4+ T cells in response to stimulation with the TLR3 ligand polyinosinic:polycytidylic acid (poly(I:C)) and the TLR9 ligand CpG. We discovered that poly(I:C) induced synthesis of both IL-17A and IL-21. Moreover, we found that poly(I:C) was able to drive the differentiation of naive Th cells into an IL-21 but not into an IL-17A-producing phenotype and did this without affecting the levels of transcription factors T-bet, GATA-3, or retinoic acid receptor-related orphan receptor C. Finally, we found that the IL-21-producing cells that were differentiated in response to poly(I:C) expressed the chemokine receptor CXCR3, which is important in the recruitment of T cells into inflamed joints in rheumatoid arthritis. This is the first report to show that the TLR3 ligand poly(I:C) can directly induce the synthesis of IL-17A and IL-21 and drive differentiation of human naive CD4+ T cells.
Monocytes from Patients with Type 1 Diabetes Spontaneously Secrete Proinflammatory Cytokines Inducing Th17 Cells
Authors: Bradshaw Elizabeth M. , Raddassi Khadir , Elyaman Wassim , Orban Tihamer , Gottlieb Peter A. , Kent Sally C. , Hafler David A. 
Published: September 2009

Abstract
Autoimmune diseases including type 1 diabetes (T1D) are thought to have a Th1/Th17 bias. The underlying mechanisms driving the activation and differentiation of these proinflammatory T cells are unknown. We examined the monocytes isolated directly from the blood of T1D patients and found they spontaneously secreted the proinflammatory cytokines IL-1β and IL-6, which are known to induce and expand Th17 cells. Moreover, these in vivo-activated monocytes from T1D subjects induced more IL-17-secreting cells from memory T cells compared with monocytes from healthy control subjects. The induction of IL-17-secreting T cells by monocytes from T1D subjects was reduced in vitro with a combination of an IL-6-blocking Ab and IL-1R antagonist. In this study, we report a significant although modest increase in the frequency of IL-17-secreting cells in lymphocytes from long-term patients with T1D compared with healthy controls. These data suggest that the innate immune system in T1D may drive the adaptive immune system by expanding the Th17 population of effector T cells.
Temporal Regulation of Ig Gene Diversification Revealed by Single-Cell Imaging
Authors: Ordinario Ellen C. , Yabuki Munehisa , Larson Ryan P. , Maizels Nancy 
Published: September 2009

Abstract
Rearranged Ig V regions undergo activation-induced cytidine deaminase (AID)-initiated diversification in sequence to produce either nontemplated or templated mutations, in the related pathways of somatic hypermutation and gene conversion. In chicken DT40 B cells, gene conversion normally predominates, producing mutations templated by adjacent pseudo-V regions, but impairment of gene conversion switches mutagenesis to a nontemplated pathway. We recently showed that the activator, E2A, functions in cis to promote diversification, and that G1 phase of cell cycle is the critical window for E2A action. By single-cell imaging of stable AID-yellow fluorescent protein transfectants, we now demonstrate that AID-yellow fluorescent protein can stably localize to the nucleus in G1 phase, but undergoes ubiquitin-dependent proteolysis later in cell cycle. By imaging of DT40 polymerized lactose operator-λR cells, in which polymerized lactose operator tags the rearranged λR gene, we show that both the repair polymerase Polη and the multifunctional factor MRE11/RAD50/NBS1 localize to λR, and that λR/Polη colocalizations occur predominately in G1 phase, when they reflect repair of AID-initiated damage. We find no evidence of induction of γ-H2AX, the phosphorylated variant histone that is a marker of double-strand breaks, and Ig gene conversion may therefore proceed by a pathway involving templated repair at DNA nicks rather than double-strand breaks. These results lead to a model in which Ig gene conversion initiates and is completed or nearly completed in G1 phase. AID deaminates ssDNA, and restriction of mutagenesis to G1 phase would contribute to protecting the genome from off-target attack by AID when DNA replication occurs in S phase.
Defucosylated Anti-CCR4 Monoclonal Antibody Exerts Potent ADCC against Primary ATLL Cells Mediated by Autologous Human Immune Cells in NOD/Shi-scid, IL-2Rγnull Mice In Vivo
Authors: Ito Asahi , Ishida Takashi , Utsunomiya Atae , Sato Fumihiko , Mori Fumiko , Yano Hiroki , Inagaki Atsushi , Suzuki Susumu , Takino Hisashi , Ri Masaki , Kusumoto Shigeru , Komatsu Hirokazu , Iida Shinsuke , Inagaki Hiroshi , Ueda Ryuzo 
Published: September 2009

Abstract
There is a lack of suitable small animal models to evaluate human Ab-dependent cellular cytotoxicity (ADCC) in vivo, because of the species incompatibility between humans and animals or due to nonspecific allogeneic immune reactions. To overcome these problems, we established a human tumor-bearing mouse model, using NOD/Shi-scid, IL-2Rγnull (NOG) mice as recipients, in which autologous human immune cells are engrafted and mediate ADCC but in which endogenous murine cells are unable to mediate ADCC. In the present study, we used NOG mice bearing primary adult T cell leukemia/lymphoma (ATLL) cells and a therapeutic chimeric anti-CCR4 mAb, the Fc region of which is defucosylated to enhance ADCC. We report significant antitumor activity in vivo associated with robust ADCC mediated by autologous effector cells from the same patients. The present study is the first to report a mouse model in which a potent antitumor effect of the therapeutic mAb against primary tumor cells is mediated by autologous human immune cells. Human autologous ADCC in mice in vivo was confirmed by the depletion of human immune cells before ATLL PBMC inoculation. In addition, NOG mice bearing primary ATLL cells presented features identical with patients with ATLL. In conclusion, this approach makes it possible to model the human immune system active in Ab-based immunotherapy in vivo, and thus to perform more appropriate preclinical evaluations of novel therapeutic mAb. Furthermore, the potent ADCC mediated by defucosylated anti-CCR4 mAb, observed here in vivo in humanized mice, will be exploited in clinical trials in the near future.
Antitumor IgE Adjuvanticity: Key Role of FcεRI
Authors: Nigro Elisa A. , Brini Anna T. , Soprana Elisa , Ambrosi Alessandro , Dombrowicz David , Siccardi Antonio G. , Vangelista Luca 
Published: September 2009

Abstract
Working with C57BL/6 mouse tumor models, we had previously demonstrated that vaccination with IgE-coated tumor cells can protect against tumor challenge, an observation that supports the involvement of IgE in antitumor immunity. The adjuvant effect of IgE was shown to result from eosinophil-dependent priming of the T cell-mediated adaptive immune response. The protective effect is likely to be mediated by the interaction of tumor cell-bound IgE with receptors, which then trigger the release of mediators, recruitment of effector cells, cell killing and tumor Ag cross-priming. It was therefore of utmost importance to demonstrate the strict dependence of the protective effect on IgE receptor activation. First, the protective effect of IgE was confirmed in a BALB/c tumor model, in which IgE-loaded modified VV Ankara-infected tumor cells proved to be an effective cellular vaccine. However, the protective effect was lost in FcεRIα−/− (but not in CD23−/−) knockout mice, showing the IgE-FcεRI interaction to be essential. Moreover, human IgE (not effective in BALB/c mice) had a protective effect in the humanized knockin mouse (FcεRIα−/− hFcεRIα+). This finding suggests that the adjuvant effect of IgE could be exploited for human therapeutics.
Engagement of TLR2 Does not Reverse the Suppressor Function of Mouse Regulatory T Cells, but Promotes Their Survival
Authors: Chen Qian , Davidson Todd S. , Huter Eva N. , Shevach Ethan M. 
Published: September 2009

Abstract
TLRs are a class of conserved pattern recognition receptors that are used by cells of the innate immune system. Recent studies have demonstrated the expression of TLRs on both human and mouse T cells raising the possibility that TLRs play a direct role in adaptive immunity. TLR2 is activated primarily by bacterial wall components including peptidoglycan and lipoproteins. Several studies have shown that mouse regulatory T (Treg) cells express TLR2 and claimed that engagement of TLR2 by synthetic ligands reversed their suppressive function. In contrary, enhancement of Treg function was observed following engagement of TLR2 on human Treg. We have reexamined the expression and function of TLR2 on mouse Treg purified from Foxp3-GFP knock-in mice. TLR2 ligation by TLR2 agonist, the synthetic bacterial lipoprotein Pam3CSK4, enhanced the proliferative responses of both conventional T cells and Treg in response to TLR stimulation in the absence of APC. Treatment of Foxp3+ Treg with Pam3CSK4 did not alter their suppressive function in vitro or in vivo and did not reduce their level of Foxp3 expression. An additional effect of TLR2 stimulation of Treg was induction of Bcl-xL resulting in enhanced survival in vitro. Treatment of mice with the TLR2 agonist enhanced the Ag-driven proliferation of Treg in vivo, but did not abolish their ability to suppress the development of experimental autoimmune encephalomyelitis. Development of methods to selectively stimulate TLR2 on Treg may lead to a novel approaches for the treatment of autoimmune diseases.
Chicken IgY Binds Its Receptor at the CH3/CH4 Interface Similarly as the Human IgA:FcαRI Interaction
Authors: Pürzel Jana , Schmitt Ramona , Viertlboeck Birgit C. , Göbel Thomas W. 
Published: September 2009

Abstract
Chicken IgY, the ancestral form of mammalian IgE and IgG, is recognized by the high-affinity FcY receptor CHIR-AB1, a member of the leukocyte receptor family. In this study, we have characterized the receptor ligand interaction site by consecutive truncations of the Fcυ IgY domains and mutational analyses of selected residues. Using several fusion proteins that linked the human Cγ2 and Cγ3 domains with the Fcυ IgY domains, a binding assay revealed that both the Fcυ3 and Fcυ4 domains were essential for the IgY CHIR-AB1 interaction. Sequence comparisons of chicken IgY with human IgA demonstrated that 11 of the 19 contact residues important for the IgA FcαRI interaction have been conserved in chicken IgY, although the overall amino acid identity is only 34%. Among the 19 amino acids at respective positions in IgY, the mutation of two residues in the Fcυ3 and two in the Fcυ4 domain completely abolished the IgY to CHIR-AB1 binding revealed by two independent assays. Three further mutations substantially altered the interaction. Molecular modeling on the Cυ3 to Cυ4 crystal structure revealed that all critical residues, although on two domains, are in close proximity. The importance of N-linked carbohydrates was demonstrated by the failure of the CHIR-AB1 interaction after mutation of the glycosylation site. The identification of the IgY Cυ3/Cυ4 interdomain region as critical for binding to CHIR-AB1 significantly enhances our understanding of the IgY receptor interaction and allows further conclusions regarding the FcR phylogeny.
Discontinued Postnatal Thymocyte Development in Sphingosine 1-Phosphate-Lyase-Deficient Mice
Authors: Weber Claudia , Krueger Andreas , Münk Anika , Bode Constantin , Van Veldhoven Paul P. , Gräler Markus H. 
Published: September 2009

Abstract
Circulation of lymphocytes through peripheral lymphoid tissues as well as progenitor entry into the thymus and its output of mature T cells are critical for normal immune function. Egress of lymphocytes from both peripheral lymphoid organs and thymus is dependent on sphingosine 1-phosphate (S1P) gradients. S1P-lyase 1 (SGPL1) deficiency leads to accumulation of S1P in lymphoid tissues, which blocks lymphocyte egress and induces thymus atrophy. In this study, we investigated thymocyte development in SGPL1-deficient mice (SGPL1−/−), which exhibited postnatal discontinuation of early thymocytopoiesis starting at 2 wk after birth. SGPL−/− thymi showed a loss of developing thymocytes in the thymic cortex between 2 and 4 wk of age, whereas mature thymocytes accumulated in the medulla. Detailed analysis demonstrated a deficit in thymic early T cell progenitors (ETP) as the principal reason for discontinued thymocyte development. This developmental block was accompanied by accumulation of ceramides, resulting in enhanced apoptosis of developing T cells. Lack of immigration or settlement of ETP completely halted thymocyte development. We conclude that increased ceramide levels in the thymus of SGPL1−/− mice abrogate thymic development postnatally by enhanced thymocyte apoptosis and depletion of thymic ETP. Our findings indicate that potentially therapeutic immunosuppression by SGPL1 inhibition should benefit from monitoring ceramides to prevent their increase to apoptosis- inducing levels.