bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary Hepatocytes from Mice Treated with IL-2/IL-12 Produce T Cell Chemoattractant Activity that Is Dependent on Monokine Induced by IFN-γ (Mig) and Chemokine Responsive to γ-2 (Crg-2)
Authors: Park Jong-Wook , Gruys M. Eilene , McCormick Kathy , Lee Jong-Keuk , Subleski Jeffrey , Wigginton Jon M. , Fenton Robert G. , Wang Ji-Ming , Wiltrout Robert H. 
Published: April 2014

Abstract
The IFN-γ-inducible proteins monokine induced by IFN-γ (Mig) and chemokine responsive to γ-2 (Crg-2) can contribute to IL-12-induced antiangiogenic and leukocyte-recruiting activities, but the extent to which leukocytes vs parenchymal cells in different organs contribute to the production of these molecules remains unclear. The results presented herein show that IFN-γ-dependent induction of Mig and Crg-2 gene expression can occur in many nonlymphoid organs, and these genes are rapidly induced in purified hepatocytes isolated from mice treated with IL-2 plus IL-12, or from Hepa 1-6 hepatoma cells treated in vitro with IFN-γ. In addition to depending on IFN-γ, the ability of IL-12 or IL-2/IL-12 to induce Mig and Crg-2 gene expression in purified hepatocytes also is accompanied by the coordinate up-regulation of the IFN-γ R α and β-chains, in the absence of IL-12R components. Supernatants of primary hepatocytes obtained from mice treated in vivo with IL-2/IL-12 or from hepatocytes treated in vitro with IFN-γ contain increased chemotactic activity for enriched human and mouse CD3+ T cells, as well as mouse DX5+ NK cells. The hepatocyte-derived chemotactic activity for mouse T cells but not NK cells was ablated by Abs specific for Mig and Crg-2. These results suggest that parenchymal cells in some organs may contribute substantially to initiation and/or amplification of inflammatory or antitumor responses.
Mouse CD94 Participates in Qa-1-Mediated Self Recognition by NK Cells and Delivers Inhibitory Signals Independent of Ly-49
Authors: Toyama-Sorimachi Noriko , Taguchi Yuriko , Yagita Hideo , Kitamura Fujiko , Kawasaki Akemi , Koyasu Shigeo , Karasuyama Hajime 
Published: April 2014

AbstractInhibitory receptors expressed on NK cells recognize MHC class I molecules and transduce negative signals to prevent the lysis of healthy autologous cells. The lectin-like CD94/NKG2 heterodimer has been studied extensively as a human inhibitory receptor. In contrast, in mice, another lectin-like receptor, Ly-49, was the only known inhibitory receptor until the recent discovery of CD94/NKG2 homologues in mice. Here we describe the expression and function of mouse CD94 analyzed by a newly established mAb. CD94 was detected on essentially all NK and NK T cells as well as small fractions of T cells in all mouse strains tested. Two distinct populations were identified among NK and NK T cells, CD94bright and CD94dull cells, independent of Ly-49 expression. The anti-CD94 mAb completely abrogated the inhibition of target killing mediated by NK recognition of Qa-1/Qdm peptide on target cells. Importantly, CD94bright but not CD94dull cells were found to be functional in the Qa-1/Qdm-mediated inhibition. In the presence of the mAb, activated NK cells showed substantial cytotoxicity against autologous target cells as well as enhanced cytotoxicity against allogeneic and “missing self” target cells. These results suggest that mouse CD94 participates in the protection of self cells from NK cytotoxicity through the Qa-1 recognition, independent of inhibitory receptors for classical MHC class I such as Ly-49.
The Maturation of Dendritic Cells Results in Postintegration Inhibition of HIV-1 Replication
Authors: Bakri Youssef , Schiffer Cécile , Zennou Véronique , Charneau Pierre , Kahn Edmond , Benjouad Abdelaziz , Gluckman Jean Claude , Canque Bruno 
Published: April 2014

Abstract
Maturation of dendritic cells (DC) is known to result in decreased capacity to produce HIV due to postentry block of its replicative cycle. In this study, we compared the early phases of this cycle in immature DC (iDC) and mature DC (mDC) generated from monocytes cultured with GM-CSF and IL-4, trimeric CD40 ligand (DCCD40LT), or monocyte-conditioned medium (DCMCM) being added or not from day 5. Culture day 8 cells exposed to X4 HIV-1LAI or R5 HIV-1Ba-L were analyzed by semiquantitative R-U5 PCR, which detects total HIV DNA. CXC chemokine receptor 4low (CXCR4low) CCR5+ iDC harbored similar viral DNA amounts when exposed to either strain. HIV-1LAI entered more efficiently into DCCD40LT or DCMCM with up-regulated CXCR4. CCR5low DCCD40LT still allowed entry of HIV-1Ba-L, whereas CCR5− DCMCM displayed reduced permissivity to this virus. Comparing amounts of late (long terminal repeat (LTR)-gag PCR) and total (R-U5 PCR) viral DNA products showed that HIV-1Ba-L reverse transcription was more efficient than that of HIV-1LAI, but was not affected by DC maturation. Southern blot detection of linear, circular, and integrated HIV DNA showed that maturation affected neither HIV-1 nuclear import nor integration. When assessing virus transcription by exposing iDC to pNL4-3.GFP or pNL4-3.Luc viruses pseudotyped with the G protein of vesicular stomatitis virus (VSV-G), followed by culture with or without CD40LT or MCM, GFP and luciferase activities decreased by 60–75% in mDC vs iDC. Thus, reduced HIV replication in mDC is primarily due to a postintegration block occurring mainly at the transcriptional level. We could not relate this block to altered expression and nuclear localization of NF-κB proteins and SP1 and SP3 transcription factors.
IL-10 Is Required for Regulatory T Cells to Mediate Tolerance to Alloantigens In Vivo
Authors: Hara Masaki , Kingsley Cherry I. , Niimi Masanori , Read Simon , Turvey Stuart E. , Bushell Andrew R. , Morris Peter J. , Powrie Fiona , Wood Kathryn J. 
Published: April 2014

AbstractWe present evidence that donor-reactive CD4+ T cells present in mice tolerant to donor alloantigens are phenotypically and functionally heterogeneous. CD4+ T cells contained within the CD45RBhigh fraction remained capable of mediating graft rejection when transferred to donor alloantigen-grafted T cell-depleted mice. In contrast, the CD45RBlow CD4+ and CD25+CD4+ populations failed to induce rejection, but rather, were able to inhibit rejection initiated by naive CD45RBhigh CD4+ T cells. Analysis of the mechanism of immunoregulation transferred by CD45RBlow CD4+ T cells in vivo revealed that it was donor Ag specific and could be inhibited by neutralizing Abs reactive with IL-10, but not IL-4. CD45RBlow CD4+ T cells from tolerant mice were also immune suppressive in vitro, as coculture of these cells with naive CD45RBhigh CD4+ T cells inhibited proliferation and Th1 cytokine production in response to donor alloantigens presented via the indirect pathway. These results demonstrate that alloantigen-specific regulatory T cells contained within the CD45RBlow CD4+ T cell population are responsible for the maintenance of tolerance to donor alloantigens in vivo and require IL-10 for functional activity.
Critical Requirement for the Membrane-Proximal Cytosolic Tyrosine Residue for CD28-Mediated Costimulation In Vivo
Authors: Harada Yohsuke , Tokushima Miyoko , Matsumoto Yasuyo , Ogawa Shuhei , Otsuka Masataka , Hayashi Katsuhiko , Weiss Bonnie D. , June Carl H. , Abe Ryo 
Published: April 2014

Abstract
The YMNM motif that exists in the CD28 cytoplasmic domain is known as a binding site for phosphatidylinositol 3-kinase and Grb-2 and is considered to be important for CD28-mediated costimulation. To address the role of the YMNM motif in CD28 cosignaling in primary T cells, we generated transgenic mice on a CD28 null background that express a CD28 mutant lacking binding ability to phosphatidylinositol 3-kinase and Grb-2. After anti-CD3 and anti-CD28 Ab stimulation in vitro, the initial proliferative response and IL-2 secretion in CD28 Y189F transgenic T cells were severely compromised, while later responses were intact. In contrast to anti-CD3 and anti-CD28 Ab stimulation, PMA and anti-CD28 Ab stimulation failed to induce IL-2 production from CD28 Y189F transgenic T cells at any time point. Using the graft-vs-host reaction system, we assessed the role of the YMNM motif for CD28-mediated costimulation in vivo and found that CD28 Y189F transgenic spleen cells failed to engraft and could not induce acute graft-vs-host reaction. Together, these results suggest that the membrane-proximal tyrosine of CD28 is required for costimulation in vivo. Furthermore, these results indicate that the results from in vitro assays of CD28-mediated costimulation may not always correlate with T cell activation in vivo.
MHC-II-Independent CD4+ T Cells Induce Colitis in Immunodeficient RAG−/− Hosts
Authors: Trobonjaca Zlatko , Leithäuser Frank , Möller Peter , Bluethmann Horst , Koezuka Yasuhiko , MacDonald H. Robson , Reimann Jörg 
Published: April 2014

Abstract
CD4+ αβ T cells from either normal C57BL/6 (B6) or MHC-II-deficient (Aα−/− or Aβ−/−) B6 donor mice engrafted into congenic immunodeficient RAG1−/− B6 hosts induced an aggressive inflammatory bowel disease (IBD). Furthermore, CD4+ T cells from CD1d−/− knockout (KO) B6 donor mice but not those from MHC-I−/− (homozygous transgenic mice deficient for β2-microglobulin) KO B6 mice induced a colitis in RAG−/− hosts. Abundant numbers of in vivo activated (CD69highCD44highCD28high) NK1+ and NK1− CD4+ T cells were isolated from the inflamed colonic lamina propria (cLP) of transplanted mice with IBD that produced large amounts of TNF-α and IFN-γ but low amounts of IL-4 and IL-10. IBD-associated cLP Th1 CD4+ T cell populations were polyclonal and MHC-II-restricted when derived from normal B6 donor mice, but oligoclonal and apparently MHC-I-restricted when derived from MHC-II-deficient (Aα−/− or Aβ−/−) B6 donor mice. cLP CD4+ T cell populations from homozygous transgenic mice deficient for β2-microglobulin KO B6 donor mice engrafted into RAG−/− hosts were Th2 and MHC-II restricted. These data indicate that MHC-II-dependent as well as MHC-II-independent CD4+ T cells can induce a severe and lethal IBD in congenic, immunodeficient hosts, but that the former need the latter to express its IBD-inducing potential.
Endogenous Glucocorticoids Play a Positive Regulatory Role in the Anti-Keyhole Limpet Hemocyanin In Vivo Antibody Response
Authors: Fleshner Monika , Deak Terrence , Nguyen Kien T. , Watkins Linda R. , Maier Steven F. 
Published: April 2014

Abstract
Glucocorticoids (GCs) are commonly reported to be immunosuppressive. Studies that support this involve the administration of synthetic GCs such as dexamethasone at high pharmacological doses and using in vitro assay systems that may have limited relevance to the role of GCs during normal in vivo immune responses. Therefore, the following experiments tested the conclusion that GCs are generally immunosuppressive. Adult male Sprague Dawley rats received adrenalectomy (ADX) or sham surgery. ADX rats were given either basal corticosterone (CORT) replacement in their drinking water (25 μg/ml) or no CORT. Rats were immunized with keyhole limpet hemocyanin (KLH), and blood samples were taken. ADX rats with no CORT replacement had reduced anti-KLH IgM and IgG responses compared with sham-operated controls. ADX rats that received basal CORT replacement had partially restored anti-KLH IgM, but still had suppressed anti-KLH IgG. Administration of GC receptor type I (RU28318) and type II (RU40555) receptor antagonists also reduced the anti-KLH IgM and IgG responses. ADX rats that received both basal CORT replacement and low dose injections of CORT on days 5 and 7 after KLH had anti-KLH IgG levels equal to those of sham-operated controls. Finally, the GC elevation 4–7 days after immunization may play a role in stimulating the IgM to IgG2a switch. GC receptor blockade reduced the anti-KLH IgG2a and splenic IFN-γ, but not the anti-KLH IgG1, response. Given that IFN-γ is an important regulator of the IgM to IgG2a switch, it is possible that the small rise in GC found 4–7 days after KLH facilitates IgG2a isotype switching.
Antiviral Cytotoxic T Cells Cross-Reactively Recognize Disparate Peptide Determinants from Related Viruses but Ignore More Similar Self- and Foreign Determinants
Authors: Regner Matthias , Lobigs Mario , Blanden Robert V. , Milburn Peter , Müllbacher Arno 
Published: April 2014

Abstract
We have investigated the reactivities of cytotoxic T (Tc) cells against the two immunodominant, H-2Kk-restricted determinants from the Flavivirus Murray Valley encephalitis virus (MVE), MVE1785 (REHSGNEI) and MVE1971 (DEGEGRVI). The respective Tc cell populations cross-reactively lysed target cells pulsed with determinants from the MVE1785- and MVE1971-corresponding positions of six other flaviviruses, despite low sequence homology in some cases. Notably, anti-MVE1785 Tc cells recognized a determinant (TDGEERVI) that shares with the determinant used for stimulation only the carboxyl-terminal amino acid residue, one of two H-2Kk anchor residues. These reactivity patterns were also observed in peptide-dependent IFN-γ production and the requirements for in vitro restimulation of memory Tc cells. However, the broad cross-reactivity appeared to be limited to flavivirus-derived determinants, as none of a range of determinants from endogenous mouse-derived sequences, similar to the MVE-determinants, were recognized. Neither were cells infected with a number of unrelated viruses recognized. These results raise the paradox that virus-immune Tc cell responses, which are mostly directed against only a few “immunodominant” viral determinants, are remarkably peptide cross-reactive.
Human CD1d Functions as a Transplantation Antigen and a Restriction Element in Mice
Authors: Wang Bin , Chun Taehoon , Rulifson Ingrid C. , Exley Mark , Balk Steven P. , Wang Chyung-Ru 
Published: April 2014

Abstract
To study the potential functions of human CD1d (hCD1d), we developed transgenic (Tg) mice that ectopically express hCD1d under the control of H-2Kb promoter. High levels of hCD1d expression were detected in all Tg tissues tested. Skin grafts from the Kb/hCD1d Tg mice were rapidly rejected by MHC-matched non-Tg recipient mice, suggesting that hCD1d can act as transplantation Ags. Furthermore, we were able to elicit hCD1d-restricted CD8+ CTLs from mice immunized with Kb/hCD1d Tg splenocytes. These CTLs express TCR rearrangements that are distinct from invariant TCR of NK T cells, and secrete significant amounts of IFN-γ upon Ag stimulation. Analysis with various hCD1d-expressing targets and use of Ag presentation inhibitors indicated the recognition of hCD1d by CTLs did not involve species or tissue-specific ligands nor require the processing pathways of endosomes or proteasomes. Additionally, the reactivity of hCD1d-specific CTLs was not affected by acid stripping followed by brefeldin A treatment, suggesting that CTLs may recognize a ligand/hCD1d complex that is resistant to acid denaturation, or empty hCD1d molecules. Our results show that hCD1d can function as an alloantigen for CD8+ CTLs. The hCD1d Tg mice provide a versatile model for the study of hCD1d-restricted cytolytic responses to microbial Ags.
A Critical Role for p38 Mitogen-Activated Protein Kinase in the Maturation of Human Blood-Derived Dendritic Cells Induced by Lipopolysaccharide, TNF-α, and Contact Sensitizers
Authors: Arrighi Jean-François , Rebsamen Michela , Rousset Françoise , Kindler Vincent , Hauser Conrad 
Published: April 2014

Abstract
We investigated the involvement of mitogen-activated protein kinases (MAPKs) in the maturation of CD83− dendritic cells (DC) derived from human blood monocytes. Maturating agents such as LPS and TNF-α induced the phosphorylation of members of the three families of MAPK (extracellular signal-regulated kinase l/2, p46/54 c-Jun N-terminal kinase, and p38 MAPK). SB203580, an inhibitor of the p38 MAPK, but not the extracellular signal-regulated kinase l/2 pathway blocker PD98059, inhibited the up-regulation of CD1a, CD40, CD80, CD86, HLA-DR, and the DC maturation marker CD83 induced by LPS and TNF-α. In addition, SB203580 inhibited the enhancement of the allostimulatory capacity and partially prevented the down-regulation of FITC-dextran uptake induced by LPS and TNF-α. Likewise, SB203580 partially prevented the up-regulation of IL-1α, IL-1β, IL-lRa, and TNF-α mRNA upon stimulation with LPS and TNF-α, as well as the release of bioactive TNF-α induced by LPS. DC maturation induced by the contact sensitizers 2,4-dinitrofluorobenzene and NiSO4, as seen by the up-regulation of CD80, CD86, and CD83, was also coupled to the phosphorylation of p38 MAPK, and was inhibited by SB203580. The irritants SDS and benzalkonium chloride that do not induce DC maturation did not trigger p38 MAPK phosphorylation. Together, these data indicate that phosphorylation of p38 MAPK is critical for the maturation of immature DC. These results also suggest that p38 MAPK phosphorylation in DC may become useful for the identification of potential skin contact sensitizers.
Human Vascular Endothelial Cells Stimulate a Lower Frequency of Alloreactive CD8+ Pre-CTL and Induce Less Clonal Expansion than Matching B Lymphoblastoid Cells: Development of a Novel Limiting Dilution Analysis Method Based on CFSE Labeling of Lymphocytes
Authors: Dengler Thomas J. , Johnson David R. , Pober Jordan S. 
Published: April 2014

Abstract
We have previously shown that human endothelial cells (EC) are less efficient than professional APC, e.g., B lymphoblastoid cells (BLC), at stimulating allogeneic CD8+ T cells to develop into CTL. In this study we describe FACS-based limiting dilution analyses using the dilution of the intracellular dye CFSE as an indicator of CD8+ T cell alloactivation and expansion with significantly increased sensitivity compared with conventional, cytotoxicity-based assays. In addition, this assay permits the relative size of clonal CTL populations that are generated in individual CD8+ T cell cultures to be determined (clonal burst size). We have applied this method to quantitatively compare the generation of CTL at the clonal level following stimulation of allogeneic CD8+ T cells by either BLC or HUVEC derived from the same donor. CD8+ T cells expanded by allostimulation were identified as CD8+, CFSElow cells and were categorized as CTL by the expression of intracellular perforin and IFN-γ. Precursor frequencies for EC-stimulated CTL were 5- to 40-fold (mean, 7.5-fold) lower compared with BLC-stimulated CTL (p &lt; 0.01). Concomitantly, the average clonal burst sizes in EC-stimulated CTL cultures were significantly smaller than those in conventional CTL cultures, primarily due to the occurrence of some very large clone sizes exclusively with BLC stimulation. Although EC-stimulated CTL were generated only from the memory subset of CD8+ T cells, BLC-stimulated very large burst sizes of CTL were observed from both naive and memory CD8+ T cell precursors. These data establish that both a lower frequency of reactive precursors and more limited clonal expansion, but not regulatory T cells, contribute to the reduced capacity of EC to promote alloreactive CTL differentiation compared with that of professional APC.
Inhibition of the MEK/ERK Signaling Pathway Blocks a Subset of B Cell Responses to Antigen
Authors: Richards James D. , Davé Shaival H. , Chou Chih-Hao G. , Mamchak Alusha A. , DeFranco Anthony L. 
Published: April 2014

AbstractSignal transduction initiated by B cell Ag receptor (BCR) cross-linking plays an important role in the development and activation of B cells. Therefore, considerable effort has gone into determining the biochemical signaling events initiated by the BCR and delineating which events participate in specific biological responses to Ag. We used two inhibitors of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) 1 and MEK2, PD98059, and U0126, to assess the role the Ras-mitogen-activated protein kinase pathway plays in several BCR-induced responses. PD98059 or U0126 treatment substantially inhibited the BCR-induced activation of the extracellular signal-regulated kinase (ERK) forms of mitogen-activated protein kinase in the immature B cell line WEHI-231, in immature splenic B cells, and in mature splenic B cells. However, MEK-ERK inhibition did not block BCR-induced growth arrest or apoptosis of WEHI-231 cells or apoptosis of immature splenic B cells, indicating that the MEK-ERK pathway is not required for these events. In contrast, PD98059 and U0126 treatment did inhibit the up-regulation of specific BCR-induced proteins, including the transcription factor Egr-1 in WEHI-231 and mature splenic B cells, and the CD44 adhesion molecule and CD69 activation marker in mature splenic B cells. Moreover, both inhibitors suppressed BCR-induced proliferation of mature splenic B cells, in the absence and in the presence of IL-4. Therefore, activation of the MEK-ERK pathway is necessary for a subset of B cell responses to Ag.
CD83 Is a Sialic Acid-Binding Ig-Like Lectin (Siglec) Adhesion Receptor that Binds Monocytes and a Subset of Activated CD8+ T Cells
Authors: Scholler Nathalie , Hayden-Ledbetter Martha , Hellström Karl-Erik , Hellström Ingegerd , Ledbetter Jeffrey A. 
Published: April 2014

Abstract
To help determine CD83 function, a cDNA encoding a soluble protein containing the CD83 extracellular domain was fused with a mutated human IgG1 constant region (CD83Ig) and expressed by stable transfection of Chinese hamster ovary cells. Purified CD83Ig bound to peripheral blood monocytes and a subset of activated CD3+CD8+ lymphocytes but did not bind to FcR. Monocytes that had adhered to plastic lost their ability to bind to CD83Ig after 90 min of in vitro incubation. CD83Ig bound to two of five T cell lines tested, HPB-ALL and Jurkat. The binding to HPB-ALL cells significantly increased when they were grown at a low pH (pH 6.5), whereas binding to Jurkat cells increased after apoptosis was induced with anti-Fas mAb. B cell and monocytic lines did not bind CD83Ig and neither did CD56+ NK cells or granulocytes. Full-length CD83 expressed by a transfected carcinoma line mediated CD83-dependent adhesion to HPB-ALL cells. CD83Ig immunoprecipitated and immunoblotted a 72-kDa protein from HPB-ALL cells. Binding of CD83Ig to HPB-ALL cells was eliminated by neuraminidase treatment of the cells. We conclude that CD83 is an adhesion receptor with a counterreceptor expressed on monocytes and a subset of activated or stressed T lymphocytes, and that interaction between CD83 and its counterreceptor is dependent upon the state of glycosylation of a 72-kDa counterreceptor by sialic acid residues. In view of the selectivity of the expression of CD83 and its ligand, we postulate that the interaction between the two plays an important role in the induction and regulation of immune responses.
Biphasic Regulation of NF-κB Activity Underlies the Pro- and Anti-Inflammatory Actions of Nitric Oxide
Authors: Connelly L. , Palacios-Callender M. , Ameixa C. , Moncada S. , Hobbs A. J. 
Published: April 2014

Abstract
Expression of inducible NO synthase (iNOS) by macrophages is a prerequisite for the production of high output NO, which mediates many bactericidal and tumoricidal actions of these immune cells. The expression of iNOS in mammalian cells is governed predominantly by the transcription factor, NF-κB, which regulates the expression of many host defense proteins. In the present study, we characterize a novel, biphasic effect of NO on NF-κB activity in murine macrophages. This mechanism depends on the local concentration of NO and enables it both to up- and down-regulate the expression of host defense proteins including iNOS, cyclooxygenase-2, and IL-6. This biphasic activity of NO appears to play a pivotal role in the time course of activation of these immune cells and, by inference, in facilitating the initiation of a defense response against pathogenic stimuli and in its termination to limit tissue damage. This mechanism may explain at least in part the reported ability of NO to act in both a pro- and anti-inflammatory manner.