bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delineation of Intrathymic T, NK, and Dendritic Cell (DC) Progenitors in Fetal and Adult Rats: Demonstration of a Bipotent T/DC Intermediate Precursor
Authors: Alonso-C. Luis M. , Muñoz Juan J. , Zapata Agustín G. 
Published: April 2014

Abstract
We previously published study results stating that the early rat fetal liver contains a high frequency of T/dendritic cells (DCs), but rarely T/NK bipotent common progenitors. Now, by using xenogenic rat/SCID mouse fetal thymic organ cultures, we extend these observations to the thymus, in which conflicting data have been published in human and mouse. On the one hand, enriched adult intrathymic CD45+CD2− triple negative for CD8, CD4, and CD3 Ag cell progenitors, which contained both rearranged TCRβ chain and pre-Tα chain transcripts, completely lacked NKR-P1A expressing cells, and upon limiting dilution conditions, generated T- and T/DC-containing lobes, but no T/NK or NK ones were found. On the other hand, the CD45+CD2− triple negative for CD8, CD4, and CD3 Ags cell population obtained from 15- and 16-day-old fetal rat thymus can be divided into NKR-P1A− and NKR-P1Alow cell subpopulations that differ in several aspects. Both cell subsets expressed pre-TCRα chain transcripts, but only the former contained fully rearranged TCRβ chain transcripts. Upon limiting dilution, T cell-committed progenitors were only found in the NKR-P1A− cell population, whereas NK-committed progenitors were present in the NKR-P1Alow population. More importantly, bipotential T/NK progenitors were very rare and were found only in the NKR-P1Alow cell population, whereas bipotential T/DC progenitors, only previously suggested in the adult mouse thymus, were observed frequently in the NKR-P1A−CD2− cell subpopulation. Our results demonstrate, therefore, that a common intrathymic T/DC intermediate represents the main T cell developmental pathway in rat thymus.
STAT5 Induces Macrophage Differentiation of M1 Leukemia Cells Through Activation of IL-6 Production Mediated by NF-κB p65
Authors: Kawashima Toshiyuki , Murata Ken , Akira Shizuo , Tonozuka Yukio , Minoshima Yukinori , Feng Sizhou , Kumagai Hidetoshi , Tsuruga Hiromichi , Ikeda Yasuo , Asano Shigetaka , Nosaka Tetsuya , Kitamura Toshio 
Published: April 2014

Abstract
We recently demonstrated that STAT5 can induce a variety of biological functions in mouse IL-3-dependent Ba/F3 cells; STAT5-induced expression of pim-1, p21WAF/Cip1, and suppressor of cytokine signaling-1/STAT-induced STAT inhibitor-1/Janus kinase binding protein is responsible for induction of proliferation, differentiation, and apoptosis, respectively. In the present study, using a constitutively active STAT5A (STAT5A1*6), we show that STAT5 induces macrophage differentiation of mouse leukemic M1 cells through a distinct mechanism, autocrine production of IL-6. The supernatant of STAT5A1*6-transduced cells contained sufficient concentrations of IL-6 to induce macrophage differentiation of parental M1 cells, and STAT3 was phosphorylated on their tyrosine residues in these cells. Treatment of the cells with anti-IL-6 blocking Abs profoundly inhibited the differentiation. We also found that the STAT5A1*6 transactivated the IL-6 promoter, which was mediated by the enhanced binding of NF-κB p65 (RelA) to the promoter region of IL-6. These findings indicate that STAT5A cooperates with Rel/NF-κB to induce production of IL-6, thereby inducing macrophage differentiation of M1 cells in an autocrine manner. In summary, we have shown a novel mechanism by which STAT5 induces its pleiotropic functions. Cytokines
Th1 Cytokine-Conditioned Bone Marrow-Derived Dendritic Cells Can Bypass the Requirement for Th Functions During the Generation of CD8+ CTL
Authors: Sato Marimo , Chamoto Kenji , Tsuji Takemasa , Iwakura Yoichiro , Togashi Yuji , Koda Toshiaki , Nishimura Takashi 
Published: April 2014

Abstract
Bone marrow-derived dendritic cell (BMDC) subsets have distinct immunoregulatory functions. Th1 cytokine-induced BMDC (BMDC1), compared with Th2 cytokine-induced BMDC2, have superior activities for the differentiation and expansion of CTL. To evaluate the cellular interactions between dendritic cells and CD8+ T cells for the induction of CTL, BALB/c-derived BMDC subsets were cocultured with purified CD8+ T cells from C57BL/6 mice. Our results demonstrate that BMDC1 support the generation of allogeneic CD8+ CTL in the absence of CD4+ Th cells. In contrast, BMDC0 (GM-CSF- plus IL-3-induced BMDC) and BMDC2 failed to promote the differentiation of CD8+ CTL. Using Ab-blocking experiments and studies with gene knockout mice, IL-2 and LFA-1 are demonstrated to be critical for BMDC1-induced CTL differentiation. Unexpectedly, BMDC1 were able to induce CTL from CD8+ T cells isolated from IFN-γ−/− and IFN-γ receptor−/− mice. However, BMDC1 produced higher levels of IFN-β than other BMDC subsets, and anti-IFN-β mAb blocked BMDC1-dependent CTL generation. These results indicated an indispensable role of IFN-β, but not IFN-γ, during BMDC1-induced CTL differentiation. We conclude that Th1-cytokine-conditioned BMDC1 can bypass Th cell function for the differentiation of naive CD8+ T cells into CTL.
Both CD34+38+ and CD34+38− Cells Home Specifically to the Bone Marrow of NOD/LtSZ scid/scid Mice but Show Different Kinetics in Expansion
Authors: Kerre Tessa C. C. , De Smet Greet , De Smedt Magda , Offner Fritz , De Bosscher José , Plum Jean , Vandekerckhove Bart 
Published: April 2014

Abstract
Human hemopoietic stem cells (HSC) have been shown to engraft, differentiate, and proliferate in the hemopoietic tissues of sublethally irradiated NOD/LtSZ scid/scid (NOD/SCID) mice. We used this model to study homing, survival, and expansion of human HSC populations from different sources or phenotype. We observed that CD34+ cells homed specifically to bone marrow (BM) and spleen, but by 3 days after injection, survived only in the BM. These BM-homed CD34+ cells proliferated intensively and gave rise to a 12-fold, 5.5-fold, and 4-fold expansion in 3 days for umbilical cord blood, adult mobilized peripheral blood, and adult BM-derived cells, respectively. By injection of purified subpopulations, it was demonstrated that both CD34+38+ and CD34+38− umbilical cord blood HSC homed to the BM and expanded. Importantly, kinetics of expansion were different: CD34+38+ cells started to increase in cell number from day 3 onwards, and by 4 wk after injection, virtually all CD34+ cells had disappeared. In contrast, CD34+38− cells remained quiescent during the first week and started to expand intensively from the third week on. In this paper, we have shown that homing, survival, and expansion of stem cells are three independent phenomena important in the early phase of BM engraftment and that kinetics of engraftment differ between CD34+38+ and CD34+38− cells.
The Rearranged VH Domain of a Physiologically Selected Anti-Single-Stranded DNA Antibody as a Precursor for Formation of IgM and IgG Antibodies to Diverse Antigens
Authors: Li Jing , Fernandez Luis , O’Connor Kevin C. , Imanishi-Kari Thereza , Stollar B. David 
Published: April 2014

Abstract
It has been proposed that autoreactivity of modest affinity contributes to positive selection of a preimmunization B cell repertoire, whereas high-affinity autoreactivity leads to negative selection. This hypothesis predicts that a B cell producing a physiologically selected unmutated ssDNA-binding Ab should be a precursor of cells that respond to diverse exogenous Ags. To test this prediction, we prepared transgenic mice bearing the rearranged VH domain of an IgM Ab from a nonautoimmune mouse immunized with a DNA-protein complex, poly(dC)-methylated BSA. The Ab, dC1, binds both poly(dC) and ssDNA. It is encoded by VH and VL gene segments with no mutations, suggesting that the producing cell may have been selected before and activated during immunization. The dC1VH transgene was targeted to the IgH locus. In heterozygous mice, on a nonautoimmune C57BL/6 background, the transgene allotype was expressed on B cell surfaces and in serum Ig, but about one-third of B cells expressed the endogenous allele instead. Total serum Ig concentrations were normal and included both transgene- and endogenous gene-coded IgM and IgG. The transgene VH DHJH was expressed in splenic IgM cDNA with few or no mutations, and in IgG cDNA with multiple mutations. The transgene allotype was also expressed in Abs formed on immunization with thyroglobulin, pneumococcal polysaccharide, and ssDNA-methylated BSA. Consistent with the hypothesis, cells with a rearranged autoreactive VH domain selected for reactivity with a form of ssDNA did serve as precursors for cells producing IgM and IgG Abs to diverse Ags.
Examination of HY Response: T Cell Expansion, Immunodominance, and Cross-Priming Revealed by HY Tetramer Analysis
Authors: Millrain Maggie , Chandler Phillip , Dazzi Francesco , Scott Diane , Simpson Elizabeth , Dyson P. Julian 
Published: April 2014

Abstract
We have applied MHC class I tetramers representing the two H2b MHC class I-restricted epitopes of the mouse male-specific minor transplantation Ag, HY, to directly determine the extent of expansion and immunodominance within the CD8+ T cell compartment following exposure to male tissue. Immunization with male bone marrow (BM), spleen, dendritic cells (DCs) and by skin graft led to rapid expansion of both specificities occupying up to &gt;20% of the CD8+ T cell pool. At a high dose, whole BM or spleen were found to be more effective at stimulating the response than BM-derived DCs. In vivo, immunodominance within the responding cell population was only observed following chronic Ag stimulation, whereas epitope immunodominance was established rapidly following in vitro restimulation. Peptide affinity for the restricting MHC molecule was greater for the immunodominant epitope, suggesting that this might be a factor in the emergence of immunodominance. Using tetramers, we were able to directly visualize the cross-primed CD8+ HY response, but we did not find it to be the principal route for MHC class I presentation. Immunization with female spleen or DCs coated with the full complement of defined HY peptides, including the Ab-restricted CD4+ Th cell determinant, failed to induce tetramer-reactive cells.
Ceramide Mediates Tumor-Induced Dendritic Cell Apoptosis
Authors: Kanto Tatsuya , Kalinski Pawel , Hunter Oriana C. , Lotze Michael T. , Amoscato Andrew A. 
Published: April 2014

Abstract
Induction of apoptosis in dendritic cells (DC) is one of the escape mechanisms of tumor cells from the immune surveillance system. This study aimed to clarify the underlying mechanisms of tumor-induced DC apoptosis. The supernatants (SN) of murine tumor cell lines B16 (melanoma), MCA207, and MCA102 (fibrosarcoma) increased C16 and C24 ceramide as determined by electrospray mass spectrometry and induced apoptosis in bone marrow-derived DC. N-oleoylethanolamine or d-l-threo 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), which inhibits acid ceramidase or glucosylceramide synthase and then increases endogenous ceramide, enhanced DC apoptosis and ceramide levels in the presence of tumor SN. Pretreatment with l-cycloserine, an inhibitor of de novo ceramide synthesis, or phorbol ester, 12-O-tetradecanoylphorbol-13-acetate reduced endogenous ceramide levels and protected DC from tumor-induced apoptosis. However, other DC survival factors, including LPS and TNF-α, failed to do so. The protective activity of 12-O-tetradecanoylphorbol-13-acetate is abrogated by pretreatment with phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. Therefore, down-regulation of PI3K is the major facet of tumor-induced DC apoptosis. Tumor SN, N-oleoylethanolamine, or PDMP suppressed Akt, NF-κB, and bcl-xL in DC, suggesting that the accumulation of ceramide impedes PI3K-mediated survival signals. Taken together, ceramide mediates tumor-induced DC apoptosis by down-regulation of the PI3K pathway.
Oxidized Low-Density Lipoprotein Promotes Mature Dendritic Cell Transition from Differentiating Monocyte
Authors: Perrin-Cocon Laure , Coutant Fredéric , Agaugué Sophie , Deforges Séverine , André Patrice , Lotteau Vincent 
Published: April 2014

Abstract
Proinflammatory oxidized phospholipids are generated during oxidative modification of low-density lipoproteins (LDL). The production of these proinflammatory oxidized phospholipids is controlled by secreted enzymes that circulate as proteins complexed with LDL and high-density lipoprotein. During the acute phase response to tissue injury, profound changes occur in lipoprotein enzymatic composition that alter their anti-inflammatory function. Monocytes may encounter oxidized phospholipids in vivo during their differentiation to macrophages or dendritic cells (DC). In this study we show that the presence of oxidized LDL (oxLDL) at the first day of monocyte differentiation to DC in vitro yielded phenotypically atypical cells with some functional characteristics of mature DC. Addition of oxLDL during the late stage of monocyte differentiation gave rise directly to phenotypically mature DC with reduced uptake capacity, secreting IL-12 but not IL-10, and supporting both syngeneic and allogeneic T cell stimulation. In contrast to known mediators of DC activation, oxLDL did not trigger maturation of immature DC. An intriguing possibility is that a burst of oxidized phospholipids is an endogenous activation signal for the immune system, which is tightly controlled by lipoproteins during the acute phase response.
Developmentally Regulated Changes in Glucosidase II Association with, and Carbohydrate Content of, the Protein Tyrosine Phosphatase CD45
Authors: Baldwin Troy A. , Ostergaard Hanne L. 
Published: April 2014

Abstract
Glucosidase II (GII) stably interacts with the external domain of CD45 in a carbohydrate-dependent manner. We have found that the association occurs in immature cells, but is significantly reduced in mature T cells. Using mannose-binding protein (MBP), in both FACS analysis and pull-down assays, we find that MBP can specifically recognize cell surface CD45 from immature, but not mature T cells. Analysis of thymocytes reveals increased MBP binding and GII association with CD45 in double-positive thymocytes compared with either double-negative or single-positive thymocytes. As well, the same pool of CD45 recognized by MBP can also associate with GII. Initial analysis of the basis of the interaction between CD45 and MBP suggests MBP binds two different glycoforms of CD45 based on the differential competition with glucose. Finally, inhibition of GII activity in cells that do not normally express MBP ligands results in significant increases in cell surface MBP ligands, including CD45. Taken together, these data suggest that the glucose content of the cell surface CD45 changes as thymocytes undergo maturation to mature T cells, and may be regulated by GII interactions. Such changes in the cell surface carbohydrate on CD45 may affect the development of thymocytes, perhaps via binding of CD45 on thymocytes to lectins on stromal cells.
Intestinal Trefoil Factor Induces Decay-Accelerating Factor Expression and Enhances the Protective Activities Against Complement Activation in Intestinal Epithelial Cells
Authors: Andoh Akira , Kinoshita Koichi , Rosenberg Ian , Podolsky Daniel K. 
Published: April 2014

Abstract
Mucosal damage induces a massive influx of serum complement components into the lumen. The epithelium produces a number of factors that can potentially ameliorate injury including intestinal trefoil factor (ITF), a small protease-resistant peptide produced and secreted onto the mucosal surface by goblet cells, and decay-accelerating factor (DAF), a protein produced by columnar epithelium which protects the host tissue from autologous complement injury. However, coordination of these intrinsic defensive products has not been delineated. DAF protein and mRNA expression were evaluated by immunoblotting and Northern blotting, respectively. NF-κB-DNA binding activity and DAF promoter activity were assessed by an electrophoretic gel mobility shift assay and a reporter gene luciferase assay, respectively. ITF induced a dose- and time-dependent increase in DAF protein and mRNA expression in human (HT-29 and T84) and rat (IEC-6) intestinal epithelial cells. In differentiated T84 cells grown on cell culture inserts, basolateral stimulation with ITF strongly enhanced DAF expression, but apical stimulation had no effects. The C3 deposition induced by complement activation was significantly blocked by the treatment with ITF. In HT-29 cells, ITF increased the stability of DAF mRNA. ITF also enhanced the promoter activity of the DAF gene via NF-κB motif and induced activation of NF-κB-DNA binding activity. ITF promotes protection of epithelial cells from complement activation via up-regulation of DAF expression, contributing to a robust mucosal defense.
Passively Acquired Antibodies Suppress Humoral But Not Cell-Mediated Immunity in Mice Immunized with Live Attenuated Respiratory Syncytial Virus Vaccines
Authors: Crowe James E. , Firestone Cai-Yen , Murphy Brian R. 
Published: April 2014

Abstract
A respiratory syncytial virus (RSV) vaccine will need to be administered by 1 mo of age to protect young infants; therefore, it will need to be effective in the presence of maternally acquired RSV Abs. In the present study, the immunogenicity and efficacy of two live attenuated RSV vaccine candidates of different level of attenuation were evaluated in mice passively immunized with varying quantities of RSV Abs. The replication of the RSV vaccines was suppressed in the lower, but not the upper, respiratory tract of the passively immunized mice. Immunization with either vaccine candidate was highly efficacious against challenge with wild-type RSV in both passively immunized and control mice. Nonetheless, a high level of immunity was seen even in passively/actively immunized animals that failed to develop a humoral immune response, suggesting that T cells mediated the immunity. Depletion of CD4+ and CD8+ T cells in passively/actively immunized and control animals at the time of challenge with wild-type RSV demonstrated that CD4+ and CD8+ T cells made significant independent contributions to the restriction of replication of RSV challenge virus in both the upper and lower respiratory tracts. Although passively acquired serum RSV Abs suppressed the primary systemic and mucosal Ab responses of IgM, IgG, and IgA isotypes, B lymphocytes were nevertheless primed for robust secondary Ab responses. Thus, immunity mediated by CD4+ and CD8+ T cells and Abs can be readily induced in mice by live RSV vaccine candidates in the presence of physiologic levels of RSV neutralizing Abs.
Chronic Inflammation and Protection from Acute Hepatitis in Transgenic Mice Expressing TNF in Endothelial Cells
Authors: Willuweit Antje , Sass Gabriele , Schöneberg Annette , Eisel Ulrich , Tiegs Gisa , Clauss Matthias 
Published: April 2014

Abstract
Endothelial activation is an important feature of many inflammatory diseases and has been implicated as the cause of vascular complications in disorders such as diabetes, atherosclerosis, and transplant rejection. One of the most potent activators of the endothelium is TNF, which can also be expressed by endothelial cells, causing a permanent, autocrine stimulatory signal. To establish a model of continuous endothelial activation and to elucidate the role of endothelial derived TNF in vivo, we generated transgenic mice expressing a noncleavable transmembrane form of TNF under the control of the endothelial-specific tie2 promoter. Adult tie2-transmembrane TNF-transgenic mice developed chronic inflammatory pathology in kidney and liver, characterized by perivascular infiltration of mononuclear cells into these organs. Along with the infiltrate, an up-regulation of the adhesion molecules ICAM-1 and VCAM-1, but not E-selectin, in the endothelium was observed. Despite predisposition to chronic inflammation these mice were protected from immune-mediated liver injury in a model of Con A-induced acute hepatitis. Although the blood levels of soluble TNF and IFN-γ were increased in transgenic animals after challenge with Con A, no damage of hepatocytes could be detected, as assessed by the lack of increase in plasma transaminase activities and the absence of TUNEL staining in the liver. We conclude that expression of transmembrane TNF in the endothelium causes continuous endothelial activation, leading to both proinflammatory and protective events.
Anaphylatoxin C5a Actions in Rat Liver: Synergistic Enhancement by C5a of Lipopolysaccharide-Dependent α2-Macroglobulin Gene Expression in Hepatocytes Via IL-6 Release from Kupffer Cells
Authors: Mäck Claudia , Jungermann Kurt , Götze Otto , Schieferdecker Henrike L. 
Published: April 2014

Abstract
The effects of the anaphylatoxins C5a and C3a on the liver are only poorly characterized in contrast to their well known systemic actions. Recently, it has been demonstrated that the anaphylatoxin C5a enhanced glucose output from hepatocytes (HC) indirectly via prostanoid release from Kupffer cells (KC). In the present study, it is shown that recombinant rat C5a (rrC5a), together with LPS, activated the gene of the acute phase protein α2-macroglobulin (α2MG) in HC also indirectly via IL-6 release from KC. RrC5a alone increased neither IL-6 mRNA in nor IL-6 release from KC, whereas LPS alone did so. However, rrC5a synergistically enhanced the LPS-dependent increase in IL-6 mRNA and IL-6 release. Only rIL-6, but not TNF-α or IL-1β, enhanced α2MG mRNA in HC. In line with the actions of rrC5a and LPS on KC, conditioned medium of KC stimulated only with rrC5a did not increase α2MG mRNA in HC. However, medium of KC stimulated with rrC5a plus LPS induced α2MG mRNA expression in HC more strongly than medium from cells stimulated only with LPS; thus, C5a acted synergistically with LPS. The stimulatory effects of KC-conditioned medium could partially be inhibited by a neutralizing anti-IL-6 Ab, indicating that KC-derived IL-6 was a major mediator in C5a- plus LPS-elicited α2MG gene expression. These results suggest that C5a, besides enhancing glucose output via prostanoids, is involved in the initiation of the acute phase response in HC via proinflammatory cytokines from KC. This provides evidence for another important function of C5a in the regulation of hepatocellular defense reactions.