bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional Regulation of the Igκ Gene by Promoter-Proximal Pausing of RNA Polymerase II
Authors: Raschke Eva E. , Albert Thomas , Eick Dirk 
Published: December 2022

Abstract
Transcriptional regulation can occur at the level of initiation and RNA elongation. We report that the rearranged, nontranscribed Igκ gene in the pre-B cell line 70Z/3 harbors a paused RNA polymerase II (pol II) at a position between 45 and 89 bp downstream of the transcription initiation site. LPS, an inducer of NF-κB, activated Igκ gene transcription by increasing the processivity of pol II. TGF-β inhibited the LPS-induced transcription of the Igκ gene, but not initiation and pausing of pol II. A rearranged copy of the Igκ gene was introduced into 70Z/3 cells using an episomal vector system. The episomal Igκ was regulated by LPS and TGF-β like the endogenous gene and established a paused pol II, whereas a construct with a deletion of the intron enhancer and the C region did not establish a paused pol II. Two distinct functions can therefore be assigned to the deleted DNA elements: loading of pol II to its pause site and induction of processive transcription upon LPS stimulation. It had been proposed that somatic hypermutation of Ig genes is connected to transcription. The pause site of pol II described in this work resides upstream of the previously defined 5′ boundary of mutator activity at Igκ genes. The possible role of pausing of pol II for somatic hypermutation is discussed.
Thermolabile H-2Kb Molecules Expressed by Transporter Associated with Antigen Processing-Deficient RMA-S Cells Are Occupied by Low-Affinity Peptides
Authors: De Silva A. Dharshan , Boesteanu Alina , Song Rui , Nagy Nancy , Harhaj Edward , Harding Clifford V. , Joyce Sebastian 
Published: December 2022

Abstract
RMA-S cells do not express functional TAP, yet they express MHC class I molecules at the cell surface, especially at reduced temperatures (26°C). It is generally assumed that such class I molecules are “empty,” devoid of any associated peptide. A radiochemical approach was used to label class I-associated peptides and to determine the extent to which Kb molecules in RMA-S cells are associated with peptides. These studies revealed that at 26°C Kb molecules in RMA-S cells are occupied with self-peptides. Such peptides stably associate with Kb at 26°C but easily dissociate from them at 37°C, suggesting low-affinity interactions between Kb and the associated peptides. At 26°C, at least some of these Kb molecules are stably expressed in a peptide-receptive state on the cell surface, whereas at 37°C they are short lived and are only transiently capable of binding and presenting exogenously supplied OVA 257–264 peptide for presentation to CD8+ Kb-restricted T lymphocytes. Thus contrary to current models of class I assembly in TAP-deficient RMA-S cells, the presumably “empty” molecules are in fact associated with peptides at 26°C. Together, our data support the existence of an alternative mechanism of peptide binding and display by MHC class I molecules in TAP-deficient cells that could explain their ability to present Ag.
Effective DNA Vaccination Against Listeriosis by Prime/Boost Inoculation with the Gene Gun
Authors: Fensterle Joachim , Grode Leander , Hess Jürgen , Kaufmann Stefan H. E. 
Published: December 2022

AbstractProtective immunity against Listeria monocytogenes strongly depends on CD8+ T lymphocytes, and both IFN-γ secretion and target cell killing are considered relevant to protection. We analyzed whether we could induce a protective type 1 immune response by DNA vaccination with the gene gun using plasmids encoding for two immunodominant listerial Ags, listeriolysin and p60. To induce a Th1 response, we 1) coprecipitated a plasmid encoding for GM-CSF, 2) employed a prime/boost vaccination schedule with a 45-day interval, and 3) coinjected oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs. DNA immunization of BALB/c mice with plasmids encoding for listeriolysin (pChly) and p60 (pCiap) efficiently induced MHC class I-restricted, Ag-specific CD8+ T cells that produced IFN-γ. Coinjection of CpG-ODN significantly increased the frequency of specific IFN-γ-secreting T cells. Although pChly induced specific CD8+ T cells expressing CTL activity, it failed to stimulate CD4+ T cells. Only pCiap induced significant CD4+ T cell and humoral responses, which were predominantly of Th2 type. Vaccination with either plasmid induced protective immunity against listerial challenge, and coinjection of CpG ODN improved vaccine efficacy in some situations. This study demonstrates the feasibility of gene gun administration of plasmid DNA for inducing immunity against an intracellular pathogen for which protection primarily depends on type 1 CD8+ T cells.
TH Cells Primed During Influenza Virus Infection Provide Help for Qualitatively Distinct Antibody Responses to Subsequent Immunization
Authors: Marshall Dana , Sealy Robert , Sangster Mark , Coleclough Christopher 
Published: December 2022

AbstractThe quality of the primary Ab-forming cell (AFC) response in cervical lymph nodes and mediastinal lymph nodes of mice to intranasal influenza virus was strongly influenced by viral replicative capacity. IgA secretors were prominent in the early AFC response to infectious virus in mediastinal lymph nodes, while IgG expression was more frequent among isotypically switched AFC in cervical lymph nodes of the same mice; this pattern was reversed in the response to inactivated virus. Influenza viruses A/PuertoRico/8/34 (A/PR8) and A/X-31 share six of eight genome segments, differing only in hemagglutinin (H1 in A/PR8, H3 in A/X-31) and neuraminidase (N1 in A/PR8, N2 in A/X-31) genes. These viruses therefore elicit extensively cross-reactive TH populations, though their glycoproteins are serologically unrelated. Mice recovered from an A/X-31 infection thus mount a primary B cell response against A/PR8 glycoproteins, when challenged with the latter virus, though this response can call upon memory TH cells. To assess the impact of memory TH populations on a primary Ab response, we compared the AFC response to inactivated A/PR8 in naive mice and mice that had cleared an A/X-31 infection. A/X-31 immune mice mounted a more vigorous AFC response against A/PR8 H1 and N1 glycoproteins than naive animals, when immunized intranasally with inactivated A/PR8. However the distribution of isotypes among H1/N1-specific AFC in lymph nodes of A/X-31-primed mice resembled that of naive mice. Evidently, in this functional context, memory TH cells retained the ability to help Ab responses different in quality from that generated during their primary reaction.
Macrophage Inflammatory Protein-3β Enhances IL-10 Production by Activated Human Peripheral Blood Monocytes and T Cells
Authors: Byrnes Heather D. , Kaminski Heather , Mirza Asra , Deno Gregory , Lundell Daniel , Fine Jay S. 
Published: December 2022

AbstractWe report that the addition of human macrophage inflammatory protein-3β (MIP-3β) to cultures of human PBMCs that have been activated with LPS or PHA results in a significant enhancement of IL-10 production. This effect was concentration-dependent, with optimal MIP-3β concentrations inducing more than a 5-fold induction of IL-10 from LPS-stimulated PBMCs and a 2- to 3-fold induction of IL-10 from PHA-stimulated PBMCs. In contrast, no significant effect on IL-10 production was observed when 6Ckine, the other reported ligand for human CCR7, or other CC chemokines such as monocyte chemoattractant protein-1, RANTES, MIP-1α, and MIP-1β were added to LPS- or PHA-stimulated PBMCs. Similar results were observed using activated purified human peripheral blood monocytes or T cells. Addition of MIP-3β to nonactivated PBMCs had no effect on cytokine production. Enhancement of IL-10 production by MIP-3β correlated with the inhibition of IL-12 p40 and TNF-α production by monocytes and with the impairment of IFN-γ production by T cells, which was reversed by addition of anti-IL-10 Abs to the cultures. The ability of MIP-3β to augment IL-10 production correlated with CCR7 mRNA expression and stimulation of intracellular calcium mobilization in both monocytes and T cells. These data indicate that MIP-3β acts directly on human monocytes and T cells and suggest that this chemokine is unique among ligands binding to CC receptors due to its ability to modulate inflammatory activity via the enhanced production of the anti-inflammatory cytokine IL-10.
Selective Up-Regulation of Phosphatidylinositol 3′-Kinase Activity in Th2 Cells Inhibits Caspase-8 Cleavage at the Death-Inducing Complex: A Mechanism for Th2 Resistance from Fas-Mediated Apoptosis
Authors: Varadhachary Arun S. , Peter Marcus E. , Perdow Somia N. , Krammer Peter H. , Salgame Padmini 
Published: December 2022

AbstractIn this study the mechanism of differential sensitivity of CD3-activated Th1- and Th2-type cells to Fas-mediated apoptosis was explored. We show that the Fas-associated death domain protein (FADD)/caspase-8 pathway is differentially regulated by CD3 activation in the two subsets. The apoptosis resistance of activated Th2-type cells is due to an incomplete processing of caspase-8 at the death-inducing signaling complex (DISC) whereas recruitment of caspase-8 to the DISC of Th1- and Th2-like cells is comparable. Activation of phosphatidylinositol 3′-kinase upon ligation of CD3 in Th2-type cells blocked caspase-8 cleavage to its active fragments at the DISC, thereby preventing induction of apoptosis. This study offers a new pathway for phosphatidylinositol 3′-kinase in mediating protection from Fas-induced apoptosis.
Emergence of T, B, and Myeloid Lineage-Committed as well as Multipotent Hemopoietic Progenitors in the Aorta-Gonad- Mesonephros Region of Day 10 Fetuses of the Mouse
Authors: Ohmura Koichiro , Kawamoto Hiroshi , Fujimoto Shinji , Ozaki Shoichi , Nakao Kazuwa , Katsura Yoshimoto 
Published: December 2022

AbstractWe investigated the developmental potential of hemopoietic progenitors in the aorta-gonad-mesonephros (AGM) region, where the definitive type hemopoietic progenitors have been shown to emerge before the fetal liver develops. By using an assay system that is able to determine the developmental potential of individual progenitors toward the T, B, and myeloid lineages, we show that not only multipotent progenitors but also progenitors committed to the T, B, or myeloid lineage already exist in this region of day 10 fetuses. Bipotent progenitors generating myeloid and T cells or those generating myeloid and B cells were also detected, suggesting that the commitment to T and B cell lineages is in progress in the AGM region. The numbers of these progenitors, however, were only 1/200–1/1000 of those in fetal liver of day 12 fetuses. Such small numbers of progenitors suggest that hemopoiesis has just started in the AGM region of day 10 fetuses. Although most of T cell lineage-committed progenitors in the AGM region generated only a small number of immature T cells, some were able to generate a large number of mature T cells. The detection of various types of lineage-committed progenitors strongly suggests that the AGM region is not only the site of stem cell emergence, but also the site of hemopoiesis, including lineage commitment. The T cell progenitors found in the AGM region may represent the first immigrants to the thymus anlage.
Mutual Regulation Between B7-1 (CD80) Expressed on T Cells and IL-4
Authors: Schweitzer A. Nicola , Sharpe Arlene H. 
Published: December 2022

AbstractWe have used T cells from B7-1-deficient TCR transgenic DO11.10 mice to demonstrate a functional role for B7-1 on T cells. B7-1-deficient DO11.10 T cells produce more IL-4 than wild-type DO11.10 T cells, suggesting that B7-1 expressed by T cells regulates the differentiation of IL-4-producing cells. In addition, we found that IL-4 inhibits B7-1 expression by wild-type DO11.10 T cells. Our results suggest that there is a reciprocal relationship between B7-1 expressed on T cells and IL-4 production, which results in a modulatory feedback loop. When high levels of IL-4 are produced by T cells, B7-1 expression by T cells is inhibited, which allows amplification of IL-4 production by these T cells. When low levels of IL-4 are produced by T cells, B7-1 expression by these T cells is increased, and a further reduction in IL-4 production follows. However, in addition to being influenced by IL-4, B7-1 expression by T cells is affected by peptide concentration and by B7 costimulation from APCs. The studies presented here demonstrate that B7-1 on T cells as well as on APCs regulates IL-4 production. However, whereas B7-1 expression on APCs can promote IL-4 production, IL-4 production is inhibited by B7-1 on T cells.
Analysis of 4-1BB Ligand (4-1BBL)-Deficient Mice and of Mice Lacking Both 4-1BBL and CD28 Reveals a Role for 4-1BBL in Skin Allograft Rejection and in the Cytotoxic T Cell Response to Influenza Virus
Authors: DeBenedette Mark A. , Wen Tao , Bachmann Martin F. , Ohashi Pamela S. , Barber Brian H. , Stocking Kim L. , Peschon Jacques J. , Watts Tania H. 
Published: December 2022

Abstract4-1BB ligand (4-1BBL) is a member of the TNF family expressed on activated APC. 4-1BBL binds to 4-1BB (CD137) on activated CD4 and CD8 T cells and in conjunction with strong signals through the TCR provides a CD28-independent costimulatory signal leading to high level IL-2 production by primary resting T cells. Here we report the immunological characterization of mice lacking 4-1BBL and of mice lacking both 4-1BBL and CD28. 4-1BBL−/− mice mount neutralizing IgM and IgG responses to vesicular stomatitis virus that are indistinguishable from those of wild-type mice. 4-1BBL−/− mice show unimpaired CTL responses to lymphocytic choriomeningitis virus (LCMV) and exhibit normal skin allograft rejection but have a weaker CTL response to influenza virus than wild-type mice. 4-1BBL−/−CD28−/− mice retain the CTL response to LCMV, respond poorly to influenza virus, and exhibit a delay in skin allograft rejection. In agreement with these in vivo results, allogeneic CTL responses of CD28−/− but not CD28+/+ T cells to 4-1BBL-expressing APC are substantially inhibited by soluble 4-1BB receptor as is the in vitro secondary response of CD28+ T cells to influenza virus peptides. TCR-transgenic CD28−/− LCMV glycoprotein-specific T cells are insensitive to the presence of 4-1BBL when a wild-type peptide is used, but the response to a weak agonist peptide is greatly augmented by the presence of 4-1BBL. These results further substantiate the idea that different immune responses vary in their dependence on costimulation and suggest a role for 4-1BBL in augmenting suboptimal CTL responses in vivo.
An Essential Role for Antibody in Neutrophil and Eosinophil Recruitment to the Cornea: B Cell-Deficient (μMT) Mice Fail to Develop Th2-Dependent, Helminth-Mediated Keratitis
Authors: Hall Laurie R. , Lass Jonathan H. , Diaconu Eugenia , Strine Ellen R. , Pearlman Eric 
Published: December 2022

Abstract
Invasion of the corneal stroma by neutrophils and eosinophils and subsequent degranulation disrupts corneal clarity and can result in permanent loss of vision. In the current study, we used a model of helminth-induced inflammation to demonstrate a novel role for Ab in mediating recruitment of these inflammatory cells to the central cornea. C57BL/6 and B cell-deficient (μMT) mice were immunized s.c. and injected intrastromally with Ags from the parasitic helminth Onchocerca volvulus (which causes river blindness). C57BL/6 mice developed pronounced corneal opacification, which was associated with an Ag-specific IL-5 response and peripheral eosinophilia, temporal recruitment of neutrophils and eosinophils from the limbal vessels to the peripheral cornea and subsequent migration to the central cornea. In contrast, the corneas of μMT mice failed to develop keratitis after intrastromal injection of parasite Ags unless Ags were injected with immune sera. Eosinophils were recruited from the limbal vessels to the peripheral cornea in μMT mice, but failed to migrate to the central cornea, whereas neutrophil recruitment was impaired at both stages. With the exception of IL-5, T cell responses and peripheral eosinophils were not significantly different between C57BL/6 and μMT mice. Taken together, these findings not only demonstrate that Ab is required for the development of keratitis, but also show that recruitment of neutrophils to the cornea is Ab-dependent, whereas eosinophil migration is only partially dependent upon Ab interactions.
T Cell-Derived IL-10 Promotes Lung Cancer Growth by Suppressing Both T Cell and APC Function
Authors: Sharma Sherven , Stolina Marina , Lin Ying , Gardner Brian , Miller Patrice W. , Kronenberg Mitchell , Dubinett Steven M. 
Published: December 2022

AbstractWe have found previously that human lung cancers potently induce T lymphocyte IL-10 production in vitro. To assess the impact of enhanced T cell-derived IL-10 on antitumor immunity in vivo, we utilized transgenic mice expressing IL-10 under the control of the IL-2 promoter. We have shown previously that Lewis lung carcinoma cells (3LL) have more aggressive growth potential in IL-10 transgenic mice compared with control littermates. In this study, we show that transfer of T cells from IL-10 transgenic mice to control littermates transferred the IL-10 immunosuppressive effect and led to enhanced 3LL tumor growth. In addition to changes in T cell-mediated immunity, professional APC from IL-10 transgenic mice were found to have significantly suppressed capacity to induce MHC alloreactivity, CTL responses, and IL-12 production. Tumor Ag-pulsed dendritic cells from IL-10 transgenic mice also failed to generate antitumor reactivity. These results suggest that increased levels of T cell-derived IL-10 severely impair antitumor immunity in vivo, due to defects in both T cell and APC function.
IL-1αβ Blockade Prevents Cartilage and Bone Destruction in Murine Type II Collagen-Induced Arthritis, Whereas TNF-α Blockade Only Ameliorates Joint Inflammation
Authors: Joosten Leo A. B. , Helsen Monique M. A. , Saxne Tore , van de Loo Fons A. J. , Heinegård Dick , van den Berg Wim B. 
Published: December 2022

AbstractAnti-TNF-α treatment of rheumatoid arthritis patients markedly suppresses inflammatory disease activity, but so far no tissue-protective effects have been reported. In contrast, blockade of IL-1 in rheumatoid arthritis patients, by an IL-1 receptor antagonist, was only moderately effective in suppressing inflammatory symptoms but appeared to reduce the rate of progression of joint destruction. We therefore used an established collagen II murine arthritis model (collagen-induced arthritis(CIA)) to study effects on joint structures of neutralization of either TNF-α or IL-1. Both soluble TNF binding protein and anti-IL-1 treatment ameliorated disease activity when applied shortly after onset of CIA. Serum analysis revealed that early anti-TNF-α treatment of CIA did not decrease the process in the cartilage, as indicated by the elevated COMP levels. In contrast, anti-IL-1 treatment of established CIA normalized COMP levels, apparently alleviating the process in the tissue. Histology of knee and ankle joints corroborated the finding and showed that cartilage and joint destruction was significantly decreased after anti-IL-1 treatment but was hardly affected by anti-TNF-α treatment. Radiographic analysis of knee and ankle joints revealed that bone erosions were prevented by anti-IL-1 treatment, whereas the anti-TNF-α-treated animals exhibited changes comparable to the controls. In line with these findings, metalloproteinase activity, visualized by VDIPEN production, was almost absent throughout the cartilage layers in anti-IL-1-treated animals, whereas massive VDIPEN appearance was found in control and sTNFbp-treated mice. These results indicate that blocking of IL-1 is a cartilage- and bone-protective therapy in destructive arthritis, whereas the TNF-α antagonist has little effect on tissue destruction.
Proteinase-Activated Receptor-2-Activating Peptides Induce Leukocyte Rolling, Adhesion, and Extravasation In Vivo
Authors: Vergnolle Nathalie 
Published: December 2022

AbstractProteinase-activated receptor 2 (PAR2) has been suggested to play a role in inflammatory reactions. Because leukocyte-endothelial cell interactions are critical events during inflammatory reactions, and because PAR2 is expressed both on endothelium and leukocytes, we have examined the effects of PAR2-activating peptides (PAR2-APs) on leukocyte rolling and adhesion in mesenteric venules and on leukocyte recruitment into the peritoneal cavity. Using intravital microscopy, leukocyte rolling, flux, and adhesion in rat mesenteric postcapillary venules were quantified. Topical addition of PAR2-APs (10 μM) for 1 min to the superfused venule induced a significant increase in leukocyte rolling and adherence. The increase in leukocyte adherence was not affected by pretreatment with a mast cell stabilizer (sodium cromoglycate) nor by prior degranulation of mast cells with compound 48/80. Nonetheless, both leukocyte rolling and adhesion were completely inhibited by pretreatment with a platelet-activating factor receptor antagonist (WEB 2086). Intraperitoneal injections of a selective PAR2-AP (SLIGRL-NH2) caused a significant increase in leukocyte migration into the peritoneal cavity. The effect of SLIGRL-NH2 on peritoneal leukocyte infiltration was completely inhibited by WEB 2086. These data suggest that PAR2 activation could contribute to several early events in the inflammatory reaction, including leukocyte rolling, adherence, and recruitment, by a mechanism dependent on platelet-activating factor release.
L-Selectin Ligands Expressed by Human Leukocytes Are HECA-452 Antibody-Defined Carbohydrate Epitopes Preferentially Displayed by P-Selectin Glycoprotein Ligand-1
Authors: Tu LiLi , Murphy Patricia G. , Li Xuan , Tedder Thomas F. 
Published: December 2022

AbstractLeukocytes express L-selectin ligands critical for leukocyte-leukocyte interactions at sites of inflammation. The predominant leukocyte L-selectin ligand is P-selectin glycoprotein ligand-1 (PSGL-1), which displays appropriate sialyl Lewis x (sLex)-like carbohydrate determinants for L-selectin recognition. Among the sLex-like determinants expressed by human leukocytes is a unique carbohydrate epitope defined by the HECA-452 mAb. The HECA-452 Ag is a critical component of L-selectin ligands expressed by vascular endothelial cells. However, HECA-452 Ag expression on human leukocyte L-selectin ligands has not been assessed. In this study, the HECA-452 mAb blocked 88–99% of neutrophil rolling on, or attachment to, adherent cells expressing L-selectin in multiple experimental systems. A function-blocking anti-PSGL-1 mAb also inhibited L-selectin binding to neutrophils by 89–98%. In addition, the HECA-452 and anti-PSGL-1 mAbs blocked the majority of P-selectin binding to neutrophils. Western blot analysis revealed that PSGL-1 immunoprecipitated from neutrophils displayed HECA-452 mAb-reactive determinants and that PSGL-1 was the predominant scaffold for HECA-452 Ag display. Leukocyte L-selectin ligands also contained sulfated determinants since culturing ligand-bearing cells with NaClO3 abrogated L-selectin binding. Consistent with this, human neutrophils expressed mRNA encoding five different sulfotransferases associated with the generation of selectin ligands: CHST1, CHST2, CHST3, TPST1, and HEC-GlcNAc6ST. Therefore, the HECA-452-defined carbohydrate determinant displayed on PSGL-1 represented the predominant L-selectin and P-selectin ligand expressed by neutrophils.