bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Human C-Reactive Protein on Chemokine and Chemotactic Factor-Induced Neutrophil Chemotaxis and Signaling
Authors: Zhong Wangjian , Zen Qin , Tebo Julie , Schlottmann Klaus , Coggeshall Mark , Mortensen Richard F. 
Published: December 2022

AbstractC-reactive protein (CRP) is a unique serum pentraxin and the prototype acute phase reactant. CRP is a ligand for specific receptors on phagocytic leukocytes, and mediates activation reactions of monocytes/macrophages, but inhibits the respiratory burst of neutrophils (PMN). Since CRP selectively accumulates at inflammatory sites in which IL-8 is also produced, we tested the effects of CRP on the responsiveness of PMN to IL-8 and the bacterial chemotactic peptide, FMLP-phenylalanine (FMLPP). Purified human CRP inhibited the chemotactic response of PMN to IL-8 and FMLPP. A mouse IgM mAb that was generated against the leukocyte CRP receptor (CRP-R) also inhibited the chemotactic response. Incubation of purified CRP with activated PMN generated CRP-derived peptides that also inhibited chemotaxis. A synthetic CRP peptide (residues 27–38) that binds to the CRP-R had weak chemotactic activity, whereas two other CRP synthetic peptides (residues 174–185 and 191–205) inhibited chemotaxis of PMNs to both IL-8 and FMLPP. CRP did not alter receptor-specific binding of IL-8, but exerted its effect at the level of signaling. CRP augmented both IL-8- and FMLPP-induced mitogen-activated protein kinase (extracellular signal-regulated kinase-2) activity. CRP at acute phase levels increased both agonist-induced and noninduced phosphatidylinositol-3 kinase activity. The results suggest a role for CRP as a regulator of leukocyte infiltration at inflammatory sites.
Mature Mainstream TCRαβ+CD4+ Thymocytes Expressing L-Selectin Mediate “Active Tolerance” in the Nonobese Diabetic Mouse
Authors: Herbelin André , Gombert Jean-Marc , Lepault Françoise , Bach Jean-François , Chatenoud Lucienne 
Published: December 2022

AbstractPathogenic autoreactive T lymphocytes are mediators of spontaneous insulin-dependent diabetes in nonobese diabetic (NOD) mice. This is demonstrated by their capacity to transfer diabetes into syngeneic immunoincompetent recipients. In addition, especially in prediabetic NOD mice, peripheral CD4+ T lymphocytes were identified that are highly effective, in conventional mixing cotransfer experiments, at preventing disease transfer. The present data demonstrate that mature heat-stable Ag−TCRαβ+CD8− thymocytes from prediabetic NOD mice also express this inhibitory capacity. Selection using an L-selectin (CD62L)-specific Ab showed that TCRαβ+CD4+CD62L+ thymocytes, emerging from the mainstream differentiation pathway, concentrate this ability to regulate autoreactive effectors. Compared with mature TCRαβ+CD8− thymocytes, significantly lower numbers of TCRαβ+CD4+CD62L+ were sufficient to achieve an efficient inhibition of disease transfer into NOD-scid recipients. This protective ability was potentiated following in vitro culture in the presence of IL-7. In contrast, TCRαβ+CD62L− thymocytes, highly enriched in class I-restricted NK T cells, were unable to influence diabetes transfer. Identical results were obtained using thymocytes that have been cultured in vitro for 4 days in the presence of IL-7. These results support the active role in NOD mice of a thymus-derived CD4+ subset that controls peripheral pathogenic autoimmune effectors.
Expansion of Functional NK Cells in Multiple Tissue Compartments of Mice Treated with Flt3-Ligand: Implications for Anti-Cancer and Anti-Viral Therapy
Authors: Shaw Samuel G. , Maung Adrian A. , Steptoe Raymond J. , Thomson Angus W. , Vujanovic3 Nikola L. 
Published: December 2022

AbstractThe generation and activity of NK cells appear to be regulated by a particular set of cytokines. We examined the in vivo effects of recombinant human Flt3 ligand (Flt3-L), a recently cloned potent hemopoietic cytokine, on NK cell development in mice. Daily i.p. administration of Flt3-L consistently induced striking increases in both the absolute number and the total cytotoxic activity of mature nonactivated NK cells within various tissues. Dose- and time-dependent increases were observed in the bone marrow (∼2- and ∼11-fold, respectively), thymus (∼2.8- and ∼2.0-fold), blood (∼11- and ∼15-fold), spleen (∼10- and ∼9-fold), and liver (∼15- and ∼39-fold). In addition, IL-2 induced a rapid increase in NK activity, NK cell proliferative responses, generation of lymphokine-activated killer activity, and development of activated adherent NK cells, which were all significantly increased by Flt3-L treatment. Thus, in addition to its recently reported capacity to stimulate dendritic cell production, Flt3-L has a prominent biologic role in NK cell generation in vivo. This is probably a result of selectively induced expansion of NK cell progenitors (pro-NK cells), because Flt3-L stimulates in vitro proliferation of pro-NK cells without affecting the cytotoxicity of mature NK cells. The results also indicate that either alone or in combination with a potent activator of NK cells, such as IL-2, Flt3-L could be used to markedly augment the number and activity of NK cells, especially in the liver. Flt3-L appears to have considerable potential for therapy of both cancer and viral infection.
Intracellular Regulation of TRAIL-Induced Apoptosis in Human Melanoma Cells
Authors: Griffith Thomas S. , Chin Wilson A. , Jackson Glenn C. , Lynch David H. , Kubin Marek Z. 
Published: December 2022

AbstractThe observation that TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF cytokine family, induces apoptosis in a number of different tumor cell types led us to compare the tumoricidal effects of TRAIL to those of other TNF family molecules on human melanoma cells. We found that a high proportion of the melanoma cell lines tested were killed by TRAIL, whereas all the melanoma lines were resistant to the other TNF family cytokines tested. TRAIL-induced death was characterized by caspase activation and cellular protein cleavage within minutes of TRAIL addition, and death could be completely inhibited by the caspase inhibitors Ile-Glu-Thr-Asp (IETD) and Val-Ala-Asp (VAD), indicating the presence of a TRAIL receptor signaling pathway similar to that identified for Fas and TNF receptors. Specific TRAIL receptor expression was determined by RT-PCR, and the presence of mRNA encoding the “protective” TRAIL receptors did not correspond to resistance or sensitivity to TRAIL-induced apoptosis. Addition of protein synthesis inhibitors to TRAIL-resistant melanomas rendered them sensitive to TRAIL, indicating that the presence or the absence of intracellular apoptosis inhibitors may mediate resistance or sensitivity to TRAIL-mediated apoptosis. Expression of one such inhibitor, FLICE-inhibitory protein (FLIP), was highest in the TRAIL-resistant melanomas, while being low or undetectable in the TRAIL-sensitive melanomas. Furthermore, addition of actinomycin D to TRAIL-resistant melanomas resulted in decreased intracellular concentrations of FLIP, which correlated with their acquisition of TRAIL sensitivity. Collectively, our results indicate that TRAIL-induced apoptosis occurs through a caspase signaling cascade and that resistance is controlled by intracellular regulators of apoptosis.
Nuclear Translocation of Upstream Stimulating Factor 2 (USF2) in Activated Mast Cells: A Possible Role in Their Survival
Authors: Frenkel Shahar , Kay Gillian , Nechushtan Hovav , Razin Ehud 
Published: December 2022

Abstract
Multiple transcription factors are activated in the cytoplasm and translocated to the nucleus where they exert positive or negative control over cellular genes. Such subcellular traffic of transcription factors usually requires the presence of a positively charged nuclear localization sequence (NLS). Upstream stimulating factor 2 (USF2) is one of the few transcription factors that contain two potential domains for nuclear localization. In addition to the conventional basic NLS, USF2 contains a highly conserved USF-specific region that is involved in its nuclear translocation. In the present work, the induction of translocation of USF2 into the mast cell nucleus was observed and found to be dependent on activation of the cells either by IL-3 or IgE-Ag. It was also observed that the prevention of the translocation of USF2 to the nucleus, using a peptide derived from the specific USF-NLS region, significantly inhibited their IL-3-mediated survival. Thus, our findings show a direct connection between mast cell surface receptor-mediated USF2 nuclear translocation and cell viability.
TCRαβ Chains Associate with the Plasma Membrane Independently of CD3 and TCRζ Chains in Murine Primary T Cells
Authors: Zhang Jian , Salojin Konstantin , Gao Jian-Xin , Cameron Mark , Geisler Carsten , Delovitch Terry L. 
Published: December 2022

AbstractThe TCR is a multisubunit complex composed of the clonotypic α/β disulfide-linked heterodimer and noncovalently linked invariant CD3γε and CD3δε and TCRζ chains. Recent studies demonstrate that the surface expression of CD3 components can occur independently of the clonotypic TCR complexes in both thymocytes and splenic T cells. In this study, we report that free noncovalently associated TCRαβ heterodimers that exist independently of CD3 and TCRζ chains are expressed on the cell surface of immature thymocytes and peripheral T cells, but not of T cell lines and T cell hybridomas. This suggests that the regulation of surface expression of TCRαβ heterodimers differs between primary T cells and T cell lines or T cell hybridomas. The isolation and biochemical characterization of surface clonotype-independent CD3 complexes and free membrane-associated TCRαβ complexes may provide a structural basis for the quantitative difference in amount of T cell proliferation stimulated by anti-CD3ε and anti-TCRβ.
Molecular Cloning of Two Isoforms of the Guinea Pig C3a Anaphylatoxin Receptor: Alternative Splicing in the Large Extracellular Loop
Authors: Fukuoka Yoshihiro , Ember Julia A. , Hugli Tony E. 
Published: December 2022

AbstractThe anaphylatoxin C3a is released from C3 during complement activation. C3a is a potent spasmogen and has recently been described as an eosinophil and mast cell chemotactic factor that mediates a number of inflammatory reactions. Previously, we demonstrated the presence of a specific C3a receptor (C3aR) on guinea pig platelets. We report here the isolation of cDNA clones encoding for two isoforms of guinea pig C3aR (gpC3aR). Hydropathy analysis of the deduced amino acid sequence of both gpC3aR clones indicated seven transmembrane domains with a large extracellular (EC) loop between the fourth and fifth transmembrane domains, which is a known characteristic of the human C3aR. Northern blot analysis revealed that the gpC3aR was abundantly expressed on macrophages and in the spleen. A comparison of the deduced amino acid sequence of the larger gpC3aR (gpC3aR-L) with the recently cloned human C3aR indicated a 59.5% identity. The deduced amino acid sequence of the second, smaller cDNA clone was identical with gpC3aR-L, except that it lacked 35 amino acids in the large EC loop. Our evidence indicates that alternative splicing occurred in the large EC loop that accounts for these two isoforms. L cells separately expressing one of these two isoforms of the gpC3aR showed similar high-affinity C3a binding. An RT-PCR analysis documented that both forms of the C3aR were expressed in a variety of guinea pig tissues. The cloning and expression of these two natural forms of gpC3aR cDNA indicated that the deletion of the 35-residue portion of the large EC loop of gpC3aR-L did not alter C3a binding.
The MHC Class I-Restricted Immune Response to HIV-gag in BALB/c Mice Selects a Single Epitope That Does Not Have a Predictable MHC-Binding Motif and Binds to Kd Through Interactions Between a Glutamine at P3 and Pocket D
Authors: Mata Marielena , Travers Paul J. , Liu Qiang , Frankel Fred R. , Paterson Yvonne 
Published: December 2022

Abstract
Using a strain of Listeria monocytogenes that stably expresses and secretes HIV gag to deliver this Ag to the MHC class I pathway of Ag processing, we have identified the immunodominant CTL epitope to gag in the BALB/c mouse and shown that it is Kd restricted. The specific motif for the peptides that bind the MHC class I molecule H-2 Kd is believed to be a nonamer with residues tyrosine or phenylalanine in the second amino acid position and leucine or isoleucine in the carboxyl-terminal or ninth amino acid position as dominant anchoring positions. Surprisingly, the identified gag peptide, AMQMLKETI, does not contain an anchoring aromatic residue in position two although competition assays with other Kd-restricted epitopes indicated that it binds to Kd with comparable affinity. Using a theoretical molecular dynamics approach to probe the stability of peptide binding to MHC class I molecules, we show that the absence of an appropriate anchor residue at P2 in AMQMLKETI is compensated by favorable interactions of the glutamine at P3 with pocket D of Kd. These findings were verified experimentally, demonstrating the predictive power of this theoretical approach in analyzing MHC class I/peptide interactions. These studies also indicate that CTL epitope prediction that relies on dominant peptide motifs may not always identify the correct epitope.
SFA-1/PETA-3 (CD151), a Member of the Transmembrane 4 Superfamily, Associates Preferentially with α5β1 Integrin and Regulates Adhesion of Human T Cell Leukemia Virus Type 1-Infected T Cells to Fibronectin
Authors: Hasegawa Hitoshi , Nomura Tetsuhiko , Kishimoto Kyoko , Yanagisawa Kohsuke , Fujita Shigeru 
Published: December 2022

Abstract
In this study we have analyzed the adhesion molecules associated with and the biologic function of SFA-1/PETA-3 (CD151) in human T cell leukemia virus type 1 (HTLV-1)-infected T cells and in freshly isolated adult T cell leukemia (ATL) cells using an anti-CD151 mAb. The anti-CD151 mAb coprecipitated α5β1 integrin from HTLV-1-infected T cells. Conversely, an anti-α5 integrin mAb coprecipitated CD151. The anti-CD151 mAb inhibited the adhesion of HTLV-1-infected T cells to fibronectin but did not have any effect on their adhesion to laminin, collagen type I, or collagen type IV. Moreover, antisense CD151 oligonucleotide-treated HTLV-1-infected T cells showed significant inhibition of adhesion to fibronectin. These findings showed that the CD151 molecule was associated with the α5β1 integrin molecule and that it enhanced α5β1 integrin-mediated adhesion to fibronectin. In addition, the expression levels of CD151, α4β1 integrin, and α5β1 integrin on ATL cells from lymph nodes of lymphoma-type ATL patients were significantly higher than those on circulating ATL cells from leukemia-type ATL patients. This suggests that the increased expression of these integrins may contribute to lymphoma formation through the adhesion of ATL cells to the extracellular matrix and dendritic cells, rather than contributing to transmigration.
Cutting Edge: Cross-Priming of CTL Responses In Vivo Does Not Require Antigenic Peptides in the Endoplasmic Reticulum of Immunizing Cells
Authors: Schoenberger Stephen P. , van der Voort Ellen I. H. , Krietemeijer G. Menno , Offringa Rienk , Melief Cornelis J. M. , Toes Rene E. M. 
Published: December 2022

Abstract
It has been proposed that the cross-priming of CTL responses in vivo involves the transfer to host APCs of heat shock protein glycoprotein 96-chaperoned antigenic peptides released from the endoplasmic reticulum (ER) of dying or infected cells. We have tested this possibility directly using TAP-deficient cell lines lacking antigenic ER peptides derived from two model Ags, the human adenovirus type 5 early regions E1A and E1B. Although both proteins were well expressed, the cells were not recognized by E1A- or E1B-specific CTLs unless the relevant epitope was either provided exogenously as a synthetic peptide or targeted to the ER in a TAP-independent fashion. Despite the absence of these ER peptides, the TAP1−/− cells were able to efficiently cross-prime E1A- and E1B-specific CTLs following immunization of syngeneic mice. These results indicate that, although purified peptide/glycoprotein 96 complexes are potent immunogens, the mechanism of CTL cross-priming in vivo does not depend upon antigenic peptides in the ER of immunizing cells.
Cutting Edge: GATA-3-Dependent Enhancer Activity in IL-4 Gene Regulation
Authors: Ranganath Sheila , Ouyang Wenjun , Bhattarcharya Deepta , Sha William C. , Grupe Andrew , Peltz Gary , Murphy Kenneth M. 
Published: December 2022

AbstractPreviously, we analyzed the proximal IL-4 promoter in directing Th2-specific activity. An 800-base pair proximal promoter conferred some Th2-selective expression in transgenic mice. However, this region directed extremely low reporter mRNA levels relative to endogenous IL-4 mRNA, suggesting that full gene activity requires additional enhancer elements. Here, we analyzed large genomic IL-4 regions for enhancer activity and interaction with transcription factors. The proximal IL-4 promoter is only moderately augmented by GATA-3, but certain genomic regions significantly enhanced GATA-3 promoter transactivation. Some enhancing regions contained consensus GATA sites that bound Th2-specific complexes. However, retroviral transduction of GATA-3 into developing T cells induced IL-5 to full Th2 levels, but only partially restored IL-4 production. Thus, we propose that GATA-3 is permissive, but not sufficient, for full IL-4 enhancement and may act through GATA elements surrounding the IL-13/IL-4 gene locus.
Qualitative and Quantitative Effects of CD28/B7-Mediated Costimulation on Naive T Cells In Vitro
Authors: Manickasingham Shivanthi P. , Anderton Stephen M. , Burkhart Christoph , Wraith David C. 
Published: December 2022

AbstractThe CD28/B7 system provides costimulatory signals necessary for optimal T cell activation. We have examined the effects of blocking B7.1 and/or B7.2 in an in vitro system using TCR transgenic T cells specific for myelin basic protein. Activation of naive T cells was found to be B7.2 dependent and not dependent on the presence of B7.1 molecules. However, increasing the strength of signal through the TCR using peptide analogues with higher affinity for MHC compensated for blockade of B7.2 molecules, suggesting that signal 1 alone can be sufficient for the activation of naive T cells. The role of B7 molecules in the differentiation of T cells was further investigated by restimulating T cells with fresh APC and peptide in B7-sufficient conditions. A down-regulation of IL-2 and IFN-γ production by T cells primed in the presence of anti-B7.2 mAb was partially overcome when high affinity peptide analogues were used to restimulate T cells. In contrast, a significant down-regulation of the differentiation of cells producing Th-2 cytokines was observed in the presence of anti-B7 Abs. Differentiation of IL-4-secreting cells was influenced by both B7.1 and B7.2, while IL-5 secretion was totally dependent on B7.2. These results suggest that B7-mediated costimulation is essential for the development of Th-2-associated cytokines, the absence of which cannot be overcome by increasing the strength of the signal through the TCR.
Transfer of Primitive Stem/Progenitor Bone Marrow Cells from LTα−/− Donors to Wild-Type Hosts: Implications for the Generation of Architectural Events in Lymphoid B Cell Domains
Authors: Mebius Reina E. , van Tuijl Silvy , Weissman Irving L. , Randall Troy D. 
Published: December 2022

AbstractTo analyze whether the phenotypic abnormalities observed in lymphotoxin-α−/− (LTα−/−) mice are intrinsic to the hemolymphoid system itself or dependent on stromal elements, wild-type (WT) mice were reconstituted with bone marrow (BM) cells enriched for hemopoietic stem cells from LTα−/− animals. WT mice reconstituted with LTα−/−c-kit+Lin−Sca-1+ BM cells do not maintain follicular dendritic cell (FDC) networks and do not form primary follicles, while clear segregation of B and T cells could be observed. Furthermore, IgM+IgD− B cells, MOMA-1 (anti-metallophilic macrophages), ERTR-9 (anti-marginal zone macrophages), and MECA-367 (anti-MAdCAM-1) were all absent from the splenic marginal zone. Surprisingly, however, the expression of MOMA-1, ERTR-9, and MAdCAM-1 was normal in the lymph nodes of mice reconstituted with LTα−/− cells. In addition, peanut agglutinin-positive germinal centers were observed in both the spleen and mesenteric lymph nodes, although in the absence of detectable FDC. Furthermore, in animals reconstituted with a mixture of LTα−/− and WT c-kit+Lin−Sca-1+, GC contained either predominantly LTα−/− B cells or WT B cells. These results suggest that although the formation of primary follicles, FDC networks, and the splenic marginal zone are all dependent on hemopoietically derived LTα, germinal center formation and the expression of MAdCAM-1, MOMA-1, and ERTR-9 in lymph nodes are not. Our results also suggest that the disturbed B-T cell separation in LTα−/− mice is unrelated to defects in the marginal zone.
Long-Lasting Protective Immunity to Experimental Autoimmune Encephalomyelitis Following Vaccination with Naked DNA Encoding C-C Chemokines
Authors: Youssef Sawsan , Wildbaum Gizi , Maor Gila , Lanir Noami , Gour-Lavie Alumit , Grabie Nir , Karin Nathan 
Published: December 2022

AbstractDNA vaccination represents a novel means of expressing Ag in vivo for the generation of both humoral and cellular immune responses. The current study uses this technology to elicit protective immunity against experimental autoimmune encephalomyelitis (EAE), a T cell-mediated autoimmune disease of the central nervous system that serves as an experimental model for multiple sclerosis. RT-PCR verified by Southern blotting and sequencing of PCR products of four different C-C chemokines, macrophage-inflammatory protein-1α (MIP-1α), monocyte-chemotactic protein-1 (MCP-1), MIP-1β, and RANTES, were performed on brain samples from EAE rats to evaluate mRNA transcription at different stages of disease. Each PCR product was then used as a construct for naked DNA vaccination. The subsequent in vivo immune response to MIP-1α or MCP-1 DNA vaccines prevented EAE, even if disease was induced 2 mo after administration of naked DNA vaccines. In contrast, administration of the MIP-1β naked DNA significantly aggravated the disease. Generation of in vivo immune response to RANTES naked DNA had no notable effect on EAE. MIP-1α, MCP-1, and MIP-1β mRNA transcription in EAE brains peaked at the onset of disease and declined during its remission, whereas RANTES transcription increased in EAE brains only following recovery. Immunization of CFA without the encephalitogenic epitope did not elicit the anti-C-C chemokine regulatory response in DNA-vaccinated rats. Thus, modulation of EAE with C-C chemokine DNA vaccines is dependent on targeting chemokines that are highly transcribed at the site of inflammation at the onset of disease.