bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of RANTES- and Aminooxypentane-RANTES- Triggered Desensitization Signals Reveals Differences in Recruitment of the G Protein-Coupled Receptor Complex
Authors: Vila-Coro Antonio J. , Mellado Mario , Martín de Ana Ana , Martínez-A. Carlos , Rodríguez-Frade José Miguel 
Published: December 2022

Abstract
The trafficking of lymphocyte populations is a complex process controlled by a vast array of molecules. In this process, cells must be able to sense small changes in chemoattractant gradients. Migration through a chemotactic gradient probably employs an on-off mechanism in which chemokine receptor desensitization, internalization, and recycling may be important steps. This multistep process requires the coordinated action of many factors, including G protein-coupled receptor kinases, arrestins, clathrin, and GTP-hydrolyzing proteins such as dynamin. In this report, we show that RANTES and its derivative, aminooxypentane (AOP)-RANTES, a potent RANTES antagonist as well as an inhibitor of HIV-1 infection, both promote CCR5 desensitization involving G protein-coupled receptor kinases-2 and β-arrestin equally well. An important difference between the two molecules is that (AOP)-RANTES is more efficient than RANTES in promoting Ser/Thr phosphorylation of the receptor and association of G protein-coupled receptor kinases-2, β-arrestin, and clathrin to the CCR5. After stimulation with either ligand, we observe rapid, transient association of dynamin to CCR5, implicating this protein in receptor sensitization, but this association is faster and longer-lasting following (AOP)-RANTES stimulation. In summary, we show that chemokine receptor internalization takes place through the formation of clathrin vesicles and involves dynamin activity. We provide compelling evidence that the differences between RANTES and (AOP)-RANTES in Gαi activation condition subsequent signaling events, including internalization and receptor recycling.
β-Glucan, a “Specific” Biologic Response Modifier That Uses Antibodies to Target Tumors for Cytotoxic Recognition by Leukocyte Complement Receptor Type 3 (CD11b/CD18)
Authors: Yan Jun , Větvička Václav , Xia Yu , Coxon Angela , Carroll Michael C. , Mayadas Tanya N. , Ross Gordon D. 
Published: December 2022

Abstractβ-Glucans were identified 36 years ago as a biologic response modifier that stimulated tumor rejection. In vitro studies have shown that β-glucans bind to a lectin domain within complement receptor type 3 (CR3; known also as Mac-1, CD11b/CD18, or αMβ2-integrin, that functions as an adhesion molecule and a receptor for factor I-cleaved C3b, i.e., iC3b) resulting in the priming of this iC3b receptor for cytotoxicity of iC3b-opsonized target cells. This investigation explored mechanisms of tumor therapy with soluble β-glucan in mice. Normal mouse sera were shown to contain low levels of Abs reactive with syngeneic or allogeneic tumor lines that activated complement, depositing C3 onto tumors. Implanted tumors became coated with IgM, IgG, and C3, and the absent C3 deposition on tumors in SCID mice was reconstituted with IgM or IgG isolated from normal sera. Therapy of mice with glucan- or mannan-rich soluble polysaccharides exhibiting high affinity for CR3 caused a 57–90% reduction in tumor weight. In young mice with lower levels of tumor-reactive Abs, the effectiveness of β-glucan was enhanced by administration of a tumor-specific mAb, and in SCID mice, an absent response to β-glucan was reconstituted with normal IgM or IgG. The requirement for C3 on tumors and CR3 on leukocytes was highlighted by therapy failures in C3- or CR3-deficient mice. Thus, the tumoricidal function of CR3-binding polysaccharides such as β-glucan in vivo is defined by natural and elicited Abs that direct iC3b deposition onto neoplastic cells, making them targets for circulating leukocytes bearing polysaccharide-primed CR3. Therapy fails when tumors lack iC3b, but can be restored by tumor-specific Abs that deposit iC3b onto the tumors.
Identification of a New Type of Invariant Vα14+ T Cells and Responsiveness to a Superantigen,Yersinia pseudotuberculosis- Derived Mitogen
Authors: Yagi Junji , Dianzani Umberto , Kato Hidehito , Okamoto Toshihiro , Katsurada Tomoko , Buonfiglio Donatella , Miyoshi-Akiyama Tohru , Uchiyama Takehiko 
Published: December 2022

AbstractWe examined the expression of the H4 T cell activation marker in thymic T cell subpopulations and found that TCR-αβ+ CD4+ thymic T cells are segregated into three subpopulations based upon H4 levels. Thymic T cells with either no or low H4 expression differentiate via the mainstream differentiation pathway in the thymus. H4int thymic T cells, which express a skewed Vβ repertoire of Vβ2, -7, and -8 in their TCRs, show the phenotype of NKT cells: CD44high, Ly6Chigh, NK1.1+, and TCR-αβlow. H4high thymic T cells also show a skewed Vβ repertoire, Vβ2, -7, and -8, and predominantly express an invariant Vα14-Jα281+ α-chain in their TCRs but constitute a distinct population in that they are CD44int, Ly6C−, NK1.1−, and TCR-αβhigh. Thus, invariant Vα14+ thymic T cells consist of ordinary NKT cells and a new type of T cell population. Vβ7+ and Vβ8.1+ invariant Vα14+ thymic T cells are present in DBA/2 mice, which carry mammary tumor virus-7-encoded superantigens, in comparable levels to those in BALB/c mice. Furthermore, Vβ7+ invariant Vα14+ thymic T cells in DBA/2 mice are in the immunologically responsive state, and Yersinia pseudotuberculosis-derived mitogen-induced Vβ7+ invariant Vα14+ thymic T cell blasts from DBA/2 and BALB/c mice exhibited equally enhanced responses upon restimulation with Y. pseudotuberculosis-derived mitogen. Thus, invariant Vα14+ thymic T cells that escape negative selection in DBA/2 mice contain T cells as functionally mature as those in BALB/c mice.
TNF-α-Induced Growth Suppression of CD34+ Myeloid Leukemic Cell Lines Signals Through TNF Receptor Type I and Is Associated with NF-κB Activation
Authors: Hu Xiaotang , Tang Menque , Fisher Ariana Brown , Olashaw Nancy , Zuckerman Kenneth S. 
Published: December 2022

AbstractConflicting results have been reported regarding the effect of TNF-α on the growth of human primitive hemopoietic cells. In this study, we have examined the effect of TNF-α on the proliferation of several CD34+/CD38+ (KG-1, TF-1) and CD34+/CD38− (KG-1a, TF-1a) myeloid leukemic progenitor cell lines. Our data show that TNF-α markedly inhibits the growth of these cells in both liquid and soft agar cultures. Addition of GM-CSF or IL-3 does not prevent TNF-α-induced growth inhibition. Flow cytometry analyses of propidium iodide-stained cells demonstrated cell death of all four cell lines, as judged by the presence of cells with hypodiploid DNA content after exposure of cells to TNF-α for 4 days. Annexin V assays detected apoptosis in TF-1, but not in TF-1a, KG-1, and KG-1a cells in terms of translocation of phosphatidylserine shortly after TNF-α treatment. Neutralizing anti-TNF receptor type I (TNFR-I; p55) Ab almost completely reversed TNF-α-induced growth inhibition in both liquid and soft agar cultures, whereas anti-TNFR-II (p75) Ab had only a marginal effect. TNF-α rapidly induced marked activation of nuclear transcription factor NF-κB in all 4 cell lines. The majority of this effect was abolished by the type I receptor Ab, whereas the type II receptor neutralizing Ab had no effect. Our data also show that TNF-α is incapable of inducing activation of the mitogen-activated protein kinase pathway in these leukemic cell lines.
Differential Control of Autoantibodies and Lymphoproliferation by Fas Ligand Expression on CD4+ and CD8+ T Cells In Vivo
Authors: Maldonado Michael A. , MacDonald Glen C. , Kakkanaiah Vellalore N. , Fecho Karamarie , Dransfield Mark , Sekiguchi Debora , Cohen Philip L. , Eisenberg Robert A. 
Published: December 2022

AbstractWe have previously shown that the gld autoimmune syndrome is suppressed in lethally irradiated gld mice reconstituted with a mixture of normal and gld bone marrow (BM). Furthermore, in vivo depletion of normal Thy-1+ cells restores lymphoproliferation and autoantibody production in such chimeras, suggesting that T cells bearing Fas ligand are responsible for correcting the gld defect. In this study, mixed-BM chimeras lacking either normal CD4+ (B6CD4KO-B6gld) or normal CD8+ T cells (B6CD8KO-B6gld) were generated to determine the contribution of the normal T cell subsets to disease suppression. Lymphoproliferation was completely suppressed in B6CD4KO-B6gld chimeras but only modestly in B6CD8KO-B6gld chimeras. On the other hand, both types of mixed-BM chimeras had incomplete effects on the suppression of serum autoantibodies when compared with B6gld reconstituted with isologous BM. These results suggest that both T cell subsets provide Fas ligand to suppress immune cells responsible for autoantibody production; however, CD8+ T cells are mainly responsible for preventing lymphoproliferation.
Role of the Costimulatory Molecule CD28 in the Development of Lupus in MRL/lprMice
Authors: Tada Yoshifumi , Nagasawa Kohei , Ho Alexandra , Morito Fumitaka , Koarada Syuichi , Ushiyama Osamu , Suzuki Noriaki , Ohta Akihide , Mak Tak W. 
Published: December 2022

AbstractMRL/Mpj-lpr/lpr (MRL/lpr) mice develop autoimmune disorders, including lymphoproliferation, glomerulonephritis, autoantibody production, and hypergammaglobulinemia. To investigate the role of the costimulatory molecule CD28 in the development of these disorders, MRL/lpr mice lacking CD28 were generated by gene targeting. Compared with CD28+/+ MRL/lpr mice, CD28−/− MRL/lpr mice showed decreased lymphadenopathy but increased splenomegaly associated with the expansion of abnormal B220+ TCRαβ+ T cells. Although levels of IgM Abs were unchanged in CD28−/− MRL/lpr mice, the production of anti-DNA IgG Abs and IgG rheumatoid factors were suppressed. IgG deposition in the glomeruli was markedly decreased, and the development of glomerulonephritis was significantly retarded. Furthermore, renal vasculitis and arthritis were absent in CD28−/− MRL/lpr mice. These results indicate that, although CD28 is not required for the generation of the abnormal T cell population in MRL/lpr mice, it does play an important role in the development of autoimmune disease in these animals.
Stochastic Acquisition of Qa1 Receptors During the Development of Fetal NK Cells In Vitro Accounts in Part But Not in Whole for the Ability of These Cells to Distinguish Between Class I-Sufficient and Class I-Deficient Targets
Authors: Toomey Jennifer A. , Salcedo Margarita , Cotterill Lisa A. , Millrain Margaret M. , Chrzanowska-Lightowlers Zosia , Lawry John , Fraser Karen , Gays Frances , Robinson John H. , Shrestha Sunil , Dyson P. Julian , Brooks Colin G. 
Published: December 2022

AbstractFetal mouse NK cells are grossly deficient in the expression of Ly49 molecules yet show a limited ability to distinguish between wild-type and MHC class I-deficient target cells. In this paper we report that during their development in vitro from immature thymic progenitors, a proportion of C57BL/6 fetal NK cells acquires receptors for a soluble form of the nonclassical class I molecule Qa1b associated with the Qdm peptide, but not for soluble forms of the classical class I molecules Kb and Db. The acquisition of these Qa1 receptors occurs in a stochastic manner that is strictly controlled by cytokines, and in particular is strongly inhibited by IL-4. All fetal NK clones tested, including those that lack detectable Qa1 receptors, express mRNA for CD94 and for both inhibitory and noninhibitory members of the NKG2 family. Fetal NK cells lacking receptors for Qa1 (and also for classical class I molecules) cannot distinguish between wild-type and class I-deficient blasts but, surprisingly, distinguish efficiently between certain wild-type and class I-deficient tumor cells. A variant line that lacks several members of the NKG2 family kills both types of tumor cell equally well, suggesting the existence of NKG2-containing inhibitory receptors that recognize as yet undefined nonclassical class I molecules of restricted distribution.
Survival, Maturation, and Function of CD11c− and CD11c+ Peripheral Blood Dendritic Cells Are Differentially Regulated by Cytokines
Authors: Kohrgruber Norbert , Halanek Nicole , Gröger Marion , Winter Dorian , Rappersberger Klemens , Schmitt-Egenolf Marcus , Stingl Georg , Maurer Dieter 
Published: December 2022

AbstractTwo types of dendritic cells (DC) are circulating in human blood and can be identified by their differential expression of the myeloid Ag CD11c. In this study, we show that CD11c− peripheral blood (PB)-DC correspond to plasmacytoid DC of lymphoid tissue not only by their surface Ag expression profile but, more impressively, by their peculiar ultramorphology. We also demonstrate that CD11c− and CD11c+ DC differ in the quality of their response to and in their requirement for certain cytokines. Freshly isolated CD11c− cells depend on IL-3 for survival and use autocrine or exogenous TNF-α as maturation signal, leading to the appearance of a highly dendritic phenotype, the up-regulation and redistribution of MHC class II from lysosomal compartments to the plasma membrane, the increased expression of costimulatory molecules, and the switch from a high Ag-processing to a low Ag-processing/potent accessory cell mode. Surprisingly, IL-4 efficiently killed freshly isolated CD11c− PB-DC, but did not impair the viability of CD11c+ PB-DC and, together with GM-CSF, induced maturation of these cells. A direct functional comparison revealed that neo-Ag-modified and subsequently matured CD11c− but to a lesser extent CD11c+ DC were able to prime naive Ag-specific CD4+ T cells. Our findings show that two diverse DC types respond to certain T cell-derived cytokines in a differential manner and, thus, suggest that suppression or activation of functionally diverse DC types may be a novel mechanism for the regulation of the quantity and quality of immune responses.
TNF-Mediated Activation of the Stress-Activated Protein Kinase Pathway: TNF Receptor-Associated Factor 2 Recruits and Activates Germinal Center Kinase Related
Authors: Shi Chong-Shan , Leonardi Antonio , Kyriakis John , Siebenlist Ulrich , Kehrl John H. 
Published: December 2022

Abstract
TNF-induced activation of stress activated protein kinases (SAPKs, Jun NH2-terminal kinases) requires TNF receptor associated factor 2 (TRAF2). TRAF2 is a potent activator of a 95-kDa serine/threonine kinase termed germinal center kinase related (GCKR, also referred to as KHS1), which signals activation of the SAPK pathway. Consistent with a role for GCKR in TNF- induced SAPK activation, a kinase-inactive mutant of GCKR is a dominant negative inhibitor of TRAF2-induced SAPK activation. Here we show that TRAF2 interacts with GCKR. This interaction depended upon the TRAF domain of TRAF2 and the C-terminal 150 aa of GCKR. The full activation of GCKR by TRAF2 required the TRAF2 RING finger domain. TNF treatment of a T cell line, Jurkat, increased both GCRK and SAPK activity and enhanced the coimmunoprecipitation of GCKR with TRAF2. Similar results were found with the B cell line HS-Sultan. These findings are consistent with a model whereby TNF signaling results in the recruitment and activation of GCKR by TRAF2, which leads to SAPK activation.
An Activation-Responsive Element in Single C Motif-1/Lymphotactin Promoter Is a Site of Constitutive and Inducible DNA-Protein Interactions Involving Nuclear Factor of Activated T Cell
Authors: Yoshida Tetsuya , Ishikawa Izumi , Ono Yuichi , Imai Toshio , Suzuki Ryuji , Yoshie Osamu 
Published: December 2022

AbstractSingle C motif-1 (SCM-1)/lymphotactin is a C-type chemokine whose expression is activation dependent, cyclosporin A sensitive and restricted to CD8+ T cells, double-negative thymocytes, γδ-type T cells, and NK cells. In humans, there are two highly homologous genes encoding SCM-1α and SCM-1β. Here we examined the regulatory mechanism of the SCM-1 genes. The luciferase reporter gene under the control of the 5′ flanking region of 0.7 kb was strongly induced upon activation with anti-CD3 or PHA plus PMA only in SCM-1-producer T cell lines through a cyclosporin A-sensitive mechanism. An element termed E1 located at −108 to −95 nt relative to the major transcription start site was found to be critical for the promoter activity. In electrophoretic mobility shift assays using the E1 oligonucleotide as probe, nuclear extracts from unstimulated T and B cell lines formed a constitutive complex termed complex I, while nuclear extracts from stimulated SCM-1-producer T cell lines formed a higher mobility complex termed complex II with a concomitant decrease in complex I. The shift from complex I to complex II seen only in SCM-1-producer T cell lines upon activation was completely suppressed by cyclosporin A. Both complexes were critically dependent on the NF-AT core sequence TTTCC in the E1 element and were partially supershifted by anti-NF-ATp. One-hybrid assays in yeast isolated NF-ATp as an E1 binding protein, and transfection of NF-ATp into T and B cell lines strongly enhanced the activation-dependent SCM-1 promoter activity. Collectively, a unique mechanism involving NF-ATp appears to regulate the cell type-specific and activation-dependent expression of the SCM-1 genes.
The Destabilization of IL-2 mRNA by a Premature Stop Codon and Its Differential Stabilization byTrans-Acting Inhibitors of Protein Synthesis Do Not Support a Role for Active Translation in mRNA Stability
Authors: Ragheb Jack A. , Deen Mary , Schwartz Ronald H. 
Published: December 2022

AbstractTo investigate the role that translation plays in the stabilization of the IL-2 mRNA, we inhibited protein synthesis in both cis and trans. To block translation in trans, we utilized the inhibitors puromycin (PUR) and cycloheximide (CHX), which differentially effect polysome structure. We found that CHX enhances the stability of IL-2 mRNA in cells stimulated with anti-TCR Ab alone, but it inhibits CD28-induced message stabilization in costimulated cells. In contrast, PUR had a minimal effect on IL-2 mRNA stability in either the presence or absence of costimulation. The differential effects of these two inhibitors suggest that: 1) CHX is unlikely to stabilize the IL-2 mRNA by inhibiting the expression of a labile RNase; 2) CD28-mediated IL-2 mRNA stabilization does not require translation; and 3) IL-2 mRNA decay is not coupled to translation. To block translation in cis, we generated sequence-tagged IL-2 genomic reporters that contain a premature termination codon (PTC). In both the presence and absence of costimulation, these PTC-containing mRNAs exhibit drastically diminished stability. Interestingly, the addition of CHX but not PUR completely restored CD28-mediated stabilization, suggesting that CHX can block the enhanced decay induced by a PTC. Finally, CHX was able to superinduce IL-2 mRNA levels in anti-TCR Ab-stimulated cells but not in CD28-costimulated cells, suggesting that CHX may also act by other mechanisms.
Visualization of Polyoma Virus-Specific CD8+ T Cells In Vivo During Infection and Tumor Rejection
Authors: Lukacher Aron E. , Moser Janice M. , Hadley Annette , Altman John D. 
Published: December 2022

AbstractT cells are critical for clearing infection and preventing tumors induced by polyoma virus, a natural murine papovavirus. We previously identified the immunodominant epitope for polyoma virus-specific CTL in tumor-resistant H-2k mice as the Dk-restricted peptide, MT389–397, derived from the polyoma middle T oncoprotein. In this study, we developed tetrameric Dk complexes containing the MT389–397 peptide to directly visualize and enumerate MT389–397-specific CTL during polyoma virus infection. We found that Dk/MT389 tetramer+CD8+ T cells undergo a massive expansion during primary infection such that by day 7 postinfection these Ag-specific CD8+ T cells constitute ∼20% of the total and ∼40% of the activated CD8+ T cells in the spleen. This expansion of Dk/MT389 tetramer+CD8+ T cells parallels the emergence of MT389–397-specific ex vivo cytolytic activity and clearance of polyoma virus. Notably, Dk/MT389 tetramer+CD8+ T cells are maintained in memory at very high levels. The frequencies of Dk/MT389 tetramer+CD8+ effector and memory T cells in vivo match those of CD8+ T cells producing intracellular IFN-γ after 6-h in vitro stimulation by MT389–397 peptide. Consistent with preferential Vβ6 expression by MT389–397-specific CD8+CTL lines and clones, Dk/MT389 tetramer+CD8+ T cells exhibit biased expression of this Vβ gene segment. Finally, we show that Dk/MT389 tetramer+CD8+ T cells efficiently infiltrate a polyoma tumor challenge to virus-immune mice. Taken together, these findings strongly implicate virus-induced MT389–397-specific CD8+ T cells as essential effectors in eliminating polyoma-infected and polyoma-transformed cells in vivo.
Inverted Immunodominance and Impaired Cytolytic Function of CD8+ T Cells During Viral Persistence in the Central Nervous System
Authors: Bergmann Cornelia C. , Altman John D. , Hinton David , Stohlman Stephen A. 
Published: December 2022

AbstractMice infected with the neurotropic JHM strain of mouse hepatitis virus (JHMV) clear infectious virus; nevertheless, virus persists in the CNS as noninfectious RNA, resulting in ongoing primary demyelination. Phenotypic and functional analysis of CNS infiltrating cells during acute infection revealed a potent regional CD8+ T cell response comprising up to 50% virus-specific T cells. The high prevalence of virus-specific T cells correlated with ex vivo cytolytic activity and efficient reduction in viral titers. Progressive viral clearance coincided with the loss of cytolytic activity, but retention of IFN-γ secretion and increased expression of the early activation marker CD69, indicating differential regulation of effector function. Although the total number of infiltrating T cells declined following clearance of infectious virus, CD8+ T cells, both specific for the dominant viral epitopes and of unknown specificity, were retained within the CNS, suggesting an ongoing T cell response during persistent CNS infection involving a virus-independent component. Reversed immunodominance within the virus-specific CD8+ T cell population further indicated epitope-specific regulation, supporting ongoing T cell activation. Even in the absence of infectious virus, the CNS thus provides an environment that maintains both unspecific and Ag-specific CD8+ T cells with restricted effector function. Chronic T cell stimulation may thus play a role in preventing viral recrudescence, while increasing the risk of pathological conditions, such as demyelination.