bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recapitulation of Normal and Abnormal BioBreeding Rat T Cell Development in Adult Thymus Organ Culture
Authors: Whalen Barbara J. , Weiser Peter , Marounek Jan , Rossini Aldo A. , Mordes John P. , Greiner Dale L. 
Published: January 2023

AbstractCongenitally lymphopenic diabetes-prone (DP) BioBreeding (BB) rats develop spontaneous T cell-dependent autoimmunity. Coisogenic diabetes-resistant (DR) BB rats are not lymphopenic and are free of spontaneous autoimmune disease, but become diabetic in response to depletion of RT6+ T cells. The basis for the predisposition to autoimmunity in BB rats is unknown. Abnormal T cell development in DP-BB rats can be detected intrathymically, and thymocytes from DR-BB rats adoptively transfer diabetes. The mechanisms underlying these T cell developmental abnormalities are not known. To study these processes, we established adult thymus organ cultures (ATOC). We report that cultured DR- and DP-BB rat thymi generate mature CD4 and CD8 single-positive cells with up-regulated TCRs. DR-BB rat cultures also generate T cells that express RT6. In contrast, DP-BB rat cultures generate fewer CD4+, CD8+, and RT6+ T cells. Analysis of the cells obtained from ATOC suggested that the failure of cultured DP-BB rat thymi to generate T cells with a mature phenotype is due in part to an increased rate of apoptosis. Consistent with this inference, we observed that addition of the general caspase inhibitor Z-VAD-FMK substantially increases the number of both mature and immature T cells produced by DP-BB rat ATOC. We conclude that cultured DR-BB and DP-BB rat thymi, respectively, recapitulate the normal and abnormal T cell developmental kinetics and phenotypes observed in these animals in vivo. Such cultures should facilitate identification of the underlying pathological processes that lead to immune dysfunction and autoimmunity in BB rats.
Failure of Measles Virus to Activate Nuclear Factor-κB in Neuronal Cells: Implications on the Immune Response to Viral Infections in the Central Nervous System
Authors: Dhib-Jalbut Suhayl , Xia Jane , Rangaviggula Himabindu , Fang Yu-Yan , Lee Terry 
Published: January 2023

Abstract
Neurons are postmitotic cells that foster virus persistence. These cells lack the HLA class I molecules required for clearance of infected cells. Previously, we showed that HLA class I is induced by measles virus (MV) on glial cells, which is primarily mediated by IFN-β. In contrast, MV was unable to induce HLA class I or IFN-β in neuronal cells. This failure was associated with lack of NF-κB binding to the positive regulatory domain II element of the IFN-β promoter, which is essential for virus-induced IFN-β gene activity. In this study, we demonstrate that the failure to activate NF-κB in neuronal cells is due to the inability of MV to induce phosphorylation and degradation of IκB, the inhibitor of NF-κB. In contrast, TNF-α induced degradation of IκBα in the neuronal cells, suggesting that failure to induce IκBα degradation is likely due to a defect in virus-mediated signaling rather than to a defect involving neuronal IκBα. Like MV, mumps virus and dsRNA failed to induce IκBα degradation in the neuronal cells, suggesting that this defect may be specific to viruses. Autophosphorylation of the dsRNA-dependent protein kinase, a kinase possibly involved in virus-mediated IκBα phosphorylation, was intact in both cell types. The failure of virus to induce IκBα phosphorylation and consequently to activate NF-κB in neuronal cells could explain the repression of IFN-β and class I gene expression in virus-infected cells. These findings provide a potential mechanism for the ability of virus to persist in neurons and to escape immune surveillance.
Expression of Murine IL-12 Is Regulated by Translational Control of the p35 Subunit
Authors: Babik Jennifer M. , Adams Elizabeth , Tone Yukiko , Fairchild Paul J. , Tone Masahide , Waldmann Herman 
Published: January 2023

AbstractIL-12 is a heterodimer of two subunits, p35 and p40, encoded by separate genes that are regulated independently. To investigate the mechanisms underlying the regulation of the p35 gene, we characterized murine p35 expression in the B cell lymphoma line A20 and in bone marrow-derived dendritic cells. Multiple transcription start sites were identified in both cell types, resulting in four p35 mRNA isoforms (types I–IV) that differ in the number and position of upstream ATGs in their 5′ untranslated regions. In nonstimulated cells, the predominant forms of p35 message (types II and IV) contained an additional upstream ATG, whose presence was shown to inhibit the downstream translation of the p35 subunit. After LPS stimulation, however, transcription initiated from alternate positions, so that the proportion of transcripts not containing this upstream ATG (types I and III) was significantly increased in the population of p35 mRNA. These type I and type III transcripts readily supported translation of the p35 subunit and its incorporation into bioactive IL-12. Furthermore, p35 mRNA levels were substantially up-regulated after LPS stimulation in both cell types. Thus, our results show that p35 gene expression is highly regulated by both transcriptional and translational mechanisms.
Scanning a DRB3*0101 (DR52a)-Restricted Epitope Cross-Presented by DR3: Overlapping Natural and Artificial Determinants in the Human Acetylcholine Receptor
Authors: Nagvekar Nita , Corlett Louise , Jacobson Leslie W. , Matsuo Hidenori , Chalkley Robert , Driscoll Paul C. , Deshpande Shrikant , Spack Edward G. , Willcox Nicholas 
Published: January 2023

AbstractA recurring epitope in the human acetylcholine receptor (AChR) α subunit (α146–160) is presented to specific T cells from myasthenia gravis patients by HLA-DRB3*0101—“DR52a”—or by DR4. Here we first map residues critical for DR52a in this epitope by serial Ala substitution. For two somewhat similar T cells, this confirms the recently deduced importance of hydrophobic “anchor” residues at peptide p1 and p9; also of Asp at p4, which complements this allele’s distinctive Arg74 in DRβ. Surprisingly, despite the 9 sequence differences in DRβ between DR52a and DR3, merely reducing the bulk of the peptide’s p1 anchor residue (Trp149→Phe) allowed maximal cross-presentation to both T cells by DR3 (which has Val86 instead of Gly). The shared K71G73R74N77 motif in the α helices of DR52a and DR3 thus outweighs the five differences in the floor of the peptide-binding groove. A second issue is that T cells selected in vitro with synthetic AChR peptides rarely respond to longer Ag preparations, whereas those raised with recombinant subunits consistently recognize epitopes processed naturally even from whole AChR. Here we compared one T cell of each kind, which both respond to many overlapping α140–160 region peptides (in proliferation assays). Even though both use Vβ2 to recognize peptides bound to the same HLA-DR52a in the same register, the peptide-selected line nevertheless proved to depend on a recurring synthetic artifact—a widely underestimated problem. Unlike these contaminant-responsive T cells, those that are truly specific for natural AChR epitopes appear less heterogeneous and therefore more suitable targets for selective immunotherapy.
In Vitro Analysis of Complement-Dependent HIV-1 Cell Infection Using a Model System
Authors: Tacnet-Delorme Pascale , Boyer Véronique , Thielens Nicole M. , Hernandez Jean-François , Bally Isabelle , Sim Robert B. , Desgranges Claude , Arlaud Gérard J. 
Published: January 2023

Abstract
Previous studies based on the use of human serum as a source of C have provided evidence for the C-dependent enhancement of cell infection by HIV-1. The present study was undertaken to distinguish C from other serum factors and to identify the proteins and the mechanisms involved in C-dependent cell infection by HIV-1. The classical C activation pathway was reconstituted from the proteins C1q, C1r, C1s, C4, C2, C3, factor H, and factor I; each were purified to homogeneity. A mixture of these proteins at physiological concentrations was shown to reproduce the ability of normal human serum to enhance the infection of MT2 cells by HIV-1 at low doses of virus. This enhancing effect was abolished when heat-inactivated serum and C2- or C3-depleted serum were used, and was restored upon addition of the corresponding purified proteins. A mixture of two synthetic peptides corresponding to positions 10–15 and 90–97 of human C receptor type 2 (CD21) as well as soluble CD4 both inhibited the C-dependent infection process. These data provide unambiguous evidence that HIV-1 triggers a direct activation of the classical C pathway in vitro and thereby facilitates the infection of MT2 cells at low doses of virus. These findings are consistent with a mechanism involving increased interaction between the virus opsonized by C3b-derived fragment(s) and the CD21 cell receptors and subsequent virus entry through CD4 receptors.
Ectopic Expression of DNA Encoding IFN-α1 in the Cornea Protects Mice from Herpes Simplex Virus Type 1-Induced Encephalitis
Authors: Noisakran Sansanee , Campbell Iain L. , Carr Daniel J. J. 
Published: January 2023

AbstractA novel approach to combat acute herpes simplex virus type 1 (HSV-1) infection has recently been developed by administration with a plasmid DNA construct encoding cytokine genes. Cytokines, especially type I IFNs (IFN-α and IFN-β) play an important role in controlling acute HSV-1 infection. The purpose of the present study was to investigate the potential efficacy of ectopically expressed IFN-α1 against ocular HSV-1 infection following in situ transfection of mouse cornea with a naked IFN-α1-containing plasmid DNA. Topical administration of the IFN-α1 plasmid DNA exerted protection against ocular HSV-1 challenge in a time- and dose-dependent manner and antagonized HSV-1 reactivation. In addition, IFN-α1-transfected eyes expressed a fivefold increase in MHC class I mRNA over vector-treated controls. The protective efficacy of the IFN-α1 transgene antagonized viral replication, as evidenced by the reduction of the viral gene transcripts (infected cell polypeptide 27, thymidine kinase, and viral protein 16) and viral load in eyes and trigeminal ganglia during acute infection. The administration of neutralizing Ab to IFN-αβ antagonized the protective effect of the IFN-α1 transgene in mice. Collectively, these findings demonstrate the potential of using naked plasmid DNA transfection in the eye to achieve ectopic gene expression of therapeutically active agents.
Nerve Growth Factor Modifies the Expression of Inflammatory Cytokines by Mast Cells Via a Prostanoid-Dependent Mechanism
Authors: Marshall Jean S. , Gomi Kaede , Blennerhassett Michael G. , Bienenstock John 
Published: January 2023

AbstractNerve growth factor (NGF) is well recognized to have a number of potent effects on mast cells, including increasing mast cell numbers in vivo and inducing mast cell degranulation in vitro. More recently, NGF has been demonstrated to induce PGD2 production by mast cells through the induction of mast cell cyclooxygenase expression. We have observed that NGF at doses as low as 10 ng/ml will induce IL-6 production and inhibit TNF-α release from rat peritoneal mast cells in the presence of lysophosphatidylserine as a cofactor. NGF synergizes with LPS treatment of peritoneal mast cells (PMC) for the induction of IL-6. Examination of the mechanism of this phenomenon has revealed that NGF can induce both rat PMC and mouse bone marrow-derived cultured mast cells to produce substantial levels of PGE2. This response is maximal at later time points 18–24 h after NGF activation. The ability of NGF to induce PGE2 is not dependent on mast cell degranulation. Other stimuli capable of inducing IL-6, such as LPS, do not induce production of this prostanoid. Inhibition of cyclooxygenase activity by PMC using either flurbiprofen or indomethacin inhibited both the NGF-induced PGE2 synthesis and the NGF-induced alterations in TNF-α and IL-6 production. These results suggest a role for mast cell-derived prostanoids in the regulation of local inflammatory responses and neuronal degeneration after tissue injury involving induction of NGF production.
Eotaxin Activates T Cells to Chemotaxis and Adhesion Only if Induced to Express CCR3 by IL-2 Together with IL-4
Authors: Jinquan Tan , Quan Sha , Feili Gong , Larsen Christian Grønhøj , Thestrup-Pedersen Kristian 
Published: January 2023

AbstractThe transmigration and adherence of T lymphocytes through microvascular endothelium are essential events for their recruitment into inflammatory sites. In the present study, we investigated the expression of CC chemokine receptor CCR3 on T lymphocytes and the capacities of the CC chemokine eotaxin to induce chemotaxis and adhesion in T lymphocytes. We have observed a novel phenomenon that IL-2 and IL-4 induce the expression of CCR3 on T lymphocytes. We also report that CC chemokine eotaxin is a potent chemoattractant for IL-2- and IL-4-stimulated T lymphocytes, but not for freshly isolated T lymphocytes. Eotaxin attracts T lymphocytes via CCR3, documented by the fact that anti-CCR3 mAb blocks eotaxin-mediated T lymphocyte chemotaxis. In combination with IL-2 and IL-4, eotaxin enhances the expression of adhesion molecules such as ICAM-1 and several integrins (CD29, CD49a, and CD49b) on T lymphocytes and thus promotes adhesion and aggregation of T lymphocytes. The eotaxin-induced T lymphocyte adhesion could be selectively blocked by a specific cAMP-dependent protein kinase inhibitor, H-89, indicating that eotaxin activates T lymphocytes via a special cAMP-signaling pathway. Our new findings all point toward the fact that eotaxin, in association with the Th1-derived cytokine IL-2 and the Th2-derived cytokine IL-4, is an important T lymphocyte activator, stimulating the directional migration, adhesion, accumulation, and recruitment of T lymphocytes, and paralleled the accumulation of eosinophils and basophils during the process of certain types of inflammation such as allergy.
Molecular Characterization of American Cockroach Tropomyosin (Periplaneta americana Allergen 7), a Cross-Reactive Allergen
Authors: Asturias Juan A. , Gómez-Bayón Nuria , Arilla M. Carmen , Martínez Alberto , Palacios Ricardo , Sánchez-Gascón Fernando , Martínez Jorge 
Published: January 2023

Abstract
Inhalation of allergens produced by the American cockroach (Periplaneta americana) induces IgE Ab production and the development of asthma in genetically predisposed individuals. The cloning and expression in Escherichia coli of P. americana tropomyosin allergen have been achieved. The protein shares high homology with other arthropod tropomyosins (80% identity) but less homology with vertebrate ones (50% identity). The recombinant allergen was produced in E. coli as a nonfusion protein with a yield of 9 mg/l of bacterial culture. Both natural and recombinant tropomyosins were purified by isoelectric precipitation. P. americana allergen 1 (Per a 1) and Per a 7 (tropomyosin) are to date the only cross-reacting allergens found in cockroaches. ELISA and Western blot inhibition experiments, using natural and recombinant purified tropomyosins from shrimp and cockroach, showed that tropomyosin induced cross-reactivity of IgE from patients allergic to these allergens, suggesting that this molecule could be a common allergen among invertebrates.
Production of High Affinity Autoantibodies in Autoimmune New Zealand Black/New Zealand White F1 Mice Targeted with an Anti-DNA Heavy Chain
Authors: Friedmann Dinorah , Yachimovich Nurit , Mostoslavsky Gustavo , Pewzner-Jung Yael , Ben-Yehuda Arie , Rajewsky Klaus , Eilat Dan 
Published: January 2023

Abstract
Lupus-prone, anti-DNA, heavy (H) chain “knock-in” mice were obtained by backcrossing C57BL/6 mice, targeted with a rearranged H chain from a VH11(S107)-encoded anti-DNA hybridoma (D42), onto the autoimmune genetic background of New Zealand Black/New Zealand White (NZB/NZW) F1 mice. The targeted female mice developed typical lupus serologic manifestations, with the appearance of transgenic IgM anti-DNA autoantibodies at a young age (2–3 mo) and high affinity, somatically mutated IgM and IgG anti-DNA Abs at a later age (6–7 mo). However, they did not develop clinical, lupus-associated glomerulonephritis and survived to at least 18 mo of age. L chain analysis of transgenic anti-DNA Abs derived from diseased NZB/NZW mouse hybridomas showed a very restricted repertoire of Vκ utilization, different from that of nonautoimmune (C57BL/6 × BALB/c)F1 transgenic anti-DNA Abs. Strikingly, a single L chain was repetitively selected by most anti-DNA, transgenic NZB/NZW B cells to pair with the targeted H chain. This L chain had the same Vκ-Jκ rearrangement as that expressed by the original anti-DNA D42 hybridoma. These findings indicate that the kinetics of the autoimmune serologic manifestations are similar in wild-type and transgenic lupus-prone NZB/NZW F1 mice and suggest that the breakdown of immunologic tolerance in these mice is associated with the preferential expansion and activation of B cell clones expressing high affinity anti-DNA H/L receptor combinations.
TNF Receptor-Associated Factor-2 Is Involved in Both IL-1β and TNF-α Signaling Cascades Leading to NF-κB Activation and IL-8 Expression in Human Intestinal Epithelial Cells
Authors: Jobin Christian , Holt Lisa , Bradham Cynthia A. , Streetz Konrad , Brenner David A. , Sartor R. Balfour 
Published: January 2023

Abstract
Cytokine signaling involves the participation of many adaptor proteins, including the docking protein TNF receptor-associated factor-2 (TRAF-2), which is believed to transmit the TNF-α signal through both the IκB/NF-κB and c-Jun N-terminal kinase (JNK)/stress-related protein kinase (SAPK) pathways. The physiological role of TRAF proteins in cytokine signaling in intestinal epithelial cells (IEC) is unknown. We characterized the effect of a dominant-negative TRAF-2 delivered by an adenoviral vector (Ad5dnTRAF-2) on the cytokine signaling cascade in several IEC and also investigated whether inhibiting the TRAF-2-transmitting signal blocked TNF-α-induced NF-κB and IL-8 gene expression. A high efficacy and level of Ad5dnTRAF-2 gene transfer were obtained in IEC using a multiplicity of infection of 50. Ad5dnTRAF-2 expression prevented TNF-α-induced, but not IL-1β-induced, IκBα degradation and NF-κB activation in NIH-3T3 and IEC-6 cells. TNF-α-induced JNK activation was also inhibited in Ad5dnTRAF-2-infected HT-29 cells. Induction of IL-8 gene expression by TNF-α was partially inhibited in Ad5dnTRAF-2-transfected HT-29, but not in control Ad5LacZ-infected, cells. Surprisingly, IL-1β-mediated IL-8 gene expression was also inhibited in HT-29 cells as measured by Northern blot and ELISA. We concluded that TRAF-2 is partially involved in TNF-α-mediated signaling through IκB/NF-κB in IEC. In addition, our data suggest that TRAF-2 is involved in IL-1β signaling in HT-29 cells. Manipulation of cytokine signaling pathways represents a new approach for inhibiting proinflammatory gene expression in IEC.
T Cell Immunity Induced by Allogeneic Microglia in Relation to Neuronal Retina Transplantation
Authors: Ma Naili , Streilein J. Wayne 
Published: January 2023

Abstract
Microglia share a lineage relationship with bone marrow-derived monocytes/macrophages and dendritic cells, and their inclusion in retinal and brain transplants may function as “passenger leukocytes.” In other solid allografts, passenger leukocytes are the primary sources of immunogenicity, triggering alloimmune rejection. We have conducted a series of in vitro and in vivo studies examining the capacity of microglia cultured from forebrain to activate alloreactive T cells and to induce and elicit alloimmunity. Cultured microglia expressed class II MHC molecules and costimulatory molecules (B7-1, B7-2, and CD40), and they secreted IL-12. Cultured microglia injected s.c. into naive recipients induced allospecific delayed hypersensitivity and elicited delayed hypersensitivity directed at alloantigens. Cultured microglia differed from conventional APCs by secreting significant amounts of mature TGF-β2, but smaller amounts of IL-12. Moreover, while both cultured microglia and conventional APC stimulated T cell proliferation in vitro, microglia directed the responding T cells toward the Th2 pathway in which IL-4, but not IL-2 and IFN-γ, was secreted. The abilities of microglia to secrete TGF-β2, to stimulate alloreactive Th2 cells, and to induce anterior chamber associated immune deviation when injected into the eye of naive allogeneic mice suggest that they are not typical passenger leukocytes. The unique functional properties of cultured microglia may account for the capacity of neonatal retinal tissue transplanted into the eye to alter the systemic alloimmune response in a manner that delays, but does not prevent, graft rejection.
Biochemical and Immunogenetic Analysis of an Immunodominant Peptide (B6dom1) Encoded by the Classical H7 Minor Histocompatibility Locus
Authors: Eden Peter A. , Christianson Gregory J. , Fontaine Pierre , Wettstein Peter J. , Perreault Claude , Roopenian Derry C. 
Published: January 2023

Abstract
Of the many minor histocompatibility (H) Ags that have been detected in mice, the ability to induce graft vs host disease (GVHD) after bone marrow transplantation is restricted to a limited number of immunodominant Ags. One such murine Ag, B6dom1, is presented by the H2-Db MHC class I molecule. We present biochemical evidence that the natural B6dom1 peptide is indistinguishable from AAPDNRETF, and we show that this peptide can be isolated from a wide array of tissues, with highest levels from the lymphoid organs and lung. Moreover, we employ a novel, somatic cell selection technique involving CTL-mediated immunoselection coupled with classical genetics, to show that B6dom1 is encoded by the H7 minor H locus originally discovered ∼40 years ago. These studies provide a molecular genetic framework for understanding B6dom1, and exemplify the fact that mouse minor H loci that encode immunodominant CTL epitopes can correspond to classical H loci originally identified by their ability to confer strong resistance to tumor transplantation. Additionally, these studies demonstrate the utility of somatic cell selection approaches toward resolving H Ag immunogenetics.
Bystander Virus Infection Prolongs Activated T Cell Survival
Authors: Mitchell Tom , Kappler John , Marrack Philippa 
Published: January 2023

AbstractIn animals, T cells often die rapidly after activation, unless activation occurs in the presence of inflammatory factors. To understand how such activated cells survive to participate in immune responses, we studied the effects of viral infection on T cells responding to an unrelated superantigen. Normal T cells activated by superantigen in uninfected mice died as a result of their activation, whereas T cells that were activated during vaccinia infection survived longer in vivo and in culture. This bystander effect of viral infection on activated T cells was independent of effects on the magnitude of the initial T cell response, on induction of Bcl-2 and Bcl-x, on T cell proliferation, and on Fas killing. The failure of such effects to predict the fate of activated T cells in vivo indicates that virus infections shape T cell responses via mechanisms that differ from those described previously. These mechanisms may contribute to the ability of viral infections to induce autoimmunity.