bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age-dependent reduction of Bcl-2 expression in peripheral T cells of lpr and gld mutant mice.
Authors: Tamura A , Yui K 
Published: December 2022

Abstract
Autoimmune-prone lpr and gld mice carry defects in the apoptosis-mediating cell surface molecule Fas and its ligand, respectively. These mice develop lymphadenopathy because of an age-related accumulation of nonmalignant CD4- CD8- T cells in the peripheral lymphoid organs, suggesting a role for Fas-mediated apoptosis in peripheral T cell homeostasis. However, these accumulating cells are more susceptible to apoptosis ex vivo than peripheral T cells from control mice. To investigate the influence of additional regulatory elements on defects in the Fas-mediated apoptosis pathway, we analyzed the expression of Bcl-2 protein, a repressor of apoptosis, in T cells of lpr and gld mice. The expression levels of Bcl-2 in peripheral T cells of aged lpr and gld mice were significantly reduced when compared with their normal counterparts. Bcl-2 expression decreased with age in peripheral T cells, but not in thymocytes, suggesting that down-regulation of Bcl-2 protein occurs in the periphery. Analysis of T cell subsets indicated that CD4+ and CD4- CD8- T cells expressed significantly reduced levels of Bcl-2, whereas CD8+ cells maintain high levels of Bcl-2 expression. However, all peripheral T cell subsets including CD8+ cells were susceptible to glucocorticoid-induced apoptosis, indicating that there is no direct correlation between the levels of Bcl-2 expression and susceptibility to glucocorticoid-induced apoptosis. These studies suggest the presence of complex regulatory mechanisms for lymphocyte apoptosis and survival.
Role of environmental antigen in the development of IgG+ cells in the bursa of fabricius.
Authors: Ekino S , Riwar B , Kroese F G , Schwander E H , Koch G , Nieuwenhuis P 
Published: December 2022

Abstract
IgG+ cells were detected in the bursa of Fabricius after hatching by immunofluorescence staining of single cells and immunohistologic studies using mAb anti-Ig gamma-heavy chain. The frequency of IgG+ cells in the bursa increased rapidly immediately after hatching. In histologic studies, most of the IgG+ cells were found in the medullary areas of the bursal follicle. Isolation of the bursa from the gut by bursal duct ligation before hatching suppressed the development of IgG+ cells in the bursa after hatching. In addition, administration of Ags into the bursal lumen just before bursal duct ligation caused a significant increase of IgG+ cells in the bursa compared with the isolated bursa. However, parenteral administration of Ags had no effect on the frequency of IgG+ cells in the isolated and normal bursa. These results suggest that Ags in the bursa are a prerequisite for the development of IgG+ cells in the bursa. Although the majority of IgG+ bursal cells were IgM+ IgG+ double-positive cells, sorted Bu1+ bursal cells, which contained 99.9% of IgG+ cells but not plasma cells, synthesized de novo IgM but little or no IgG. Therefore, it is likely that surface IgG on the bursal cells is not produced locally, but is trapped by IgM+ bursal cells. We speculate that Ags derived from the bursal lumen form immune complexes within the bursa, which are subsequently trapped on the surface of IgM+ bursal cells mediated either by Fc-receptors, C3 receptors, or surface Ig.
Activation of the signal transducer and transcription (STAT) signaling pathway in a primary T cell response. Critical role for IL-6.
Authors: Henttinen T , Levy D E , Silvennoinen O , Hurme M 
Published: December 2022

Abstract
The T cell activation is initiated by interaction of specific Ags with TCR, followed by activation of intracellular biochemical events leading to activation of several genes. The activation of signal transducer and activator of transcription (STAT) proteins in a primary TCR-mediated activation of T cells have been explored. In purified human peripheral blood T cells, nuclear STAT proteins were activated approximately 3 h after activation by cross-linked anti-CD3 Abs. These STAT proteins were detected by using the IFN-gamma-activated sequence (GAS) and related oligonucleotides as probes in electrophoretic mobility shift assay. Analysis of the nuclear extracts with anti-STAT Abs indicated that they contained STAT-3 and additional proteins crossreactive with the STAT family. The induction of STAT activity was inhibited completely by pretreatment with either cycloheximide or cyclosporin A, thus indicating that the induction was due to a secondary factor produced by the activated T cells. As neutralizing anti-IL-6 Abs effectively down-regulated the early induction of STAT proteins and as exogenously added IL-6 rapidly activated DNA binding similar to TCR-mediated bindings, it can be concluded that IL-6 is the factor responsible for the activation of STAT proteins in a primary T cell response.
IL-12 as mediator and adjuvant for the induction of contact sensitivity in vivo.
Authors: Müller G , Saloga J , Germann T , Schuler G , Knop J , Enk A H 
Published: December 2022

Abstract
To determine whether IL-12 serves as a regulator of contact sensitivity reactions, mice were painted with either 1.0% trinitrochlorobenzene or 0.5% dinitrofluorobenzene on abdominal skin. At various time points thereafter, regional lymph nodes or spleens were prepared for RNA extraction, and the signals for IL-12 p35 and p40 chain were sought by quantitative reverse transcriptase-PCR. Time course analysis showed a constitutive expression of p35 chain mRNA signals throughout the experiment (0 to 72 h), whereas the signal for the p40 chain was transiently induced in lymph node and spleen cells after 12 to 14 h. Cellular depletion experiments and double label in situ hybridization studies showed that dendritic cells were sources for a major part of the p40 chain message. The presence of functional IL-12 in culture supernatants was indirectly assessed by addition of anti-IL-12 antiserum and analysis of IFN-gamma production. Significant amounts of IFN-gamma could only be detected in supernatants of allergen-treated animals. Addition of anti-IL-12 antiserum inhibited IFN-gamma production by about 55%. In a further attempt to assess the role of IL-12 in contact sensitivity, anti-IL-12 antiserum was injected i.p. into mice, and ear swelling responses were assessed following challenge. Injection of anti-IL-12 antiserum significantly reduced ear swelling responses by 85%. Thus anti-IL-12 treatment almost completely prevented sensitization. To assess whether IL-12 would be able to overcome in vivo tolerance, UV-tolerized animals were treated with i.p. IL-12 in a contact allergy system. Treatment of mice with IL-12 not only prevented tolerance induction, but was able to reverse UV-induced tolerance. In aggregate, our data point to an important role for IL-12 as a mediator and adjuvant for the induction of contact sensitivity in vivo.
CD28 delivers costimulatory signals independently of its association with phosphatidylinositol 3-kinase.
Authors: Truitt K E , Shi J , Gibson S , Segal L G , Mills G B , Imboden J B 
Published: December 2022

Abstract
CD28, a cell-surface molecule expressed by T cells, delivers costimulatory signals during the activation of T cells by Ag. Stimulation of CD28 induces its association with phosphatidylinositol 3'-kinase (PI3-K), raising the possibility that PI3-K plays a critical role in CD28 signaling. We find, however, that wortmannin, a potent inhibitor of PI3-K, does not block CD28-mediated costimulation of Jurkat (a human T cell line) or of murine CD4+ T cells. To address further the role of PI3-K in CD28-mediated signaling, we expressed mutant murine CD28 molecules in Jurkat cells. Mutation of Tyr 170 of murine CD28 to Phe abrogates the association of murine CD28 with PI3-K but does not affect the ability of murine CD28 to augment IL-2 production by Jurkat cells in response to the combination of ionomycin and PMA. Conversely, a mutant of murine CD28 that has a Tyr at position 170 but has Phe substitutions at the remaining three cytoplasmic tyrosines retains the ability to associate with PI3-K and has an impaired ability to deliver a costimulus that augments IL-2 production. CD28, therefore, can deliver costimulatory signals independently of its interaction with PI3-K, and association with PI3-K is insufficient to mediate the full effector function of CD28. Optimal signaling by CD28 requires the integrity of one or more of the carboxyl-terminal three Tyr residues.
Differences in MHC class I self peptide repertoires among HLA-A2 subtypes.
Authors: Sudo T , Kamikawaji N , Kimura A , Date Y , Savoie C J , Nakashima H , Furuichi E , Kuhara S , Sasazuki T 
Published: December 2022

Abstract
To investigate how single amino acid substitutions in MHC class I molecules affect differences in peptide repertoires, we eluted and sequenced the naturally processed peptides from three HLA-A2 subtypes (HLA-A*0204, -A*0206, and -A*0207) that differ by a single amino acid residue substitution each with HLA-A*0201 at the floor of the binding groove. Allele-specific peptide motifs for each HLA-A2 subtype substantially differed from that of HLA-A*0201 in the dominant anchor residues. The relative signal intensities for 18 self peptides, determined by mass spectrometry, precisely reflected these peptide motifs. Some overlapping peptides were isolated from both HLA-A*0201 and a single HLA-A2 variant, but no peptide was ubiquitously found across all variants. To rationalize the differences in peptide motifs, possible conformations of each allele were computer modeled by energy minimization calculations based on the reported crystal structure of HLA-A*0201. According to our models, the differences in peptide motifs could be explained by substituted-residue-driven conformational changes for each MHC-peptide complex. These results demonstrate the fine differences between HLA-A2 subtype self peptide repertoires and contribute to the prediction of antigenic peptides.
Early IL-4 production by non-CD4+ cells at the site of antigen deposition predicts the development of a T helper 2 cell response to Schistosoma mansoni eggs.
Authors: Sabin E A , Pearce E J 
Published: December 2022

Abstract
Cytokines play a major role in promoting naive Th cells to differentiate into Th1 or Th2 cells. While IL-4 is recognized as the primary pro-Th2 inducing cytokine, the identity of its cellular sources during the development of a Th2 response remains unclear. We have used Schistosoma mansoni eggs, potent stimulators of Th2 responses both during the natural progression of murine schistosomiasis and when experimentally isolated and injected into normal mice, to examine IL-4 production early in the evolution of an Ag-driven Th2 response. Analysis of peritoneal exudate cells by IL-4 specific reverse transcriptase-PCR and ELISPOT, at times following i.p. egg injection in naive C57BL/6 mice, revealed a marked, transient elevation in IL-4 production at 2 to 12 h after Ag exposure. This response was temporally accompanied by eosinophil and neutrophil infiltration and mast cell disappearance. The pattern of early IL-4 production and peritoneal cell infiltration was observed in egg-injected CD4+ cell-depleted and nude C57BL/6 mice, strongly suggesting that a non-T cell is the source of early IL-4 and that the stimulus leading to the egg-induced changes in cellular composition are T cell independent. In addition to IL-4 transcripts, peritoneal exudate cells from egg-injected T cell replete or deficient mice contained IFN-gamma and IL-12 transcripts. Control i.p. PBS injections led to no or minimal cytokine gene transcription. Early IL-4 was predictive of subsequent Th2 response development since, in contrast to C57BL/6 mice, egg-injected BALB/c mice demonstrated no detectable IL-4 production at 12 h and mounted a comparatively weak egg Ag-specific Th2 response.
Soluble CD23 directly activates monocytes to contribute to the antigen-independent stimulation of resting T cells.
Authors: Armant M , Rubio M , Delespesse G , Sarfati M 
Published: December 2022

Abstract
The majority of T cells at the site of an inflammatory lesion do not appear to be Ag-specific, but they still contribute to the inflammatory response. Herein, we report that sCD23 activates monocytes to participate in the stimulation of resting T cells in the absence of TCR engagement. First, sCD23 selectively triggers monokine release by purified monocytes in the absence of costimulus. It induces TNF-alpha, IL-1 beta, IL-8, granulocyte-macrophage-CSF, and prostaglandin E2 but no IL-10, IL-12, TGF-beta, or leukotriene B4. The sCD23-induced TNF-alpha production is significantly inhibited by IL-4 and IL-10 but not by TGF-beta. Also, monocytes activated by sCD23 express decreased levels of HLA-DR and increased levels of CD14, CD54, CD40, and B7 Ag. Next, we show that, in the presence of monocytes, sCD23 is a potent costimulator of IL-2 or IL-12-induced IFN-gamma production by resting T cells in the absence of exogenous Ag and that this effect is partially reduced by anti-TNF-alpha mAb. B cells cannot substitute for monocytes, and CD4+ and CD8+ T cells are equal responders. The data further indicate that monocyte-T cell contact, more particularly CD40-CD40L interactions, is required for IFN-gamma production in response to IL-2 plus sCD23, and the response to IL-12 plus sCD23 is CD40- and B7-independent but is still partially contact-dependent. It is proposed that sCD23, when produced locally at a site of immune response, may trigger an inflammatory process via monokine release and may further amplify it via the stimulation of bystander non-Ag-specific T cells.
Differential utilization of IFN-gamma-responsive elements in two maturationally distinct macrophage cell lines.
Authors: McDowell M A , Lucas D M , Nicolet C M , Paulnock D M 
Published: December 2022

Abstract
We have characterized the transcriptional response to IFN-gamma in two maturationally distinct macrophage populations: the mature RAW 264.7 cell line, phenotypically identical to thioglycollate-elicited peritoneal macrophages, and the less mature WEHI-3 cell line. We first investigated the use of two IFN-gamma-responsive regulatory elements, the interferon-stimulated response element (ISRE) and the gamma-activated sequence (GAS), in these cells. Transient transfection assays revealed that synthetic promoter constructs containing either the ISRE or GAS regulatory motif fused to a luciferase reporter gene were transcriptionally inactive in the WEHI-3 cell line. We then analyzed the expression in the two cell lines of a panel of known IFN-gamma-responsive genes that are transcriptionally controlled by different regulatory elements. RT-PCR analysis revealed that both cell lines responded to IFN-gamma treatment by up-regulating genes that are transcriptionally controlled by kappa B or W box DNA binding motifs. However, genes regulated by ISRE or GAS elements were induced by IFN-gamma only in the RAW 264.7 cell line. Kinetic analysis of the transcriptional activity of synthetic promoter constructs in the RAW 264.7 cell line showed rapid IFN-gamma induction through both the ISRE and GAS motifs, indicating that both elements are utilized early after IFN-gamma stimulation in mature macrophages. These results suggest that cis-acting DNA response element utilization, and the subsequent profiles of IFN-gamma-induced gene expression, differ in macrophages at different stages of maturation.
p21ras links Fc epsilon RI to NF-AT family member in mast cells. The AP3-like factor in this cell type is an NF-AT family member.
Authors: Prieschl E E , Pendl G G , Harrer N E , Baumruker T 
Published: December 2022

Abstract
Very recently, an AP3-like transcription factor regulating the chemokine gene MARC and an NF-AT family member regulating IL-5 were the first components of the transcription factor repertoire to be described as activated in mast cells after an allergic triggering. In this study, we show that with respect to cross-competition in a gel shift analysis using an NF-AT consensus oligonucleotide binding site, the antigenicity to a recently generated serum against T cell NF-AT, and the sensitivity to macrolide immunosuppressants, the AP3-like activity on the MARC promoter is indistinguishable from that described for NF-AT in T cells. Additionally, we show that this factor functions on the MARC chemokine promoter without the AP1 cofactor, a situation reminiscent of the function of NF-AT in Th2-type T cells. In all of these aspects, and strengthened further by a gel shift competition analysis, the AP3-like transcription factor is identical to the NF-AT family member recently described by an analogous set of experiments as regulating IL-5 in mast cells. Our finding that p21ras, but probably not protein kinase C, is necessary to activate this factor after Fc epsilon RI triggering indicates a situation in which a common transcription factor denominator in mast cells induces chemokine (MARC) and lymphokine (IL-5) gene expression in a manner closely similar to Th2-type T cells, which are induced along the ras/raf signal pathway.
Regulation of polymorphonuclear neutrophil CD16 and CD11b/CD18 expression by matrix proteins during hypoxia is VLA-5, VLA-6 dependent.
Authors: Simms H , D'Amico R 
Published: December 2022

Abstract
We investigated the effects of hypoxia on matrix protein regulation of polymorphonuclear neutrophil (PMN) CD16 and CD11b/CD18 expression. Adherence of PMN to fibronectin increased CD16 expression during hypoxia over levels seen during normoxia, while adherence of PMN to either fibronectin or laminin increased CD11b/CD18 expression during hypoxia over levels seen during normoxia. Kinetics assays demonstrated a t1/2 approximately 60 min and 30 min of hypoxia for maximal up-regulation of CD16 and CD11b/CD18, respectively. Incubation of fluid-phase PMN with anti-VLA-5 (alpha 5/beta 1) and anti-VLA-6 (alpha 6/beta 1) mAbs blocked the effect of fibronectin and laminin on CD16 and CD11b/CD18 expression. Cross-linking of both fluid-phase and adherent PMN VLA-5 and VLA-6 receptors resulted in a progressive increase in CD16 and CD11b/CD18 expression during hypoxia, but not normoxia. Increases in CD16 and CD11b/CD18 expression resulted in increased E anti-Fc gamma RIII and EC3bi rosetting. Inhibition of GPLC activity and IP3 production with U73122 and cyclopiazonic acid blocked the ability of fibronectin to increase CD16 expression and E anti-Fc gamma RIII rosetting. Inhibition of protein tyrosine kinase with genistein and herbimycin A blocked the ability of laminin to increase CD11b/CD18 expression and EC3bi rosetting. Depletion of intracellular Ca2+ abrogated the effects of fibronectin and laminin on CD16 and CD11b/CD18 expression, while restoration of intracellular Ca2+ restored the ability of fibronectin and laminin to increase CD16 and CD11b/CD18 expression. These results demonstrate that during hypoxia integrin signaling via alpha 5/beta 1 and alpha 6/beta 1 results in the increased expression of CD16 and CD11b/CD18. This increase in receptor expression results in biologically active receptors and is dependent upon intracellular Ca2+, GPLC, and protein tyrosine kinase activity.
Neuroantigen-specific Th2 cells are inefficient suppressors of experimental autoimmune encephalomyelitis induced by effector Th1 cells.
Authors: Khoruts A , Miller S D , Jenkins M K 
Published: December 2022

Abstract
We have identified a method of polarizing polyclonal populations of activated T helper cells toward either the Th1 or Th2 phenotype using different short-term in vitro culture conditions. Since the Ag used was an encephalitogenic peptide for SJL/J mice, the pathogenic potential of these cell populations was tested in an adoptive transfer model of experimental autoimmune encephalomyelitis (EAE). Th1 cells reproducibly caused severe EAE, whereas highly polarized Th2 cells did not. Furthermore, highly polarized Th2 cells did not suppress EAE caused by Th1 cells. The anti-inflammatory cytokines made by Th2 cells may simply fail to inhibit tissue destruction mediated by differentiated Th1 cells at the effector phase of the disease. It is also possible that highly polarized Th2 cells may be inefficient at crossing the blood-brain barrier, which may limit their suppressive potential. In contrast, incompletely skewed T cell populations that produced high levels of both Th1 and Th2 cytokines were consistently only weakly encephalitogenic. Therefore, disease inhibition by Th2 cytokines may best be accomplished by intervention at earlier points preceding development of differentiated Th1 cells.
Elevated Th1- or Th0-like cytokine mRNA in peripheral circulation of patients with rheumatoid arthritis. Modulation by treatment with anti-ICAM-1 correlates with clinical benefit.
Authors: Schulze-Koops H , Lipsky P E , Kavanaugh A F , Davis L S 
Published: December 2022

Abstract
The current studies examined whether cytokine patterns indicative of an imbalance in Th1 and Th2 cells could be identified in PBMC of patients with active rheumatoid arthritis (RA). To investigate this possibility, a reproducible PCR technique to assess cytokine mRNA levels in PBMC was employed that minimized in vitro manipulation of the cells. Seven of 14 RA patients had increased mRNA levels for IL-2, 5/14 for IFN-gamma, 3/14 for IL-4, and 4/14 for the IL-2R alpha-chain, compared with normal donors. Whereas 4 patients had elevated mRNA for IL-2 and IFN-gamma, indicative of an increase in activated Th1 or Th0 cells, 1 of 14 patients expressed low levels of IL-2 and IFN-gamma and high levels of IL-4 mRNA. Seven RA patients were treated with a mAb to ICAM-1 (CD54). To determine whether changes in cytokine mRNA levels might be associated with and/or account for the anti-inflammatory effect of anti-ICAM-1 mAb therapy, changes in cytokine mRNA levels were assessed and correlated with clinical improvement. Anti-ICAM-1 mAb administration was followed by a prompt and transient increase of IFN-gamma mRNA. Elevation of IFN-gamma mRNA expression throughout the treatment period reflected a temporary increase in the number of circulating CD3+CD4+ T cells, suggestive of altered circulatory patterns of activated Th1-like cells and was related to clinical efficacy. The results indicate that elevated cytokine mRNA levels characteristic for Th1 cells can be detected in the PBMC in active RA and, furthermore, that anti-ICAM-1 mAb may be beneficial in RA by altering the recruitment of activated Th1-like cells into the synovium. This assumption further strengthens the hypothesis of a significant contribution of Th1-like cells to the pathogenesis of RA.