bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preprosomatostatin Messenger RNA Is Expressed by Inflammatory Cells and Induced by Inflammatory Mediators and Cytokines
Authors: Elliott David E. , Blum Arthur M. , Li Jie , Metwali Ahmed , Weinstock Joel V. 
Published: January 2023

AbstractSomatostatin (SOM) is a 14-amino acid cyclic peptide that regulates granulomatous inflammation. SOM inhibits the release of IFN-γ from murine granuloma T cells that express SOM receptors. SOM is synthesized as preprosomatostatin (ppSOM), a precursor peptide that is cleaved to release active SOM. In this paper, we demonstrate that granuloma cells express mRNA for this important immunoregulator, and that inflammatory mediators rapidly induce ppSOM mRNA in the splenocytes of uninfected, normal (NL) mice. We developed a sensitive, quantitative PCR assay that measures ppSOM mRNA down to 100 transcripts per μg of total RNA. Dispersed granuloma cells expressed authentic ppSOM mRNA as determined by RT-PCR and cDNA sequencing. The PCR assay readily detected ppSOM mRNA in splenocytes isolated from schistosome-infected mice, but not in splenocytes from NL mice. Splenic ppSOM mRNA expression correlated with the onset of parasite egg deposition and granuloma formation. A 4-h in vitro stimulation with LPS, rIL-10, rIFN-γ, rTNF-α, prostaglandin E2, or dibutyryl cAMP induced ppSOM mRNA in NL splenocytes that otherwise lacked this transcript. Splenocytes from severe combined immunodeficient or recombination activating gene 1-deficient mice expressed ppSOM after exposure to rIL-10, suggesting that neither T nor B cells are necessary for ppSOM mRNA induction. A survey of cell lines demonstrated expression of ppSOM mRNA by P388D1 and J774A.1 macrophage-like cells. These data suggest that SOM, which is probably derived from macrophages, is an inducible component of the innate immune system that regulates T cell IFN-γ production.
Lidocaine and its Analogues Inhibit IL-5-Mediated Survival and Activation of Human Eosinophils
Authors: Okada Shinji , Hagan John B. , Kato Masahiko , Bankers-Fulbright Jennifer L. , Hunt Loren W. , Gleich Gerald J. , Kita Hirohito 
Published: January 2023

AbstractEosinophils and cytokines active on eosinophils, especially IL-5, are believed to be critically involved in chronic allergic diseases. IL-5 activates eosinophils and enhances their survival in vitro by delaying apoptosis. In this study, we found that lidocaine and six analogues blunt responses of eosinophils to IL-5. Lidocaine and its derivatives inhibit IL-5-mediated eosinophil survival in a concentration-dependent manner (IC50 = 110 μM for 30 pg/ml IL-5). At suboptimal lidocaine concentrations, the eosinophil survival response to IL-5 shifts and more IL-5 is required to maintain survival. The inhibitory effect requires at least 24-h exposure of eosinophils to lidocaine, and the protein kinase C activator, PMA, completely reverses the inhibition. A multiparameter flow-cytometric analysis shows that lidocaine hastens the apoptosis of eosinophils normally delayed by IL-5. Lidocaine does not affect IL-5R expression or IL-5-induced protein tyrosine phosphorylation. Lidocaine also inhibits eosinophil survival mediated by IL-3 or granulocyte-macrophage CSF, although less potently than that mediated by IL-5. Furthermore, lidocaine inhibits eosinophil superoxide production stimulated by IL-5, granulocyte-macrophage CSF, or IL-3, but not that stimulated by platelet-activating factor, immobilized IgG, or PMA. Lidocaine and its derivatives show novel immunomodulatory properties and are able to blunt eosinophil responses to cytokines in addition to their local anesthetic or antiarrhythmic properties. Thus, lidocaine and its derivatives may represent a new class of therapeutic agents to treat patients with allergic diseases.
Cutting Edge: Mice Defective in Fas Are Highly Susceptible toLeishmania majorInfection Despite Elevated IL-12 Synthesis, Strong Th1 Responses, and Enhanced Nitric Oxide Production
Authors: Huang Fang-Ping , Xu Damo , Esfandiari Ehsan-O , Sands William , Wei Xiao-qing , Liew Foo Y. 
Published: January 2023

AbstractMRL/MP-lpr/lpr (MRL/lpr) mice have a single mutation (lpr) of the fasapoptosis gene. The mutant mice developed significantly smaller lesions than the wild-type mice at the earlier stage of infection with the intracellular protozoan parasite Leishmania major. However, while all the wild-type mice achieved complete lesion resolution, the disease in the mutant mice progressed inexorably. The mutant mice had more IL-12 and nitrite/nitrate in the serum than wild-type mice following infection. Lymphoid cells from infected MRL/lpr mice produced more IFN-γ but less IL-4 and IL-5 than cells from MRL-+/+ mice. Peritoneal macrophages from the mutant mice also produced more IL-12 and NO after stimulation with LPS. Thus, Fas expression is essential for resistance against leishmaniasis, and Fas-mediated apoptosis may form an integral part of the Th1-mediated microbicidal function.
Inhibition of Mitogen-Activated Protein Kinase Kinase Blocks T Cell Proliferation But Does Not Induce or Prevent Anergy
Authors: DeSilva Dimuthu R. , Jones Elizabeth A. , Favata Margaret F. , Jaffee Bruce D. , Magolda Ronald L. , Trzaskos James M. , Scherle Peggy A. 
Published: January 2023

AbstractThree mitogen-activated protein kinase pathways are up-regulated during the activation of T lymphocytes, the extracellular signal-regulated kinase (ERK), Jun NH2-terminal kinase, and p38 mitogen-activated protein kinase pathways. To examine the effects of blocking the ERK pathway on T cell activation, we used the inhibitor U0126, which has been shown to specifically block mitogen-activated protein kinase/ERK kinase (MEK), the kinase upstream of ERK. This compound inhibited T cell proliferation in response to antigenic stimulation or cross-linked anti-CD3 plus anti-CD28 Abs, but had no effect on IL-2-induced proliferation. The block in T cell proliferation was mediated by down-regulating IL-2 mRNA levels. Blocking Ag-induced proliferation by inhibiting MEK did not induce anergy, unlike treatments that block entry into the cell cycle following antigenic stimulation. Surprisingly, induction of anergy in T cells exposed to TCR cross-linking in the absence of costimulation was also not affected by blocking MEK, unlike cyclosporin A treatment that blocks anergy induction. These results suggest that inhibition of MEK prevents T cell proliferation in the short term, but does not cause any long-term effects on either T cell activation or induction of anergy. These findings may help determine the viability of using mitogen-activated protein kinase inhibitors as immune suppressants.
Activation of p21-CDC42/Rac-Activated Kinases by CD28 Signaling: p21-Activated Kinase (PAK) and MEK Kinase 1 (MEKK1) May Mediate the Interplay Between CD3 and CD28 Signals
Authors: Kaga Shuji , Ragg Scott , Rogers Kem A. , Ochi Atsuo 
Published: January 2023

AbstractCD28, a T cell costimulatory receptor, provides a signal that induces both optimal proliferation and the production of IL-2 by TCR-activated T cells. We show that the stimulation of CD28 leads to the activation of p21-activated kinase and MEK kinase 1. The same pathway was also stimulated in T cells treated with the cell-permeable ceramide analogue, C2-ceramide. The combined stimulation of either CD3 and CD28 or CD3 concurrently with C2-ceramide largely enhanced the activity of p21-activated kinase and MEK kinase 1. Therefore the Rac1/CDC42-coupled pathway(s) is a candidate that transduces and facilitates cross-talk between the CD28 costimulatory signal and the TCR signal.
Expression of ADP-Ribosyltransferase on Normal T Lymphocytes and Effects of Nicotinamide Adenine Dinucleotide on Their Function
Authors: Okamoto Shigefumi , Azhipa Olga , Yu Yajing , Russo Elizabeth , Dennert Gunther 
Published: January 2023

AbstractADP-ribosyltransferase (ADPRT) is a glycosylphosphatidylinositol-anchored cell surface enzyme on CTL. Expression of this enzyme correlates with suppression of CTL functions in the presence of its substrate β-nicotinamide adenine dinucleotide (NAD). To investigate the immunoregulatory importance of ADPRT on normal lymphocytes in vivo, NAD was injected into mice and the effects on cell-mediated and humoral immunity were assessed. Induction of both delayed-type hypersensitivity and CTL, but not Ab responses, are shown to be suppressed by NAD. Consistent with this, mature T cells, but not B cells or macrophages, express ADPRT and are able to ADP-ribosylate cell surface proteins. ADP-ribosylated molecules were identified as LFA-1, CD8, CD27, CD43, CD44, and CD45. Concomitant to ADP-ribosylation of these molecules, T cell trafficking to secondary lymphoid organs is suppressed by NAD. To examine whether this is due to effects of NAD on cell activation, Ag-stimulated responses were assayed in vitro. NAD is shown to inhibit induction of cell proliferation, cytotoxicity, and cytokine secretion. It is suggested that ADPRT regulates T cells on the level of transmembrane signaling via ADP-ribosylation of cell surface molecules. This effect is reported to be indirect, as it involves transmission of signals through TCRs, which are not ADP-ribosylated.
Type I IFNs Inhibit Human Dendritic Cell IL-12 Production and Th1 Cell Development
Authors: McRae Bradford L. , Semnani Roshanak Tolouei , Hayes Mark P. , van Seventer Gijs A. 
Published: January 2023

AbstractWe have investigated the role of type I IFNs (IFN-α and -β) in human T cell differentiation using anti-CD3 mAb and allogeneic, in vitro-derived dendritic cells (DC) as APCs. DC were very efficient activators of naive CD4+ T cells, providing necessary costimulation and soluble factors to support Th1 differentiation and expansion. Addition of IFN-αβ to DC/T cell cultures resulted in induction of T cell IL-10 production and inhibition of IFN-γ, TNF-α, and LT secretion. Diminished T cell IFN-γ production correlated with IFN-αβ-mediated inhibition of the p40 chain of the IL-12 heterodimer secreted by DC. Suppression of p40 IL-12 and IFN-γ was not due to increased levels of IL-10 in these cultures, and production of IFN-γ could be restored by exogenous IL-12. These data indicate that type I IFNs inhibit DC p40 IL-12 expression, which is required for development of IFN-γ-producing CD4+ T cells. Furthermore, when T cells were restimulated without IFN-β, these cells induced less p40 IL-12 from DC, suggesting that the functional properties of T cells may regulate DC function. Thus, IFN-αβ inhibits both IL-12-dependent and independent Th1 cytokine production and provides a mechanism for inhibition of IL-12-mediated immunity in viral infections.
TAP-Independent MHC Class I Peptide Antigen Presentation to Alloreactive CTL Is Enhanced by Target Cell Incubation at Subphysiologic Temperatures
Authors: Shi Yan , Smith Kelly D. , Lutz Charles T. 
Published: January 2023

AbstractWe investigated the peptide dependency of a group of CD8+ anti-HLA-B7 alloreactive CTL. The CTL killed target cells after acid denaturation of more than 98% of target cell surface peptide/MHC class I complexes. The CTL also killed TAP− HLA-B7-transfected T2 (T2B7) cells. The killing was enhanced by target cell incubation at 26°C. Despite these findings, which suggested peptide-independent allorecognition, CTL-mediated cytolysis was reduced or abolished by several point mutations affecting the HLA-B7 peptide-binding groove. Acid denaturation of HLA complexes on T2B7 cells prohibited CTL recognition. CTL recognition was restored by T2B7 cell incubation with β2-microglobulin and a single HPLC fraction containing peptides extracted from TAP+HLA-B7+ cells, but not by any of a panel of 17 synthetic HLA-B7-binding peptides. These findings indicated that CTL allorecognition was peptide specific. Sensitizing peptide was extracted from T2B7 cells only after incubation at 26°C. The amount of peptide detected in TAP+ cells was at least 10-fold and 100-fold greater than that detected in TAP− cells incubated at 26°C and at 37°C, respectively. TAP-independent peptide epitope presentation was sensitive to treatment with brefeldin A, but not sensitive to treatment with chloroquine, consistent with an endogenous peptide source. We propose that subphysiologic temperature incubation can enhance peptide/MHC class I presentation in the total absence of TAP function.
Analysis of the IFN-γ-Signaling Pathway in Macrophages at Different Stages of Maturation
Authors: Lucas David M. , Lokuta Mary A. , McDowell Mary Ann , Doan Joyce E. S. , Paulnock Donna M. 
Published: January 2023

Abstract
We previously demonstrated that the macrophage cell lines RAW 264.7 and WEHI-3 exhibit distinct patterns of gene expression in response to IFN-γ. This difference is controlled at the transcriptional level and results from a specific inability of the less mature WEHI-3 cells to utilize either the IFN-stimulated response element or the γ-activated sequence DNA regulatory element in response to stimulation with IFN-γ, while other aspects of IFN-γ gene induction remain intact. In the work described here, we examined the components of the IFN-γ signal transduction pathway in RAW 264.7 and WEHI-3 cells to determine whether differences in pathway components or activity exist in WEHI-3 cells that could give rise to this difference in transcriptional response. Reverse transcriptase-PCR (RT-PCR) and flow cytometric analyses indicated that the levels of IFN-γ receptor mRNA accumulation and protein expression are comparable for RAW 264.7 and WEHI-3 cells. RT-PCR and immunoblot analyses revealed that the principal components of this signaling pathway, including JAK1, JAK2, and STAT1, are present in both RAW 264.7 and WEHI-3 cells. However, analysis of STAT1 DNA-binding activity by electrophoretic mobility shift assay and of STAT1 phosphorylation by immunoblot revealed that this DNA-binding factor is active in RAW 264.7, but not in WEHI-3, cells after IFN-γ stimulation. These results demonstrate that the components of the IFN-γ signal transduction pathway are intact in WEHI-3 cells, but stimulation of these cells by IFN-γ does not result in STAT1 activation.
Interaction of HLA-E with Peptides and the Peptide Transporter In Vitro: Implications for its Function in Antigen Presentation
Authors: Ulbrecht Matthias , Modrow Susanne , Srivastava Rakesh , Peterson Per A. , Weiss Elisabeth H. 
Published: January 2023

AbstractThe assembly of MHC Ia molecules in the endoplasmic reticulum requires the presence of peptide ligands and β2m and is facilitated by chaperones in an ordered sequence of molecular interactions. A crucial step in this process is the interaction of the class I α-chain/β2m dimer with TAP, which is believed to ensure effective peptide loading of the empty class I molecule. We have previously demonstrated impaired intracellular transport of the class Ib molecule HLA-E in mouse myeloma cells cotransfected with the genes for HLA-E and human β2m, which is most likely attributable to inefficient intracellular peptide loading of the HLA-E molecule. We therefore analyzed the ability of HLA-E in the transfectant cell line to bind synthetic peptides by means of their ability to enhance cell surface expression of HLA-E. Peptide binding was confirmed by testing the effect on the thermostability of soluble empty HLA-E/human β2m dimers. Two viral peptides binding to HLA-E were thus identified, for which the exact positioning of the N terminus appeared critical for binding, whereas the contribution of the length of the C terminus seemed to be minor, allowing peptides as short as seven amino acids and up to 16 amino acids to exhibit considerable binding activity. Furthermore, we demonstrate that HLA-E interacts with TAP and that this interaction can be prolonged by the proteasome inhibitor N-acetyl-l-leucyl-l-leucyl-l-norleucinal, which reduces the intracellular peptide pool. The presented data indicate that HLA-E is capable of presenting peptide ligands similar to the repertoire of HLA class Ia molecules.
Transcriptional Repression of the IL-2 Gene in Th Cells by ZEB
Authors: Yasui Dag H. , Genetta Tom , Kadesch Tom , Williams Thomas M. , Swain Susan L. , Tsui Lisa V. , Huber Brigitte T. 
Published: January 2023

AbstractTh1- and Th2-type cells mediate distinct effector functions via cytokine secretion in response to immunologic challenge. Precursor Th cells transcribe IFN-γ, IL-2, and IL-4 upon activation. Repeated stimulation of Th precursor cells in the presence of IL-4 leads to terminally differentiated Th2 cells that have lost the ability to transcribe the IL-2 gene. We provide evidence that repression of IL-2 gene expression in Th2 cells and partial repression in Th1 cells are mediated by ZEB, a zinc finger, E box-binding transcription factor. This factor binds to a negative regulatory element, NRE-A, in the IL-2 promoter, thereby acting as a potent repressor of IL-2 transcription.
In Situ Cancer Vaccination: An IL-12 Defective Vector/Replication-Competent Herpes Simplex Virus Combination Induces Local and Systemic Antitumor Activity
Authors: Toda Masahiro , Martuza Robert L. , Kojima Hidefumi , Rabkin Samuel D. 
Published: January 2023

AbstractIntratumoral inoculation of replication-competent, attenuated herpes simplex virus (HSV) mutants inhibits tumor growth by direct cytotoxic viral replication and induction of a tumor-specific immune response. To boost the antitumor response, we describe a defective HSV vector encoding IL-12 as an adjuvant to in situ vaccination by the replication-competent HSV helper virus. The defective HSV vector system consists of defective particles containing tandem repeats of the cytokine genes (p40 and p35) in combination with a HSV helper virus. Heterodimeric IL-12 was expressed and secreted after IL-12 defective vector infection of tumor cells. In a syngeneic, bilateral established tumor model with CT26 murine colon carcinoma, unilateral intratumoral inoculation with an IL-12 defective/replication-competent HSV vector combination significantly reduced tumor growth of the inoculated and noninoculated contralateral tumors. This antitumor effect was significantly greater than with a lacZ-defective/replication-competent HSV vector combination, which itself was significantly greater than the mock inoculation. Efficacy is associated with enhancement of tumor-specific CTL activity, including specificity against the CT26 immunodominant MHC class I restricted Ag AH1, and IFN-γ production. There was no significant tumor growth inhibition after intratumoral inoculation of s.c. CT26 tumors in athymic mice. We conclude that this defective HSV vector system is an effective method for cytokine gene delivery to tumors in situ and IL-12 expression in tumors synergizes the antitumor activity mediated by the replication-competent HSV helper virus.
Cellular Mechanisms Involved in Protection Against Influenza Virus Infection in Transgenic Mice Expressing a TCR Receptor Specific for Class II Hemagglutinin Peptide in CD4+ and CD8+ T Cells
Authors: Bot Adrian , Casares Sofia , Bot Simona , von Boehmer Harald , Bona Constantin 
Published: January 2023

AbstractMice transgenic for a TCR that recognizes peptide110–120 of hemagglutinin of PR8 influenza virus in the context of MHC class II I-Ed molecules express the transgenes in both CD4+ and CD8+ T cells. We have found that these TCR-hemagglutinin (TCR-HA) transgenic mice display a significantly increased resistance to the primary infection with PR8 virus compared with the wild-type mice. The TCR-HA transgenic mice mounted significant MHC type II and enhanced MHC type I-restricted cytotoxicity as well as increased cytokine responses in both spleen and lungs after infection with PR8 virus. In contrast, the primary humoral response against PR8 virus was not significantly different from that of the wild-type mice. In vivo depletion and adoptive cell transfer experiments demonstrated that both CD4+ and CD8+ TCR-HA+ T cell subsets were required for the complete clearance of pulmonary virus following infection with a dose that is 100% lethal in wild-type mice. Whereas CD4+ TCR-HA+ T cells were necessary for effective activation and local recruitment of CD8+ T cells, CD8+ TCR-HA+ T cells showed a Th1-biased pattern and MHC type II-restricted cytotoxicity. However, in the absence of in vivo expression of MHC type I molecules on the infected cells, the protection conferred by the TCR-HA+ T cells was impaired, indicating that the enhanced MHC class I-restricted cytotoxicity due to TCR-HA+ CD4+ Th cells was a critical element for clearance of the pulmonary virus by the transgenic mice.
Analysis of Ligand-Induced and Ligand-Attenuated Epitopes on the Leukocyte Integrin α4β1: VCAM-1, Mucosal Addressin Cell Adhesion Molecule-1, and Fibronectin Induce Distinct Conformational Changes
Authors: Newham Peter , Craig Sue E. , Clark Katherine , Mould A. Paul , Humphries Martin J. 
Published: January 2023

AbstractThe leukocyte integrin α4β1 is a receptor for both cell surface ligands (VCAM-1 and mucosal addressin cell adhesion molecule-1 (MAdCAM-1)) and extracellular matrix components (fibronectin). Through regulated interactions with these molecules, α4β1 mediates leukocyte migration from the vasculature at sites of inflammation. Regulation of integrin activity plays a key role in controlling leukocyte-adhesive events and appears to be partly determined by changes in integrin conformation. Several mAbs that recognize ligand-induced binding site epitopes on integrins have been characterized, and a subset of these mAbs are capable of stimulating integrin-ligand binding. Conversely, some mAbs recognize epitopes that are attenuated by ligand engagement and allosterically inhibit ligand binding. To gain insight into ligand-specific effects on integrin conformation, we have examined the ability of different ligands to modulate the binding of four distinct classes (A, B1, B2, and C) of anti-α4 Abs to α4β1. VCAM-1 attenuated B (antifunctional) class epitopes via an allosteric mechanism and also allosterically inhibited the binding of the function-blocking anti-β1 mAb 13. Additional α4β1 ligands (fibronectin fragments, MAdCAM-1, and the CS1 peptide) also inhibited mAb 13-integrin binding; however, the epitopes of the class B anti-α4 mAbs were attenuated by the fibronectin fragments, but not by MAdCAM-1 or the CS1 peptide. Of the two anti-α4 class A mAbs examined, one recognized an epitope that was induced uniquely by VCAM-1. Taken together, these data suggest that overlapping but distinct binding mechanisms exist for different α4β1 ligands and that distinct conformational changes are induced upon integrin engagement by different ligands.