bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of p59fyn Kinase with the Dynein Light Chain, Tctex-1, and Colocalization During Cytokinesis
Authors: Campbell Kerry S. , Cooper Suzanne , Dessing Mark , Yates Sol , Buder Annie 
Published: December 2022

Abstract
The protein tyrosine kinase p59fyn (Fyn) plays important roles in both lymphocyte Ag receptor signaling and cytokinesis of proB cells. We utilized yeast two-hybrid cloning to identify the product of the tctex-1 gene as a protein that specifically interacts with Fyn, but not with other Src family kinases. Tctex-1 was recently identified as a component of the dynein cytoskeletal motor complex. The capacity of a Tctex-1-glutathione S-transferase fusion protein to effectively bind Fyn from cell lysates confirmed the authenticity of this interaction. Tctex-1 binding required the first 19 amino acids of Fyn and integrity of two lysine residues within this sequence that were previously shown to be important for Fyn interactions with the immunoreceptor tyrosine-based activation motifs (ITAMs) of lymphocyte Ag receptors. Expression of tctex-1 mRNA and protein was observed in all lymphoma lines analyzed, and immunofluorescence confocal microscopy localized the protein to the perinuclear region. Analysis of a T cell hybridoma revealed prominent colocalization of Tctex-1 and Fyn at the cleavage furrow and mitotic spindles in cells undergoing cytokinesis. Our results provide a unique insight into a mechanism by which Tctex-1 might mediate specific recruitment of Fyn to the dynein complex in lymphocytes, which may be a critical event in mediating the previously defined role of Fyn in cytokinesis.
Impaired Antibody Responses in H-2Ab Mice
Authors: Gustavsson Susanne , Hjulström-Chomez Susanna , Lidström Bo-Marcus , Ahlborg Niklas , Andersson Roland , Heyman Birgitta 
Published: December 2022

Abstract
In murine in vivo systems, Ags administered in physiologic solutions together with specific IgE induce a significantly higher Ab response than Ags administered alone. In vitro, IgE in complex with Ag enhances B cell-mediated presentation of the Ag to T cells. Both phenomena require an intact low affinity receptor for IgE (FcεRII/CD23), suggesting that the effect on in vivo Ab responses is caused by increased Ag presentation. We here show that mice carrying the MHC class II Ab molecule (e.g., C57BL/6 and 129/Sv) do not produce Abs to BSA when immunized with BSA-2,4,6-trinitrophenyl (TNP) in complex with monoclonal IgE anti-TNP. In contrast, strains of all other MHC haplotypes tested (H-2d, H-2k, H-2p, H-2q, and H-2s) respond vigorously to IgE/BSA-TNP complexes, with Ab responses several hundred-fold higher than the responses in H-2b mice. C57BL/6 mice were unable to produce a carrier-specific response also after immunization with IgE/OVA-TNP, IgE/diphtheria toxoid-TNP, or IgE/tetanus toxoid-TNP. Although the low responsiveness mapped to the Ab region, responsiveness was not restored in C57BL/6 mice carrying transgenic Ak, suggesting that a nonclassical A-region-encoded gene product is involved. Most importantly, our data call attention to the fact that the C57BL/6 and 129 mouse strains, which are widely used for producing transgenic animals, have defective immune responses.
TGF-β Inhibits IL-12-Induced Activation of Jak-STAT Pathway in T Lymphocytes
Authors: Bright John J. , Sriram Subramaniam 
Published: December 2022

AbstractIL-12 is a macrophage-derived heterodimeric cytokine, capable of inducing proliferation, cytokine production, and cytotoxic activity of NK cells and T cells, and is critical for the development of Th1 responses. TGF-β is an immunosuppressive cytokine that inhibits IL-12-mediated responses in NK and T cells. To determine the mechanism of action of TGF-β, we examined its inhibitory effect on IL-12 signal-transduction pathway in T cells. Stimulation of activated T cells with IL-12 leads to tyrosine phosphorylation and activation of Jak-2 and Tyk-2 kinases and STAT3 and STAT4 transcription factors. Treatment of activated T cells with TGF-β blocked IL-12-induced tyrosine phosphorylation and activation of both Jak-2 and Tyk-2 kinases. Furthermore, inhibition of Jak kinases by TGF-β was associated with a decrease in tyrosine phosphorylation of STAT3 and STAT4 proteins. Abrogation of IL-12-induced Jak-Stat pathway by TGF-β resulted in decreased T cell proliferation and IFN-γ production, and increased apoptotic cell death. These findings highlight that TGF-β inhibits IL-12-mediated responses by blocking IL-12 signal transduction in T cells.
Characterization of a Mobile Stat6 Activation Motif in the Human IL-4 Receptor
Authors: Ryan John J. , McReynolds Lisa J. , Huang Hua , Nelms Keats , Paul William E. 
Published: December 2022

Abstract
The IL-4R induces proliferation and gene expression through the use of conserved tyrosine residues located in growth and gene regulation domains, respectively. We demonstrate that residues surrounding these conserved tyrosines (juxtatyrosine residues) are essential for the proper activation of the signaling molecules IRS-2 and Stat6, as well as for IL-4-induced gene expression. Further, we found that the IL-4R gene regulation domain (amino acids 557–657) contains a tyrosine-based sequence (EAGYKAF) that can convey Stat6 DNA binding and gene expression activities to a minimally active IL-4R mutant, Δ557. Thus, this tyrosine-based sequence can function as a mobile Stat6 activation cassette. However, mutants bearing this sequence induced CD23 expression much less efficiently than did wild-type IL-4R, requiring 150-fold more IL-4 to reach maximal CD23 expression. Our results indicate the importance of juxtatyrosine residues in IL-4R signaling and argue for an essential role of extended domain structure in the recognition and function of juxtatyrosine sequences.
Translational Control of MHC Class II I-A Molecules by IFN-γ
Authors: Goñalons Eduard , Barrachina Marta , García-Sanz José A. , Celada Antonio 
Published: December 2022

AbstractMHC class II molecules are expressed in a limited number of cell types, including B lymphocytes and macrophages (Mφ). IFN-γ increases the surface expression of class II molecules in a murine B cell line without inducing detectable changes in either I-A or I-A mRNA levels. In bone marrow-derived Mφ, IFN-γ causes an increase in class II expression at both the mRNA and surface levels. In addition to the increase in transcription rates described for Mφ, IFN-γ increases the rate of synthesis of IAα and IAβ proteins and the ribosome loading for both mRNA molecules in both cell types. Interestingly, there is a significant peak of free I-A mRNA in noninduced cells. Therefore, IFN-γ regulates the expression of MHC class II molecules at the translational level in both B cells and Mφ and, as already reported, at the transcriptional level only in Mφ. The actual mechanism of regulation causes changes in the translation initiation rates in both cell types, as demonstrated by an increase in ribosome loading in polysome gradients.
Signal-Regulatory Protein Is Selectively Expressed by Myeloid and Neuronal Cells
Authors: Adams Susan , van der Laan Luc J. W. , Vernon-Wilson Elizabeth , Renardel de Lavalette Chantal , Döpp Ed A. , Dijkstra Christine D. , Simmons David L. , van den Berg Timo K. 
Published: December 2022

AbstractSignal-regulatory proteins (SIRP) are transmembrane glycoproteins with three extracellular Ig-like domains, closely related to Ag receptors Ig, TCR, and MHC, and a cytoplasmic domain with two immunoreceptor with tyrosine-based inhibition motifs that can interact with src homology 2 domain-containing phosphatases. SIRP have previously been shown to inhibit signaling through receptor tyrosine kinases, but their physiologic function is unknown. Here we demonstrate by expression cloning that the mAbs ED9, ED17, and MRC-OX41 recognize rat SIRP. In addition, we show for the first time that rat SIRP is selectively expressed by myeloid cells (macrophages, monocytes, granulocytes, dendritic cells) and neurons. Moreover, SIRP ligation induces nitric oxide production by macrophages. This implicates SIRP as a putative recognition/signaling receptor in both immune and nervous systems.
Lung Injury Induced by Alloreactive Th1 Cells Is Characterized by Host-Derived Mononuclear Cell Inflammation and Activation of Alveolar Macrophages
Authors: Clark Joan G. , Madtes David K. , Hackman Robert C. , Chen Wei , Cheever Martin A. , Martin Paul J. 
Published: December 2022

AbstractWe have investigated a murine model of acute lung injury caused by i.v. administration of a T cell clone (CD4+, Th1 phenotype) that recognizes Ly5, a polymorphic cell surface glycoprotein expressed on hemopoietic cells. Alloreactive cloned T cells, specific for host Ly5 Ag, cause a mononuclear cell pulmonary vasculitis and interstitial pneumonitis. In further studies of the cellular mechanisms involved in this model, we found that mature host T cells or B cells are not required, since lung injury was comparable in transgenic host mice that lack these cells (RAG-1 knockout). Cloned T cells labeled in vitro with bromodeoxyuridine were localized in inflammation foci in lung, but the majority of cells in the foci were not labeled. Using transgenic mice that constitutively express lacZ, we determined that the mononuclear cell vasculitis is of host cell origin. Alveolar macrophages (AM) from T cell-treated mice spontaneously secreted TNF-α in culture, whereas TNF-α was not detected in AM cultures from control mice. TNF-α production in response to LPS stimulation was significantly higher in AM cultures derived from T cell-treated mice than in those from control mice. Challenge with sublethal doses of LPS resulted in 50% mortality in T cell-treated mice and was associated with augmented AM TNF-α production and protein in bronchoalveolar lavage fluid. We conclude that immune activation of T cells of the Th1 phenotype can initiate lung injury characterized by a host-derived mononuclear cell inflammation and activation of AM.
The Differential Production of Three Forms of IL-1 Receptor Antagonist by Human Neutrophils and Monocytes
Authors: Malyak Mark , Smith Michael F. , Abel Ashley A. , Hance Kenneth R. , Arend William P. 
Published: December 2022

AbstractIL-1R antagonist (IL-1Ra) exists as three well-characterized isoforms. The 17-kDa secretory IL-1Ra (sIL-1Ra) and 18-kDa intracellular IL-1Ra (icIL-1RaI) arise by alternative transcription of the same IL-1Ra gene. The recently described 16-kDa intracellular IL-1Ra (icIL-1RaII) is formed by alternative translation initiation of sIL-1Ra mRNA. Transcription and translation of IL-1Ra isoforms were examined in LPS-stimulated human neutrophils and PBMC using RT-PCR, ELISA, and Western blot analysis. LPS stimulation of neutrophils resulted in elevated sIL-1Ra mRNA levels by 1 h, whereas icIL-1RaI mRNA remained undetectable through 22 h of culture. Extracellular glycosylated sIL-1Ra protein and intracellular icIL-1RaII were observed in LPS-stimulated neutrophils by 3 h of culture; no icIL-1RaI protein was detected by immunoblot. LPS stimulation of PBMC resulted in elevated sIL-1Ra mRNA levels by 1 h and detectable icIL-1RaI mRNA at 8 h of culture. LPS-stimulated PBMC demonstrated extracellular glycosylated sIL-1Ra protein and intracellular icIL-1RaII within 3 h of stimulation, whereas detection of icIL-1RaI protein was delayed until 15 h of culture. Subcellular localization experiments established that both icIL-1RaI and icIL-1RaII were present primarily within the cytoplasmic compartment, as expected by their lack of a signal peptide. These results demonstrate that although both LPS-stimulated neutrophils and PBMC synthesize sIL-1Ra and icIL-1RaII, only PBMC transcribe and translate icIL-1RaI. Furthermore, sIL-Ra transcription and translation (and translation of icIL-1RaII) are early events, whereas icIL-1RaI transcription in PBMC is delayed.
IFN-α Priming of Human Monocytes Differentially Regulates Gram-Positive and Gram-Negative Bacteria-Induced IL-10 Release and Selectively Enhances IL-12p70, CD80, and MHC Class I Expression
Authors: Hermann Patrice , Rubio Manuel , Nakajima Toshi , Delespesse Guy , Sarfati Marika 
Published: December 2022

AbstractAdministration of IFN-γ and IFN-α may protect or induce autoimmune diseases. Although the in vitro regulation of monokine secretion by IFN-γ have been extensively studied, the regulatory function of IFN-α has not yet been elucidated. We compared IFN-α and IFN-γ, added alone or simultaneously before bacterial stimulation, for the control of monokine release and the expression of costimulatory molecules by human monocytes. Our data show that: 1) IFN-α primes monocytes for increased production of IL-10 in response to Staphylococcus aureus Cowan I strain (SAC) but not to LPS, leading to a lack of IFN-α priming for TNF-α secretion; 2) pretreatment of monocytes with IFN-α inhibits LPS- or SAC-induced IL-12p40 production but unexpectedly enhances the release of the biologically active form of IL-12 (IL-12p70); 3) IFN-α and IFN-γ exert an antagonistic effect on LPS- and SAC-induced IL-10 as well as IL-12p40 release, whereas they further enhance IL-12p70 production when added simultaneously; 4) in contrast to IFN-α, IFN-γ primes monocytes to enhance LPS- or SAC-induced TNF-α and IL-12 production, but surprisingly, it increases IL-10 production by monocytes following LPS but not SAC stimulation; and finally, 5) IFN-α pretreatment selectively up-regulates CD80 and MHC class I expression on monocytes. It is proposed that the outcome of the immune response at the site of inflammation may depend on both the type of bacterial injury (Gram-positive or -negative) and of locally produced IFNs, and that the differential and opposite effects of type I and type II IFNs on monocytes may account for the beneficial or detrimental effects of IFN-α therapy.
Anti-β2-Glycoprotein I Autoantibodies from Patients with the “Antiphospholipid” Syndrome Bind to β2-Glycoprotein I with Low Affinity: Dimerization of β2-Glycoprotein I Induces a Significant Increase in Anti-β2-Glycoprotein I Antibody Affinity
Authors: Sheng Yonghua , Kandiah David A. , Krilis Steven A. 
Published: December 2022

Abstract“Antiphospholipid” autoantibodies are associated with arterial and venous thrombosis, recurrent fetal loss, and thrombocytopenia. At present, the best-characterized antigenic target for these autoantibodies (or Abs) is the phospholipid-binding protein β2-glycoprotein I (β2GPI). These Abs bind β2GPI only in the presence of negatively charged phospholipids or microtiter polystyrene plates that have been specially treated to give the surface a negative charge. To determine whether the binding of these Abs to β2GPI on negatively charged surfaces is dependent on increased density or neo-epitopes formed as a consequence of a conformational change on β2GPI, we generated mutants of β2GPI by site-directed mutagenesis and assessed the binding characteristics of anti-β2GPI Abs to these mutants. Our results demonstrate that mutant F307*, which spontaneously forms significant dimerization, is bound best by all the anti-β2GPI Abs in an anti-β2GPI ELISA using irradiated polystyrene microtiter plates. In addition, these Abs bound mutant F307* coated onto standard polystyrene microtiter wells in the absence of phospholipid, whereas there was minimal binding with wild-type and mutant F307*/C288A, which formed minimal dimerization. Affinity-purified anti-β2GPI Abs from patients with the antiphospholipid syndrome demonstrated significantly higher binding affinity for mutant F307* in fluid phase than for wild-type or mutant F307*/C288A of β2GPI. These results demonstrate that autoantibody binding to β2GPI is intrinsically of low affinity and that the binding is dependent on the density of the Ag and not on neo-epitope formation.
Primary Th1 Cell Immunization Against HIVgp160 in SCID-hu Mice Coengrafted with Peripheral Blood Lymphocytes and Skin
Authors: Delhem Nadirah , Hadida Fabienne , Gorochov Guy , Carpentier Françoise , de Cavel Jean-Pierre , Andréani Jean-François , Autran Brigitte , Cesbron Jean-Yves 
Published: December 2022

AbstractSCID-hu mouse models are of interest in the pathologic investigation of HIV infection, but obtaining a T cell response in SCID-hu-PBL mice is still controversial. We have developed a SCID model by engrafting human skin and autologous PBLs from HIV-seronegative individuals. The study describes the ability of this human-mouse chimera to generate in vivo a primary T lymphocyte response against HIV Ag. The injection of human autologous PBLs was performed 4 to 5 wk after the skin engraftment. Two weeks after injection of PBLs, chimeric mice were immunized with recombinant canary pox virus expressing HIV-1 LAIgp160 (vCP-LAIgp160) and supplemented or not with rIL-2. Intradermal vCP-LAIgp160 injection induced an intradermal perivascular human lymphocytic infiltrate and an epidermic network of CD1a+, CD80+, and CD86+ cells. We derived CD4+ T cell lines (STLs) from the human skin graft of immunized mice, showing that STLs mediated an MHC class II-restricted cytolytic activity directed against HIV-LAIgp160 Ags. Cytokine gene expression in both human skin cells and in STLs showed a predominance of IL-2, IFN-γ, and IL-12 transcripts. Finally, the T cell repertoire analysis using the immunoscope technique showed a very limited CDR3 length polymorphism in the skin infiltrating lymphocytes suggesting an Ag-specific repertoire. The ability to induce a primary Th1 cell response in vivo affords a useful preclinical model for testing vaccine strategies.
MHC Class II Transport from Lysosomal Compartments to the Cell Surface Is Determined by Stable Peptide Binding, But Not by the Cytosolic Domains of the α- and β-Chains
Authors: Théry Clotilde , Brachet Valérie , Regnault Armelle , Rescigno Maria , Ricciardi-Castagnoli Paola , Bonnerot Christian , Amigorena Sebastian 
Published: December 2022

AbstractInside APCs, MHC class II molecules associate with antigenic peptides before reaching the cell surface. This association takes place in compartments of the endocytic pathway, more related to endosomes or lysosomes depending on the cell type. Here, we compared MHC class II transport from endosomal vs lysosomal compartments to the plasma membrane. We show that transport of MHC class II molecules to the cell surface does not depend on the cytosolic domains of the α- and β-chains. In contrast, the stability of the αβ-peptide complexes determined the efficiency of transport to the cell surface from lysosomal, but not from endosomal, compartments. In murine B lymphoma cells, SDS-unstable and -stable complexes were transported to the cell surface at almost similar rates, whereas after lysosomal relocalization or in a cell line in which MHC class II molecules normally accumulate in lysosomal compartments, stable complexes were preferentially addressed to the cell surface. Our results suggest that when peptide loading occurs in lysosomal compartments, selective retention and lysosomal degradation of unstable dimers result in the expression of highly stable MHC class II-peptide complexes at the APC surface.
Critical Role of IL-12 in Dendritic Cell-Induced Differentiation of Naive B Lymphocytes
Authors: Dubois Bertrand , Massacrier Catherine , Vanbervliet Béatrice , Fayette Jérome , Brière Francine , Banchereau Jacques , Caux Christophe 
Published: December 2022

AbstractDendritic cells (DC) are potent APCs initiating immune responses. In a previous report, we demonstrated that DC directly enhance both proliferation and differentiation of CD40-activated naive and memory B cells. The present study deciphers the molecular mechanisms involved in DC-dependent regulation of B cell responses. Herein, we have identified IL-12 as the mandatory molecule secreted by CD40-activated DC that promote the differentiation of naive B cells into plasma cells secreting high levels of IgM. In fact, IL-12 synergizes with soluble IL-6R α-chain (sgp80), produced by DC, to drive naive B cell differentiation. IL-12 is critical for the differentiation of naive B cells into IgM plasma cells, whereas IL-6R signaling mainly promotes Ig secretion by already differentiated B cells. The differentiation of naive B cells in cocultures of B cells, T cells, and DC is IL-12 dependent, definitely demonstrating that the role of DC in humoral responses is not confined to the activation of T cells and further extending the physiologic relevance of DC/B cell interaction. Finally, this study also identifies differential requirements for DC-dependent naive and memory B cell differentiation, the latter being IL-12 independent. Altogether these results indicate that, in addition to prime T cells toward Th1 development, DC, through the production of IL-12, may also directly signal naive B cell during the initiation of the immune response.
Substance P (Neurokinin-1) Receptor Is a Marker of Human Mucosal But Not Peripheral Mononulear Cells: Molecular Quantitation and Localization
Authors: Goode Triona , O’Connell Joe , Sternini Catia , Anton Peter , Wong Helen , O’Sullivan Gerald C. , Collins J. Kevin , Shanahan Fergus 
Published: December 2022

AbstractReciprocal communication between the immune sytem and the neuroendocrine system is mediated via a common chemical language of shared ligands and receptors. The neuropeptide substance P (SP) has been implicated as a mediator of immunomodulation. The evidence for substance P receptors on human lymphocytes is, however, controversial. The aims of the present study are to investigate substance P receptor (SPR) expression in human peripheral and mucosal mononuclear cells and to identify cellular sites of expression in human colonic mucosa. Using reverse-transcriptase PCR, we demonstrate that PBMC isolations are negative for SPR mRNA expression, whereas lamina propria mononuclear cell (LPMC) isolations express on average eight SPR mRNA transcripts per cell. In situ hybridization performed on surgically resected colonic tissue confirms the expression of SPR mRNA in LPMC in vivo. SPR mRNA signal was detected in LPMC, lymphoid follicles, and epithelium. The complementary technique of immunohistochemistry gave a similar distribution of SPR expression that colocalized with CD45 immunoreactivity. Dual-fluorochrome flow cytometry revealed SPR expression by CD4, CD45RO, CD45RA, CD8, CD19, and CD14 LPMC subsets, but not PBMC. Our findings suggest that SPR expression is distinctive of human colonic mucosal mononuclear cells and support a direct role for SP in mucosal immunomodulation.
A Plasmid Encoding Murine Granulocyte-Macrophage Colony-Stimulating Factor Increases Protection Conferred by a Malaria DNA Vaccine
Authors: Weiss Walter R. , Ishii Ken J. , Hedstrom Richard C. , Sedegah Martha , Ichino Motohide , Barnhart Kerry , Klinman Dennis M. , Hoffman Stephen L. 
Published: December 2022

AbstractUsing the murine parasite Plasmodium yoelii (Py) as a model for malaria vaccine development, we have previously shown that a DNA plasmid encoding the Py circumsporozoite protein (PyCSP) can protect mice against sporozoite infection. We now report that mixing a new plasmid PyCSP1012 with a plasmid encoding murine granulocyte-macrophage colony-stimulating factor (GM-CSF) increases protection against malaria, and we have characterized in detail the increased immune responses due to GM-CSF. PyCSP1012 plasmid alone protected 28% of mice, and protection increased to 58% when GM-CSF was added (p &lt; 0.0001). GM-CSF plasmid alone did not protect, and control plasmid expressing inactive GM-CSF did not enhance protection. GM-CSF plasmid increased Abs to PyCSP of IgG1, IgG2a, and IgG2b isotypes, but not IgG3 or IgM. IFN-γ responses of CD8+ T cells to the PyCSP 280–288 amino acid epitope increased but CTL activity did not change. The most dramatic changes after adding GM-CSF plasmid were increases in Ag-specific IL-2 production and CD4+ T cell proliferation. We hypothesize that GM-CSF may act on dendritic cells to enhance presentation of the PyCSP Ag, with enhanced IL-2 production and CD4+ T cell activation driving the increases in Abs and CD8+ T cell function. Recombinant GM-CSF is already used in humans for medical purposes, and GM-CSF protein or plasmids may be useful as enhancers of DNA vaccines.