bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human T lymphocyte chemotaxis and adhesion induced by vasoactive intestinal peptide.
Authors: Johnston J A , Taub D D , Lloyd A R , Conlon K , Oppenheim J J , Kevlin D J 
Published: December 2022

Abstract
Vasoactive intestinal peptide (VIP), a 28-amino acid peptide of the glucagon-secretin family, has been reported to have significant immunoregulatory properties. In the present study, we demonstrate that VIP has potent chemotactic effects on T lymphocytes. At concentrations of between 10(-8) and 10(-9) M, VIP stimulated significant in vitro chemotaxis of T lymphocytes from both CD4+ and CD8+ subsets. VIP produced more potent chemotactic effects on unstimulated T cells than on anti-CD3-activated cells. Following anti-CD3 activation, binding of 125I-labeled VIP to T cells was reduced and this correlated with a reduction in receptor number without any change in affinity. Preincubation of unstimulated T cells with VIP produced increases in adhesion to ICAM and VCAM integrins. In addition, VIP pretreatment significantly increased unstimulated T cell adhesion to the extracellular matrix protein fibronectin. However, VIP induced less binding of activated T cells to fibronectin. Taken together these results suggest that VIP is a potent chemoattractant and stimulant of adhesion for T lymphocytes. In contrast to chemokines that are more active on stimulated T cells, such as RANTES, this neuropeptide preferentially targets unactivated T cells, suggesting that it may play a greater role in homing and distribution of lymphocytes.
Murine hepatocyte apoptosis induced in vitro and in vivo by TNF-alpha requires transcriptional arrest.
Authors: Leist M , Gantner F , Bohlinger I , Germann P G , Tiegs G , Wendel A 
Published: December 2022

Abstract
Freshly isolated mouse hepatocytes were essentially insensitive to TNF-alpha cytotoxicity. However, TNF-alpha induced a concentration-dependent cell death in hepatocytes that had been pretreated with the transcriptional inhibitors actinomycin D (ActD), D-galactosamine, or alpha-amanitin. Unlike RNA synthesis inhibition, a translational block in the presence of cycloheximide (CHX) or puromycin did not sensitive hepatocytes to TNF. On the contrary, these agents prevented hepatocytotoxicity induced by ActD/TNF. Pretreatment with peroxides or glutathione depletors had no significant influence on TNF cytotoxicity. In vivo treatment of mice with ActD/TNF caused hepatic failure, which was significantly reduced by co-treatment with CHX. These findings demonstrate that protein synthesis is required for this mechanism of cell death. To test whether TNF may trigger an endogenous suicide program in hepatocytes, we examined whether DNA fragmentation preceded cell death. In the culture system, hepatocellular DNA fragmentation in the presence of ActD/TNF was observed several hours before lactate dehydrogenase release and was inhibited by CHX. Similar results were obtained in vivo. Chromatin condensation and the formation of apoptotic bodies were observed in livers from mice treated with ActD/TNF and significant DNA fragmentation was detected as early as 4 h after challenge. At this time, organ total glutathione content and plasma transaminase levels were not significantly different from those of untreated controls. The findings of this study demonstrate that direct hepatotoxicity of TNF-alpha is associated with an apoptotic mechanism that becomes manifest under the metabolic condition of arrested transcription and functional translation.
Elevation of lymphocyte CD45 protein tyrosine phosphatase activity during mitosis.
Authors: Melkerson-Watson L J , Waldmann M E , Gunter A D , Zaroukian M H , Esselman W J 
Published: December 2022

Abstract
CD45 is an abundant cell-surface protein tyrosine phosphatase (PTPase) of hematopoietic cells that mediates specific tyrosine dephosphorylation in lymphocyte Ag activation. The hypothesis that CD45 PTPase activity varies during progression through the cell cycle was examined in this study. Expression of CD45 PTPase activity was determined in pre-B lymphoma (70Z/3.12) and cytolytic T lymphocyte (CTLL-2) cell lines after fractionation by counterflow centrifugal elutriation into cell cycle-stage-enriched subpopulations. For both cell lines, CD45 PTPase activity was elevated 2- to 10-fold in late G2 + M fractions compared with the PTPase activity of asynchronous cells. FACS and SDS-PAGE analyses indicated that there was only a minor increase in CD45 protein expression during progression through the cell cycle, suggesting that increased CD45 PTPase activity was a result of increased enzymatic activity. Cyclin B expression in 70Z/3.12 cells was evaluated in elutriated subpopulations and intact cyclin B was present in all cell cycle phases from G1 to late G2 + M, disappearing in mitosis and just before those fractions containing maximum CD45 activity. This observation indicated that the peak PTPase activity of CD45 occurred in late mitosis or in cytokinesis. The elevation of CD45 PTPase activity in mitosis supports the hypothesis that CD45 has a role in phosphorylation events occurring during cell division.
Dominant negative mutant of c-Jun inhibits NF-AT transcriptional activity and prevents IL-2 gene transcription.
Authors: Petrak D , Memon S A , Birrer M J , Ashwell J D , Zacharchuk C M 
Published: December 2022

Abstract
Expression of the transcription complex AP-1, composed of Jun and Fos family members, can be induced by a variety of stimuli. In lymphocytes, AP-1 transcriptional activity increases after TCR ligation and plays an important role in T cell activation events such as lymphokine secretion. To explore the requirements for AP-1 in IL-2 production, the AP-1 complex was targeted with a dominant negative mutant c-Jun protein, TAM-67, from which the transactivation domain has been deleted. In transient transfections of Jurkat cells, TAM-67 efficiently inhibited endogenous AP-1 transcriptional activity and blocked the activity of a reporter construct containing the 5' regulatory region of the IL-2 gene. TAM-67 also inhibited the transcriptional activity of nuclear factor-AT (NF-AT), whereas the NF-kappa B, NF-IL-2A, and the proximal TRE-like sites were relatively unaffected. The use of this dominant negative transcription factor suggests that: 1) transactivation-defective nuclear factors represent a novel approach to study the functional consequences of nuclear protein interactions on gene transcription; 2) the proximal TRE-like site from the IL-2 promoter is different from the consensus TRE; and 3) AP-1 plays an important role in the transcriptional activation mediated by the NF-AT binding complex.
IL-4 directly modulates function of a model human intestinal epithelium.
Authors: Colgan S P , Resnick M B , Parkos C A , Delp-Archer C , McGuirk D , Bacarra A E , Weller P F , Madara J L 
Published: December 2022

Abstract
Intestinal epithelia are in intimate contact with subepithelial and intraepithelial lymphocytes. When stimulated, mucosal lymphocytes generate inflammatory cytokines such as IL-4 and IFN-gamma. We have shown that IFN-gamma directly regulates epithelial function. It is unknown whether IL-4 might influence epithelial function and, if so, whether such influences are similar to or differ from those exerted by IFN-gamma. In this study, we examine the effect of human IL-4 on barrier function, ion transport, and immune accessory ligand expression on T84 cells, a crypt-like epithelial cell line. Basolateral exposure of epithelial monolayers to IL-4 attenuated epithelial barrier function by greater than 65% in a dose (50% of effective dose = 1 U/ml)- and time (t1/2 = 24 h)-dependent fashion, and was inhibitable by neutralizing anti-IL-4 and anti-IL-4R Ab. Stimulated Cl- secretion, as measured by epithelial short circuit current, was diminished by as much as 70% by IL-4. Epithelial preexposure to IL-4 brought about a greater than twofold increase in beta 2 integrin-dependent neutrophil adhesion to epithelial, but retarded neutrophil migration into and across epithelial monolayers. ELISAs revealed that epithelial exposure to IL-4 had no effect on cell surface expression of MHC class I, MHC class II, or ICAM-1. These results indicate that IL-4, like IFN-gamma, may serve to regulate intestinal epithelial function, but that resulting phenotypes may be cytokine specific. We speculate from these data that activation of the basolateral receptor for IL-4 potentially provides a new strategy for damping the cellular component of active inflammation in the intestine.
Tenidap modulates cytoplasmic pH and inhibits anion transport in vitro. I. Mechanism and evidence of functional significance.
Authors: McNiff P , Svensson L , Pazoles C J , Gabel C A 
Published: December 2022

Abstract
Tenidap is a novel anti-inflammatory and antiarthritic agent that in clinical studies of rheumatoid arthritis patients, displays symptomatic efficacy superior to nonsteroidal anti-inflammatory drugs (NSAIDs) and equivalent to combinations of NSAIDs and second line agents. Clinical and preclinical biochemical studies have demonstrated that tenidap combines cytokine modulation with suppression of prostaglandin biosynthesis. To better understand tenidap's mechanism of action, in vitro studies of intracellular pH (pHi) were conducted. In cells loaded with the pH-sensitive fluorescence dye 2',7'-bis-(2-carboxyethyl)-5-(and -6) carboxyfluorescein, tenidap, but not NSAIDs, caused a rapid and sustained acidification of the cytoplasmic compartment. Tenidap did not act as a proton ionophore, as it did not dissipate the low pH within lysosomes. Mammalian cells regulate pHi through the concerted action of a number of specific transport proteins, including sodium-proton antiporters and chloride-bicarbonate exchangers. Tenidap did not alter pHi via inhibition of the sodium-proton antiporter, but inhibited activity of chloride-bicarbonate exchangers, as did UK5099, a known anion-transport inhibitor that also lowers pHi. This similar activity suggests that the pHi change is coupled to anion transport inhibition. As a result of the pHi change, tenidap affected pH-dependent cellular activities. Tenidap inhibited mannose 6-phosphate receptor-mediated endocytosis, inhibited protein synthesis, and stimulated accumulation of the amino acid leucine. Effects on these cellular processes rapidly reversed when tenidap was removed from the culture medium. Tenidap's in vitro activities were highly dependent on the medium composition; protein content, pH, and bicarbonate concentration all were important factors that influenced activity. These results indicate that tenidap is a potent anion-transport inhibitor and modulator of pHi. Within the appropriate cell or tissue microenvironment, these activities may contribute to tenidap's novel therapeutic profile.
IFN-gamma selectively inhibits lipopolysaccharide-inducible JE/monocyte chemoattractant protein-1 and KC/GRO/melanoma growth-stimulating activity gene expression in mouse peritoneal macrophages.
Authors: Ohmori Y , Hamilton T A 
Published: December 2022

Abstract
IFN-gamma and LPS have both been shown to stimulate enhanced chemoattractant cytokine gene expression in mononuclear phagocytes. In this report, IFN-gamma was found to suppress LPS-induced chemokine mRNA expression in a cell type- and gene-specific fashion. Expression of JE (monocyte chemoattractant protein-1) and KC (GRO/melanoma growth-stimulating activity) mRNA in macrophages stimulated with LPS was markedly suppressed by IFN-gamma in a dose- and time-dependent fashion. LPS-induced IP-10 mRNA was unaffected by IFN-gamma under identical experimental conditions. This effect was cell type-specific because JE and KC mRNA expression in LPS-stimulated murine endothelial cells, TNF-alpha-stimulated endothelial cells, and NIH-3T3 cells were unaffected by IFN-gamma. The IFN-gamma-mediated suppression of LPS-stimulated KC mRNA expression was independent of protein synthesis and mediated at the transcriptional level. These observations indicate that IFN-gamma may function as a negative regulatory signal for the expression of some proinflammatory cytokines in macrophages. The cell type-dependent differential behavior of individual members of the chemokine family may be an important determinant of the cellular composition and outcome of an inflammatory response.
Ligand binding to monocyte alpha 5 beta 1 integrin activates the alpha 2 beta 1 receptor via the alpha 5 subunit cytoplasmic domain and protein kinase C.
Authors: Pacifici R , Roman J , Kimble R , Civitelli R , Brownfield C M , Bizzarri C 
Published: December 2022

Abstract
Regulation of the functional status of integrin receptors plays a critical role in inflammation and tissue remodeling, as it affects cell adherence and cytokine secretion. We have previously shown that in monocytes the binding of collagen to the alpha 2 beta 1 integrin induces the release of IL-1, an event that is potentiated by binding of fibronectin (Fn) to the alpha 5 beta 1 integrin. In this study, we have investigated the mechanisms leading to this phenomenon. Fn binding to alpha 5 beta 1 induced intracellular signals which increased the alpha 2 beta 1-dependent adhesiveness of monocytes to collagen without modifications of alpha 2 beta 1 expression. By using Abs against the intracellular region of the alpha 5 subunit of the alpha 5 beta 1 receptor, and specific inhibitors of protein kinase C (PKC), we found that the potentiation effect of Fn on monocyte IL-1 production and their adherence to collagen was dependent on an intact alpha 5 subunit cytoplasmic domain, and required PKC activation. Although the alpha 2 beta 1 could be activated by several intracellular second messengers, including protein kinase A and intracellular calcium, the potentiating effect of Fn was mediated only by PKC. These data provide an example of a novel regulatory mechanism: potentiation of beta 1 integrin-mediated events as a result of ligand binding to another integrin of the same class. They also show that the intracellular region of alpha 5 beta 1 plays a critical role in transducing signals generated by ligand binding to alpha 5 beta 1.
Cytokine profile and ultrastructure of intraepithelial gamma delta T cells in chronically inflamed human gingiva suggest a cytotoxic effector function.
Authors: Lundqvist C , Baranov V , Teglund S , Hammarström S , Hammarström M L 
Published: December 2022

Abstract
We have shown that gamma delta T cells in human gingiva have an intraepithelial location and, that in the chronic inflammatory disease periodontitis, the expression of CD45RO and CD8 or CD4 is induced on gamma delta T cells. To study the role of gamma delta T cells in local antibacterial responses, we determined the cytokine profiles of isolated human gingival cells. Different T cell subpopulations, isolated by positive selection with mAb-coated magnetic beads and macrophages, as well as epithelial cells, were analyzed for expression of mRNA for 15 cytokines by reverse transcriptase-PCR. The ultrastructure of gingival gamma delta T cells was also studied. The gamma delta T cells expressed mRNA for IFN-gamma, TNF-alpha, TGF-beta 1, and IL-6. Expression of IFN-gamma was a consequence of inflammation. CD4+ gamma delta T cells expressed IFN-gamma only, whereas CD8+ gamma delta T cells expressed all four cytokines. CD8+ cells expressing IFN-gamma, TNF-alpha, and IL-6 in combination suggest a cytotoxic effector function. Gingival gamma delta T cells contained cytoplasmic electron-dense membrane-bound granules and multivesicular bodies that are ultrastructural characteristics of cytotoxic cells. Epithelial cells from inflamed gingiva expressed HLA-DR, CD1a, CD1c, and heat shock protein 60 on the cell surface. They also expressed mRNA for IL-1 beta, IL-6, IL-8, TNF-alpha, and TGF-beta 1. Thus, epithelial cells may function as accessory cells in immune activation and, at the same time, be target cells for CD8+ gamma delta T cells reactive with CD1 Ag or heat shock protein. These results suggest that gamma delta T cells constitute a first line of defense in gingiva, preventing entrance of pathogens by cytotoxicity against infected and stressed epithelial cells, and by control of epithelial cell growth through secretion of regulatory cytokines.
Adult onset immunodeficiency caused by inherited adenosine deaminase deficiency.
Authors: Shovlin C L , Simmonds H A , Fairbanks L D , Deacock S J , Hughes J M , Lechler R I , Webster A D , Sun X M , Webb J C , Soutar A K 
Published: December 2022

Abstract
Adenosine deaminase (ADA) deficiency is identified here as a cause of adult onset immunodeficiency. Two sisters who noted recurrent, predominantly chest infections in their twenties were found in their thirties to have CD4+ lymphopenia and lymphocyte ADA activity of approximately 5% of the lower limit of normal. Immune function, measured by proliferation of PBMCs in vitro to mitogens and specific Ags, was impaired. Inheritance of a polymorphic marker showed that both patients were heterozygous at the ADA locus. In the paternal allele there was a deletion resulting from homologous recombination between two alu elements that normally flank the first exon and the polymorphic marker. The recombination site was distinct from that in similar deletions described in two infants having severe combined immunodeficiency. This allele is predicted to result in a null phenotype. In the mutant allele inherited from the mother, a C to T transition in a CpG dinucleotide changed the codon for arginine 211, which lies in a conserved sequence close to the active site, to that for cysteine. This mutation has been observed previously in a child in whom the other allele was also a null mutation, but who was diagnosed as having partial ADA deficiency because immune function was apparently normal. The late onset of immunodeficiency in our patients suggests that immune function in children with partial ADA deficiency may deteriorate with time and that ADA deficiency should be regarded as a possible cause of adult onset immune dysfunction of unknown etiology.
IFN-gamma prevents Th2 cell-mediated pathology after neonatal injection of semiallogenic spleen cells in mice.
Authors: Donckier V , Abramowicz D , Bruyns C , Florquin S , Vanderhaeghen M L , Amraoui Z , Dubois C , Vandenabeele P , Goldman M 
Published: December 2022

Abstract
BALB/c mice injected at birth with 10(8) (A/J X BALB/c)F1 hybrid spleen cells develop an autoimmune host-vs-graft (HVG) disease as a result of activation of donor B cells by host CD4+ cells. The antidonor CD4+ cells seem to be Th2-like cells, inasmuch as they are profoundly deficient in IL-2 and IFN-gamma production, but secrete high levels of IL-4 and IL-10. As IFN-gamma is known to inhibit the development of TH2 cells, we attempted to modulate HVG disease by injecting rIFN-gamma. First, we found that 10 micrograms of rIFN-gamma given on days 1 and 3 after birth reduced the serum hyper-IgE of HVG mice by 90% and the serum hyper-IgG1, by 70%. In addition, rIFN-gamma administration significantly decreased the anti-DNA IgG1 titers and prevented the occurrence of anti-glomerular basement membrane and anti-laminin IgG1 Abs as well as the formation of immune deposits in renal glomeruli. These effects were not caused by the abrogation of chimerism, as indicated by the persistence of donor-type B cells in lymph nodes and of Igs bearing donor allotype in serum. MLC experiments indicated that the major effect of early rIFN-gamma administration was to restore the production of IL-2 and IFN-gamma by donor-specific T cells while these cells still secreted significant amounts of IL-4 and IL-10. Unresponsiveness of antidonor cytolytic T cells was not influenced by rIFN-gamma. We conclude that rIFN-gamma prevents the TH2-type response induced by the neonatal injection of semiallogeneic spleen cells and the associated pathology.
Activation and serine phosphorylation of the p56lck protein tyrosine kinase in response to antigen receptor cross-linking in B lymphocytes.
Authors: Gold M R , Chiu R , Ingham R J , Saxton T M , van Oostveen I , Watts J D , Affolter M , Aebersold R 
Published: December 2022

Abstract
We show that cross-linking the B cell AgR with anti-Ig Abs activates p56lck (Lck) in both the immature B cell line WEHI-231 and mature resting B cells from mouse spleen. Anti-Ig-stimulated Lck activity peaked after 1 to 2 min, but remained elevated for at least 15 min. Consistent with the proposed role for src family tyrosine kinases in AgR signaling, we found that Lck could phosphorylate the cytoplasmic tails of the Ig-alpha and Ig-beta components of the B cell AgR in vitro. Lck phosphorylated both of the tyrosines in the Ig-beta AgR homology motif and one of the two tyrosines in the Ig-alpha AgR homology motif. Finally, we show that AgR ligation in B cells caused a significant portion of the Lck to migrate with an apparent molecular mass of 60 kDa on SDS-PAGE gels. Conversion of p56lck to p60lck was maximal at 5 to 15 min, at which times Lck activity in the cells was decreasing. This Lck "band shift" has been observed previously in activated T cells and correlates with phosphorylation of Lck at serine 59. We show that the 60-kDa form of Lck induced by AgR cross-linking in B cells is also phosphorylated at serine 59. Phosphorylation of Lck at this site in vitro decreases its activity. Thus, in B cells, AgR cross-linking activates Lck and subsequently activates a kinase that phosphorylates Lck at serine 59, a potential negative regulatory site.
Developmentally ordered appearance of a functional Fc gamma receptor on TCR V gamma 3 thymocytes. Evidence for stimulation-induced expression.
Authors: Leclercq G , Plum J 
Published: December 2022

Abstract
In the present report, we show that the Fc gamma receptor (Fc gamma R) becomes expressed on mature TCR V gamma 3 thymocytes, but it is absent on immature TCR V gamma 3 cells. Both Fc gamma RIII are Fc gamma RIII are expressed. The in vivo expression of the Fc gamma R on mature TCR V gamma 3 thymocytes coincides with an activated phenotype of the cells. In vitro, anti-CD3 stimulation of Fc gamma R-negative, immature TCR V gamma 3 thymocytes results in the expression of the Fc gamma R. The Fc gamma R of short-term IL-2-cultured, mature TCR V gamma 3 thymocytes is functional in an Ab-mediated cytotoxicity assay. In addition, it is shown that cross-linking of the Fc gamma R induces an increase in cytoplasmic Ca2+. Collectively, our findings show that mature TCR V gamma 3 thymocytes express a functional Fc gamma R; evidence is presented that this could be a result of in vivo activation of these cells.