bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultraviolet light suppresses IFN-gamma-induced IL-7 gene expression in murine keratinocytes by interfering with IFN regulatory factors.
Authors: Aragane Y , Schwarz A , Luger T A , Ariizumi K , Takashima A , Schwarz T 
Published: December 2022

Abstract
UV light is a potent stimulus for keratinocytes to release several cytokines. Recently, UV light was shown to inhibit keratinocyte release of IL-7, a growth factor for dendritic epidermal T cells. Since to date IL-7 is the only keratinocyte-derived cytokine down-regulated by UV light, we addressed the molecular mechanisms involved. IFN-gamma treatment of the murine keratinocyte cell line Pam 212 resulted in an up-regulation of IL-7 mRNA, while IL-7 transcripts were suppressed in cells exposed to UV before IFN-gamma. Because IFN-gamma induces IL-7 via activation of an IFN-stimulated response element (ISRE) located in the 5' upstream region of the IL-7 gene, bandshift assays were performed using the ISRE sequence from the IL-7 gene. Nuclear extracts from untreated cells revealed two bands, a slower migrating band identified by supershift analysis as IFN regulatory factor-2 (IRF-2), a transcriptional repressor, and a more rapidly migrating band identified as IRF-1, a transcriptional activator. IFN-gamma significantly induced IRF-1 binding, whereas UV treatment plus IFN-gamma decreased IRF-1 binding, suggesting that UV light suppresses IFN-gamma-induced expression of IL-7 by interfering with IRF-1. Chloramphenicol transferase assay confirmed functional relevance, showing that the minimal promoter sequence for the ISRE explicitly responded to IFN-gamma, which was suppressed by UV irradiation. Northern blot analysis using an IRF-1 cDNA probe revealed that UV light reduced IFN-gamma-induced IRF-1 mRNA. This study demonstrates that UV light can inhibit cytokine activities by interference with transcriptional activators. This newly described ability of UV light may contribute to its immunosuppressive properties.
A TCR V alpha CDR3-specific motif associated with Lewis rat autoimmune encephalomyelitis and basic protein-specific T cell clones.
Authors: Buenafe A C , Tsu R C , Bebo B , Bakke A C , Vandenbark A A , Offner H 
Published: December 2022

Abstract
To investigate TCR V alpha gene expression in the Lewis rat model of experimental autoimmune encephalomyelitis, we obtained V alpha chain sequences from two V beta8.2+-encephalitogenic, BP72-89-specific T cell clones. Two different V alpha genes, a V alpha2 gene and a V alpha23 gene, are utilized, but both were found to contain an asparagine repeat (Asn3+) sequence present in the V alpha CDR3 region. This Asn3+ motif is also present in the previously reported sequence of a BP68-88-specific hybridoma, 510, which utilizes a different V alpha2 gene family member. In further experiments, spinal cord T cells were isolated at the onset of basic protein (BP)-induced disease and sorted for the OX-40 activation marker, which we have previously used to enrich for specifically activated T cells. Analysis of V alpha expression in the OX-40+ population revealed the biased use of three V alpha genes, V alpha1, V alpha2, and V alpha23. The Asn3+ motif was present in the V alpha CDR3 region of V alpha1, V alpha2, and V alpha23 cDNA derived from OX-40+ spinal cord T cells but found to be generally absent in the OX-40- spinal cord population. Since these Asn3+ motif-bearing V alpha chain sequences are nearly identical to those utilized by the BP-specific encephalitogenic clones described, it is likely that these V alpha sequences are derived from disease-associated T cells in the spinal cord. Thus, we demonstrate that the Asn3+ V alpha CDR3 motif is strongly associated with experimental autoimmune encephalomyelitis in the Lewis rat and propose that it plays a role in TCR recognition of a specific BP peptide/MHC complex.
Concomitant killing in vitro of both gp120-coated CD4+ peripheral T lymphocytes and natural killer cells in the antibody-dependent cellular cytotoxicity (ADCC) system.
Authors: Jewett A , Cavalcanti M , Giorgi J , Bonavida B 
Published: December 2022

Abstract
NK cells play an important immunoregulatory role in first line defense mechanisms against infection. As disease progresses, HIV-1 infected patients show loss of NK cytotoxic function, down-modulation and/or loss of expression of both CD16 and CD56 surface Ags on NK cells and a gradual loss of both CD4+ T cells and NK cell numbers. A potential mechanism by which these manifestations may occur in vivo was investigated. We hypothesized that NK-mediated Ab-dependent cellular cytotoxicity (ADCC), using gp120-coated CD4+ peripheral T lymphocytes as targets and anti-HIV serum, will result in the concomitant killing of the CD4+ T lymphocyte targets and the NK lymphocytes. This hypothesis was examined in an in vitro model system. The findings demonstrate that gp120-coated peripheral T lymphocytes can serve as targets and are killed in ADCC. Further, the NK cells that recover from the ADCC reaction show a loss of cytotoxic function, acquire the CD16(dim/-) CD56(dim/-) phenotype and a significant fraction is killed by activation-induced cell death or apoptosis. These findings are reminiscent of the properties of circulating NK cells in HIV-infected patients. The implication of these findings in the pathogenesis of AIDS is discussed.
Corticosteroids inhibit IL-12 production in human monocytes and enhance their capacity to induce IL-4 synthesis in CD4+ lymphocytes.
Authors: Blotta M H , DeKruyff R H , Umetsu D T 
Published: December 2022

Abstract
We examined the effects of corticosteroids on IL-12 production by human monocytes and on cytokine synthesis in T cells. To distinguish the effects of corticosteroids on the APC used to activate the T cell from direct effects of corticosteroids on the T cell, experiments were performed by exposing the APC and not the T cell to corticosteroids. We found that corticosteroids significantly inhibited the production in monocytes of IL-12, a cytokine that is extremely potent in enhancing IFN-gamma and inhibiting IL-4 synthesis in T cells. We demonstrated that reduced production of IL-12 in corticosteroid-treated monocytes resulted in a decreased capacity of the monocytes to induce IFN-gamma and an increased ability to induce IL-4 in T cells. These results suggest that although corticosteroids may be beneficial for the treatment of asthma or allergic disease due to direct inhibitory effects of corticosteroids on cytokine synthesis in T cells, chronic corticosteroid therapy may indirectly exacerbate the long-term course of allergic disease. This deleterious effect of corticosteroids would result from a limitation in IL-12 production in tissue monocytes and macrophages, which would enhance production of Th2 cytokines (which augment allergic disease), and would reduce production of Th1 cytokines (which attenuate allergic disease) in T cells that subsequently infiltrate the tissues.
Streptococcal preparation OK-432 is a potent inducer of IL-12 and a T helper cell 1 dominant state.
Authors: Fujimoto T , Duda R B , Szilvasi A , Chen X , Mai M , O'Donnell M A 
Published: December 2022

Abstract
Streptococcal preparation OK-432 is a bacterial immunopotentiator extensively used in Japan for adjuvant cancer therapy. Using a C57BL/6 mouse model, OK-432 was found to induce multiple cytokines including the Th1 polarizing cytokine IL-12. Expression of IL-12 protein by murine splenocytes was restricted to macrophages and B cells and led to high levels of IFN-gamma production from both CD4+ and CD8+ T cells. Of the Th2 cytokines IL-4 and IL-10, only IL-10 protein was detected and originated primarily from the adherent cell population. Its expression was delayed relative to IL-12. A similar pattern of cytokine induction was observed from human PBMCs. OK-432-driven IFN-gamma production was inhibited by anti-IL-12 Ab, anti-IL-2 Ab, anti-TNF-alpha Ab, and anti-IL-2R alpha Ab, suggesting that IFN-gamma production from Th1 cells is induced by the cooperation action of these cytokines through the IL-2R alpha pathway. When compared with another widely used immunopotentiator bacillus Calmette-Guérin (BCG), OK-432 was a stronger IL-12 and IFN-gamma inducer. Furthermore, the mechanism of IFN-gamma induction by OK-432 differed from BCG in that coincident granulocyte-macrophage CSF and IL-1 expression played little to no role. These results suggest that OK-432 is a potent multicytokine inducer, specifically a strong inducer of IL-12, and that OK-432 may exert its antitumor effect by promoting a Th1-dominant state.
Evidence for self and nonself peptide partial agonists that prolong clonal survival of mature T cells in vitro.
Authors: Matsushita S , Kohsaka H , Nishimura Y 
Published: December 2022

Abstract
When examining the effects of peptide analogues without proliferation-inducing activity on three human CD4+ T cell clones with distinct TCRbeta recognizing a nonself mycobacterial bacillus Calmette-Guerin a (BCGa) peptide fragment (EEYLILSARDVLAVVSK)/HLA-DR14 complex, we found that 1) stimulation of T cells with a one-residue-substituted analogue or a minimally homologous self peptide fragment derived from human connexin 26 (IMILVVAAKEVWGDEQA) can prolong the in vitro survival of T cells, in a clone specific-manner; 2) this prolongation is associated with the up-regulation of Bcl-xL without proliferation; and 3) these peptide-clone combinations are capable of inducing lymphokine secretion. Thus, peptide partial agonism may play a role in the survival of not only thymocytes but also mature T cells, in the absence of wild-type ligands.
IL-6 rescues resting mouse T cells from apoptosis.
Authors: Teague T K , Marrack P , Kappler J W , Vella A T 
Published: December 2022

Abstract
It has previously been demonstrated that mature mouse T cells live for many weeks in vivo. In contrast, explanted lymph node or splenic T cells undergo spontaneous death within days, suggesting that survival factors supplied in vivo are not present in normal tissue culture medium. We discovered that IL-6 can rescue resting T cells from apoptosis in vitro. We show that recombinant mouse IL-6 as well as IL-6 in endothelial cell supernatants are sufficient to rescue T cells from death in the absence of additional cytokines. We show that CD4+ T cells express Bcl-2 immediately following isolation from the mouse, but after 24 h in culture Bcl-2 is undetectable. If during this time period the T cells are incubated with rIL-6, Bcl-2 expression is not down-regulated. It is, therefore, possible that IL-6 rescue from death is mediated by maintenance or induction of Bcl-2 expression. Addition of rIL-6 does not by itself induce blastogenesis or proliferation, and therefore, this cytokine appears to be a true survival factor rather than a mitogenic factor for resting T cells. Together, these results support a potential role for IL-6 as one of the factors important for prolonging resting T cell survival in vivo.
A naturally processed peptide presented by HLA-A*0201 is expressed at low abundance and recognized by an alloreactive CD8+ cytotoxic T cell with apparent high affinity.
Authors: Wang W , Gulden P H , Pierce R A , Shabanowitz J , Man S T , Hunt D F , Engelhard V H , Shabanowitz J A 
Published: December 2022

Abstract
In contrast to T cells that respond to peptides presented by self MHC molecules, alloreactive T cells recognize determinants expressed on nonself MHC molecules. Because current positive selection models suggest that T cell affinity toward a nonself MHC molecule would be lower than that toward a self MHC molecule, we previously proposed that vigorous alloreactive responses would be generated preferentially toward those antigenic peptide complexes presented at the highest density on the cell surface. The high abundance of two class I MHC-associated peptides that have been identified as allo- or xenoantigens is consistent with this hypothesis. We report here the identification of a naturally processed peptide YLDPAQQNL that is presented by HLA-A*0201 and recognized by an alloreactive T cell clone. This peptide appears to originate from an unknown member of the zinc finger proteins. Quantitation by mass spectrometry indicates that this peptide is present on the surface at 85 to 125 copies per cell, comparable with the density of several other epitopes presented by HLA-A*0201 to self MHC-restricted T cells. In addition, based on the affinity of the peptide for HLA-A*0201 and the half-maximal peptide concentration required for T cell sensitization, this alloreactive T cell appears to have an affinity similar to or higher than that of many self MHC-restricted T cells. These data suggest that allogeneic responses can be directed against antigenic determinants of low abundance and that recognition of alloreactive peptides is not limited by a lower affinity of T cells for nonself MHC molecules.
Glycosylphosphatidylinositol-anchored mucin-like glycoproteins isolated from Trypanosoma cruzi trypomastigotes initiate the synthesis of proinflammatory cytokines by macrophages.
Authors: Camargo M M , Almeida I C , Pereira M E , Ferguson M A , Travassos L R , Gazzinelli R T 
Published: December 2022

Abstract
Components of Trypanosoma cruzi able to induce the production of IL-12 and other proinflammatory cytokines by macrophages were identified. Murine inflammatory macrophages were cultured with live parasites or with cellular components from different developmental forms of T. cruzi (i.e., trypomastigotes, amastigotes, metacyclic trypomastigotes, and epimastigotes), and the cytokine levels were measured after 24 and 48 h. Our results indicate that live trypomastigotes or live amastigotes (but not live epimastigotes or live metacyclic trypomastigotes) as well as trypomastigote extracts (but not extracts derived from epimastigotes) induce IL-12 and TNF-alpha synthesis by macrophages. Such biological activity is enhanced in membrane preparations from trypomastigotes. Further enrichment of the trypomastigote-derived monokine-inducing factor was obtained by solvent extraction and hydrophobic-interaction chromatography. The resultant purified molecules are a family of closely related glycoconjugates with predominant species at 70 to 80 and 120 to 200 kDa. These molecules are composed of carbohydrate chains O-linked to a polypeptide backbone that is anchored to the trypomastigote membrane via a glycosylphosphatidylinositol structure. The trypomastigote-derived glycoconjugates are active in inducing cytokine synthesis by macrophages at concentrations of 100 ng/ml. These effects are highly potentiated by IFN-gamma. Mapping of the glycoconjugate molecules to characterize the structural requirements for macrophage activation suggested that nonsaturated acyl fatty acid chains and periodate-sensitive units from the glycosylphosphatidylinositol anchor are important elements for the infective trypomastigote form to initiate cytokine synthesis by macrophages.
The differential ability of IL-8 and neutrophil-activating peptide-2 to induce attenuation of chemotaxis is mediated by their divergent capabilities to phosphorylate CXCR2 (IL-8 receptor B).
Authors: Ben-Baruch A , Grimm M , Bengali K , Evans G A , Chertov O , Wang J M , Howard O M , Mukaida N , Matsushima K , Oppenheim J J 
Published: December 2022

Abstract
IL-8 and neutrophil-activating peptide-2 (NAP-2) are two closely related C-X-C chemokines that differ in their abilities to induce chemotaxis of human polymorphonuclear leukocytes (PMN). Although two IL-8R types are expressed by PMN, only CXCR2 binds NAP-2 and IL-8 with equally high affinity. By using enriched CXCR2-transfected 293 cells, we show that high doses of IL-8 induce attenuation of chemotaxis, while equivalent doses of NAP-2 do not. Phosphorylation analysis shows that IL-8 induces higher levels of phosphorylation of the carboxyl terminus of CXCR2 than does NAP-2, suggesting that the level of phosphorylation contributes to the ability of the chemokines to attenuate the chemotactic response. To directly evaluate this difference, we analyzed the ability of receptors mutated to delete regions that highly express potential phosphorylation sites to be phosphorylated and to mediate chemotactic attenuation. We found that a carboxyl terminus-truncated mutant of CXCR2 was not phosphorylated by high doses of IL-8, as determined by in vivo phosphorylation assays and by analysis of the electrophoretic mobility of the receptors on SDS-PAGE gels. This mutated receptor had a significantly lower ability to attenuate IL-8-induced chemotaxis, indicating that the attenuation of chemotaxis is mediated by chemokine-induced receptor phosphorylation. In conclusion, the data show that the greater ability of IL-8 to induce receptor phosphorylation contributes to its more potent attenuation of chemotaxis as compared with NAP-2. This differential phosphorylation by IL-8 and NAP-2 of CXCR2 provides a basis for the divergent outcome of PMN-induced inflammation in response to these two closely related C-X-C chemokines.
Increased acute-phase response and renal amyloidosis in aged CD2-fas-transgenic mice.
Authors: Hsu H C , Zhou T , Yang P A , Herrera G A , Mountz J D 
Published: December 2022

Abstract
We previously demonstrated that increased Fas expression in T cells of aged CD2-fas transgenic (Fas-Tg) CD-1 mice results in an increased immune response and T cell apoptosis. Surprisingly, despite prevention of T cell immune senescence, the average life span of Fas-Tg mice is comparable with that of nontransgenic (non-Tg) mice. Histopathologic evaluation of tissue sections showed that nearly 50% of the aged (&gt;18-mo-old) Fas-Tg mice developed renal amyloid A amyloidosis, whereas no amyloid deposition was observed in aged non-Tg mice. The amyloid A deposition was observed primarily in glomeruli by using immunohistochemical stains and electron microscopy. The full-length amino acid coding sequence of serum amyloid A2 cDNA in CD-1 mice was identical to that of amyloid A amyloidosis-susceptible BALB/c mice. Although there was no significant difference in steady-state serum amyloid A level in the serum of aged non-Tg and Fas-Tg mice, challenging mice with staphylococcal enterotoxin B resulted in significantly higher serum levels of serum amyloid A on day 2 and IL-6 on days 1 and 2 and a higher magnitude of weight loss on day 7 in aged Fas-Tg mice compared with young mice. These parameters, at the indicated time points, were equivalent between young and aged non-Tg mice. Taken together, our data suggest that prevention of T cell senescence in Fas-Tg mice may be a factor in induction of an excessive acute-phase response triggered by T cell activation. The Fas-Tg mice are a novel model for understanding the immunologic mechanisms leading to secondary amyloidosis.
The IL-4-induced tyrosine phosphorylation of the insulin receptor substrate is dependent on JAK1 expression in human fibrosarcoma cells.
Authors: Wang H Y , Zamorano J , Yoerkie J L , Paul W E , Keegan A D 
Published: December 2022

Abstract
It has been shown that IL-4 induces the tyrosine phosphorylation of JAK1 and JAK3 in the majority of hemopoietic cell types, and JAK2 and TYK2 in several other types. However, the significance of this tyrosine phosphorylation in regulating IL-4 signaling has not been shown. To determine whether JAKs play a role in activating a signal transduction pathway different from the classical JAK/STAT pathway, we analyzed the ability of huIL-4 to stimulate the tyrosine phosphorylation of one of its major cellular substrates, the insulin receptor substrate (IRS). Using human fibrosarcoma cell lines with mutations in JAK1, JAK2, and TYK2, we found that expression of functional JAK1, but not TYK2 or JAK2, is essential for IL-4-induced tyrosine phosphorylation of IRS. We also provide evidence that the IRS pathway is independent of STAT-6, showing that JAK1 is essential for activating a STAT-independent pathway.
T cell adhesion to P-selectin induces tyrosine phosphorylation of pp125 focal adhesion kinase and other substrates.
Authors: Haller H , Kunzendorf U , Sacherer K , Lindschau C , Walz G , Distler A , Luft F C 
Published: December 2022

Abstract
Lymphocyte binding to endothelial surface adhesion molecules is an important early step in inflammation, which is mediated initially by P-selectin and E-selectin. We tested the hypothesis that lymphocyte binding to the selectin adhesion molecules induces intracellular signaling by tyrosine phosphorylation. We used an adhesion assay, which relied on cell binding to chimeric proteins consisting of the extracellular domains for P-selectin and E-selectin. Tyrosine phosphorylation was determined using anti-phosphotyrosine Abs by confocal microscopy and Western blot. Binding to P-selectin induced a significant increase in anti-phosphotyrosine immunoreactivity. The P-selectin effect was time dependent with an early response after 10 min and a maximum effect at 30 min. Western blot showed a time-dependent phosphorylation of two distinct 68- and 125-kDa proteins. These proteins were pp125 focal adhesion kinase (FAK) and paxillin, as shown by immunoprecipitation and colocalization. Phosphorylation of pp125 FAK was time dependent reaching a maximum after 30 min. Incubation with the tyrosine kinase inhibitor genistein, and, to a lesser extent, with the protein kinase C inhibitor staurosporine, resulted in decreased pp125 FAK phosphorylation. Our results are the first to demonstrate that lymphocyte binding to P-selectin induces tyrosine phosphorylation of distinct proteins. Thus, lymphocyte activation may occur already at the initial contact with surface adhesion molecules.
Fc(gamma) receptor cross-linking induces peripheral blood mononuclear cell monocyte chemoattractant protein-1 expression: role of lymphocyte Fc(gamma)RIII.
Authors: Marsh C B , Wewers M D , Tan L C , Rovin B H 
Published: December 2022

Abstract
Immune complexes activate cells by cross-linking leukocyte surface Fc(gamma)Rs. Diseases associated with immune complex deposition, such as rheumatoid arthritis, glomerulonephritis, or idiopathic pulmonary fibrosis, are characterized by compartmentalized monocyte infiltration. The factors that recruit monocytes to these compartments are not well characterized; however, monocyte chemoattractant protein-1 (MCP-1) has been found in areas of tissue injury. To account for these observations we hypothesized that PBMC Fc(gamma)R cross-linking may induce MCP-1 synthesis, which stimulates further monocyte recruitment. To test this hypothesis, PBMC were incubated on increasing concentrations of immobilized human IgG, a stimulus for Fc(gamma)R cross-linking. Immunoreactive MCP-1 was produced in a dose-dependent manner (p &lt; 0.0001). MCP-1 was specifically induced by Fc(gamma)R cross-linking, since immobilized F(ab')2 fragments of human IgG did not activate MCP-1 production. This effect was reproduced by directly cross-linking PBMC Fc(gamma)RIII, but not by cross-linking Fc(gamma)RI or Fc(gamma)RII. PBMC-derived MCP-1 stimulated monocyte chemotaxis that was inhibited by a neutralizing anti-MCP-1 Ab. MCP-1 levels correlated with increased PBMC mRNA expression. Interestingly, Fc(gamma)R cross-linking with either immobilized IgG or anti-Fc(gamma)RIII induced more MCP-1 release from PBMC than from autologous monocytes (p = 0.02). Lymphocytes, the main cell type found in PBMC preparations, did not independently produce a significant amount of MCP-1, but when incubated on immobilized IgG or anti-Fc(gamma)RIII secreted a soluble factor(s) that induced monocyte MCP-1 production. These data suggest that cross-linking PBMC Fc(gamma)R induces the production of bioactive MCP-1. This occurs in part at the level of gene transcription and involves a cooperative interaction between monocytes and lymphocytes.