bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD45-cross-linking stimulates IFN-gamma production in NK cells.
Authors: Shen F , Xu X L , Graf L H , Chong A S 
Published: December 2022

Abstract
The in vitro demonstration of the ability of NK cells to secrete cytokines prompted in vivo studies that illustrated the importance of NK cell-derived cytokines in regulating immune responses. Cross-linking of CD16 on NK cells can stimulate cytokine production. CD16-independent interactions capable of stimulating cytokine production have also been described, but molecules mediating such stimulations remain to be biochemically defined. We report here that cross-linking of CD45 specifically stimulates IFN-gamma production in human NK cells. The NK cells used were IL-2-activated adherent NK cells and from the NK3.3 cell line. The ability of CD45 mAbs to stimulate NK cells appears not to be dependent on CD16, as CD45 mAbs of both IgG1 and IgG2a isotypes were equally stimulatory, as were F(ab')2 compared with whole anti-CD45 mAbs. Resting NK cells, like T cells, express predominantly CD45RA, whereas IL-2 activated adherent NK cells acquire expression of CD45RO. Abs specific for CD45RO, but not CD45RA, were able to stimulate IFN-gamma production in NK cells. It has been reported that one ligand for CD45RO is CD22 beta. We tested the ability of CD22-expressing transfectants to bind to and stimulate NK cells. Whereas NK cells bound to CD22 alpha and CD22 beta transfectants, this interaction was not inhibited by CD45RO Abs. In addition, neither of the CD22-transfectants were able to stimulate NK3.3 cells to secrete IFN-gamma. These observations collectively suggest that binding of NK3.3 cells to CD22 may be independent of CD45RO on NK3.3 cells.
Cis-acting DNA elements of mouse granulocyte-macrophage colony-stimulating factor gene responsive to Fc epsilon receptor cross-linking stimulation in the mouse mast cell line MC/9.
Authors: Nishikomori R , Kawai M , Jung E Y , Tai G , Miyajima A , Arai N , Mayumi M , Heike T 
Published: December 2022

Abstract
Mouse mast cells produce many kinds of cytokines in response to cross-linking of high affinity Fc epsilon receptor (Fc epsilon RI). Among these cytokines, granulocyte-macrophage CSF (GM-CSF) gene induction in mouse mast cells has been reported to be regulated at both the transcriptional level and the post-transcriptional level. We analyzed the mechanism of the transcriptional regulation of GM-CSF gene induction through Fc epsilon RI cross-linking stimulation in the mouse mast cell line MC/9. In MC/9, the GM-CSF gene was activated transcriptionally by Fc epsilon RI cross-linking stimulation. The 5' deletion analysis of GM-CSF gene promoter indicated that the 5' boundary of the responsive promoter region lay between positions -113 and -95. When the deletion was extended to positions -72 or -60, the stimulatory effect was significantly diminished. We then examined 3' deletion of pmGMCAT -113 from position -60. This analysis indicated that the 3' boundary lay between positions -84 and -72. No subfragments of the region spanning positions -113 to -72 could cover the full induction level. A site-directed mutagenesis experiment revealed that the sequence spanning positions -108 to -72 was needed for full activation. These data indicate that GM-CSF gene in mast cells is activated mainly through the sequence spanning positions -108 to -72.
HLA-A*0201 complexes with two 10-Mer peptides differing at the P2 anchor residue have distinct refolding kinetics.
Authors: Robbins P A , Garboczi D N , Strominger J L 
Published: December 2022

Abstract
The immune response to viruses partially depends on the biochemical interaction between viral peptides and histocompatibility molecules. In this study, the refolding of recombinant HLA-A*0201 heavy chain and beta 2-microglobulin (beta 2-m) in the presence of peptides from influenza B nucleoprotein (BNP), influenza A matrix protein, and HIV gp120 and their analogues was examined. The plateau value for the amount of refolded complex with three peptides, a 10-mer BNP 85-94 (A86) with alanine substituted for leucine at the P2 anchor residue and two BNP 8-mers, was significantly lower than the native peptide epitope BNP 85-94 or with other peptides tested. To attempt to understand the basis for the lower yield of complex, equilibrium dissociation constants (KdS) for the two 10-mers, BNP 85-94 (A86) and BNP 85-94, were determined from association and dissociation rates and from Scatchard plots, all measured at 10 degrees C. In addition, dissociation rates were measured at 0 degrees, 26 degrees, and 37 degrees C. Although the kinetics were similar at 0 degrees and 10 degrees, at 37 degrees these two complexes had distinct rates of dissociation, resulting in relatively stable or unstable complexes. The behavior of the unstable complexes paralleled the behavior of empty complexes described in vivo; they are unstable at physiologic temperature, produced in low yield, and stabilized by low temperature. Comparison of all of the kinetic data suggests that the equilibrium amounts of the two HLA/peptide complexes (plateau values) result from distinct reaction pathways, i.e., that the molecules that form stable complexes may undergo an additional reaction to those that form unstable complexes.
A cDNA clone coding for a novel allergen, Cla h III, of Cladosporium herbarum identified as a ribosomal P2 protein.
Authors: Zhang L , Muradia G , Curran I H , Rode H , Vijay H M 
Published: December 2022

Abstract
Mold allergens represent a major cause of atopic disorders. Progress in the molecular characterization of allergens has been hampered by batch-to-batch variation and poor yields in mold extracts. In the present study, we established a cDNA library in lambda ZAP II by using mRNA isolated from a major allergen-producing mold, Cladosporium herbarum. From this library, a novel allergen has been cloned and sequenced. The clone encodes a full length protein of 111 amino acids with a molecular mass of 11.1 kDa and pI of 3.94. By using sequence homology analysis, the allergen was found to belong to the ribosomal P2 protein family. Approximately 60% peptide sequence homology was found between the cloned protein and other known fungal ribosomal P2 proteins. In addition to conserved C-terminal sequences and serine blocks for phosphorylation in all eukaryotic ribosomal P2 proteins, this protein also contains a potential N-glycosylation site at position 15-17. Northern blots demonstrated that mRNA molecules of this gene are present even at late stages of culture. The gene was expressed in Escherichia coli by using the pMAL-2c system, and murine antisera against the recombinant allergen (rCh2.1) were generated. The antisera revealed that the native allergen corresponding to rCh2.1 was present in extracts prepared by grinding mycelia under liquid nitrogen in the presence of protease inhibitors, but absent in extracts prepared by conventional methods. This result indicates the usefulness of recombinant allergens in characterization and standardization of mold allergenic extracts.
Activation-induced CD4+ T cell death by apoptosis in experimental Chagas' disease.
Authors: Lopes M F , da Veiga V F , Santos A R , Fonseca M E , DosReis G A 
Published: December 2022

Abstract
Infection of mice with Trypanosoma cruzi, the causative protozoan agent of human Chagas' disease, leads to immunosuppression of the T cell compartment and to chronic cardiac inflammation which resembles the human infection. Recently, reinduction of programmed cell death by apoptosis in mature T cells has been demonstrated. It has been suggested that mature T cell apoptosis could play a role in immunosuppression caused by virus infection. In this report, we have investigated the occurrence of mature T cell apoptosis in murine experimental Chagas' disease. Infection with T. cruzi metacyclic forms led to a relative accumulation of CD8 T cells over CD4 T cells in the spleens of infected mice. Splenic T cells from T. cruzi-infected donors, but not from control littermates, died in vitro upon stimulation with T cell mitogens Con A and anti-TCR-alpha beta mAb in a dose-dependent fashion. DNA fragmentation into nucleosome-sized bands was detected in the supernatants of CD4+ T cells from infected origin, after stimulation with the T cell mitogen Con A. Upon in vitro stimulation with either anti-TCR-alpha beta or Con A, CD4+ T cells were susceptible to elimination, whereas CD8+ T cells were not. Splenic T cells from infected donors were markedly unresponsive to anti-TCR mAb in proliferative assays and underwent apoptosis in vitro, as assessed by electron microscopy. Apoptosis also occurred in vivo in the course of acute infection, as seen by DNA fragmentation in freshly explanted splenic cells and purified T cell subsets. The data indicate that activation-induced CD4+ T cell death by apoptosis is a prominent feature of experimental infection with T. cruzi, and could play a role in immunosuppression and parasite persistence in infected hosts.
Generation of tumor-specific CTLs from melanoma patients by using peripheral blood stimulated with allogeneic melanoma tumor cell lines. Fine specificity and MART-1 melanoma antigen recognition.
Authors: Stevens E J , Jacknin L , Robbins P F , Kawakami Y , el Gamil M , Rosenberg S A , Yannelli J R 
Published: December 2022

Abstract
PBLs were isolated from 13 patients with metastatic melanoma. Mixed lymphocyte tumor cell cultures (ML TCs) were established (15 times) by using irradiated HLA-matched (one class I locus) allogeneic melanoma tumor cell lines (13 times) or autologous melanoma tumor cell lines (two times) in medium containing 120 IU/ml IL-2 and 100 IU/ml IL-4. PBLs grew to levels that could be assessed for functional reactivity 9 of 15 times. In seven of nine cases, CD3+CD8+ CTLs grew from MLTCs that were tumor specific; five were restricted by HLA-A2 and two were restricted by HLA-A24. Four of the tumor-specific CTL lines lysed autologous fresh tumor cells. Tumor-specific CTLs from two of three patients had cytolytic activity identical with tumor-infiltrating lymphocytes (TIL) derived from tumor biopsies removed earlier and grown in high concentrations (6000 IU/ml) of IL-2. Three of the HLA-A2-restricted tumor-specific CTLs were shown to recognize 293 cells transfected with HLA-A2.1 cDNA and the gene encoding the melanoma Ag, MART-1. In addition, these CTLs recognized the T2 cell line pulsed exogenously with the peptide MART-1(27-35), which is the nine-amino acid immunodominant epitope of the MART-1 Ag recognized on melanoma tumor cells by nearly all HLA-A2-restricted TIL. Thus, we have demonstrated the ability to generate tumor-specific CTLs from PBLs that are similar in their reactivity to TIL. This technique obviates the need for autologous tumor tissue and suggests that PBLs contain sufficient CTL precursors for use in generating antitumor CTLs for cellular immunotherapy trials.
NK cell response to viral infections in beta 2-microglobulin-deficient mice.
Authors: Tay C H , Welsh R M , Brutkiewicz R R 
Published: December 2022

Abstract
Because class I MHC Ags have been implicated as modulators of target cell sensitivity to NK cell-mediated lysis, the regulation of virus infections and the fate of NK cells and their natural targets was examined in beta 2-microglobulin-deficient mice, which have defective class I MHC expression. Infections with either the NK cell-sensitive murine cytomegalovirus (MCMV) or the NK cell-resistant lymphocytic choriomeningitis virus (LCMV) significantly augmented NK cell activity in either C57BL/6 (+/+) or beta 2-microglobulin knockout (-/-) mice. Depletion of NK cells in vivo with antiserum to asialo-GM1 markedly enhanced the synthesis of MCMV but had no effect on the synthesis of LCMV in either strain of mouse. Analysis of naturally NK cell-sensitive thymocyte targets from these virus-infected -/- mice revealed no cell surface expression of class I MHC detectable by conformation-dependent or -independent Abs, but the virus infections enhanced class I expression on thymocytes from +/+ mice. The sensitivity of +/+ thymocytes to NK cell-mediated lysis was markedly reduced after in vivo poly inosinic:cytidylic and treatment or viral infection; in contrast, the sensitivity of the -/- thymocytes was significantly less affected by poly inosinic:cytidylic acid treatment or viral infection. These data indicate that the normal expression of class I MHC Ags on NK cells or their targets is not required for the antiviral functions of NK cells against a NK-sensitive virus (MCMV) nor do they protect a NK-resistant virus (LCMV) from the antiviral activity of NK cells.
IL-13 selectively induces vascular cell adhesion molecule-1 expression in human endothelial cells.
Authors: Bochner B S , Klunk D A , Sterbinsky S A , Coffman R L , Schleimer R P 
Published: December 2022

Abstract
Previous studies with human umbilical vein endothelial cells (HUVEC) have shown that the cytokine IL-4 induces adherence of human eosinophils, but not neutrophils, because of its ability to selectively induce surface expression of vascular cell adhesion molecule-1 (VCAM-1). Because the cytokine IL-13 shares a number of biologic properties with IL-4, we examined the effect of IL-13 on the expression and function of adhesion molecules on HUVEC. Incubation of HUVEC for 4 to 48 h with IL-13 (0.1 to 15 U/ml) induced surface expression of VCAM-1, as detected by indirect immunofluorescence and flow cytometry, without significantly affecting expression of E-selectin or intercellular adhesion molecule-1. The kinetics and maximal IL-13-induced expression of VCAM-1 were similar to those seen with IL-4. Treatment of HUVEC with an optimal concentration of IL-13 (15 U/ml for 24 h) induced adhesiveness for eosinophils, but not for neutrophils, and adhesion was completely inhibited by mAb recognizing VCAM-1 or alpha 4 integrin (CD49d). These results demonstrate that IL-13, like IL-4, selectively stimulates HUVEC to express functional cell surface VCAM-1 and suggest a possible role for IL-13 in promoting VCAM-1/alpha 4 integrin-dependent accumulation of eosinophils during allergic and other inflammatory reactions in vivo.
Complement component C7 is a plasminogen-binding protein.
Authors: Reinartz J , Hänsch G M , Kramer M D 
Published: December 2022

Abstract
Ab deposition, whether by reaction with the specific Ag or by preformed immune complexes, is followed by activation and deposition of complement components. Tissue destruction is observed in the Ab- and complement-induced lesions. The proteolytic enzyme plasmin is thought to participate in the Ab- and complement-mediated organ pathology. Plasmin is generated from plasma-derived plasminogen by cell-derived plasminogen activators (PAs). Two types of PAs are known, urokinase-type PA (uPA) and tissue-type PA (tPA). We investigated whether the PA system and the complement system can interact to promote local plasmin generation. Among the terminal complement components C5b6, C7, C8, and C9, the nonenzymatic component C7 is a plasminogen-binding protein. Radioligand binding studies revealed that the isolated component, as well as C7 after its incorporation into the terminal complement complex C5b-9, can bind plasminogen. Binding was inhibited by the lysine analogues 6-aminohexanoic acid and tranexamic acid, implicating the lysine binding sites of plasminogen into the binding interaction. tPA-mediated plasminogen activation was enhanced in the presence of C7. Based on these findings, an interaction is proposed between the complement system and the plasminogen activator system; a mechanism that may focus plasmin activity to structures that have been tagged by Ab and complement deposition.
Heparan sulfate initiates signals in murine macrophages leading to divergent biologic outcomes.
Authors: Wrenshall L E , Cerra F B , Singh R K , Platt J L 
Published: December 2022

Abstract
We have previously shown that the interaction of heparan sulfate (HS), a constituent of cell surfaces and extracellular matrices, with murine macrophages causes activation of the macrophages leading to the production of cytokines and PGE2 and profound changes in the cellular immune responses triggered by the macrophages. Here we describe the molecular mechanisms that underlie these immunoregulatory changes. We demonstrate that HS delivers signals to macrophages through at least two pathways, one involving the activation of a tyrosine kinase and of nuclear factor-KB, and the other involving the activation of protein kinase C and the elevation of intracellular calcium. The former pathway is associated with the production of IL-6, and the latter pathway is associated with the production of PGE2. Our findings suggest a model in which components of the microenvironment, such as HS, may determine the functional state of an APC, thereby modifying immune responses.
Synergistic effect of rapamycin and cyclosporin A in the treatment of experimental autoimmune uveoretinitis.
Authors: Martin D F , DeBarge L R , Nussenblatt R B , Chan C C , Roberge F G 
Published: December 2022

Abstract
Immunosuppressive drugs currently available for the treatment of autoimmune diseases display a narrow therapeutic window between efficacy and toxic side effects. The use of combinations of drugs that have a synergistic effect may expand this window and reduce the risk of toxicity. We evaluated the combination effect of rapamycin (Rapa) and cyclosporin A (CsA) in an autoimmune disease model of the eye. The dose-effect relationship of Rapa with CsA was measured in vitro on the inhibition of proliferation of retinal S-Ag-primed lymphocytes. A median effect analysis was performed and a combination index (CI) calculated for 50% inhibition of proliferation. Rapa and CsA were markedly synergistic over a wide dose range (lowest CI = 0.31). Calculated dose reduction factors indicated that Rapa could be reduced nine-fold and CsA reduced five-fold when these drugs were used in combination. These reduced doses were tested in vivo for the treatment of experimental autoimmune uveoretinitis (EAU). Twelve of 15 rats treated with CsA, 2 mg/kg/day, developed EAU with a median severity of 2.5. Fourteen of 15 rats treated with Rapa, 0.01 mg/kg/day, developed EAU with a median severity of 3.25. Complete inhibition of EAU was achieved in all 15 animals treated with the combination of Rapa and CsA (combined vs CsA alone, p &lt; 0.0002; combined vs Rapa alone, p &lt; 0.00001). The demonstrated synergistic relationship between Rapa and CsA will allow the use of reduced doses of each drug to achieve a therapeutic effect. The use of lower doses may reduce the toxicity of these drugs for the treatment of autoimmune uveitis.
In vitro transformation of murine pro-B and pre-B cells by v-mpl, a truncated form of a cytokine receptor.
Authors: Fichelson S , Vigon I , Dusanter I , Charon M , Velu T , Baillou C , Gisselbrecht S , Lemoine F M 
Published: December 2022

Abstract
v-mpl is a constitutively activated, truncated form of a cytokine receptor that has been transduced in a murine retrovirus, the myeloproliferative leukemia virus (MPLV). Expression of this oncogene results in the factor-independent proliferation of myeloid, erythroid, megakaryocytic, and mast precursor cells, which retain the ability to differentiate. However, no lymphoid disease was ever reported. To determine whether MPLV could infect and transform very early B cells and their precursors (BCPs), lymphoid long-term bone marrow cultures were infected with a helper-free MPLV. Within 3 wk after infection, highly proliferating BCPs could be isolated. These cells were able to clone spontaneously in semi-solid cultures, grown in the absence of feeder cell layer or exogenous growth factor and rapidly produced tumors after s.c. injection into synegic irradiated mice. In addition, MPLV transformation of pre-B cells led to the induction of an autocrine activity. Immunophenotypic and molecular analysis indicated that MPLV transformed early pro-B, pro-B, and pre-B cells, according to the expression of HSA, CD43, B220, Thy1, s-IgM and BP1 Ags, and to the rearrangements of Ig genes. Interestingly, MPLV-transformed BCPs expressed Mac1 Ag without acquiring further characteristics of macrophagic differentiation. Although the v-mpl cytoplasmic domain is devoid of tyrosine kinase consensus sequence, MPLV-transformed pre-B cells contained a major approximately 105-kDa tyrosine-phosphorylated protein that was not detected in uninfected cells or in cells transformed by the Abelson viral oncogene (v-abl). These results demonstrate that, like v-abl, the truncated cytokine receptor v-mpl is able to transform BCPs in vitro and suggest that the oncogenic transformation of BCPs by either v-mpl or v-abl use different pathways.
Activation of intracellular proteases is an early event in TNF-induced apoptosis.
Authors: Voelkel-Johnson C , Entingh A J , Wold W S , Gooding L R , Laster S M 
Published: December 2022

Abstract
The serine protease inhibitor tosyl-argenine methyl ester inhibits TNF-induced apoptosis, suggesting that proteolysis is necessary for this response. To test this hypothesis, we asked whether protein fragmentation occurs during the death of C3HA fibroblasts, a 3T3-like cell that was rendered sensitive to TNF by cycloheximide. Our results show that the binding of fluorescamine, which binds primary amines, was increased in apoptotic cells by approximately 50%. We also found that 10-15% of the protein in apoptotic cells was no longer precipitable by TCA. Evidence for proteolysis was also revealed by SDS-PAGE analysis and from Western blots. We observed fragmentation and/or degradation of lamin B, topoisomerase I, histone H1, protein kinase C beta 1, and cPLA2, indicating that proteolysis during apoptosis is non-specific. We also found evidence of proteolysis in C3HA cells sensitized to TNF by the adenovirus dl758 (which lacks the E3 14.7-kDa resistance gene) suggesting that protease activation is common in TNF-induced apoptosis. In contrast, the adenovirus E3 14.7-kDa resistance gene prevented proteolysis suggesting that this protein acts at, or upstream of the proteases activated in this response. Finally, because tosyl-argenine methyl ester inhibits the release of [3H]arachidonic acid from apoptotic cells, we tested whether proteolysis of cPLA2 is necessary for enzyme activation. Our results failed, however, to reveal a common proteolytic fragment in different cell types, and when tested in vitro the cytosol from apoptotic cells had less cPLA2 activity. It is unlikely, therefore, that proteolysis is necessary for the activation of this enzyme during TNF-induced apoptosis.
Isolation of a gene encoding a developmentally regulated T cell-specific protein with a guanine nucleotide triphosphate-binding motif.
Authors: Carlow D A , Marth J , Clark-Lewis I , Teh H S 
Published: December 2022

Abstract
In this study, we describe a novel full length cDNA clone designated Tgtp that encodes a predicted 415-amino acid a T cell-specific guanine nucleotide triphosphate-binding protein (TGTP) bearing the characteristic motifs of a guanine nucleotide triphosphate (GTP) binding protein. Tgtp is expressed preferentially, if not exclusively, in T cells, and is up-regulated in both unfractionated and in purified CD4+8+ thymocytes upon TCR cross-linking. In contrast, expression of Tgtp is peripheral T cells is maintained at relatively high levels and is not grossly affected by TCR cross-linking. Antiserum generated against synthetic peptides from the predicted TGTP amino acid sequence recognized a single protein with a molecular mass of approximately 50 kDa, corresponding well with the computed molecular mass of 47 kDa. The only known relative of Tgtp is MUSGTP, which is reportedly expressed in B cells and bears a GTP binding motif. Thus, the discovery of Tgtp resolves a subfamily of molecules with GTP binding motifs and apparent lymphoid lineage-restricted expression. Given the restricted expression pattern in T cells, the up-regulated expression observed in response to TCR signaling in immature thymocytes, and the presence of the motifs characteristic of GTP binding proteins, we suggest that TGTP may have an important function in T cell development and/or T cell activation.