bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human placental HLA-G expression is restricted to differentiated cytotrophoblasts.
Authors: McMaster M T , Librach C L , Zhou Y , Lim K H , Janatpour M J , DeMars R , Kovats S , Damsky C , Fisher S J 
Published: December 2022

Abstract
Human placental trophoblasts lie at the maternal-fetal interface, a position in which they could play an important role in maternal tolerance of the fetal semi-allograft. Central to this hypothesis is their unusual MHC class I expression: they suppress class Ia production while expressing HLA-G, a class Ib molecule. We investigated human trophoblast HLA-G protein production in vivo and in vitro. We first used a synthetic peptide corresponding to the variable sequence of the alpha 1 domain to produce mAbs that recognized HLA-G. Ab specificity was demonstrated by immunoaffinity purification of a single protein with the same molecular mass (38 kDa) as HLA-G from choriocarcinoma cells. Use of these Abs to stain tissue sections of the maternal-fetal interface containing cytotrophoblasts in all stages of differentiation showed that HLA-G is expressed only by cytotrophoblasts that invade the uterus. Our previous in vitro studies showed that when early-gestation cytotrophoblast stem cells are cultured, they differentiate rapidly along the invasive pathway, as demonstrated by their expression of stage-specific markers. Here we show they also up-regulate HLA-G production. Cytotrophoblasts from term placentas, which have reduced invasive capacity in vitro, also had decreased ability to up-regulate HLA-G protein expression. We detected high levels of HLA-G mRNA in cytotrophoblasts isolated from first- and second-trimester placentas, but only trace amounts in term cells. Taken together, these results suggest that HLA-G production is a critical component of cytotrophoblast differentiation along the invasive pathway.
cDNA cloning of a NGFI-B/nur77-related transcription factor from an apoptotic human T cell line.
Authors: Okabe T , Takayanagi R , Imasaki K , Haji M , Nawata H , Watanabe T 
Published: December 2022

Abstract
A human T lymphoid cell line, PEER, dies by apoptosis in the presence of PMA and calcium ionophore. A new gene, TINUR, was cloned from apoptotic PEER cells. The expression of the TINUR gene is induced within 1 h after the cross-linking of the T cell Ag receptor complex. TINUR belongs to the NGFI-B/nur77 family of the steroid receptor superfamily and is an orphan receptor. TINUR binds to the same DNA sequence as NGFI-B/nur77. We also propose that the NGFI-B/nur77 family can be classified into two subtypes.
Transcription of the TCR-beta locus initiates in adult murine bone marrow.
Authors: Soloff R S , Wang T G , Lybarger L , Dempsey D , Chervenak R 
Published: December 2022

Abstract
Successful expression of the TCR beta-chain gene is a multistep process that involves: 1) initial transcription of multiple, unrearranged gene segments, 2) rearrangement of V, D, and J gene segments to form a complete beta-chain gene, and 3) transcription of the fully rearranged beta gene. All of these events have been shown to occur in the thymus, where the majority of T cell development takes place; however, the extent to which any of these events may occur prethymically has not been established. To examine prethymic TCR-beta gene expression, RNA was isolated from a precursor T cell-enriched population (Thy 1low CD3-) of C58/J mouse bone marrow, and analyzed by reverse transcriptase-PCR. A transcript containing TCR-beta constant (C) region sequences but not variable (V) region sequences was amplified, suggesting that an unrearranged TCR-beta gene locus is transcriptionally active in this bone marrow population. The same product was detected in Thy 1+ CD3- bone marrow cells from nude mice, indicating that the thymic microenvironment is not necessary for initiation of TCR-beta gene transcription. This C beta transcript is not confined to pre-B cells, as it was identified in RNA isolated from Thy 1low CD3- B220- bone marrow cells. Germline V beta transcripts were also detected in RNA from this bone marrow population. Furthermore, Sca-1+ Lin- and Sca-1+ Lin+ bone marrow populations from both C58/J mice and nude mice also expressed the C beta transcript. DNA-PCR analyses with D beta-J beta primer sets revealed that partial rearrangement of the beta locus had occurred in all bone marrow populations analyzed. These data suggest that both transcription and partial rearrangement of the TCR-beta locus can initiate in bone marrow cells of adult mice, before exposure of these cells to the thymus.
T lymphocytes infiltrating sites of tumor rejection and progression display identical V beta usage but different cytotoxic activities.
Authors: Kurt R A , Park J A , Panelli M C , Schluter S F , Marchalonis J J , Carolus B , Akporiaye E T 
Published: December 2022

Abstract
Most tumors grow progressively and overwhelm the host. The rare but documented cases of spontaneous regression of primary tumors are indicative of the potential of tumor-bearing hosts to develop a significant antitumor response. Because most tumors grow progressively in the host, it is not surprising that the majority of studies have focused on T lymphocytes that infiltrate these tumors. Although these studies have generated significant and useful information during the period of tumor growth, they can only speculate on the mechanisms that are involved in tumor rejection. We have used a well developed sponge model of concomitant tumor immunity that allows us to compare the immunologic events that occur during tumor progression vs rejection. In this model, an animal harboring a primary EMT6 mammary tumor is challenged with a secondary tumor implant through a pre-implanted gelatin sponge. During the manifestation of concomitant tumor immunity, the secondary tumor is rejected and the effector cells mediating the response are retained within the sponge matrix. Using this model we analyzed the TCR usage, cytotoxic activity of lymphocytes, and cytokine production at both tumor sites. The data revealed that tumor-rejecting lymphocytes isolated from the site of secondary tumor implant were cytotoxic toward EMT6 cells, whereas tumor-infiltrating lymphocytes isolated from the progressing primary tumor were not. Interestingly, the TCR-V beta repertoire of the tumor-infiltrating lymphocytes and tumor-rejecting lymphocytes were identical with V beta 1 and V beta 8 being predominant at both sites. Furthermore, the rejection site showed higher gene expression of IFN-gamma, TNF-alpha, and IL-10 whereas TGF-beta expression was slightly higher in the progressing tumors. These findings suggest that the disparate effector functions observed during tumor progression vs rejection are not caused by different T cell phenotypes but may be due instead to influences exerted by cytokines produced at the tumor sites.
Differentiation-dependent effects of IL-1 and TGF-beta on human articular chondrocyte proliferation are related to inducible nitric oxide synthase expression.
Authors: Blanco F J , Geng Y , Lotz M 
Published: December 2022

Abstract
This study analyzed the effect of chondrocyte differentiation on iNOS expression and responses to IL-1 and TGF-beta. During subculturing of chondrocytes, the growth-stimulatory effects of TGF-beta decreased, and cells in later passages even were growth inhibited by TGF-beta. IL-1 beta responses showed an inverse pattern. The antiproliferative effects of IL-1 beta decreased, and, after passage 6, IL-1 beta became a growth stimulator for chondrocytes. This change in growth factor response pattern was associated with a decrease in type II collagen expression. To determine whether these changes in the growth regulatory effects of IL-1 beta and TGF-beta were related to nitric oxide (NO), inducible nitric oxide synthase (iNOS) expression and NO release were analyzed. In primary chondrocytes, TGF-beta did not stimulate iNOS mRNA expression or NO release, and, during co-incubation, it did not detectably alter the IL-1 beta effect. Preincubation with TGF-beta resulted in a time-dependent increase in IL-1-induced NO. With increasing passage number, the IL-1 beta effects decreased, and, after passage 6, IL-1 beta no longer detectably stimulated iNOS expression or NO release. However, TGF-beta increased NO production synergistically with IL-1 beta during the same culture period when it lost its growth-stimulatory effects. The antiproliferative effects of TGF-beta in late passage chondrocytes were reversed by the NO synthase inhibitor NG-monomethylarginine. These results suggest a novel pattern of iNOS regulation by IL-1 and TGF-beta and show that the factors that modulate iNOS expression and proliferation are dependent on the differentiation status of the cells.
Exogenous and endogenous nitric oxide attenuates tumor necrosis factor synthesis in the murine macrophage cell line RAW 264.7.
Authors: Eigler A , Moeller J , Endres S 
Published: December 2022

Abstract
Effects of TNF on nitric oxide (NO) production have been well documented in a variety of experimental and clinical settings, as for example, in septic shock. Investigations focusing on an inverse relation of NO on TNF synthesis are rare. Previously we could demonstrate that exogenous NO-releasing agents suppress LPS-induced TNF production in human PBMC. We now investigate whether a regulatory role on TNF synthesis could also be ascribed to endogenous NO. This was studied in the murine macrophage cell line RAW 264.7, which is able to express both TNF and the inducible NO synthase. No production was determined by measuring nitrite with Griess reagents. TNF formation was quantified by L929 cytotoxicity. We found a suppression of LPS-induced TNF synthesis by the exogenous addition of NO-releasing agents in the murine cell line, as previously observed in human cells. The application of NO synthase inhibitors led to a decrease in NO production, associated with an increase in TNF synthesis. TNF production increased from a base line (stimulation with 1 microgram/ml LPS alone) of 20.8 ng/ml to 36.3 ng/ml (means of six experiments) in the presence of the NO synthase inhibitor NG-monomethyl L-arginine (100 microM). Similar results were obtained with another NO synthase inhibitor, NG-nitro L-arginine-methylester. Lack of L-arginine in the medium resulted in a threefold increase in LPS-stimulated TNF synthesis compared with medium containing the usual concentration of 1 mM L-arginine. Restitution of L-arginine but not of D-arginine reversed this increase in TNF synthesis in a dose-dependent manner. To our knowledge these results indicate for the first time a negative feedback by endogenous NO on TNF synthesis in vitro. This finding may be relevant in pathophysiologic processes in which both TNF and NO are formed and in experimental therapies aiming at changes of NO concentrations.
Inducible expression of type 2 IL-1 receptors by cultured human keratinocytes. Implications for IL-1-mediated processes in epidermis.
Authors: Groves R W , Giri J , Sims J , Dower S K , Kupper T S 
Published: December 2022

Abstract
Two species of cell surface receptor for IL-1 (IL-1R) have been characterized. Only one of these, the type 1 IL-1R, transduces a signal after ligand binding. Whereas mRNA for the nonsignal transducing type 2 IL-1R seems to have a broad tissue distribution, functional type 2 IL-1R has been carefully studied only in leukocytes and related cell lines. Because normal human keratinocytes, which are IL-1 alpha-producing epithelial cells, inducibly express large numbers of IL-1R, we have studied their putative type 1 and type 2 IL-1R at the level of RNA, protein, and biologic function. At the level of function, gene expression of the IL-1-inducible cytokine granulocyte-macrophage-CSF by keratinocytes was mediated entirely by low numbers of type 1 IL-1R, although type 2 IL-1R were more numerous on both resting and activated keratinocytes. Type I IL-1R mRNA was detected only at very low levels, whereas a marked induction of type 2 IL-1R mRNA was readily observed in activated keratinocytes. A sensitive and specific ELISA demonstrated shed type 2 IL-1R in the conditioned medium of IFN-gamma or PMA-activated keratinocytes. Keratinocyte type 2 IL-1R bound IL-1 alpha with higher affinity (Kd approximately 3 x 10(-9) M) than type 2 IL-1R on leukocytes; however, the intracellular epithelial form of the IL-1R antagonist was bound 100-fold less avidly. These findings demonstrate that a normal nontransformed epithelial cell may express large numbers of the nonsignal transducing type 2 IL-1R that binds IL-1 with high affinity and can be shed into the pericellular environment. This receptor may function as an IL-1 antagonist in autocrine, juxtacrine, and paracrine cutaneous pathways.
Hyaluronic acid enhances cell proliferation during eosinopoiesis through the CD44 surface antigen.
Authors: Hamann K J , Dowling T L , Neeley S P , Grant J A , Leff A R 
Published: December 2022

Abstract
We examined the effect of hyaluronic acid in promoting proliferation of undifferentiated progenitor cells through the CD44 receptor during eosinopoiesis in vitro. Undifferentiated umbilical cord blood cells were purified on the first day to isolate primitive progenitor cells expressing the CD34 hemopoietic surface marker. Culture in wells coated with 100 micrograms/ml hyaluronic acid caused a 198 +/- 28.7% augmentation of proliferation of CD34+ progenitor cells at 3 wk (p &lt; 0.01). By contrast, concentrations of hyaluronic acid &gt; 10 micrograms/ml inhibited proliferation of unfractionated cord blood mononuclear cells. The augmented proliferation of precursor cells caused by hyaluronic acid was associated with complete (93.0 +/- 5.12%) differentiation to eosinophil morphology. By contrast, concentrations of hyaluronic acid &gt; or = 10 micrograms/ml inhibited eosinophilic differentiation of unfractionated mononuclear cells. Wright-Giemsa staining demonstrated 95.4 +/- 2.92% eosinophils for CD34+ cells cultured for 3 wk without hyaluronic acid (control) and 93.8 +/- 5.11% for CD34+ cells cultured in hyaluronic acid-coated wells (100 micrograms/ml); for unfractionated cells, 94.0 +/- 3.02% demonstrated eosinophilic morphology in control wells at 3 wk vs 55.4 +/- 8.34% in hyaluronic acid-coated (100 micrograms/ml) wells (p &lt; 0.05). Augmented proliferation caused by hyaluronic acid was attenuated completely by the anti-CD44 mAbs, 212.3 and IM7.8.1. Pretreatment of CD34+ cells with 5 micrograms/ml 212.3 inhibited the augmented proliferation caused by the optimal concentration of hyaluronic acid (100 micrograms/ml) from 260 +/- 39.2% of control growth to 114 +/- 16.4% of control growth (p = 0.02). Inhibition was comparable for IM7.8.1. Control mAb (LM2) to the beta 2 integrin subunit CD11b had no effect on proliferation induced by hyaluronic acid. We demonstrate that hyaluronic acid stimulates the growth of CD34+ selected umbilical cord blood cells into specifically differentiated mature eosinophils. This process is modulated by the CD44 receptor on the progenitor cell population.
Effect of IL-6 receptor antisense oligodeoxynucleotide on in vitro proliferation of myeloma cells.
Authors: Keller E T , Ershler W B 
Published: December 2022

Abstract
IL-6 stimulates proliferation of various tumors, including lymphoma and myeloma; thus, inhibiting IL-6 may decrease the growth of these tumors. Accordingly, we examined the effect of IL-6 and IL-6R antisense phosphorothioated oligodeoxynucleotides (ODNs) on proliferation of IL-6 responsive (U266) and nonresponsive (RPMI 8226) myeloma cell lines. Cells were grown in the presence or absence of IL-6, with added antisense to either IL-6 or IL-6R. Cells were evaluated for proliferation ([3H]thymidine uptake) and steady state levels of both IL-6 and IL-6R mRNA by competitive PCR (C-PCR). Proliferation of U266 cells was decreased markedly by IL-6 antisense ODN in the absence of IL-6, but not in its presence. In contrast, IL-6R antisense ODN inhibited proliferation of U266 cells in both the presence and absence of IL-6. As anticipated, neither IL-6 nor IL-6R antisense ODN had an effect on RPMI 8226 proliferation. C-PCR demonstrated a marked and specific decrease of IL-6 and IL-6R mRNA in cells exposed to IL-6 ODN and IL-6R ODN, respectively. These results suggest that IL-6R antisense ODN may be a more effective inhibitor of IL-6-stimulated cells than IL-6 antisense in a therapeutic setting.
5-Oxo-6,8,11,14-eicosatetraenoic acid is a potent stimulator of human eosinophil migration.
Authors: Powell W S , Chung D , Gravel S 
Published: December 2022

Abstract
Human neutrophils and monocytes contain a highly specific dehydrogenase which converts 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) to 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). We have previously shown that 5-oxo-ETE is a potent stimulus of neutrophil calcium levels and migration and have now investigated its effects on human eosinophils. 5-Oxo-ETE is a potent stimulus of eosinophil migration, with significant effects being detected at concentrations as low as 1 nM and a maximal response at 1 microM. The responses elicited by 5-oxo-ETE were about two to three times greater than those to platelet-activating factor (PAF) and 5-oxo-15-hydroxy-6,8,11,13-eicosatetraenoic acid (5-oxo-15-hydroxy-ETE) at all concentrations tested between 10 nM and 1 microM. Leukotrienes B4 and D4 also significantly stimulated eosinophil migration, but the maximal responses to these agonists were only about 4% of the maximal response to 5-oxo-ETE. A low concentration of 5-oxo-ETE (1 nM) potentiated eosinophil migration in response to PAF. Eosinophils were capable of converting 5-HETE to 5-oxo-ETE, and this reaction was enhanced by phorbol myristate acetate. Stimulation of eosinophils with A23187 in the presence of low concentrations of arachidonic acid and phorbol 12-myristate 13-acetate led to the formation of 5-oxo-ETE and 5-oxo-15-hydroxy-ETE, but the amounts were considerably less than those of other eicosanoids such as leukotriene C4, cysteine-containing lipoxins, and 5,15-dihydroxy-6E,8Z,11Z,13E-eicosatetraenoic acid. In summary, of all the lipid mediators tested, 5-oxo-ETE was the most effective in stimulating migration of human eosinophils. Although eosinophils are capable of synthesizing 5-oxo-eicosanoids, the amounts detected were relatively small, and other leukocytes such as neutrophils, monocytes, or macrophages may be more important sites for the synthesis of this compound.
Monocyte chemotactic protein MCP-2 activates human basophil and eosinophil leukocytes similar to MCP-3.
Authors: Weber M , Uguccioni M , Ochensberger B , Baggiolini M , Clark-Lewis I , Dahinden C A 
Published: December 2022

Abstract
It has been shown that CC chemokines activate basophil and eosinophil leukocytes with different selectivities and patterns of activity. The most effective are monocyte chemotactic protein-1 (MCP-1), a potent stimulus of mediator release in basophils without effects on eosinophils, RANTES, a weak stimulus of release and strong chemoattractant for basophils and eosinophils, and MCP-3, which combines the activities of MCP-1 and RANTES. We have now compared MCP-2, which has 62 and 60% of sequence identity with MCP-1 and MCP-3, respectively, with the other CC chemokines. MCP-2 induced mediator release by human basophils with lower efficacy and potency than MCP-1 and MCP-3. It promoted transient changes of cytosolic-free calcium concentration ([Ca2+]i) and chemotactic responses in both basophils and eosinophils, however somewhat less efficiently than MCP-3 and RANTES. Desensitization studies indicate that MCP-2 interacts with receptors recognizing MCP-1 as well as RANTES. These results demonstrate that MCP-2 and MCP-3 exert qualitatively similar biologic activities on basophils and eosinophils. In basophils that had not been treated with IL-3, MCP-2 induced minimal exocytosis only, but desensitized the cells toward MCP-1 and MCP-3, suggesting that MCP-2 may act as a functional inhibitor of CC chemokine actions. The results of this study further indicate that MCP analogues display partially distinct, partially overlapping bioactivities toward eosinophils and basophils, and may thus regulate inflammatory processes involving these effector cell types.
CTLs from lymphoid organs recognize an optimal HLA-A2-restricted and HLA-B52-restricted nonapeptide and several epitopes in the C-terminal region of HIV-1 Nef.
Authors: Hadida F , Haas G , Zimmermann N , Hosmalin A , Spohn R , Samri A , Jung G , Debre P , Autran B 
Published: December 2022

Abstract
In a previous analysis of HIV-1-specific CTLs in lymphoid organs from HIV-seropositive patients, we reported high frequencies of in vivo differentiated CTLs directed against two immunodominant regions in the central and in the C-terminal part of the HIV-1 Nef protein. The present study analyzes the epitopes recognized by CTLs in the carboxyl terminus of Nef (amino acids 182-205). In addition to several epitopes that are recognized in association with different HLA molecules (A1, A2, A25(10), B35, B52), we defined an optimal nonapeptide (190-198). This nonapeptide was recognized by CTLs down to nanomolar concentrations in the context of at least two HLA molecules, HLA-B52 and HLA-A2, including three HLA-A2 subtypes: HLA-A2.1, -A2.2, and -A2.4. We also determined the relative frequencies of effector CTLs directed against peptide 190-198 to be as high as 10(-4), as opposed to lower frequencies ranging between 5 x 10(-5) and 5 x 10(-6) observed for the other peptides recognized in the same region, thus confirming the optimal presentation of this nonapeptide in vivo. Molecular modeling of the interactions between HLA-A2.1 and Nef peptide 190-198 suggests the formation of a stable complex and allowed us to study sequence motifs that are important for the binding of the HIV-1 peptide in the pockets of the HLA-A2.1 molecule.
Bee venom immunotherapy results in decrease of IL-4 and IL-5 and increase of IFN-gamma secretion in specific allergen-stimulated T cell cultures.
Authors: Jutel M , Pichler W J , Skrbic D , Urwyler A , Dahinden C , Müller U R 
Published: December 2022

Abstract
The mechanisms of bee venom immunotherapy (VIT) are largely unknown. The aim of this study was to follow the changes of T cell cytokine secretion during the course of VIT. Ten bee venom-allergic patients with a history of severe systemic reactions, positive skin tests, and bee venom (BV)-specific serum IgE Abs were treated as follows: on the first day, a cumulative dose of 111 micrograms, starting with 0.1 microgram, was administered s.c. under intensive care conditions. Further injections of 100 micrograms BV were given on day 7, day 21, and thereafter at intervals of 4 wk. Blood samples were obtained just before the initiation of VIT, after the last injection on the same day, and before the subsequent BV injections on days 7, 21, and 50 of VIT. Peripheral blood mononuclear cells (PBMC) were stimulated with phospholipase A (PLA), the major BV allergen, or with a control Ag tetanus toxoid (TT). Cytokine secretion was measured 24 h after restimulation of the cultures with solid-phase bound OKT3 F(ab')2 mAbs after 7 days of culture. In PLA-stimulated cultures, VIT resulted in decreased IL-4 and IL-5 and increased IFN-gamma secretion. In TT-stimulated cultures, we observed similar levels of cytokines before and during VIT. We conclude that ultra-rush VIT changes allergen-specific T cell reactivity.