bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-affinity oligonucleotide ligands to human IgE inhibit binding to Fc epsilon receptor I.
Authors: Wiegand T W , Williams P B , Dreskin S C , Jouvin M H , Kinet J P , Tasset D 
Published: December 2022

Abstract
Using the systematic evolution of ligands by exponential enrichment (SELEX) method, we have identified oligonucleotides that bind to human IgE with high affinities and high specificity. These ligands were isolated from three pools of oligonucleotides, each representing 10(15) molecules: two pools contained 2'-NH2 pyrimidine-modified RNA with either 40 or 60 randomized sequence positions, and the third pool contained ssDNA with 40 randomized sequence positions. Based on sequence and structure similarities, these oligonucleotide IgE ligands were grouped into three families: 2'-NH2 RNA group A ligands are represented by the 35-nucleotide truncate IGEL1.2 (Kd = 30 nM); 2'-NH2 RNA group B ligands by the 25-nucleotide truncate IGEL2.2 (Kd = 35 nM); and the ssDNA group ligands by the 37-nucleotide truncate DI 7.4 (Kd = 10nM). Secondary structure analysis suggests G quartets for the 2'-NH2 RNA ligands, whereas the ssDNA ligands appear to form stem-loop structures. Using rat basophilic leukemia cells transfected with the human high-affinity IgE receptor Fc epsilon RI, we demonstrate that ligands IGEL1.2 and D17.4 competitively inhibit the interaction of human IgE with Fc1 epsilon RI. Furthermore, this inhibition is sufficient to dose-dependently block IgE-mediated serotonin release from cells triggered with IgE-specific Ag or anti-IgE Abs. Therefore, these oligonucleotide ligands represent a novel class of IgE inhibitors that may prove useful in the fight against allergic diseases.
The cytoplasmic domains of E- and P-selectin do not constitutively interact with alpha-actinin and are not essential for leukocyte adhesion.
Authors: Kansas G S , Pavalko F M 
Published: December 2022

Abstract
The selectins are a family of carbohydrate-binding adhesion molecules involved in the regulation of leukocyte migration. Although there is strong homology between different selectins in their extracellular regions, there is none in the cytoplasmic tails, suggesting selectin-specific functions for these domains. Our previous work showed that the cytoplasmic tail of L-selectin interacts with the actin cytoskeleton via alpha-actinin and vinculin, and that truncation of the cytoplasmic tail of L-selectin blocked both association with alpha-actinin and vinculin and leukocyte adhesion. In the present study, the effects of truncation of the cytoplasmic tails of E- or P-selectin on cell adhesion and cell surface expression were examined, and possible interactions between alpha-actinin and the E- and P-selectin cytoplasmic tails were assessed. In contrast to previous observations demonstrating a requirement for the L-selectin cytoplasmic tail, truncation of the E- or P-selectin cytoplasmic domains had no effect on cell adhesion, or on cell surface expression, when assessed in transiently transfected COS cells. This lack of effect on cell surface expression and adhesion was also observed when transfections were performed with lower amounts of cDNA, which led to submaximal levels of expression. In addition, no interaction between alpha-actinin and the cytoplasmic tails of either E- or P-selectin could be detected under conditions in which binding of alpha-actinin to the L-selectin cytoplasmic tail could be readily demonstrated. Therefore, interactions between the cytoplasmic tail of E- or P-selectin and alpha-actinin or other cytoskeletal proteins are not necessary for leukocyte adhesion per se, but may facilitate downstream biologic events.
Selective growth of human mast cells induced by Steel factor, IL-6, and prostaglandin E2 from cord blood mononuclear cells.
Authors: Saito H , Ebisawa M , Tachimoto H , Shichijo M , Fukagawa K , Matsumoto K , Iikura Y , Awaji T , Tsujimoto G , Yanagida M , Uzumaki H , Takahashi G , Tsuji K , Nakahata T 
Published: December 2022

Abstract
To establish the method for generating a large number of mature human mast cells, we cultured cord blood mononuclear cells (CBMC) in several conditions in the presence of Steel factor (SF). Among several cytokines tested, IL-6 enhanced SF-dependent mast cell growth from purified CD34+ cells for more than 8 wk in culture. When CBMC were cultured instead of CD34+ cells, IL-6 enhanced the mast cell development in the presence but not in the absence of PGE2. PGE2 enhanced the SF- and IL-6-dependent development of mast cells from CBMC probably by blocking granulocyte-macrophage CSF (GM-CSF) secretion from accessory cells, because 1) PGE2, or anti-GM-CSF enhanced the mast cell development induced by SF and IL-6 from CBMC, but not from CD34+ cells; 2) GM-CSF inhibited the enhancing effect of IL-6 on the mast cell development from CD34+ cells; and 3) PGE2 inhibited GM-CSF secretion from CBMC. The mast cells cultured in the presence of SF, IL-6, and PGE2 for &gt;10 wk were 99% pure, and seemed to be functionally mature, because 1) they contained 5.62 micrograms of histamine and 3.46 micrograms of tryptase per 10(6) cells; and 2) when sensitized with human IgE and then challenged with anti-human IgE, the cells released a variety of mediators such as histamine, and an increase in intracellular Ca2+ was found in advance of the activation of membrane movement by using a confocal laser-scanning microscope. Electron-microscopic analysis revealed that some of the cultured mast cells are morphologically mature since they filled with scroll granules and contained crystal granules.
Transforming growth factor-beta 1 inhibits the production of IL-8 and the transmigration of neutrophils through activated endothelium.
Authors: Smith W B , Noack L , Khew-Goodall Y , Isenmann S , Vadas M A , Gamble J R 
Published: December 2022

Abstract
A central mechanism of inflammation is the activation of vascular endothelium by the inflammatory cytokines TNF-alpha and IL-1. These cytokines induce the expression of adhesion molecules, the elaboration of chemokines, and the transendothelial migration of white cells. TGF-beta 1 has anti-inflammatory properties, is expressed in the vessel wall, and has previously been shown to inhibit leukocyte adhesiveness to the endothelium at least in part by inhibiting the expression of E-selectin. We now show that TGF-beta 1 also inhibits the migration of neutrophils through endothelial monolayers activated by TNF-alpha. At a dose of 10 U/ml TNF-alpha, the transmigration of neutrophils was inhibited 42.7 +/- 7.9% (n = 8) by 0.2 ng/ml TGF-beta 1. Furthermore, TGF-beta 1 inhibited, in a time- and dose-dependent fashion, the elaboration of IL-8 by TNF-activated endothelial cells by between 33 and 78% (TNF doses from 100 down to 0.1 U/ml) and the elaboration of mRNA for IL-8 by 69%. TGF-beta 1 treatment did not significantly alter the TNF-induced IL-8 mRNA stability, suggesting that the mechanism of action of TGF-beta 1 is on gene transcription. Neutrophil transmigration through cytokine-activated endothelium involves both IL-8-dependent and IL-8-independent mechanisms. Using an anti-IL-8 Ab, we show that TGF-beta 1 inhibits only the IL-8-dependent pathway, but does not affect the IL-8-independent transendothelial migration mechanism. These and our previous results show that TGF-beta1, achieves its anti-inflammatory properties by inhibiting the expression of at least two genes, E-selectin and IL-8, which are essential in the inflammatory pathway.
Modulation by IL-10 of antigen-induced IL-5 generation, and CD4+ T lymphocyte and eosinophil infiltration into the mouse peritoneal cavity.
Authors: Zuany-Amorim C , Créminon C , Nevers M C , Nahori M A , Vargaftig B B , Pretolani M 
Published: December 2022

Abstract
Sensitized BALB/c mice challenged i.p. with 1 microgram of OVA showed IL-5 release in the peritoneal lavage fluid, which peaked at 6 h and decreased thereafter. This was followed by a massive eosinophil accumulation, which started at 6 h and reached a plateau between 24 and 48 h. The i.p. injection of recombinant murine (rm) IL-10 (0.01-0.1 microgram/cavity) along with OVA reduced IL-5 release at 6 h and allergic eosinophilia at 6, 24, and 48 h. rmIL-10 also blocked in vitro IL-5 generation by sensitized peritoneal cells cultured in the presence of OVA. The inhibitory effect of rmIL-10 on Ag-induced eosinophilia and IL-5 release was suppressed by pretreatment of the animals with 1 mg/mouse of a neutralizing anti-mIL-10 mAb. Flow cytometric analysis revealed an increase in the number of CD4+ and CD8+ T lymphocytes and in the number of CD25+/CD4+ cells in the peritoneal lavage fluid collected 24 and 48 h after challenge, respectively; these numbers were reduced significantly by the administration of 0.1 microgram of rmIL-10. Finally, rmIL-10 failed to modify the anti-CD3-induced IL-5 release in vivo in the peritoneal cavity and in vitro from purified spleen CD4+ T lymphocytes. This suggests that rmIL-10 acts indirectly, by deactivating APC, rather than directly on T cell activation. These findings indicate that rmIL-10 displays anti-allergic activity in sensitized BALB/c mice by preventing Ag-induced CD4+ T lymphocyte and eosinophil accumulation as well as IL-5 release in the peritoneal cavity.
CRP-mediated activation of complement in vivo: assessment by measuring circulating complement-C-reactive protein complexes.
Authors: Wolbink G J , Brouwer M C , Buysmann S , ten Berge I J , Hack C E 
Published: December 2022

Abstract
The in vivo function of C-reactive protein (CRP) is unknown. Among the in vitro functions assigned to CRP is the ability to activate complement via the classical pathway. To date, there is no evidence supporting that CRP exerts this function in vivo. We here show a novel approach to assess CRP-mediated complement activation in vivo, which is based on the property that activated complement factors C3 and C4 fix to CRP during complement activation induced by this acute phase protein. We developed specific ELISAs for complexes between CRP and C4b, C4d, C3b, or C3d. We established that in vitro complement-CRP complexes were formed only during CRP-dependent activation, and not during activation by other activators, even in the presence of high CRP levels. Circulating levels of complement-CRP complexes were undetectable in normal donors, but significantly increased in nine patients following implantation of a renal allograft. Importantly, levels of complement-CRP complexes did not change in these patients upon a bolus infusion of mAb OKT3, which induces activation of the classical complement pathway, demonstrating in vivo that complement-CRP complexes are not formed during CRP-independent activation of complement, even when CRP is elevated. We conclude that measurement of complement-CRP complexes provides a suitable tool to study CRP-mediated activation of complement in vivo. Furthermore, increased levels of these complexes occur in clinical samples, indicating that CRP may induce activation of complement in vivo.
IL-15 can substitute for the marrow microenvironment in the differentiation of natural killer cells.
Authors: Puzanov I J , Bennett M , Kumar V 
Published: December 2022

Abstract
NK cells require an intact bone marrow microenvironment to acquire lytic function. In mice rendered osteopetrotic by 17beta-estradiol treatment, NK1.1 positive cells are arrested in a nonlytic state. Culture with as little as 2 ng/ml of murine IL-15 (mIL-15), a cytokine produced by macrophages and stromal cells, causes these immature NK1.1+ cells to acquire lytic activity. By contrast, approximately 10- to 50-fold greater amount of mIL-2 was required to induce similar level of cytotoxicity. After culture with mIL-15, the relatively low expression of B220, CD11b, and Ly-49 molecules on immature NK1.1+ cells was increased to levels comparable to those of mature splenic NK1.1+ cells. mIL-15 also caused a greater expansion of NK1.1+CD3- cells as compared with NK1.1+CD3+ cells. We conclude that IL-15 is a specific maturation factor for NK cells and that it can mimic the marrow microenvironment in vitro.
TCR gene recombination and alpha beta-gamma delta lineage divergence: productive TCR-beta rearrangement is neither exclusive nor preclusive of gamma delta cell development.
Authors: Burtrum D B , Kim S , Dudley E C , Hayday A C , Petrie H T 
Published: December 2022

Abstract
Two types of T lymphocytes can be generated intrathymically, distinguishable by either TCR-gamma delta or -alpha beta surface expression. Regulation of the intrathymic divergence of these cells is unresolved, at least in part because thymically derived gamma delta cells have rarely been studied. We used quantitative Southern blotting together with PCR-based cloning/sequencing and restriction fragment length polymorphism to analyze TCR-alpha and -beta gene recombination in thymically derived gamma delta cells. We found that TCR-beta gene recombination is a frequent occurrence in thymic gamma delta cells. Furthermore, not only do complete (V-D-J) TCR-beta gene rearrangements occur in thymic gamma delta cells, but the frequency of in-frame rearrangements is greater than would be predicted based upon random occurrence. In contrast, we show that thymically derived gamma delta cells do not make detectable rearrangements of the TCR-alpha locus. These studies clearly demarcate a point for alpha beta vs gamma delta commitment in the thymus, after TCR-beta but before TCR-alpha gene recombination. Further, while our data support gamma delta lineage commitment as a consequence of successful TCR-gamma and -delta gene rearrangement, we do not find support for a competitive model of lineage commitment, since productive TCR-beta gene rearrangement does not necessarily relegate cells to the alpha beta lineage.
Lack of IL-12 signaling in human allergen-specific Th2 cells.
Authors: Hilkens C M , Messer G , Tesselaar K , van Rietschoten A G , Kapsenberg M L , Wierenga E A 
Published: December 2022

Abstract
IL-12 is a powerful skewer of CD4+ T cell responses toward the Th1 phenotype by inducing IFN-gamma production in naive Th cells. In the present study we addressed the question of whether IL-12 can reverse established Th2 responses into Th1/Th0 responses by inducing IFN-gamma production in memory Th2 cells. To this aim, allergen-specific CD4+ T cell clones (TCC) were generated from the peripheral blood of three atopic patients, and their cytokine profiles were analyzed. The majority of these TCC exhibited a strongly polarized Th2 cytokine profile, and the production of IFN-gamma could not be induced by exogenous IL-12. Only those TCC with low IFN-gamma levels in the absence of IL-12 responded to IL-12 by additional enhancement of IFN-gamma production. The IL-12 nonresponsiveness of the Th2 clones was further evident by the total lack of IL-12-induced phosphorylation of STAT4 (signal transducer and activator of transcription-4), a transcription factor that is typically involved in IL-12 signaling. Consequently, IL-12 also failed to induce the DNA-binding activity of STAT4-containing complexes in the nuclei of these Th2 clones. All TCC expressed equal levels of the low-affinity IL-12R beta1 subunit. Our results indicate that human allergen-specific Th cells with strongly polarized Th2 cytokine profiles do not respond to IL-12 and, therefore, cannot be induced to produce IFN-gamma. The apparent high frequency of IL-12-nonresponsive Th cells within the allergen-specific populations in atopic patients predicts a limited skewing potential of IL-12 in the case of established Th2 responses, but only affecting newly recruited naive Th cells.
Tyrosine phosphorylation and recruitment of ZAP-70 to the CD3-TCR complex are defective after CD2 stimulation.
Authors: Hubert P , Lang V , Debré P , Bismuth G 
Published: December 2022

Abstract
CD2 has been described as an alternative transduction pathway sharing the same biochemical cascade as CD3. The T cell-specific protein tyrosine kinase (PTK) ZAP-70 is believed to play a key role in early tyrosine phosphorylations of cellular proteins induced by CD3 stimulation. We show in the present report that ZAP-70 is insignificantly tyrosine phosphorylated and recruited to CD3 after CD2 stimulation in Jurkat T cells. The same result is obtained for p72syk, a PTK structurally and functionally related to ZAP-70. Several studies have suggested a model in which p56lck would be responsible after CD3 triggering for the phosphorylation of particular tyrosine residues in the immunoreceptor tyrosine-based activation motifs of the CD3 chains, inducing the recruitment and the tyrosine phosphorylation of ZAP-70. In Jurkat cells, p56lck is required for CD3- or CD2-induced tyrosine phosphorylations and clearly activated after CD2 cross-linking. However, we find that the CD3 complex, and especially its zeta-chain, are faintly tyrosine phosphorylated after CD2 triggering. By contrast, CD2 induces PLCgamma-1 tyrosine phosphorylation as efficiently as CD3, with a correlated inositol phosphate production and intracellular calcium increase, and even a higher production of IL-2. Interestingly, the SH2 domains of PLCgamma-1 associate with ZAP-70 upon CD3 stimulation while they bind, in CD2-activated cells, to a heavily tyrosine-phosphorylated 62-kDa protein. Altogether, these findings suggest that CD2 could bypass the PTK ZAP-70 for PLCgamma-1 activation and involves a preferential cascade comprising p56lck and a p62 protein, possibly acting as an anchor molecule.
IL-5 receptor expression and Ig secretion from murine B lymphocytes requires coordinated signaling by membrane Ig, IL-4, and IL-5.
Authors: Weber J D , Isakson P C , Purkerson J M 
Published: December 2022

Abstract
Interleukin-5 plays a pivotal role in the regulation of Ig secretion from murine B cells. Resting B cells express few, if any, IL-5 receptors and do not respond to the lymphokine. Culture of resting B cells with IL-4 induced expression of the IL-5R alpha-chain, while signaling through membrane Ig stimulated expression of the IL-5R beta-chain. Surprisingly, IL-4 suppressed expression of the beta-chain on activated B cells and inhibited responsiveness to IL-5 in subsequent cultures. Simultaneous culture of B lymphoblasts with IL-4 and IL-5 elicited sustained expression of the beta-chain and promoted secretion of IgM. Thus, expression of IL-5 receptors and induction of Ig secretion requires coordination of signals provided by membrane Ig, IL-4, and IL-5.
Interdependence of N nucleotide addition and recombination site choice in V(D)J rearrangement.
Authors: Kepler T B , Borrero M , Rugerio B , McCray S K , Clarke S H 
Published: December 2022

Abstract
Diversity in the Ag binding receptors of B and T cells is achieved through a process of genomic rearrangement involving selection of recombination sites and, in adult mice, addition of nontemplated (N) nucleotides. We have analyzed 543 Ig heavy chain nonproductive rearrangements, involving a single variable region gene segment, from adult and perinatal mice. We infer several fundamental and novel features of the recombination mechanism. N regions are formed predominantly from the DNA plus strand or from the DNA minus strand polymerizations, rather than as a concatenation of the two. Homologous overlaps of as few as one nucleotide between gene segments cause significant skewing of recombination sites. The V(H) recombination site spectrum differs in perinatal and adult mice, with sites representing overlap between V(H) and D over-represented in the perinatal mice, and sites representing overlaps between V(H) and the N strand polymerized onto the D segment over-represented in the adult mice. Thus, in V(D)J joining, N nucleotide addition and recombination site choice are highly interdependent events.
The outcome of the parasitic process initiated by Leishmania infantum in laboratory mice: a tissue-dependent pattern controlled by the Lsh and MHC loci.
Authors: Leclercq V , Lebastard M , Belkaid Y , Louis J , Milon G 
Published: December 2022

Abstract
Human visceral leishmaniasis is mainly due to intracellular protozoan parasites of the Leishmania donovani complex, i.e., L. donovani and L. infantum (or L. chagasi). A mouse model has been established to monitor 1) the parasitic process initiated by L. infantum in three tissues they invade, and 2) parameters of the acquired immune response they trigger. Mice congenic at the Lsh locus and mice of inbred strains differing at the MHC locus have been inoculated by the i.v. route with L. infantum. The parasitic process has been evaluated by the follow-up of the parasitic load in the liver, the spleen, and, for the first time, in the bone marrow using a very sensitive limiting dilution assay. As previously established for L. donovani, the early outcome of L. infantum is also under the control of the Lsh locus in the liver; genes of the MHC complex are involved in the development of the subsequent acquired immune response. "Cure" or "noncure" haplotypes are the same for the two species of Leishmania; as far as the cure haplotype is concerned, whatever the tissues being screened, the parasites are never totally cleared, although the liver is the tissue in which the best parasite load reduction is achieved. Through immunostaining, it was established that sialoadhesin-positive stromal bone marrow macrophages contain parasites; such long-lived mononuclear phagocytes could be the host cells where the parasite can find "safe targets" unreactive to the dominant effector immune mechanism triggered by the replicative stage of the parasites.
Chlamydia trachomatis major outer membrane protein (MOMP) epitopes that activate HLA class II-restricted T cells from infected humans.
Authors: Ortiz L , Demick K P , Petersen J W , Polka M , Rudersdorf R A , Van der Pol B , Jones R , Angevine M , DeMars R 
Published: December 2022

Abstract
We localized peptide epitopes within the Chlamydia trachomatis (Ct) major outer membrane protein (MOMP) that activate human T cells. T-MOMP' cells were prepared by culturing PBL from 38 humans who had Ct infections in the presence of Ct serovar E MOMP. Some epitopes were first localized by quantifying proliferative responses of T-MOMP' cells to overlapping MOMP segments (sixths) that were produced in Escherichia coli. Further localization was achieved by using overlapping synthetic 16-22 mers that spanned stimulatory MOMP sixths as Ags. The APCs used were human B cell lines (LCL) that were matched or mismatched with respect to HLA class II alleles of the T-MOMP' cells. T cell epitopes were detected in 18 Ct serovar E MOMP 16-22 mers and were presented in association with HLA-DR1, -7, -13, -17, HLA-DRw52, HLA-DQ3 and at least two from among HLA-DR4, -8, -11, -14, -18, in probable addition to HLA-DP4. Peptide 249-265 stimulated T-MOMP' cells from 83% of the subjects; studies with overlapping 11-13 mers spanning peptide 249-265 revealed at least six epitopes presented with different HLA-class II allotypes. Diverse T-MOMP' cultures responded to between 2 and 7 MOMP epitopes. All but 1 of the 23 epitopes localized to date are distributed among four MOMP constant segments. T-MOMP' cells from subjects infected with serovars other than E also responded.