bluuebunny/crossref_metadata_2025_split huggingface dataset:
Galectin-3 promotes adhesion of human neutrophils to laminin.
Authors: Kuwabara I , Liu F T 
Published: December 2022

Abstract
Galectin-3 is a member of a growing family of animal lectins composed of three domains, with the amino-terminal half consisting of a short segment followed by tandem repeats, and the carboxyl-terminal half representing the carbohydrate-recognition domain. Previously, we have shown that galectin-3 binds to the surface of human neutrophils and is capable of activating these cells. We have now studied the effect of exogenous galectin-3 on adhesion of human neutrophils to laminin-coated microtiter plates and found that this lectin promotes the adhesion in a dose-dependent manner. The effect was dependent on the lectin's carbohydrate-binding function, as well as its amino-terminal region. The galectin-3-induced adhesion was reduced significantly in the presence of EDTA, even though Ca2+ and Mg2+ are not required for the lectin binding, and the adhesion was significantly less at 4 degrees C, as compared with 37 degrees C. Galectin-3 also induced neutrophil adhesion to fibronectin, which is not recognized by the lectin, but much higher concentrations of the lectin were required, and the effect is completely dependent on Ca2+ and Mg2+. We conclude that galectin-3 induces neutrophil adhesion to laminin through a combination of two distinct mechanisms: 1) the lectin bridges neutrophils to laminin, in a carbohydrate-dependent and Ca2+-, Mg2+-independent manner, and 2) the lectin induces activation of neutrophils, in the presence of the divalent cations, resulting in the positive regulation of other cell adhesion molecules and enhanced adhesion to laminin. The results suggest that galectin-3 may play a role in the traversing of neutrophils through the basement membrane at inflammation sites.
Salicylates inhibit I kappa B-alpha phosphorylation, endothelial-leukocyte adhesion molecule expression, and neutrophil transmigration.
Authors: Pierce J W , Read M A , Ding H , Luscinskas F W , Collins T 
Published: December 2022

Abstract
The expression of leukocyte adhesion molecules on endothelial cells is induced by TNF-alpha and other inflammatory cytokines. This induction of endothelial-leukocyte adhesion molecule-1, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 requires the transcription factor nuclear factor-kappa B (NF-kappa B). Recent work has suggested that some nonsteroidal anti-inflammatory agents, including sodium salicylate and aspirin, can inhibit NF-kappa B-dependent gene activation. We studied the effects of salicylates on expression of adhesion molecules in HUVECs. We found that sodium salicylate inhibited activation of NF-kappa B (p50/p65 and p65/p65) by preventing phosphorylation and subsequent degradation of the inhibitor 1 kappa B-alpha. Salicylate treatment had no effect on TNF-alpha-induced phosphorylation of the transcription factor ATF-2. Salicylate blocked the TNF-alpha-induced increase in mRNA levels of adhesion molecules and gave a dose-dependent inhibition of TNF-alpha-induced surface expression of vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 with higher doses required to inhibit endothelial-leukocyte adhesion molecule-1 expression. Indomethacin, a nonsalicylate cyclooxygenase inhibitor, had no effect on surface expression of adhesion molecules, suggesting that the effects were not due to inhibition of cyclooxygenase. Treatment of endothelial cell monolayers with sodium salicylate inhibited transendothelial migration of neutrophils but had no significant effect on neutrophil adhesion under flow conditions. The clinical importance of high-dose salicylates in inflammation may be due, in part, to the ability to prevent expression of inducible adhesion molecules and recruitment of leukocytes.
Extracellular ATP activates mast cells via a mechanism that is different from the activation induced by the cross-linking of Fc receptors.
Authors: Sudo N , Tanaka K , Koga Y , Okumura Y , Kubo C , Nomoto K 
Published: December 2022

Abstract
In this study, the extracellular ATP (ATPo)-induced biochemical events were elucidated by comparing them with either the Fc epsilon RI- or Fc gamma R-induced events in the mouse mast cell line MC9. The omission of extracellular Ca2+ almost completely abolished the elevation of intracellular Ca2+ ([Ca2+]i) in the ATPo-stimulated cells, but only suppressed the second phase of the increase of [Ca2+]i in FcR-stimulated cells, thus suggesting that the ATPo-induced elevation of [Ca2+]i is totally dependent on the entry of extracellular Ca2+. Pretreatment with genistein, which inhibits protein kinases, especially protein tyrosine kinase, inhibited the FcR-triggered increase of [Ca2+]i, but not the ATPo-triggered one; however, such pretreatment did suppress both ATPo- and FcR-mediated beta-hexosaminidase release. An immunoblot analysis revealed that both ATPo and the cross-linking of FcRs led to tyrosine phosphorylation of 44- and 110-kDa proteins, which thus suggested that these tyrosine-phosphorylated proteins are involved in a modulation of the degranulation process following an elevation of [Ca2+]i. Pretreatment with PMA inhibited the FcR-induced [Ca2+]i increase, while not inhibiting the ATPo-induced one, thus suggesting that ATPo can mobilize [Ca2+]i even when protein kinase C (PKC) has already been activated. Pretreatment of calphostin C, a specific PKC inhibitor, had little effect on the ATPo-mediated beta-hexosaminidase secretion, thus indicating that the ATPo-induced degranulation is not mediated by PKC. Taken together, these results demonstrate that ATPo activates MC9 mast cells by a mechanism that is different from the activation induced by the cross-linking of FcRs.
Human lupus anti-spliceosome A protein autoantibodies bind contiguous surface structures and segregate into two sequential epitope binding patterns.
Authors: James J A , Harley J B 
Published: December 2022

Abstract
High levels of anti-spliceosomal autoantibodies are commonly found in systemic lupus erythematosus (lupus) sera. We have evaluated the binding of lupus autoantibodies to octapeptides of nuclear ribonucleoprotein (nRNP) A, identified patterns of binding that vary between sera, quantified the proportion of anti-nRNP that binds individual peptides, and related these data to the partial tertiary structure of nRNP A. Anti-nRNP A-positive lupus sera share binding to eight antigenic groups of octapeptides from nRNP A. The four shared antigenic sites in the known nRNP A tertiary structure are contiguous on its surface and include surface loops between beta sheets and/or alpha helices. Anti-peptide Abs account for a significant portion of the human autoimmune response to nRNP A. Lupus sera are also obviously divisible into two subsets by their binding to nRNP A-derived peptides. Eight of the thirteen anti-nRNP A sera tested bind most of the eight common antigenic regions of nRNP A. All five sera in the other subset bind to two and only two groups of nRNP A octapeptides. Of this subset, absorption experiments show that as much as 75% of the anti-nRNP found in a patient serum is bound to these two octapeptides from nRNP A. The 70K spliceosome protein contains similar peptides that are also bound by these sera (OR=13.5, p&lt;0.001). Lupus autoantibodies bind to peptides of nRNP A in discernibly consistent patterns that identify serologic subsets and in a manner that provides useful insights into the autoimmunity and antigenic structure of the nRNP A spliceosomal protein.
Murine lupus in the absence of alpha beta T cells.
Authors: Peng S L , Madaio M P , Hughes D P , Crispe I N , Owen M J , Wen L , Hayday A C , Craft J 
Published: December 2022

Abstract
To investigate the possibility that non-alpha beta T cell-dependent mechanisms can induce systemic autoimmune disease, and to address the roles of alpha beta T cells in murine lupus, we analyzed lupus-prone MRL mice congenitally deficient in alpha beta T cells. Surprisingly, TCR-alpha-/- MRL mice developed several characteristics of human systemic lupus erythematosus, including hypergammaglobulinemia, autoantibodies against DNA and small nuclear ribonucleoproteins, and immune deposits in kidneys. These results, which contrast with past studies concluding that MRL autoimmunity requires CD4+ alpha beta T cells, demonstrate that non-alpha beta T cell-dependent mechanisms are capable of inducing lupus phenomena, and further suggest that MRL disease may consist of both alpha beta T cell-independent and alpha beta T cell-dependent mechanisms.
Complete TCR-delta rearrangements and partial (D-J) recombination of the TCR-beta locus in CD34+7+ precursors from human cord blood.
Authors: Ktorza S , Blanc C , Laurent C , Sarun S , Verpilleux M P , Debré P , Schmitt C 
Published: December 2022

Abstract
In the neonatal human thymus, early immature precursors co-express CD34 and CD7 cell surface Ags, and we have recently shown that its most primitive CD34+7+1- fraction includes TCR-beta-rearranging cells. Bone marrow and cord blood also contain a CD34+7+ population. Although this population is heterogeneous in terms of both phenotype and differentiation capacities, it may include T cell-committed thymus colonizing precursors (prothymocytes). Recently, it has been shown in the mouse that initiation of TCR-beta rearrangements is not restricted to early thymocytes. In the present study, we examined the TCR-beta and TCR-delta rearrangement and transcription status of cord blood CD34+7- and CD34+7+ subpopulations. RNA and DNA were isolated from these cell subsets purified by two consecutive rounds of fluorescence-activated cell sorting from CD3-depleted cord blood cells. Using D-J(beta) or V-J(beta) primer sets and genomic DNA PCR amplification, we showed that CD34+7+, but not CD34+7-, contained D-J(beta) rearrangements without concomitant V-D(beta) recombination. These partial TCR-beta rearrangements within CD34+7+ progenitors were also confirmed at the transcriptional level. Furthermore, whereas none of the CD34+ cord blood cell fraction expressed TCR-alpha transcripts, mature V(delta)1-C(delta) mRNA could be amplified from the CD34+7+ subset. The TdT gene was also transcriptionally active in CD34+7+ cells, thus confirming their lymphoid progenitor content. These data indicate that cord blood CD34+7+ cells, like CD34+7+1- neonatal thymocytes, can initiate TCR-beta gene recombination, reinforcing the idea that T cell commitment may occur before prothymocyte migration to the thymus.
Inactivation of the small GTP binding protein Rho induces multinucleate cell formation and apoptosis in murine T lymphoma EL4.
Authors: Moorman J P , Bobak D A , Hahn C S 
Published: December 2022

Abstract
The small G-protein Rho regulates the actin microfilament-dependent cytoskeleton. Exoenzyme C3 of Clostridium botulinum ADP-ribosylates Rho at Asn41, a modification that functionally inactivates Rho. Using a Sindbis virus-based transient gene expression system, we studied the role of Rho in murine EL4 T lymphoma cells. We generated a double subgenomic infectious Sindbis virus (dsSIN:C3) recombinant which expressed C3 in &gt;95% of EL4 cells. This intracellular C3 resulted in modification and inactivation of virtually all endogenous Rho. dsSIN:C3 infection led to the formation of multinucleate cells, likely by inhibiting the actin microfilament-dependent step of cytokinesis. Intriguingly, in spite of the inhibition of cytokinesis, karyokinesis continued, with the result that cells containing a nuclear DNA content as high as 16N (eight nuclei) were observed. In addition, dsSIN:C3-mediated inactivation of Rho was a potent activator of apoptosis in EL4 cells. To discern whether the formation of multinucleate cells was responsible for the activation of apoptosis, 5-fluorouracil (5-FUra) was used to induce cell cycle arrest. As expected, EL4 cells treated with 5-FUra were prevented from forming multinucleate cells upon infection with dsSIN:C3. dsSIN:C3 infection, however, still caused marked apoptosis in 5-FUra-treated cells, indicating that this activation of apoptosis was independent of multinucleate cell formation.
Inhibition of constitutive serine phosphatase activity in T lymphoma cells results in phosphorylation of pp19/cofilin and induces apoptosis.
Authors: Samstag Y , Dreizler E M , Ambach A , Sczakiel G , Meuer S C 
Published: December 2022

Abstract
In untransformed T lymphocytes, pp19/cofilin, a cytoplasmic actin-binding protein, undergoes dephosphorylation and nuclear translocation in response to costimulation through accessory receptors (e.g., CD2), but not following TCR/CD3 triggering. In malignant T lymphoma cells, dephosphorylation and nuclear translocation of pp19/cofilin occur spontaneously through constitutive activation of a serine phosphatase. Blockade of these processes by the serine phosphatase inhibitor okadaic acid leads to apoptosis. Moreover, lowering the intracellular pp19/cofilin concentrations by antisense-cofilin transfection results in reduced cloning efficiencies. These findings provide support for the view that pp19/cofilin plays a critical role in the growth and survival of both untransformed and malignant T lymphocytes.
Expression of HLA-G in human mononuclear phagocytes and selective induction by IFN-gamma.
Authors: Yang Y , Chu W , Geraghty D E , Hunt J S 
Published: December 2022

Abstract
In situ hybridization studies have shown that at early but not late stages of gestation, human placental stromal cells, many of which are macrophages (Hofbauer cells), contain HLA-G message. In this study, the HLA-G protein was identified in the macrophage-like stromal cells by immunohistochemistry using the anti-HLA-G mAb, 87G. Expression of the HLA-G gene was then analyzed in macrophage cell lines (U937, HL-60, THP-1) and blood monocytes. HLA-G mRNA identified by using reverse transcriptase PCR was consistent with production of a transcript containing intron 4, which codes for a soluble form of HLA-G. Low levels of HLA-G mRNA were identified in mononuclear phagocytes by Northern blot hybridization, and little if any HLA-G Ag was detectable. By contrast, essentially all of the cells displayed high levels of HLA-B/C H chains detected by the mAb, 4E, and B2m. Treatment of macrophage cell lines and monocytes with IFN-gamma increased steady-state levels of HLA-G mRNA, stimulated higher levels of cell surface and intracellular HLA-G Ag in a dose-dependent manner, and increased the proportions of HLA-G relative to HLA-B/C. INF-alpha and IFN-beta enhanced steady-state levels of HLA-G mRNA and in some lines modestly increased the numbers of weakly positive cells but were poor inducers of cell-surface and intracellular HLA-G and did not increase HLA-G relative to HLA-B/C. Thus, mononuclear phagocytes express low levels of HLA-G mRNA and protein, and IFN-gamma selectively enhances expression of this HLA class Ib gene relative to HLA class Ia, which could influence the repertoire of peptides presented during embryogenesis as well as during inflammatory situations in adults. Soluble HLA-G might influence both fetal and maternal immune responses.
Characterization and subcellular localization of target membrane soluble NSF attachment protein receptors (t-SNAREs) in macrophages. Syntaxins 2, 3, and 4 are present on phagosomal membranes.
Authors: Hackam D J , Rotstein O D , Bennett M K , Klip A , Grinstein S , Manolson M F 
Published: December 2022

Abstract
Phagosomes formed during ingestion of microorganisms by leukocytes undergo a rapid maturation, generating an acidic, microbicidal organelle. Maturation requires interactions with intracellular vesicles that dock and fuse preferentially with the phagosomal membrane. The basis of specificity of vesiculo-phagosomal interaction has not been elucidated. By contrast, the molecular basis of vesicular fusion in other systems is better understood. At neural synapses, vesicular docking and fusion to the plasma membrane are mediated by a protein complex including syntaxin 1. We explored whether macrophages contain syntaxins, and whether selective fusion of vesicles with the phagosome results from the accumulation of syntaxins in the phagosomal membrane. Isoform-specific Abs were utilized to demonstrate utilized to demonstrate that syntaxins 2, 3, and 4, but not syntaxin 1, are present in murine and human macrophages. Biochemical characterization demonstrated the presence of these syntaxins on microsomes, where they are integral membrane proteins. Subcellular localization using confocal immunofluorescence microscopy demonstrated that syntaxins 3 and 4 are present on the plasma membrane as well as on intracellular vesicles. Importantly, phagosomes isolated by fractionation were shown by immunoblotting to contain syntaxins 2, 3, and 4, suggesting that they may participate in phagosomal maturation. The density of the syntaxins on the phagosomal membrane was found to be comparable with that on the surface membrane. This suggests that preferential fusion of vesicles with the phagosomal membrane is not the result of segregation of the syntaxins to this organelle. Instead, local generation of second messengers in the vicinity of the phagosomal membrane may trigger focal fusion.
Stimulation of macrophages and neutrophils by complexes of lipopolysaccharide and soluble CD14.
Authors: Hailman E , Vasselon T , Kelley M , Busse L A , Hu M C , Lichenstein H S , Detmers P A , Wright S D 
Published: December 2022

Abstract
Sensitive responses of monocytes, macrophages, and neutrophils to bacterial LPS require membrane-bound CD14 (mCD14) and a plasma protein called LPS-binding protein (LBP). Cells lacking mCD14 respond to complexes of LPS and soluble CD14 (sCD14); these responses do not require LBP. To determine whether LBP is necessary for responses of mCD14-bearing cells to LPS, we measured responses of macrophages and neutrophils to complexes of LPS and sCD14 formed in the absence of LBP. We found that the amount of LPS needed to induce adhesive responses of neutrophils or cytokine production by macrophages was the same whether LPS was added with LBP or as LPS-sCD14 complexes, and was &gt;100-fold less than when LPS was added alone. This result supports the view that LBP transfers LPS to CD14, but is not directly involved in responses of CD14-bearing cells to LPS. Responses of neutrophils to LPS-sCD14 complexes could be inhibited partially by blocking mCD14, suggesting that LPS may move rapidly from sCD14 to mCD14. Additionally, we found that responses of neutrophils to LBP and smooth LPS were made 30 to 100 times more sensitive when sCD14 was added. Our findings show that LBP is not necessary for the activation of CD14-bearing cells with LPS, and suggest that LPS-sCD14 complexes are an important intermediate in the inflammatory responses of leukocytes to LPS.
Calreticulin binds hYRNA and the 52-kDa polypeptide component of the Ro/SS-A ribonucleoprotein autoantigen.
Authors: Cheng S T , Nguyen T Q , Yang Y S , Capra J D , Sontheimer R D 
Published: December 2022

Abstract
Calreticulin (CR) is a multifunctional, calcium-binding protein that has recently been shown to bind to and promote the replication of the rubella virus genome in mammalian cells. While CR is now widely recognized as a new human autoantigen, the relationship between CR and the Ro/SS-A ribonucleo-protein (RNP) autoantigen has been somewhat controversial. In this work, we demonstrate that unphosphorylated human rCR binds specifically and distinctly to in vitro transcribed forms of hYRNA, the RNA backbone of the Ro/SS-A RNP particle. This interaction appears to be mediated by binding through the N- and C-terminal domains of CR, but not by the central proline-rich domain. Furthermore, our studies indicate that CR can facilitate the binding of the 60-kDa polypeptide component of the Ro/SS-A RNP (Ro60) to hYRNA. In addition, CR and the 52-kDa Ro/SS-A polypeptide (Ro52) appear to be capable of interacting through direct protein-protein binding. These studies confirm that CR is an hYRNA-binding protein, and provide for the first time a molecular mechanism by which Ro52 can be linked physically to hYRNA. Through these molecular interactions and its known functional role as a chaperone, it is suggested that CR plays a supportive role in the formation of the Ro/SS-A RNP complex. The capacity of CR to interact with RNA viruses such as rubella provides an additional argument for an infectious trigger for autoantibody production against self RNP particles such as Ro/SS-A.
Selection of antigenic and immunogenic mimics of hepatitis C virus using sera from patients.
Authors: Prezzi C , Nuzzo M , Meola A , Delmastro P , Galfrè G , Cortese R , Nicosia A , Monaci P 
Published: December 2022

Abstract
Using sera from hepatitis C virus (HCV)-infected patients and noninfected subjects to screen random peptide libraries displayed on phage, we selected peptides specifically reacting with sera from infected patients. These phage- borne peptides were shown to mimic distinct HCV determinants. They detected in all cases the presence of anti-HCV Abs in a large panel of patients' sera, thus demonstrating the high sensitivity of the selected peptides as diagnostic markers. In addition, this diagnostic approach allowed a detailed characterization of the individual humoral response to viral infection. Phage-displayed HCV mimics were substitutes for the authentic HCV epitopes in inducing a strong specific response against HCV when used as immunogens in mice. These results support the search for HCV mimics with the potential to elicit a protective immune response as leads for the development of a mimotope-based vaccine against viral infection.
Anti-psoriatic drug anthralin activates transcription factor NF-kappa B in murine keratinocytes.
Authors: Schmidt K N , Podda M , Packer L , Baeuerle P A 
Published: December 2022

Abstract
Anthralin is one of the most effective and safest therapeutic agents for the treatment of psoriasis, a skin disease characterized by epidermal hyperproliferation and hyperkeratosis. The drug induces and inflammatory response in the skin involving the expression of cytokine and cell adhesion molecule genes that is thought to be essential for its therapeutic efficacy. Reactive oxygen intermediates (ROIs) generated in vivo during the auto-oxidation of anthralin were discussed as mediators of the inflammatory response, but it is not yet understood how this is translated into novel inflammatory gene expression. In this study, we show that at little as 10 microM anthralin can activate a prototypic form of transcription factor NF-(kappa)B, a central transcriptional regulator of inflammatory and immune responses. Two different lines of evidence show that ROIs, in particular H2O2, are second messengers for the anthralin-induced NF-(kappa)B activation. Firstly, the activation could be inhibited by the structurally unrelated antioxidants N-acetyl-L-cysteine and pyrrolidinedithiocarbamate. Secondly, keratinocytes stably overexpressing catalase showed a significant reduction of NF-(kappa)B activation, while stable overexpression of Cu/Zn-superoxide dismutase augmented the anthralin effect. Our data suggest that ROI-induced NF-(kappa)B plays a role in the anti-psoriatic activity of the drug anthralin.