bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell surface P- and E-selectin support shear-dependent rolling of bovine gamma/delta T cells.
Authors: Jutila M A , Bargatze R F , Kurk S , Warnock R A , Ehsani N , Watson S R , Walcheck B 
Published: December 2022

Abstract
The vascular selectins P- and E-selectin are inducible adhesion proteins expressed by endothelial cells that have been shown to support shear-dependent rolling of myeloid cells. This interaction is thought to be a prerequisite event for subsequent steps, such as tight adhesion/aggregation and transendothelial cell migration, involved in the accumulation of leukocytes into tissues. Certain lymphocyte subsets have also been shown to bind the vascular selectins, but the importance of this interaction in mediating shear-dependent rolling, as described for myeloid cells, has not been demonstrated. We expand on our earlier observation that bovine gamma/delta T cells bind E-selectin by showing that this interaction leads to a reproducible rolling event in assays done under shear forces that approximate those that occur in vivo. E-selectin, expressed by L cell transfectants or cytokine-stimulated human and bovine endothelial cells, equally supports the shear-dependent rolling interaction. The lymphocyte adhesion proteins L-selectin, CD44, and CD2 do not contribute to this event. Neuraminidase treatment of the gamma/delta T cells or addition of EDTA to the assay completely blocks the rolling interaction. We further show for the first time that P-selectin expressed by thrombin-activated platelets or a soluble P-selectin/human Ig chimera specifically binds gamma/delta T cells. The P-selectin interaction is similar to the rolling event mediated by E-selectin--it requires divalent cations and sialic acid on the lymphocyte, it lacks involvement of L-selectin and CD44, and rolling occurs under physiologic shear conditions. These results provide the documentation that the vascular selectins can support shear-dependent rolling of a lymphocyte subset and that P-selectin mediates the adhesion of gamma/delta T cells.
T lymphocyte development and function in dogs with X-linked severe combined immunodeficiency.
Authors: Somberg R L , Robinson J P , Felsburg P J 
Published: December 2022

Abstract
Canine X-linked severe combined immunodeficiency disease (XSCID) is characterized by a failure to thrive, thymic dysplasia, and a lack of a T lymphocyte mitogenic response. As in human XSCID, affected dogs in our colony have a mutation in the IL-2R-gamma gene. This mutation dramatically altered T lymphocyte development, because XSCID thymi were severely reduced in size and cellularity, contained an increased proportion of immature CD4-CD8- thymocytes, a decreased proportion of intermediate CD4+CD8+ thymocytes, and a normal proportion of CD4+CD8- and CD4-CD8+ thymocytes. XSCID thymi were also deficient in the percentage of CD3-L+ thymocytes. Interestingly, several XSCID dogs had normal percentages of CD3-L+ PBL. Although the mutation did not interfere with IL-2 production, PHA-activated XSCID PBL demonstrated severely diminished IL-2 binding and were nonresponsive to IL-2. These results indicate that the lack of a functional IL-2R-gamma chain in dogs with XSCID primarily affects developing CD4-CD8- thymocytes as they acquire the cell surface Ag CD3-L and interferes with the ability of peripheral T lymphocytes to bind and respond to IL-2.
Regulation of cytotoxic T cells by ecto-nicotinamide adenine dinucleotide (NAD) correlates with cell surface GPI-anchored/arginine ADP-ribosyltransferase.
Authors: Wang J , Nemoto E , Kots A Y , Kaslow H R , Dennert G 
Published: December 2022

Abstract
This report demonstrates that incubation of cytotoxic T cells with NAD causes suppression of their ability to proliferate in response to stimulator cells or to lyse targets. Effects are evident after incubation for 3 h with concentrations of NAD as low as 1 microM and are sustained for many hours after removal of NAD from culture media. Suppression is a result of the failure of CTL to form specific conjugates with targets as well as a lower level of activation in response to TCR-mediated stimulation, although TCR-mediated transmembrane signaling is demonstrable. Metabolites of NAD such as nicotinamide, ADP-ribose, and cyclic-ADP-ribose have no detectable effect, indicating that NAD-glycohydrolase or ADP-ribose cyclase do not mediate suppression. Incubation of intact CTL with [32P]NAD leads to incorporation of 32P into a particulate, subcellular fraction, a reaction that is not inhibitable by ADP-ribose. Hydroxylamine, but not mercuric ion releases [32P]ADP-ribose, whereas phosphodiesterase releases [32P]AMP from the particulate subcellular fraction, suggesting that labeling is a result of enzymatic mono-ADP-ribosylation of arginines. In support of this, treatment of intact CTL with phosphatidylinositol-specific phospholipase C releases an arginine-specific ADP-ribosyltransferase and causes insensitivity to ecto-NAD suppression. These results suggest that a GPI-anchored ADP-ribosyltransferase uses ecto-NAD to ADP-ribosylate proteins that regulate CTL function.
The role of NF-Y and IRF-2 in the regulation of human IL-4 gene expression.
Authors: Li-Weber M , Davydov I V , Krafft H , Krammer P H 
Published: December 2022

Abstract
Activity of the IL-4 promoter was shown to be regulated by multiple cis-acting elements. In this study, two additional regulatory elements, a CCAAT element and a 15-nucleotide element homologous to the IFN- and virus-stimulation response element (ISRE), were identified in the human promoter region at -195 to -172. The ISRE-homologous sequence was shown to interact with two nuclear proteins, IRF-2, a transcriptional repressor of the IFN genes, and an NF-1-like factor. Mutations of the ISRE site increased overall IL-4 promoter activity twofold, suggesting a possible negative role of IRF-2 in the regulation of IL-4 transcription. The CCAAT element was found to interact with NF-Y, a nuclear factor essential for expression of MHC class II genes. Mutations of the CCAAT element at -195 to -172 resulted in a substantial decrease of IL-4 promoter activity. Furthermore, NF-Y was also found to bind to the previously described NF-ATp binding site of the IL-4 promoter (-79 to -62, originally described as "P element"), and the previously described P-binding complex NF-P was shown to contain NF-Y. These findings suggest that NF-Y may play an important role in the regulation of IL-4 gene expression.
Bovine C4b binding protein. Molecular cloning of the alpha- and beta-chains provides structural background for lack of complex formation with protein S.
Authors: Hillarp A , Thern A , Dahlbäck B 
Published: December 2022

Abstract
C4b binding protein (C4BP) regulates the complement system. It also interacts with anticoagulant protein S and with serum amyloid P component. Human C4BP is composed of seven identical 70-kDa alpha-chains and one 45-kDa beta-chain. The binding site for C4b is located on the alpha-chain, whereas the beta-chain binds protein S. Nothing is known about the structure and function of bovine C4BP. No complexed form of protein S was detected by using a gel filtration chromatography system combined with Western blotting. Bovine cDNA clones encoding the C4BP alpha- and beta-chains were isolated from a bovine liver cDNA library. Three overlapping alpha-chain clones predicted a 562-amino acid residues-long mature polypeptide. The overall amino acid sequence similarity with the human alpha-chain was 61%. Like its human counterpart, the bovine alpha-chain is composed of eight contiguous short consensus repeat units, each of approximately 60 amino acid residues, and a carboxyl-terminal nonrepeat region. One bovine beta-chain clone was found and characterized. It predicted a mature bovine beta-chain of 181 amino acid residues. The identity with the human beta-chain was 65% at the amino acid level. A noteworthy difference between bovine and human beta-chains was that the bovine beta-chain only contained two short consensus repeats compared with three in human beta-chain. Sequence alignment indicates that the region corresponding to residues 1-60 (repeat 1) in the human beta-chain is absent in the homologous bovine polypeptide. Because the short consensus repeats of the human beta-chain contain the binding site for protein S, the lack of one repeat unit in the bovine beta-chain may provide a clue to the lack of complex formation between C4BP and protein S in bovine plasma.
L-selectin and very late antigen-4 integrin promote eosinophil rolling at physiological shear rates in vivo.
Authors: Sriramarao P , von Andrian U H , Butcher E C , Bourdon M A , Broide D H 
Published: December 2022

Abstract
Adherence of eosinophils to vascular endothelium and their accumulation at sites of allergen challenge are hallmarks of allergic inflammation. However, the molecular mechanisms mediating eosinophil adhesion under conditions of blood flow are not well understood. The present studies were performed to identify the receptors on human eosinophils involved in initiating adhesion to activated endothelium at physiologic shear rates in vivo. We have compared the relative contribution of L-selectin, VLA-4 (CD49d), and CD18 integrins in mediating eosinophil adhesion to microvascular endothelial cells in the rabbit mesentery by using intravital video microscopy. Eosinophils were found to roll in venules, but not arterioles, and this rolling could be stimulated by activation of endothelium with IL-1. In contrast to neutrophil rolling, which is predominantly L-selectin-dependent, eosinophil rolling was mediated by L-selectin, and also VLA-4. mAbs to L-selectin and VLA-4 alpha, but not CD18, significantly inhibited eosinophil rolling in vivo. The inhibition of VLA-4-mediated eosinophil rolling was not caused by modulation of eosinophil L-selectin or CD18 expression. This inhibition also was not caused by nonspecific inhibitory effect of the Abs studied, because the anti-VLA-4 mAbs inhibited eosinophil (VLA-4+) but not neutrophil (VLA-4-) rolling in the mesenteric venules. These results demonstrate that early events of eosinophil adhesion, i.e., rolling, are mediated by multiple adhesion receptors, including L-selectin and VLA-4, at physiologic shear rates in vivo.
Apoptotic cell death induced by intracellular proteolysis.
Authors: Williams M S , Henkart P A 
Published: December 2022

Abstract
To mimic the injection of granzymes into target cells by cytotoxic lymphocytes or the activation of endogenous proteases in programmed cell death, the proteases chymotrypsin, proteinase K, or trypsin were loaded into the cytoplasm of several different cell types using the osmotic lysis of pinosomes technique. Internalization of these proteases caused cell lysis within several hours, accompanied by extensive nuclear damage in most but not all combinations of target cells and proteases. This nuclear damage, quantitated by DNA release from nuclei, was associated with apoptotic features including DNA fragmentation into nucleosomal ladders, chromatin condensation, nuclear fragmentation, and membrane blebbing. Agents reported to block programmed cell death, including aurintricarboxylic acid, inhibitors of energy metabolism, and protein or RNA synthesis, failed to block this protease-induced death, although some inhibited nuclear damage. In separate experiments, introduction of staphylococcal nuclease into cells led to near complete (at least 75% of total) nucleosomal DNA fragmentation within 6 to 8 h. Condensation of chromatin did not accompany this fragmentation to the same extent, and there was approximately a 10-h lag between half-maximal DNA fragmentation and 50% loss of membrane integrity. The results suggest that activation of intracellular proteases during cell death by any molecular pathway could give rise to apoptotic morphology and DNA fragmentation.
HIV-1 suppression of hematopoiesis in vitro mediated by envelope glycoprotein and TNF-alpha.
Authors: Maciejewski J P , Weichold F F , Young N S 
Published: December 2022

Abstract
Dysmorphic marrow morphology and bone marrow failure are common in AIDS patients, but the mechanism of HIV-1 effects on blood cell production is unclear. Experiments to test the susceptibility of hematopoietic progenitor cells to HIV-1 infection have led to conflicting results. We found that hematopoietic colony formation by burst-forming units-erythroid and CFU-GM was equivalently inhibited by both active and heat-inactivated, noninfectious virus. Inhibition was dependent on the presence of macrophages and was not observed in cultures derived from highly enriched CD34+ cells. We hypothesized that TNF-alpha, produced by mononuclear phagocytes after contact with HIV-1 or gp120 and itself a potent suppressor of hematopoiesis, might mediate this effect. The addition of anti-TNF-alpha neutralizing Abs to marrow cultures abrogated inhibition by gp120 or virus. In contrast, neutralizing Abs to Il-4, IFN-alpha, and TGF-beta failed to improve colony formation. TNF-alpha was released from blood monocytes and marrow mononuclear cells stimulated by gp120. TNF-alpha is increased in the blood of patients with late stage AIDS and may mediate many of the symptoms of the disease. Our data do not support a requirement of direct infection of hematopoietic progenitor cells by HIV-1 for the inhibition of hematopoiesis in vitro. We propose instead an indirect mechanism of viral suppression of hematopoiesis as a result of TNF-alpha induction by virus or viral envelope glycoprotein. The importance of local TNF-alpha production in patients' marrow is amenable to clinical testing.
Characterization and expression of alternatively spliced IgE heavy chain transcripts produced by peripheral blood lymphocytes.
Authors: Batista F D , Efremov D G , Burrone O R 
Published: December 2022

Abstract
We have investigated the IgE heavy chain isoforms produced in vivo by analyzing the epsilon mRNA species present in unstimulated PBL and expressing them individually in a myeloma cell line. Seven epsilon mRNA species were identified by using reverse transcription-PCR, cloning, and sequencing analysis. These species included the classical secreted (epsilon CH4-S) and membrane-bound (epsilon CH4-M1'-M2) IgE and five alternatively spliced epsilon transcripts. At the protein level, the five alternatively spliced epsilon transcripts (epsilon CH4*, epsilon CH4-M2', epsilon CH4'-1, epsilon CH4'-1-M2, and epsilon CH3-13-CH4) corresponded to four epsilon heavy chain isoforms, in which various parts of the CH4 domain were replaced by new stretches of amino acids at the carboxyl termini. The same epsilon mRNA species also were present in the IgE producing myeloma cell line U266. However, except for the classical membrane and secreted IgE, the corresponding proteins could not be identified. To further characterize the epsilon CH4-S, epsilon CH4*, epsilon CH4-M2', epsilon CH4'-1, and epsilon CH4-M1'-M2 species, we expressed them as chimeric mouse/human anti-4-hydroxy-5-iodo-3-nitrophenacetyl Abs in a mouse myeloma cell line. Only the classical secreted and membrane isoforms were found to be secreted or expressed on the cell surface, respectively, and the other forms were retained within the cells and degraded. These data suggest that some of the epsilon mRNA isoforms produced by PBL are aberrantly spliced mRNAs, the protein products of which are eliminated by post-translational events.
The E2 molecule (CD99) specifically triggers homotypic aggregation of CD4+ CD8+ thymocytes.
Authors: Bernard G , Zoccola D , Deckert M , Breittmayer J P , Aussel C , Bernard A 
Published: December 2022

Abstract
We have previously described E2 as a 32-kDa transmembrane glycoprotein displaying an isomorphism, as two epitopes (defined by mAbs O662 and L129) are widely distributed on T cells whereas two epitopes are restricted to T cell subsets (defined by mAbs D44 and 12E7). E2, the MIC-2 gene product, is involved in T cell adhesion because anti-E2 mAbs against pan T epitopes block spontaneous T cell rosettes. Pan T E2 mAbs are also able to induce exposure of the phosphatidylserine at the thymocyte surface but not at the surface of mature T lymphocytes, an event most likely linked to adhesion phenomena. We now show here that the anti-E2 mAbs (0662 and L129) that block rosettes and induce phosphatidylserine exposure at the thymocyte surface, and not those reacting with epitopes not involved in adhesion, also trigger aggregation of certain immature T cell lines and no other cell lines tested. Among the normal cells tested, anti-E2 mAbs exclusively induce homotypic aggregation of CD4+ CD8+ human thymocytes. This phenomenon is temperature, energy, and Mg++ dependent, and requires an intact cytoskeleton. These adhesion properties are rather characteristic of integrins. Nevertheless, mAb against beta 1, beta 2, and beta 3 integrin chains, as well as those against alpha-chains known to be present on thymocytes, are unable to block corticothymocyte aggregation. We conclude that E2 triggers on corticothymocytes and no other T cells a homotypic adhesion pathway most likely mediated by an uncharacterized integrin.
Characterization of regions of herpes simplex virus type 1 glycoprotein E involved in binding the Fc domain of monomeric IgG and in forming a complex with glycoprotein I.
Authors: Basu S , Dubin G , Basu M , Nguyen V , Friedman H M 
Published: December 2022

Abstract
Glycoprotein E (gE) and glycoprotein I (gI) of herpes simplex virus type 1 form a molecular complex that binds the Fc domain of monomeric IgG. Two approaches were used to define regions of gE-1 involved in monomeric IgG binding and complex formation with gI-1. First, we constructed 22 in-frame gE-1 linker-insertion mutants and, in cotransfection experiments with gI-1, assayed each mutant for IgG monomer binding and the ability to complex with gI-1. Nine mutants with insertions between gE-1 amino acids 235 and 380 failed to bind IgG monomers, whereas mutants outside this region retained binding activity. Each mutant reacted with several gE-1 mAbs, was detected at the cell surface, and was fully processed. Only two gE-1 mutants with insertions at residues 235 and 264 lost the ability to co-immunoprecipitate with gI-1, which defines a region of gE-1 that complexes with gI-1. As an additional approach, we assayed 8 gE-1/gD-1 fusion proteins containing large overlapping gE-1 peptides inserted within the ectodomain of gD-1 for binding of IgG monomers and complex formation with gI-1. Three fusion proteins containing gE-1 peptides that overlap at residues 183-402 bound monomeric IgG. This region of gE-1 includes the Fc binding region defined by linker insertion mutagenesis. Five fusion proteins containing gE-1 peptides that overlap at residues 183-288 were co-immunoprecipitated with gI-1, confirming results of gE-1 linker insertion mutagenesis. These studies define two regions on gE-1 involved in Fc binding activity, one that interacts with gI-1, and another that binds IgG.
Antitumor activities of subsets of human IL-2-activated natural killer cells in solid tissues.
Authors: Vujanovic N L , Yasumura S , Hirabayashi H , Lin W C , Watkins S , Herberman R B , Whiteside T L 
Published: December 2022

Abstract
Human NK cells can be separated into two functionally distinct subpopulations based on the ability to rapidly respond to IL-2 by adherence to solid surfaces. To determine functions of the NK cell subsets in solid tumor tissues, adherent (A) and nonadherent (NA) NK cells were evaluated for their ability to infiltrate multicellular tumor spheroids in vitro, to kill carcinoma (CA) cell targets in these spheroids, and to mediate antitumor activity in vivo. A-NK cells were less cytolytic than NA-NK cells against CA targets in single cell suspensions or in monolayers. However, A-NK cells showed a significantly better ability than NA-NK cells to infiltrate tumor tissues and kill tumor cells in spheroids of human squamous cell CA of the head and neck or breast CA. Perilesional delivery of human A-NK cells and IL-2 resulted in regression of established human squamous cell carcinoma of the head and neck tumors growing subcutaneously in immunosuppressed nude mice. Similarly, in a xenograft model of human gastric CA metastatic to liver of nude mice, a single intrasplenic injection of A-NK cells in combination with i.p. infusions of IL-2 significantly reduced the number of established hepatic metastases (p &lt; 0.007) and prolonged survival of the mice (p &lt; 0.003). In contrast, NA-NK cells were ineffective in either of the in vivo xenograft tumor models. These findings demonstrate that A-NK cells represent a biologically unique and important subset of NK cells that, in contrast to the rest of NK cells, function as effector cells in solid tumor tissues and, consequently, have a great antitumor therapeutic potential.
Characterization of surface lymphotoxin forms. Use of specific monoclonal antibodies and soluble receptors.
Authors: Browning J L , Dougas I , Ngam-ek A , Bourdon P R , Ehrenfels B N , Miatkowski K , Zafari M , Yampaglia A M , Lawton P , Meier W 
Published: December 2022

Abstract
Lymphotoxin (LT) is a cytokine related to TNF, found in human systems in both secreted and membrane bound forms. The well characterized secreted form is a trimer of a single protein, LT-alpha, whereas the surface form is composed of a complex between two related molecules, LT-alpha and LT-beta. Because there is a distinct receptor for the complex, the membrane form is believed to signal via events different from those elicited by TNF and secreted LT-alpha. By using a battery of anti-LT-alpha and LT-beta mAbs, it is clear that two LT surface forms exist on the surface of PMA-activated II-23 cells, a human T cell hybridoma. Assuming that these surface forms are trimers, a minor form appears early after induction having an apparent stoichiometry of LT-alpha 2/beta 1 and is recognized by one group of anti-LT-alpha mAbs and the p55-TNF receptor. The second and predominant form has an apparent LT-alpha 1/beta 2 composition and is recognized by a second group of pantrophic anti-LT-alpha mAbs and the LT-beta receptor. Neither of the heteromeric forms nor a putative LT-beta homotrimeric form were found to be secreted. The properties of surface LT on the II-23 cell system were similar to those of the surface LT forms on Chinese hamster ovary cells transfected with both LT-alpha and LT-beta genes and a number of lymphoid tumor lines. These experiments point toward the LT-alpha 1/beta 2 complex as the predominant membrane form of LT on the lymphocyte surface, and this complex is the primary ligand for the LT-beta receptor.