bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recognition and destruction of virus-infected cells by human gamma delta CTL.
Authors: Bukowski J F , Morita C T , Brenner M B 
Published: January 2023

Abstract
We examined the response of human gamma delta T cells to herpes simplex virus (HSV). PBMC from HSV seropositive individuals were stimulated with autologous HSV-infected PHA blasts. There was a 4- to 28-fold expansion of gamma delta T cells that were &gt; 95% positive for TCR variable region genes V gamma 2 paired with V delta 2 (V gamma 2V delta 2 T cells). PBMC from these cultures lysed Daudi cells and HSV-infected, but not mock-infected targets. The cytotoxicity was contained predominantly within the gamma delta T cell subset, because depletion of alpha beta T cells enriched the cytotoxic activity, whereas depletion of gamma delta T cells abrogated it. Surprisingly, cloned V gamma 2V delta 2 T cells derived from PHA or mycobacterial stimulation also lysed HSV-infected, but not mock-infected targets. Moreover, both the polyclonal HSV-stimulated gamma delta T cells and the cloned V gamma 2V delta 2 T cells derived from unrelated stimulators (PHA or mycobacteria) also lysed targets infected with vaccinia virus, which is unrelated to HSV. Cytotoxic activity was not restricted by classical HLA class I or class II molecules, and could be blocked with mAbs to CD3 and the gamma delta TCR. These data demonstrate that gamma delta T cells proliferate in response to virus-infected cells and mediate their destruction. Such virus-stimulated gamma delta T cells seem to mediate a TCR-dependent antiviral effector function which is most likely not directed against Ags specific to a particular virus, but presumably directed against a cellular ligand induced or modified by acute viral infection.
TNF-alpha and IFN-gamma stimulate a macrophage precursor cell line to kill Listeria monocytogenes in a nitric oxide-independent manner.
Authors: Leenen P J , Canono B P , Drevets D A , Voerman J S , Campbell P A 
Published: January 2023

Abstract
Macrophages are important effector cells for resolving infection with the facultative intracellular bacterium Listeria monocytogenes. However, not all macrophages have the ability to kill this organism. Certain factors, such as cytokines, are apparently required for induction of macrophage bactericidal activity. In vivo studies have shown that both TNF-alpha and IFN-gamma play important roles in resistance against Listeria. Yet whether they act directly on macrophages has been difficult to determine, because homogeneous populations of cells that can be induced to express microbicidal activity have not been available. Instead, bactericidal macrophages are typically found in heterogeneous exudates, such as those elicited by inflammatory agents. In this study we show that sequential stimulation with TNF-alpha and IFN-gamma induces the nonphagocytic, nonbactericidal mouse macrophage precursor hybrid cell line W1C3 to phagocytose and kill Listeria efficiently. This provides the first direct evidence that TNF-alpha and IFN-gamma are both necessary and sufficient to induce macrophages to kill Listeria, and that they act directly on macrophages. Data presented here also show that TNF-alpha and IFN-gamma induced the macrophages to produce large amounts of reactive nitrogen intermediates (RNI), but complete inhibition of RNI generation did not decrease bactericidal activity. This indicates that induction of listericidal activity in these cells does not require generation of RNI. Taken together, these findings suggest that TNF-alpha and IFN-gamma act in synergy directly on at least some macrophages to induce them to express listericidal activity in a RNI-independent manner.
Differential modulation of astrocyte cytokine gene expression by TGF-beta.
Authors: Benveniste E N , Kwon J , Chung W J , Sampson J , Pandya K , Tang L P 
Published: January 2023

Abstract
In this study, we demonstrate that TGF-beta inhibits TNF-alpha expression, and induces/enhances IL-6 expression by primary rat astrocytes. Treatment of astrocytes with TGF-beta alone had no effect on TNF-alpha mRNA or protein expression; however, TGF-beta suppressed induction of TNF-alpha expression by three different stimuli (IFN-gamma/LPS, IFN-gamma/IL-1 beta, TNF-alpha) at both the protein and mRNA level. The extent of TGF-beta-mediated inhibition was greatest when astrocytes were pretreated with TGF-beta for 6 to 24 h, then exposed to the inducing stimuli. Inhibition of TNF-alpha mRNA steady-state levels by TGF-beta was a result of inhibition of TNF-alpha gene transcription, rather than degradation of the TNF-alpha message. In contrast, TGF-beta alone induced expression of IL-6 by astrocytes and synergized with two other cytokines, IL-1 beta and TNF-alpha, for enhanced IL-6 expression. TGF-beta-induced/enhanced IL-6 expression was mediated by transcriptional activation of the IL-6 gene. These results indicate that TGF-beta is an important regulator of cytokine production by astrocytes under inflammatory conditions in the brain.
Novel cell-surface Ag expressed on rat osteoclasts regulating the function of the calcitonin receptor.
Authors: Kukita T , Kukita A , Nagata K , Maeda H , Kurisu K , Watanabe T , Iijima T 
Published: January 2023

Abstract
Osteoclasts are known to be hematopoietic in origin. However, the detailed mechanisms of their differentiation and activation are not known. Cell-surface molecules preferentially expressed on cells of the osteoclast lineage may play some important roles in these processes. We prepared a mAb that recognizes a unique cell-surface membrane protein specifically expressed on rat osteoclasts. Expression of this Ag, designated as Kat1 Ag, was markedly stimulated by a factor secreted by the osteoblastic cell line ROS 17/2.8. Binding studies of 125I-labeled calcitonin (CT) showed that the Ag was not the CT receptor (CTR). However, interestingly, studies of the biologic activity of this mAb that recognizes Kat1-antigen (mAb Kat1) revealed possible regulatory functions of this Ag in osteoclasts. Firstly, mAb Kat1 significantly elevated the binding affinity of the CTR expressed on osteoclast-like cells without altering the number of receptors. Secondly, CT-sensitivity of the osteoclast progenitor cells in the system of osteoclast differentiation showed marked augmentation on treatment of these cells with this mAb. Even a very low concentration of CT (0.1 ng/ml) significantly inhibited osteoclast differentiation in the presence of mAb Kat1, whereas a higher concentration of CT (10 ng/ml) was required to inhibit their differentiation in the absence of this mAb. Thirdly, mAb Kat1 inhibited dentin-resorbing activity of osteoclast-like cells. Furthermore, the inhibitory effects of CT on osteoclast-mediated dentin resorption was augmented by the presence of this mAb. These observations strongly suggest that Kat1-antigen is a unique cell-surface protein regulating the affinity of the CTR expressed on osteoclasts and also the bone-resorbing function of these cells.
Inhibitors of serotonin synthesis and antagonists of serotonin 1A receptors inhibit T lymphocyte function in vitro and cell-mediated immunity in vivo.
Authors: Aune T M , Golden H W , McGrath K M 
Published: January 2023

Abstract
The serotonin (5HT1A) receptor subtype is one member of the 5HT1 receptor family and is constitutively expressed on Jurkat cells and is elevated on human T lymphocytes after mitogenic activation. Published reports show that human T lymphocytes and monocytes also release 5HT after stimulation with PHA or IFN-gamma. In lymphocytes and the central nervous system, the 5HT1A receptor is coupled to regulation of adenylate cyclase. The 5HT1A receptor agonists inhibit activation of adenylate cyclase. The purpose of the experiments reported here was to investigate further the role 5HT and the 5HT1A receptor may play in the regulation of human and murine T cell activity. For this purpose, human PBMC or murine spleen cells were used for experimental purposes rather than Jurkat cells. The results show that inhibition of 5HT synthesis inhibits IL-2-stimulated human T cell proliferation and that addition of 5-hydroxytryptophan, a precursor of 5HT, reverses inhibition of T cell proliferation. The 5HT1 receptor antagonist, metitepine, and the 5HT1A selective antagonist, pindobind-5HT1A, also block T cell proliferation. Inhibition by metitepine is reversed by 5HT and by the selective 5HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) (8-OH-DPAT). Selective 5HT1A receptor antagonists cause elevation of cAMP in human T cells. In a murine model, selective 5HT1A receptor antagonists inhibit contact sensitivity responses but not Ab responses to oxazalone in vivo. Inhibition is reversed by 8-OH-DPAT. In addition, production of Th1 cytokines, such as IL-2 and IFN-gamma, by Ag-stimulated, immune murine spleen cells is inhibited by 5HT1A receptor antagonists in vitro but not by 5HT1C/2 receptor antagonists.
Human T cell lymphotropic virus type I-induced T cell activation. Resistance to TGF-beta 1-induced suppression.
Authors: Höllsberg P , Ausubel L J , Hafler D A 
Published: January 2023

Abstract
T cell proliferation is potently suppressed by TGF-beta during the G1 phase of the cell cycle. The mechanism appears to involve inhibition of cell cycle kinases that phosphorylate the retinoblastoma protein (pRb), a key regulator of cell cycle progression from G1 to S phase. Although productive infection with the human T cell lymphotropic virus type I (HTLV-I) induces T cell activation, it also, paradoxically, leads to increased production of TGF-beta. To investigate whether infection by HTLV-I conferred resistance to TGF-beta in non-immortalized T cells, we generated T cell clones from patients with HTLV-I myelopathy by direct single cell cloning. Here we report that HTLV-I-infected but not uninfected T cell clones have hyperphosphorylated pRb consistent with viral-induced T cell activation. Furthermore, the HTLV-I-infected T cells were resistant to growth suppression by rTGF-beta 1 and this correlated with the inability of TGF-beta 1 to prevent hyperphosphorylation of pRb. However, when spontaneously proliferating HTLV-I-infected T cell clones were further stimulated by cross-linking of the CD3/TCR complex, the superimposed proliferation was significantly inhibited by TGF-beta 1, suggesting that the TGF-beta 1 signaling pathway was intact. Together these findings suggest that HTLV-I induces T cell activation through a pathway that is insensitive to TGF-beta 1. This may have implications for the altered immune regulation in patients with HTLV-I myelopathy.
NF-kappa B regulates IL-1 beta transcription through a consensus NF-kappa B binding site and a nonconsensus CRE-like site.
Authors: Cogswell J P , Godlevski M M , Wisely G B , Clay W C , Leesnitzer L M , Ways J P , Gray J G 
Published: January 2023

Abstract
In these studies, we show that NF-kappa B induces transcription from the human pro-IL-1 beta (IL-1 beta) gene. A recombinant plasmid pIL-1(-4000)-CAT, containing 4 kb of the IL-1 beta gene upstream regulatory sequence was transactivated by the p65 subunit of NF-kappa B or by treatment of the cells with a combination of NF-kappa B inducers including LPS, PMA, and dibutyryl cyclic AMP (L+P+C) in U937 cells. Coexpression of p65 with L+P+C treatment led to a synergistic response, whereas coexpression of the I kappa B alpha/MAD-3 protein, in place of p65, blocked L+P+C induction. A series of 5' deletion mutants of the IL-1 beta promoter were used to define two p65 response regions: region I located between -2800 to -2720 bp and region II located between -512 and -133 bp. Electrophoretic mobility shift assays confirmed that NF-kappa B-like proteins could bind to two consensus binding sites in region II. A site-specific mutation in only one of these NF-kappa B sites (-296/-286 bp) caused a specific loss of induction by p65 or L+P+C. A cyclic AMP response element (CRE) site (-2761/-2753 bp) in region I has been shown previously to be critical for L+P+C induction. Mutation of the CRE in an enhancerless test plasmid containing two copies of region I blocked transactivation by p65. Likewise, coexpression of I kappa B alpha inhibited CRE-dependent L+P+C induction of the wild-type counterpart. These data show that NF-kappa B regulates a nonconsensus CRE site in addition to the consensus binding site at -296/-286 bp and suggest that NF-kappa B may play multiple roles in the induction of IL-1 beta transcription.
Identification of a structural epitope by using a peptide library displayed on filamentous bacteriophage.
Authors: Hoess R H , Mack A J , Walton H , Reilly T M 
Published: January 2023

Abstract
The screening of phage-displayed random peptide libraries has recently emerged as a powerful technique for probing Ab-Ag interactions. We have used this method to identify the epitope recognized by a mAb, CB5B10, raised against plasminogen activator inhibitor type-1 (PAI-1). Two phage libraries, displaying random hexapeptides with or without flanking cysteine residues, were screened for binding to mAb CB5B10. The selected phages were shown to contain similar peptide sequences, all of which were flanked by cysteines. When compared with the crystal structure of PAI-1, the selected peptides closely resemble the sequence of a solvent-exposed loop connecting the COOH-terminal of an alpha-helix at Phe114 to a beta-sheet at Ser119. Because of the constraints imposed by the flanking cysteine residues, the selected peptides appear to mimic the structure and the sequence of the PAI-1 epitope. Specific contacts between the amino acids displayed by the phage and the mAb were explored using site-directed mutants of the phage peptide. The effects of these substitutions on binding to the mAb correlated well with the accessibility of the corresponding residues in the PAI-1 epitope. This is the first example of the use of phage-displayed peptide libraries to identify a structural epitope.
The murine Ig 3' alpha enhancer is a target site with repressor function for the B cell lineage-specific transcription factor BSAP (NF-HB, S alpha-BP).
Authors: Neurath M F , Strober W , Wakatsuki Y 
Published: January 2023

Abstract
Using electrophoretic mobility shift assays (EMSAs) we have identified several target sites for nuclear proteins in the murine heavy chain Ig 3' alpha enhancer. Two of these sites, denoted oligo-H and oligo-K, were shown by several criteria, including cell distribution and stimulation experiments, EMSA cross-competition studies, and proteolytic clipping bandshift assays, to bind to the same protein identical to the transcription factor B cell lineage-specific activator protein (BSAP) (NF-HB, S alpha-BP). To assess the possible functional role of these BSAP binding sites in the 3' alpha enhancer, we transiently transfected a construct containing a 314-bp 3' alpha enhancer fragment upstream of a luciferase reporter gene in MOPC-315 cells, a plasmacytoma line lacking BSAP. In these cells, co-transfection with a vector expressing recombinant BSAP led to significant reduction in the activity of the 3' alpha enhancer fragment. Conversely, in the mature B lymphoma cell line CH12.LX, a cell line that expresses BSAP and has a less active 3' alpha enhancer, selective BSAP down-regulation by an antisense phosphorothioate oligonucleotide was sufficient to considerably up-regulate 3' alpha enhancer activity, as were mutations of both binding sites that prevented binding of BSAP to the 3' alpha enhancer. Our findings thus suggest that the natural loss of BSAP expression in terminally differentiated plasma cells contributes to the activation of the murine Ig 3' alpha enhancer.
Molecular cloning, characterization, and tissue distribution of rat lipopolysaccharide binding protein. Evidence for extrahepatic expression.
Authors: Su G L , Freeswick P D , Geller D A , Wang Q , Shapiro R A , Wan Y H , Billiar T R , Tweardy D J , Simmons R L , Wang S C 
Published: January 2023

Abstract
LPS binding protein (LBP) is a glycoprotein present in normal serum that becomes markedly elevated during acute phase responses. LBP has been reported to greatly potentiate host responses to endotoxin or LPS. Therefore, LBP may play a critical role in the body's response to injury and infection. Little is known about the factors regulating production of LBP. To investigate the regulation of LBP expression, we have cloned the full-length cDNA for rat LBP. The deduced amino acid sequence of rat LBP was highly homologous with that reported for rabbit and human LBP. The sequence of rat LBP further refines the conserved regions found within the family of proteins that bind LPS; this family is comprised of bactericidal permeability-increasing protein and LBP from multiple species. Use of the rat LBP cDNA clone for Northern blot analysis reveals that LBP mRNA levels are markedly up-regulated in liver during acute phase responses. However, in contrast to previous reports, we also find evidence of extrahepatic expression of LBP under these induced conditions. The presence of LBP mRNA in activated tissues other than liver suggests that LBP may play a larger role in local tissue responses to LPS than previously appreciated.
Identification of an N-terminally acetylated encephalitogenic epitope in myelin proteolipid apoprotein for the Lewis rat.
Authors: Zhao W , Wegmann K W , Trotter J L , Ueno K , Hickey W F 
Published: January 2023

Abstract
Proteolipid apoprotein (PLP) is a major component of the central nervous system myelin. As such, it is capable of inducing experimental allergic encephalomyelitis (EAE) in many subhuman species. On the basis of a putative MHC class II binding motif in Lewis rats (RT-1B1) recently identified in our laboratory, the present study identifies one pathogenic T cell epitope of PLP for the Lewis rat, located in the area between amino acid residues 217 and 240. Four overlapping synthetic peptides derived from this region were tested for their antigenicity and encephalitogenicity. Although the longer peptides could not induce EAE in the Lewis rats in their "theoretically" native form after immunization, they were endowed with encephalitogenic ability when modified by N-terminal acetylation. All animals immunized with N-acetylated peptides PLP 217-233 and PLP 224-240 developed inflammation in the lower spinal cord, but with very low incidence of clinical EAE (1 of 12). In contrast, none of the animals immunized with nonacetylated peptides developed either clinical or histologic EAE. Mild inflammation of the spinal cord was also found in two of four rats immunized with N-acetylated peptide PLP 220-234. The animals immunized with the decapeptide, N-acetylated PLP 224-233, did not develop inflammation of the spinal cord. Despite the low incidence of clinical disease, it was possible to generate vigorous T cell lines against all the peptides synthesized from this region of PLP.(ABSTRACT TRUNCATED AT 250 WORDS)
Dendritic epidermal T cells inhibit T cell proliferation and may induce tolerance by cytotoxicity.
Authors: Love-Schimenti C D , Kripke M L 
Published: January 2023

Abstract
Hapten-conjugated cells of the dendritic epidermal T cell (DETC) line AU16 induce specific immunologic tolerance in vivo and inhibit the proliferation of native T cells in response to hapten-bearing dendritic cells in vitro. The purpose of this study was to test the hypothesis that these activities of DETC are mediated by a cytotoxic mechanism. In addition, because AU16 cells, unlike most DETC, express a TCR-alpha beta, we compared their activity in the in vivo and in vitro assays with a TCR(+)-gamma delta DETC line (T245) and an TCR(+)-alpha beta, FITC-specific T cell line (T4/28). Hapten-conjugated AU16 and T245 cells, but not T4/28 cells, induced tolerance to FITC in vivo. In addition, the proliferative response of naive T lymphocytes to gamma-irradiated, hapten-bearing APCs was inhibited by the addition of gamma-irradiated, FITC-conjugated DETC to the cultures on day 0. To determine whether the T cell or the APC was the target, AU16 cells were added to the cultures on day 4, when few APCs remained. FITC-conjugated AU16 and T245 cells profoundly inhibited [3H]thymidine incorporation by the T cells, indicating that the T cell was the target of the DETC. Furthermore, AU16 cells reduced the number of T cells in the in vitro proliferation assay, suggesting that inhibition of [3H]thymidine incorporation was a result of the cytotoxic activity of DETC. We speculate that cytotoxicity may also account for the ability of DETC to induce tolerance in vivo.
Functional role and signal-induced modulation of proteins recognizing the conserved TCATTT-containing promoter elements in the murine IL-5 and GM-CSF genes in T lymphocytes.
Authors: Naora H , van Leeuwen B H , Bourke P F , Young I G 
Published: January 2023

Abstract
The TCATTT-containing element extending from -61 to -41 of the mouse IL-5 gene is highly conserved in the corresponding region of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene and has been previously shown to be involved in regulating inducible GM-CSF gene expression. By using stable transfection assays in the mouse Th2 clone D10.G4.1, we show that the TCATTT-containing element is also involved in the regulation of inducible IL-5 gene expression. The mouse IL-5 and GM-CSF homologues of this element were found by gel shift analysis to form DNA-nuclear protein complexes of similar electrophoretic mobility under conditions in which expression of these genes is induced. However, comparative studies using extracts of D10.G4.1 cells treated with the cellular activators Con A and PMA and the inhibitors cycloheximide and cyclosporin A indicated that the binding activities to the conserved elements in the IL-5 and GM-CSF genes (designated NF-IL-5A and NF-GM-CSFA, respectively) are regulated by different signaling pathways. In addition, NF-IL-5A is not induced in the Th1 clone HDK-1 which does not express the IL-5 gene. The strong correlation between the signal-dependent and cell-specific modulation of IL-5 and GM-CSF gene expression patterns and the binding activities of NF-IL-5A and NF-GM-CSFA suggests that these nuclear proteins are involved in the transduction of T cell activation signals to the transcriptional machinery of these genes through their interactions with their respective TCATTT-containing elements.
Beta 2-microglobulin induces a conformational change in an MHC class I H chain that occurs intracellularly and is maintained at the cell surface.
Authors: Danliczyk U G , Delovitch T L 
Published: January 2023

Abstract
beta 2-microglobulin (beta 2-m) can regulate the cell surface conformation and expression of a class I MHC H chain. To further determine how the intracellular association of beta 2-m with a class I H chain influences the subsequent cell surface conformation and expression of the H chain, we examined the expression of HLA-A3 H chains in transgenic mice. We found that the overall conformation and level of expression of a transgenic HLA-A3 H chain is determined by its previous intracellular association with beta 2-m during its maturation in the endoplasmic reticulum, and that this conformation is not altered appreciably after the H chain reaches the cell surface. This conclusion is based on two observations. First, the conformation-dependent W6/32 mAb reacts with an HLA-A3 H chain bound to human beta 2-m (h beta 2-m) on the surface of lymphocytes from (A3 x h beta 2-m)F1 double transgenic mice in which the two chains associate intracellularly after synthesis and are then co-transported to the surface membrane. Second, this W6/32 mAb does not react with an HLA-A3 H chain/h beta 2-m surface complex formed by the exchange of H chain bound mouse beta 2-m for exogenously added h beta 2-m on lymphocytes from A3 single transgenic mice in which the HLA-A3 H chain is synthesized and transported to the cell surface in association with mouse beta 2-m.