bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engagement of the vitronectin receptor (alpha V beta 3) on murine T cells stimulates tyrosine phosphorylation of a 115-kDa protein.
Authors: Brando C , Shevach E M 
Published: December 2022

Abstract
The murine vitronectin receptor (VNR, alpha V beta 3) is expressed on T cell hybridomas expressing both the alpha beta and the gamma delta TCR as well as on TCR-alpha beta cells activated for prolonged periods of time by mitogens or alloantigens. The VNR functions as a costimulatory molecule for the activation of a subset of gamma delta T cells that express the V gamma 1.1 C gamma 4 V delta 6 TCR and that may recognize a ubiquitously expressed autoantigen. To characterize further some of the signal transduction parameters observed after engagement of the VNR in stimulated T lymphocytes, we have examined the effect of ligation of the VNR by RGDS-containing proteins on the pattern of protein phosphorylation. We demonstrate the appearance of a 115-kDa, tyrosine-phosphorylated protein (pp115) after engagement of the VNR with its ligand, RGDS. pp115 was shown to be immunologically distinct from focal adhesion kinase, did not possess inherent kinase activity, and may represent an as yet unidentified substrate in the integrin signal transduction pathway. Although induction of pp115 was independent of TCR expression, because it was seen in the TG40 hybridoma, which expresses neither the alpha beta nor the gamma delta TCR, pp115 could also be induced by cross-linking of the TCR in a murine TCR gamma delta hybridoma in the absence of any extracellular matrix proteins. This result raises the possibility that induction of pp115 is a common biochemical step in signal transduction by both the TCR and the VNR.
A monoclonal autoantibody that promotes central nervous system remyelination in a model of multiple sclerosis is a natural autoantibody encoded by germline immunoglobulin genes.
Authors: Miller D J , Rodriguez M 
Published: December 2022

Abstract
Antibodies directed against self-Ags are frequently considered detrimental, and have been shown to play a pathogenic role in certain autoimmune diseases. However, the presence of autoreactive Abs in normal individuals suggests that some autoantibodies could participate in normal physiology. Our previous studies demonstrated that monoclonal autoantibodies SCH94.03 and SCH94.32, generated from the splenocytes of uninfected SJL/J mice injected with normal homogenized spinal cord, promote central nervous system remyelination when passively transferred into syngeneic mice chronically infected with Theiler's murine encephalomyelitis virus, an established experimental model of multiple sclerosis. In this study we show that these two monoclonal autoantibodies are identical, and have phenotypic characteristics of natural autoantibodies. By using a solid phase assay system, SCH94.03 and SCH94.32 showed reactivity toward several protein Ags and chemical haptens, with prominent reactivity toward spectrin, (4-hydroxy-3-nitrophenyl)acetyl, and fluorescein. Sequence analysis showed that both SCH94.03 and SCH94.32 were encoded by identical germline Ig light chain V kappa 10/J kappa 1 and heavy chain V23/DFL16.1/JH2 genes, with no definitive somatic mutations. These results indicate that a natural autoantibody participates in a beneficial physiologic response to central nervous system injury.
Three functional soluble forms of the human apoptosis-inducing Fas molecule are produced by alternative splicing.
Authors: Cascino I , Fiucci G , Papoff G , Ruberti G 
Published: December 2022

Abstract
Fas/Apo-1 molecule is an apoptosis-signaling cell surface Ag belonging to the TNFR family. To investigate the possibility that soluble forms of the Fas receptor are expressed in human cells, we analyzed Fas mRNA transcripts obtained from activated peripheral mononuclear cells of healthy donors and from human tumor cell lines. We identified and characterized three human mRNA Fas variants: FasTMDel, FasDel2, and FasDel3. To determine whether the three transcripts were derived by alternative splicing, the Fas genomic intron/exon organization of the regions surrounding the deleted sequences was analyzed in Fas clones isolated from a human genomic library. Expression of the transcripts was studied in COS cells transiently transfected with the FasTMDel, FasDel2, and FasDel3 cDNAs. Immunocytochemical and in vitro apoptosis inhibition studies suggest that the transcripts are expressed as soluble Fas proteins that may play a functional role in the regulation of apoptosis.
Recall of long-lived immunity to Mycobacterium tuberculosis infection in mice.
Authors: Andersen P , Andersen A B , Sørensen A L , Nagai S 
Published: December 2022

Abstract
Our study investigates the recall of immunity in the mouse model of memory immunity to tuberculosis infection. The results provide evidence that recall of immunity is expressed as an accelerated accumulation of potent effector cells in the infected target organs. These effector cells were recruited from the resting pool of memory cells and were immediately triggered to exert their effector functions, leading to a massive release of Th1 cytokines detectable both in splenic extracts and in the serum within the first 24 h of infection. During a primary infection, in contrast, a 14-day delay was observed before significant cytokine levels were reached. After the initial effector phase, the cells blasted and entered into clonal expansion, resulting in a rapid increase in the total number of CD4 CD45RBlow cells in the spleen. The recall of memory immunity was highly efficient and controlled an infectious challenge within the first week. The molecules recognized by the memory effector subset were the proteins secreted from Mycobacterium tuberculosis during growth. By separating the CD4 population into CD45RBhigh and CD45RBlow subsets, the memory effector cells were demonstrated to reside predominantly in the activated population of CD45RBlow CD44high LFA-1high L-selectinlow cells. The key antigenic targets recognized by these cells were identified as Ag85B and a secreted 6-kDa protein (ESAT-6) that elicited the release of exceedingly high levels of IFN-gamma. ESAT-6 was biochemically purified, characterized, and the gene encoding the protein was cloned.
An adenovirus type 5 early region 1B-encoded CTL epitope-mediating tumor eradication by CTL clones is down-modulated by an activated ras oncogene.
Authors: Toes R E , Offringa R , Blom R J , Brandt R M , van der Eb A J , Melief C J , Kast W M 
Published: December 2022

Abstract
Mouse embryo cells (C57BL/6, H-2b) transformed by the E1A and E1B genes of adenovirus type 5 (Ad5E1 MEC) are highly immunogenic. Previously, CTL were cloned from mice immunized with Ad5E1 MEC. These CTL clones were capable of tumor eradication in nude mice, and were directed against the Ad5E1A-encoded decapeptide SGPSNTPPEI, presented by the H-2Db MHC molecule. We have now generated Ad5E1 MEC containing a mutated Ad5E1A-encoded epitope. The mutant Ad5E1 MEC induce a strong CTL response when injected into immunocompetent mice. CTL clones generated against mutant Ad5E1-transformed tumor cells recognize an Ad5E1B-encoded epitope (VNIRNCCYI) in the context of H-2Db. Because this epitope is also present on wild-type Ad5E1 MEC, it is concluded that Ad5E1-transformed tumor cells express at least two CTL epitopes. Interestingly, the lysis of Ad5E1 MEC by the Ad5E1B-specific, but not by the Ad5E1A-specific, CTL clones was strongly diminished by the action of the activated ras oncogene. CTL directed against the Ad5E1B-encoded epitope were, like Ad5E1A-specific CTL, able to eradicate large established Ad5E1-induced tumors in B6 nude mice, demonstrating that CTL activity directed against different CTL epitopes expressed by the same tumor can be exploited for immunotherapy of cancer.
Nonopsonic phagocytosis of Pseudomonas aeruginosa requires facilitated transport of D-glucose by macrophages.
Authors: Barghouthi S , Everett K D , Speert D P 
Published: December 2022

Abstract
Pseudomonas aeruginosa is the predominant respiratory tract pathogen in patients with cystic fibrosis (CF), and its resistance to phagocytosis may contribute to its virulence. P. aeruginosa ingestion by macrophages occurs only in the presence of D-glucose or D-mannose, sugars present in low concentrations in the endobronchial space. Here we show that only isolates of P. aeruginosa and not other bacterial species were ingested by murine macrophages in a glucose-dependent manner. Glucose transport inhibitors blocked both [3H]-2-deoxy-glucose (2dG) uptake and phagocytosis of P. aeruginosa. P. aeruginosa pretreated with 2dG or 5-thio-D-glucose (5TG) was efficiently ingested. Macrophages pretreated with 2dG or 5TG were able to bind but unable to ingest P. aeruginosa in the presence of glucose; however, they efficiently ingested zymosan or IgG-coated sheep erythrocytes. Macrophages produced lactate only from glucose or mannose. The facilitative glucose transporter GLUT1 mRNA transcript was detected by PCR in preparations from purified macrophages. The nucleotide sequence of the PCR product was identical to that published for murine GLUT1. GLUT1 protein was detected with anti-GLUT1-peptide polyclonal Abs. We conclude that glucose exerts its effect on the macrophage, not on the bacterium, in the glucose-dependent nonopsonic phagocytosis of P. aeruginosa and that glucose transport via GLUT1 by the macrophages is required to trigger ingestion. The unique glucose dependency for phagocytosis of P. aeruginosa by macrophages may contribute to the pathogenicity of this bacterial species in CF patients.
CD8 T lymphocytes specific for the secreted p60 antigen protect against Listeria monocytogenes infection.
Authors: Harty J T , Pamer E G 
Published: December 2022

Abstract
The ability of Listeria monocytogenes to gain access to the cytoplasm of infected cells results in the processing and presentation of bacterial Ags through the MHC class I pathway. As a result, CD8 T cells are the most effective mediators of acquired immunity in the mouse model of L. monocytogenes infection. CD8 T cells specific for a single nonamer epitope derived from the secreted virulence factor listeriolysin O (LLO) can protect H-2d mice against lethal infection. Bacteria lacking LLO are avirulent and do not elicit protective immunity in mice. Thus, the failure of LLO minus L. monocytogenes to elicit protective immunity could be caused either by their inability to enter the cytoplasm or to the lack of LLO-derived peptide epitopes. In this report we provide evidence that H-2d restricted CD8 T cells with specificity for another L. monocytogenes protein, the secreted p60 molecule, can protect against infection. Our studies further demonstrate that LLO-dependent induction of protective immunity results from access of the bacterium to the cytoplasm. In addition, these studies provide support for the hypothesis that secreted bacterial proteins are the most important targets for protective CD8 T cell-mediated immunity.
Suppression of TNF-alpha mRNA expression in LPS-primed macrophages occurs at the level of nuclear factor-kappa B activation, but not at the level of protein kinase C or CD14 expression.
Authors: Takasuka N , Matsuura K , Yamamoto S , Akagawa K S 
Published: December 2022

Abstract
Previously, we reported that preexposure of proteose peptone-elicited murine peritoneal exudate macrophages (P-PEM) to a low dose of LPS suppressed the expression of TNF-alpha mRNA, but not of IL-1 beta mRNA, induced by a second round of LPS exposure. To elucidate the mechanisms underlying this hyporesponsiveness to LPS, we focused on two molecules: nuclear factor (NF)-kappa B and CD14. Activation of NF-kappa B induced by a second round of LPS was suppressed in LPS-primed P-PEM much like the suppression of TNF-alpha mRNA expression. However, protein kinase C (PKC), a candidate as an activator of NF-kappa B, was not desensitized by LPS priming. LPS-induced TNF-alpha production was not affected by depletion of PKC, and LPS could not induce translocation of PKC. CD14 expression showed no significant difference between control and primed P-PEM. In contrast with J774.1 cells and thioglycolate medium-elicited macrophages (T-PEM), P-PEM exhibited serum-independent TNF-alpha production, and a polyclonal Ab to murine CD14 had no inhibitory effect on the LPS-induced TNF-alpha production by P-PEM. These results suggest that priming by LPS causes blockage at an early step, at least before the activation of NF-kappa B, in the LPS signal transduction pathway, but not at the expression of CD14. Our results also suggest that, in P-PEM, in contrast to J774.1 cells and T-PEM, neither PKC nor CD14 is involved in the LPS-induced activation and suppression of TNF-alpha gene expression.
Progesterone favors the development of human T helper cells producing Th2-type cytokines and promotes both IL-4 production and membrane CD30 expression in established Th1 cell clones.
Authors: Piccinni M P , Giudizi M G , Biagiotti R , Beloni L , Giannarini L , Sampognaro S , Parronchi P , Manetti R , Annunziato F , Livi C 
Published: December 2022

Abstract
The effect of progesterone (P) on the cytokine production profile of Ag-specific human CD4+ T cell lines and clones was investigated. T cell lines specific for purified protein derivative or streptokinase (SK) derived in the presence of P exhibited significant increased ability to produce IL-5 in comparison with T cell lines derived in the absence of P. Moreover, IL-4 was significantly increased in SK-specific T cell lines derived in the presence of P in comparison with SK-specific T cell lines derived in the absence of this hormone. In addition, SK-specific T cell lines generated in the presence of P developed into T cell clones showing a Th0-, instead of Th1-like, cytokine profile. Furthermore, SK-specific T cell clones with an established Th1 profile of cytokine secretion did express mRNA for, and produced detectable amounts of, IL-4 when stimulated with P in combination with insoluble anti-CD3 mAb. Combined stimulation with P and insoluble anti-CD3 mAb also enabled Th1 clones to express CD30 on their surface membrane. These results indicate that P can favor the development of Th cells producing Th2-type cytokines and is an inducer of both transient IL-4 production and CD30 expression in established Th1 cells. Thus, P production at the placental level may be responsible, at least in part, for increased production of Th2-type cytokines which have been implied in fetal allograft survival and maintenance of successful pregnancy.
Processing of exogenous heat-aggregated (denatured) and particulate (native) hepatitis B surface antigen for class I-restricted epitope presentation.
Authors: Schirmbeck R , Böhm W , Melber K , Reimann J 
Published: December 2022

Abstract
Many cell types efficiently present an epitope of the hepatitis B surface Ag (HBsAg) to murine class I-restricted CTL following an in vitro pulse with native 22-nm HBsAg particles. Processing of exogenous HBsAg particles required its cytochalasin B-insensitive uptake and acid proteolysis in an endocytic compartment, was insensitive to brefeldin A and cycloheximide, and did not involve regurgitation of antigenic peptides. In contrast, after an in vitro pulse of cells with exogenous, heat-denatured 1-micron HBsAg aggregates, only macrophages (but not other cell types tested) presented the Ld-restricted HBsAg epitope efficiently to CTL. Processing of exogenous HBsAg aggregates required its cytochalasin B-sensitive uptake, was insensitive to brefeldin A, and involved regurgitation of antigenic peptides. Processing of the two different, exogenous HBsAg preparations for class I-restricted epitope presentation thus involved alternative pathways: an "endocytic pathway" for native 22-nm particles, and a "phagocytic pathway" for denatured 1-microns aggregates. Both HBsAg preparations displayed different immunogenicity for class I-restricted CTL in vivo when delivered without adjuvants: native HBsAg particles were of high immunogenicity, and denatured HBsAg aggregates were of low immunogenicity. Class I-restricted CTL are thus primed in vivo after "endocytic processing" of native HBsAg particles as well as "phagocytic processing" of denatured HBsAg aggregates.
Constitutive production of IL-2 by human carcinoma cells, expression of IL-2 receptor, and tumor cell growth.
Authors: Lin W C , Yasumura S , Suminami Y , Sung M W , Nagashima S , Stanson J , Whiteside T L 
Published: December 2022

Abstract
Human carcinomas spontaneously express abundant IL-2R beta but little IL-2R alpha on the cell surface, contain mRNA for IL-2R beta- and IL-2R alpha-chains, and may be inhibited in growth by exogenous IL-2. To study the relationship between IL-2R expression and growth inhibition by IL-2, carcinoma cells were transduced with IL-2R alpha and IL-2R gamma cDNAs or IL-2R beta antisense cDNA. Transfectants with the IL-2R alpha gene expressed high levels of the alpha- and beta-receptor chains and showed increased binding of [125I]IL-2. Exogenous IL-2 at the picometer concentrations inhibited their growth, and Abs to IL-2R alpha- or IL-2R beta-chains reversed the inhibition. After transduction of IL-2R beta antisense cDNA, gastric carcinoma (HR) cells no longer expressed IL-2R beta-chain, and their proliferation was depressed in the absence of exogenous IL-2. Transduction of IL-2R gamma-chain cDNA into tumor cells increased sensitivity to growth inhibition by exogenous IL-2 of a squamous cell carcinoma line, but not of HR or renal cell carcinoma lines. All of the parental and transduced tumor cell lines were found to constitutively express intracellular IL-2, detectable by immunostaining or flow cytometry of permeabilized cells. IL-2 was present on the surface of some tumor cells. Intracellular IL-2R beta and IL-2R gamma proteins were also detectable in tumor cells. Using reverse-transcription PCR combined with Southern blots or in situ hybridization, mRNA for IL-2 was found to be present in parental and transduced tumor cells. Expression on human carcinomas of IL-2R beta, inhibition of their growth by IL-2R beta antisense cDNA, and their ability to constitutively produce IL-2 and its presence on the cell surface, all suggest that endogenous IL-2 may play a role in tumor cell growth.
bcl-2 transgenic Lpr mice show profound enhancement of lymphadenopathy.
Authors: Reap E A , Felix N J , Wolthusen P A , Kotzin B L , Cohen P L , Eisenberg R A 
Published: December 2022

Abstract
The lpr gene encodes a defective form of the fas gene that mediates apoptosis, and its expression results in autoantibodies and massive lymphadenopathy. bcl-2, another gene locus that affects programmed cell death, acts to inhibit apoptosis. Since multiple mechanisms controlling programmed cell death may contribute to systemic autoimmunity, the effect of the bcl-2 transgene on the lpr model was examined by crossing bcl-2 transgenic and C57BL/6-lpr mice. Compared with bcl-2-/lpr mice, bcl-2+/lpr showed dramatic increases in lymphadenopathy and T cell accumulation, but not in autoantibodies or B cell numbers. Short term transfer studies demonstrated that double negative T cells normally have a limited lifespan, and their survival is enhanced by the bcl-2 transgene. Thus, defects in separate apoptosis mechanisms may combine to produce enhanced pathologic effects.
Treatment with okadaic acid reveals strong threonine phosphorylation of CD18 after activation of CD11/CD18 leukocyte integrins with phorbol esters or CD3 antibodies.
Authors: Valmu L , Gahmberg C G 
Published: December 2022

Abstract
The CD11/CD18 leukocyte integrins comprise three heterodimers involved in leukocyte adhesion. CD11/CD18 avidity may be regulated intracellularly, and the CD18 polypeptide has previously been shown to become phosphorylated in leukocytes after phorbol ester stimulation. The importance of phosphorylation in the regulation of CD11/CD18 avidity has, however, remained unclear. We have now activated T cells using phorbol esters, CD3, and CD44 Abs. Both phorbol ester and CD3 treatment activated protein kinase C. CD18 was shown to become more stably phosphorylated after phorbol ester treatment and more transiently so after CD3 stimulation. The phosphorylation was strongly augmented by okadaic acid, a serine/threonine phosphatase inhibitor. While phorbol ester treatment caused phosphorylation mainly on serine, in okadaic acid-pretreated cells, both phorbol ester treatment as well as CD3 stimulation revealed strong threonine phosphorylation. Since earlier mutational studies have demonstrated the functional importance of cytoplasmic threonine residues in CD18, the threonine phosphorylation reported here indicates the role of threonine phosphorylation in the regulation of CD11/CD18 avidity.
Activation of src-related tyrosine kinases by IL-3.
Authors: Anderson S M , Jorgensen B 
Published: December 2022

Abstract
The activation of src-related tyrosine kinases following IL-3 stimulation was examined in 32Dcl3 cells. Three src-related tyrosine kinases were activated following IL-3 stimulation: fyn, hck, and lyn. 32Dcl3 cells were transfected with retroviral vectors expressing each of these kinases and independent clones overexpressing each kinase were isolated. In cells overexpressing either fyn or hck, IL-3 stimulated a rapid increase in catalytic activity, which remained elevated longer compared with the kinetics observed in parental 32Dcl3 cells. An increase in the number of tyrosine-phosphorylated proteins in the presence and absence of IL-3 stimulation was observed in cells overexpressing fyn or hck. Transfection of 32Dcl3 cells with a retroviral vector encoding lyn also resulted in an elevated level of kinase activity, although the increase was not as dramatic as that observed with fyn or hck. Consistent with observations in parental 32Dcl3 cells, a high basal level of lyn kinase activity was observed in unstimulated lyn-transfected cells and IL-3 stimulation resulted in an approximate threefold increase in kinase activity. Overexpression of c-src in 32Dcl3 did not result in IL-3-stimulated activation of c-src, indicating specificity for fyn, hck, and lyn. While the overexpression of fyn, hck, or lyn in 32Dcl3 cells resulted in increased kinase activity and IL-3 stimulated tyrosine phosphorylation, it did not render the cells more sensitive to IL-3. These results suggests that in addition to the JAK2 tyrosine kinase, src-related kinases may play a significant role in signal transduction by cytokine receptors.