bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid increase of the human IFN-gamma receptor phosphorylation in response to human IFN-gamma and phorbol myristate acetate. Involvement of different serine/threonine kinases.
Authors: Mao C , Merlin G , Ballotti R , Metzler M , Aguet M 
Published: December 2022

Abstract
Various cell surface receptors are phosphorylated upon binding of their ligand, and this phosphorylation seems to be involved in the signal transduction or in the feedback regulation of this signal. The possibility of a phosphorylation of the human IFN-gamma receptor (hu-IFN-gamma-R) has been investigated with 32P-labeled whole Raji cells and receptor purification either by immunoprecipitation with an anti-hu-IFN-gamma-R polyclonal antiserum or by affinity chromatography. The hu-IFN-gamma-R was found to be phosphorylated at a basal level. Upon incubation of the cells with recombinant hu-IFN-gamma, a dose-dependent two-fold increase of this phosphorylation was observed. Phosphoamino acid analysis by TLC showed that the same amino acids, serine and threonine, are phosphorylated at a basal level and after incubation with hu-IFN-gamma. Protein kinase C and Ca2+/calmodulin-dependent kinase pathways have been reported in some cases to be involved in the signal transduction pathway of hu-IFN-gamma. Both pathways involved the activation of a serine/threonine kinase and therefore we have investigated the possibility of hu-IFN-gamma-R phosphorylation by these kinases. PMA, an activator of protein kinase C, induced a rapid increase of the receptor phosphorylation in Raji cells, whereas the Ca2+ ionophore A23187 did not. PMA-induced hu-IFN-gamma-R phosphorylation was not associated with any effect on expression or inactivation of the receptor. PMA alone did not mimic the hu-IFN-gamma effect in Raji cells as measured by induction of IP-10 gene expression, a high specific marker of hu-IFN-gamma response. But the protein kinase C inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H7) and staurosporine, reduced this IFN-gamma-induced expression. However, H7 and staurosporine treatment as well as protein kinase C depletion suppressed PMA-induced receptor phosphorylation, whereas constitutive and hu-IFN-gamma-induced phosphorylation remained unchanged. Our results suggest that the serine/threonine kinase involved in the hu-IFN-gamma-R phosphorylation induced by IFN-gamma is different from protein kinase C.
Modulation of IgM secretion and H chain mRNA expression in CH12.LX.C4.5F5 B cells by adrenocorticotropic hormone.
Authors: Bost K L , Clarke B L , Xu J C , Kiyono H , McGhee J R , Pascual D 
Published: December 2022

Abstract
The murine B cell line CH12.LX.C4.5F5 (CH12 (5F5) expresses adrenocorticotropin (ACTH) receptors, which can modulate IgM secretion by these cells. Interestingly, the response to ACTH was concentration dependent, inducing IgM secretion at subnanomolar amounts and suppressing secretion at micromolar amounts. With the use of an enzyme-linking immunospot assay it was possible to demonstrate that the ACTH-induced increase in IgM secretion by CH12 (5F5) cells was caused at least in part by an increase in the number of cells secreting IgM. CH12 (5F5) cells activated with suboptimal concentrations of LPS demonstrated a similar biphasic response. ACTH at concentrations of 10(-13) to 10(-9) M augmented IgM secretion in LPS-activated cells as much as sixfold, whereas 10(-6) M ACTH slightly decreased LPS-induced IgM secretion. At the mRNA level, subnanomolar concentrations of ACTH increased microH chain mRNA expression up to twofold in unstimulated or LPS-stimulated CH12 (5F5) cells. Taken together, these studies show that physiologically relevant concentrations of ACTH can interact directly with receptors on these B lymphocytes to enhance IgM secretion and microH chain mRNA expression. Although ACTH does increase intracellular cAMP levels in CH12 (5F5) B cells, it is unlikely that the induction of this second messenger pathway is by itself responsible for the ACTH induced B cell differentiation. The concentration of ACTH necessary to stimulate significant intracellular cAMP increases was 10- to 100-fold higher than that required to increase IgM secretion. Furthermore, CH12 (5F5) cells treated with varying concentrations of 8-bromo cAMP or cholera toxin were inhibited in their ability to secrete IgM. These results strongly suggest that the enhancing effects of ACTH on CH12 (5F5) IgM secretion are via mechanisms independent of those mediated by cAMP.
Differences in transcriptional enhancers of HIV-1 and HIV-2. Response to T cell activation signals.
Authors: Tong-Starksen S E , Welsh T M , Peterlin B M 
Published: December 2022

Abstract
T cell activation results in high levels of HIV replication and is thought to be one mechanism leading to the conversion from latent to active viral infection. In HIV-1, the sequences that respond to these signaling events are found in the long terminal repeat (LTR) and comprise the transcriptional enhancer, which contains two conserved binding sites for the nuclear factor kappa B (NF kappa B). The corresponding region in the second AIDS retrovirus, HIV-2, contains a conserved and a divergent NF kappa B binding site. We demonstrate that the HIV-1 LTR responds better than the HIV-2 LTR to T cell activation signals. These qualitative differences in the response to T cell activation are reproduced not only when HIV-1 or HIV-2 enhancers are placed upstream of a heterologous promoter but also when these enhancers are switched between their respective LTR. In electrophoretic mobility shift assays, NF kappa B binds to both conserved sites in the HIV-1 transcriptional enhancer and only to the single conserved site in the HIV-2 transcriptional enhancer. Instead of NF kappa B, the activator protein 3 binds to the divergent site in HIV-2. In conclusion, HIV-1 and HIV-2 are differentially regulated by T cell activation signals, and this difference may account for the longer period of viral latency observed with HIV-2 than with HIV-1 infection.
Heterogeneity in direct cytotoxic function of L3T4 T cells. TH1 clones express higher cytotoxic activity to antigen-presenting cells than TH2 clones.
Authors: Chang J C , Zhang L , Edgerton T L , Kaplan A M 
Published: December 2022

Abstract
In the process of generating culture supernatant from T cell clones, with anti-CD3 antibodies and the B lymphoma A20 as APC, a striking difference in the stimulation of TH1 and TH2 clones was observed, i.e., TH2 clones produced higher levels of lymphokines than TH1 clones. This prompted us to test the hypothesis that differential killing of APC (thus the removal of stimuli) by T cells led to differential T cell activation. By studying a panel of five TH1 and seven TH2 clones, it was demonstrated that TH1 clones mediated significantly higher levels of cytotoxicity toward A20 cells in the presence of soluble anti-CD3 antibody (as opposed to immobilized anti-CD3). Although T cell clones could, when activated with immobilized anti-CD3, produce lymphokines cytotoxic to A20 cells, experiments in which lymphokine production was blocked indicated that T cell clones, in the presence of soluble anti-CD3, mediated killing of A20 through direct cytotoxicity. A higher level of cytotoxicity, by TH1 compared with TH2 clones, was not restricted to anti-CD3 or a particular target cell type, because it also occurred with Con A- or Ag-dependent killing (a monocyte-macrophage cell line), and LPS blasts. Furthermore, the higher cytotoxic activity of TH1 clones compared with TH2 clones was independent of the stage of T cell activation and was unlikely a result of the length of in vitro culture. High levels of killing of APC led to low levels of T cell activation, the significance of which may be as a negative feedback mechanism in the immune response. Other biologic relevancies of higher cytotoxic activity in TH1 vs TH2 cells were also discussed.
Alloantigen-specific T suppressor-inducer and T suppressor-effector cells can be activated despite blocking the IL-2 receptor.
Authors: Tan P , Anasetti C , Martin P J , Hansen J A 
Published: December 2022

Abstract
To determine IL-2 requirement for activation of suppressor cells, PBMC were primed in one-way MLR in the presence of 10 micrograms/ml anti-IL-2R beta-chain antibody 2A3 (CD25) or control antibody, then irradiated and added as regulators in a fresh MLR. Cells primed in the presence of antibody 2A3 suppressed the proliferative response to fresh autologous lymphocytes to specific alloantigen but had no effect on the response to cells from third party donors. Priming in the presence of an antibody of irrelevant specificity induced only limited suppressor activity. Activated suppressor cells did not show cytolytic activity specific for the stimulators when tested at the time of the suppressor cell assay. To identify the subset(s) responsible for suppression, cells primed in the presence of antibody 2A3 were separated into CD4+/CD45RA+, CD4+/CD45RA-, and CD8+ subsets, which were irradiated and then tested. The suppressive activity was found predominantly in the CD4+/CD45RA+ subset, whereas CD8+ cells had some activity and CD4+/CD45RA- cells had none. No subset suppressed the response of autologous cells to third-party cells. When primed CD4+/CD45RA+ cells were cocultured with fresh autologous lymphocytes depleted of CD8+ cells, no suppression was observed, indicating that, although the CD4+/CD45RA+ cells can function as inducers of suppressors, they cannot function as suppressor-effectors. Conversely, CD8+ cells activated in MLR in the presence of 2A3 caused suppression, regardless of whether the fresh autologous responder population contained CD8+ cells. CD4+/CD45RA+ and CD8+ subsets isolated after priming in the presence of 2A3 also demonstrated Ag-specific suppression in the generation of cytotoxic T lymphocytes whereas CD4+/CD45RA- cells had no activity. Our data are consistent with the model that suppression of alloreactivity requires the cooperation of two types of cells, a CD4+/CD45RA+ suppressor-inducer and a CD8+ suppressor-effector population. Activated Tsi and fresh Tse or activated Tse alone can suppress lymphocyte proliferation and generation of CTL in response to specific Ag. Activation of Ag-specific T suppressor-inducer and T suppressor-effector cells appears to be relatively IL-2 independent and presumably require one or more other growth factors.
Bone marrow-derived cells are essential for intrathymic deletion of self-reactive T cells in both the host- and donor-derived thymocytes of fully allogeneic bone marrow chimeras.
Authors: Yoshikai Y , Ogimoto M , Matsuzaki G , Nomoto K 
Published: December 2022

Abstract
The fate of self-reactive T cells was examined in both the host- and donor-derived thymocytes of fully allogeneic bone marrow (BM) chimeras of two strain combinations of AKR/J (H-2k, IE+, Thy-1.1, Mls-1a2b) and C57BL/6 (H-2b, IE-, Thy-1.2, Mls-1b2b). Sequential appearance of host- and donor-derived T cells occurred in the thymus of both AKR----B6 and B6----AKR chimeras in which 5 x 10(6) of T cell-depleted BM cells were used to reconstitute recipients lethally irradiated with 950 rad. Thymocytes bearing V beta 6 high, which recognize MHC class II IE-binding Ag encoded by Mls-1a allele, were detected in neither host- nor donor-derived thymocytes of AKR-B6 chimeras in which Mls-1a and IE were expressed only by the BM-derived cells. Thymocytes bearing V beta 11high capable of recognizing IE were also deleted in the host- and donor-derived thymocytes of the AKR----B6 chimeras. One million of BM cells were inadequate to deletion of the B beta 6high and V beta 11high T cells in the host-derived thymocytes of these chimeras. On the other hand, significant number of V beta 6high and V beta 11high thymocytes were detected in both the host- and donor-derived thymocytes in B6----AKR chimeras where sufficient dose of IE- stem cells were used to reconstitute irradiated Mls-1aIE+ recipients. These results suggest that clonal deletion of the host- and donor-reactive T cells in both the host- and donor-derived thymocytes is an important mechanism for the induction of transplantation tolerance in allogeneic BM chimeras and that BM-derived APC may be essential for the intrathymic elimination of both the host- and donor-reactive T cells in the BM chimeras.
Differential regulation of IL-1 production in human monocytes by IFN-gamma and IL-4.
Authors: Donnelly R P , Fenton M J , Finbloom D S , Gerrard T L 
Published: December 2022

Abstract
We have demonstrated that IL-4 markedly inhibits IL-1 production by highly purified normal human monocytes. When added to monocyte cultures, IL-4 suppressed LPS-induced IL-1 production in a time- and dose-dependent manner. Concentrations of IL-4 as low as 100 pg/ml reduced IL-1 production by approximately 50%, and doses of 1 ng/ml or higher suppressed IL-1 production by more than 90%. Maximal inhibition required that IL-4 be added before or simultaneous with LPS. Northern dot blot analyses revealed that IL-4 not only dramatically reduced the steady-state IL-1 beta mRNA levels in LPS-stimulated monocytes, but also those of TNF-alpha and IL-6. The inhibitory effect was not stimulus-specific because IL-4 suppressed IL-1 production induced by a variety of monocyte activation stimuli, including LPS, PMA, and Staphylococcus aureus Cowan strain. Monocytes expressed a relatively small number of high affinity IL-4R (approximately 150/cell; Ka = 3.15 +/- 1.13 x 10(10) M-1) indicating that relatively few receptors are necessary to generate the inhibitory effect. IL-4 enhanced monocyte MHC class II Ag (HLA-DR) expression in a manner similar to that of IFN-gamma. However, although both IFN-gamma and IL-4 up-regulated HLA-DR expression, they exhibited opposite effects on IL-1 production: IFN-gamma significantly enhanced monocyte IL-1 production induced by submaximal concentrations of LPS; whereas, IL-4 suppressed IL-1 production. Moreover, IL-4 largely neutralized the potentiating effect of IFN-gamma suggesting that IL-4 may be an effective antagonist of certain IFN-gamma-induced effects. Together these findings demonstrate that the relative levels of IFN-gamma and IL-4 may profoundly influence the state of monocyte activation by differentially regulating the expression of IL-1.
Cytokine regulation of C3 and C5 production by the human type II pneumocyte cell line, A549.
Authors: Rothman B L , Despins A W , Kreutzer D L 
Published: December 2022

Abstract
A growing body of literature suggests that a variety of cell products (e.g., cytokines, C components, etc.) likely play an important role during inflammation and host defense by locally regulating the diverse functions of recruited (i.e., immunologic cells) as well as tissue cells. Previously, a number of investigations have demonstrated the ability of immunologic cells to produce C components in vitro, and further studies have identified a variety of cytokines that can regulate C component production by these cells. Recently, we have demonstrated the ability of lung tissue cells, including epithelial cells and fibroblasts, to synthesize and secrete numerous C components and complement regulatory proteins in vitro. Additionally, we have demonstrated that C component production can be modulated by a variety of factors including endotoxin and serum. In our studies we investigated the effects of specific cytokines, i.e., IL and IFN, on the production of the third (C3) and fifth (C5) C components by the continuous cell line of human type II pneumocytes (A549). Specifically, using sensitive ELISA we demonstrated that A549 pneumocytes exposed to IL-1 alpha, IL-1 beta, or IL-2 induced a dose-dependent, more than twofold, increase in C3 production and a 50% decrease in C5 production when compared to control (untreated) A549 cells. Interestingly, IFN-alpha significantly decreased both C3 and C5 production, i.e., 38 and 71%, respectively, in a dose-dependent manner. IFN-gamma had no effect on C3 production, but significantly decreased C5 production by A549 pneumocytes by 84%. These data not only demonstrate that cytokines have the capability to modulate C3 and C5 production by human type II pneumocytes in vitro, but that C3 and C5 production by these cells can be regulated independently by different cytokines. In vivo, cytokine modulation of C component production by local tissue cells likely plays an important role in the regulation of inflammation and host defense within the lung.
Natural killer (NK) cell subsets in the mouse. NK-1.1+/LGL-1+ cells restricted to lysing NK targets, whereas NK-1.1+/LGL-1- cells generate lymphokine-activated killer cells.
Authors: Mason L H , Mathieson B J , Ortaldo J R 
Published: December 2022

Abstract
Our laboratory has recently identified a novel Ag, LGL-1, that is expressed on a major population of mouse NK cells. Two color immunofluorescence analysis has demonstrated that spleen cells consist of two major subsets of NK cells. We have identified an NK-1.1+/LGL-1+ subset that consists of 50% of the total NK cells and an NK-1.1+/LGL-1- subset comprising the remaining 50%. Because numerous reports have identified NK cells as the major cell type mediating lymphokine-activated killing (LAK), the NK-1.1+/LGL-1+ and NK-1.1+/LGL-1- subsets were examined for their contribution toward LAK generation, as defined by their ability to lyse P815 tumor targets. Antibody plus C depletion experiments with the use of anti-LGL-1 indicated that LGL-1+ cells were not found on LAK precursor or effector cells. Two-color cell sorting experiments were also performed to separate freshly isolated NK-1.1+/LGL-1+ spleen cells from the NK-1.1+/LGL-1- subset. It was found that the vast majority of LAK activity (greater than 95%) is derived from the NK-1.1+/LGL-1- cells. Cell sorting of LAK effectors also demonstrated that the NK-1.1+/LGL-1- cells mediated the vast majority of lysis against P815 targets. Similar results were obtained when NK cell subsets were analyzed for their contribution toward ADCC. These findings may prove important in understanding and further elucidating the contribution of NK cells to the LAK phenomenon. Our data also indicates that subsets of NK cells exist that may function differently in response to stimulation by various lymphokines and cytokines.
Bovine natural killer-like cell responses against cell lines expressing recombinant bovine herpesvirus type 1 glycoproteins.
Authors: Palmer L D , Leary T P , Wilson D M , Splitter G A 
Published: December 2022

Abstract
The murine retrovirus shuttle vector pZipNeo SV(X)1 was used to construct plasmids encoding the three major surface glycoproteins of bovine herpesvirus-1 (BHV-1). Each plasmid was transfected into D17, a canine osteosarcoma cell line sensitive to lysis by bovine NK-like cells when infected with BHV-1. After selection in G418 sulfate, cell lines expressing the recombinant gene products were sorted by flow microfluorimetry, radioimmunoprecipitated, and analyzed by SDS-PAGE for fidelity as compared to the native viral glycoproteins. Two of the three genetically engineered cell lines (gI and gIV) could successfully serve as targets to detect bovine NK-like cytolysis. These findings support and extend a previous study from our laboratory indicating a role for BHV-1 glycoproteins in the cytolytic response by bovine NK-like cells. Additionally, this study demonstrated that individual proteins are recognized by these effector cells, and that recombinant glycoproteins can direct cytolytic activity in the absence of host cell infection-associated proteins. This is the first known report of Ag directed cytotoxicity by bovine null (non-B, non-T) cells.
IL-4 regulates endothelial cell activation by IL-1, tumor necrosis factor, or IFN-gamma.
Authors: Thornhill M H , Haskard D O 
Published: December 2022

Abstract
Alteration in the surface membrane of endothelial cells (EC) is a feature of endothelial activation both at sites of inflammation in vivo and after stimulation with cytokines in vitro. The effects of stimulating EC with IL-1 or TNF include enhanced adhesiveness for polymorphonuclear leukocytes (PMN) and T cells, the induction of EC leukocyte adhesion molecule-1 (ELAM-1) expression, and the increased expression of intercellular adhesion molecule-1 (ICAM-1) and the 1.4C3 Ag. In contrast, IFN-gamma stimulation increases EC binding of T cells but not PMN and enhances ICAM-1 expression but not ELAM-1 or 1.4C3 Ag expression. Recently we have reported that the T cell-derived cytokine IL-4 also increases EC adhesiveness for T cells but not PMN. In this study we have examined the effect of IL-4 on the expression of several cytokine-inducible EC activation Ag, by using a previously described ELISA technique. IL-4 modulation of activation Ag expression was concentration dependent, optimal at around 100 U/ml, and exhibited a unique pattern compared to that seen with the other cytokines. Although, IL-4 stimulation increased 1.4C3 Ag expression (p less than 0.001), it significantly inhibited constitutive ICAM-1 expression (p less than 0.01) and did not induce ELAM-1. Furthermore, IL-4 exhibited significant synergy with IL-1 or TNF in inducing 1.4C3 Ag expression (p less than 0.001) but inhibited the increased expression of ICAM-1 produced by IL-1, TNF, or IFN-gamma (p less than 0.01) and inhibited the induction of ELAM-1 by IL-1 and TNF (p less than 0.001). In contrast, IL-4 had no effect on the expression of EC HLA-class I, -DR, -DP, or -DQ and neither enhanced nor inhibited the effect of IFN-gamma on the expression of these molecules. Finally, although IL-4 alone caused little if any shape change in EC monolayers, it strongly synergized with TNF or IFN-gamma in causing a change in shape to a more fibroblastic morphology. These observations indicate that IL-4 increases EC adhesiveness for T cells by the induction of a different adhesion molecule to ICAM-1. Furthermore, the ability of IL-4 to both enhance and inhibit the expression of activation Ag on EC already activated by IL-1, TNF, or IFN-gamma suggests that it may be important in altering the quality of inflammatory responses such as may occur during the development and maintenance of chronic or immune-mediated inflammation.
CD38 molecule: structural and biochemical analysis on human T lymphocytes, thymocytes, and plasma cells.
Authors: Alessio M , Roggero S , Funaro A , De Monte L B , Peruzzi L , Geuna M , Malavasi F 
Published: December 2022

Abstract
The structure of the CD38 molecule has been evaluated by one- and two-dimensional gel analysis and by enzymatic digestions. The source of the Ag was mainly membrane preparations obtained from MLC cells, from normal thymocytes, and from the plasmocytoma line LP-1. Membranes were solubilized in NP-40 and the extracts fractionated by immunoaffinity chromatography [using a specific anti-CD38 antibody (A10 mAb) covalently linked to Sepharose protein A]. The purified Ag migrated as a single chain of Mr = 45,000 not associated with beta 2-microglobulin. Two-dimensional IEF gel electrophoresis revealed five spots (isoelectric point (pI) range: 6.5 to 6.9). After neuraminidase treatment, the mobility of the five polypeptides shifted to a more basic pI. Endoglycosidase-H treatment reduced the Mr of CD38 by 20%, revealing a broader band centered at Mr = 36,000. Treatment of CD38 molecule with V8 Staphylococcus aureus protease yielded a single dominant band at Mr = 38,000 which was still reactive with A10 mAb. The CD38 molecular was trypsin-resistant in both denatured or native conditions. These results clearly show the glycoprotein nature of CD38 molecule, which includes 2 to 4 N-linked oligosaccharide chains containing sialic acid residues. Furthermore, the present data indicate that the CD38 molecule does not display an apparent biochemical polymorphism among the different CD38+ cells or lines.