bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resistance of mice to experimental leishmaniasis is associated with more rapid appearance of mature macrophages in vitro and in vivo.
Authors: Sunderkötter C , Kunz M , Steinbrink K , Meinardus-Hager G , Goebeler M , Bildau H , Sorg C 
Published: January 2023

Abstract
Resistance to murine leishmaniasis has been related to the propagation of specific Th cell subsets (Th1 and Th2). This study shows that there are differences between resistant and susceptible mice in the initial myelomonocytic infiltrate, which precede the specific T cell response. After subcutaneous injection of 2 x 10(7) Leishmania major into footpads of resistant C57Bl/6 and susceptible BALB/c mice we performed immunohistochemical studies on the infiltrate. Two days after infection the percentage of more mature, F4/80-positive macrophages in the lesion increased faster in C57Bl/6 mice (63%) than in BALB/c mice (29%). The same strain-specific differences were observed after infection of corresponding strains of athymic mice (57.2% in C57Bl/6 nu/nu; 33.6% in BALB/c nu/nu), thus excluding a T cell-controlled phenomenon. After 1 wk the infiltrate in susceptible mice began to reveal significantly more cells containing MRP14, which is expressed by granulocytes and less mature monocytes but not by mature macrophages. No corresponding differences were found between athymic strains, suggesting that at this point organization of the infiltrate falls under control of protective T cells. In bone marrow cultures of BALB/c and C57Bl/6 mice, the percentage of F4/80-positive macrophages was also increasing faster in C57Bl/6 mice than in BALB/c mice. Increased expression of the F4/80 Ag was associated with higher leishmanicidal activity of C57Bl/6 macrophages. MRP14-positive bone marrow cells on the other hand were rarely infected by parasites. We suggest 1) that the earlier appearance of leishmanicidal macrophages in lesions of C57Bl/6 mice could influence propagation of either Th1 or Th2 cells by reduction of parasite load or by differential secretion of decisive cytokines and 2) that the diffuse accumulation of granulocytes and inflammatory monocytes in susceptible mice facilitates spread of disease.
IL-4 inhibits growth factor-stimulated rheumatoid synoviocyte proliferation by blocking the early phases of the cell cycle.
Authors: Dechanet J , Briolay J , Rissoan M C , Chomarat P , Galizzi J P , Banchereau J , Miossec P 
Published: January 2023

Abstract
A major feature of rheumatoid arthritis is an uncontrolled proliferation of synoviocytes. This is consistent with the active production of factors such as platelet-derived growth factor (PDGF) and IL-1 by the synovitis, which act in vivo as well as in vitro as potent synoviocyte growth factors. We have previously shown that IL-4 is able to inhibit growth factor production in an ex vivo model of synovitis. Herein, we show that IL-4 strongly inhibited PDGF and IL-1 beta stimulated rheumatoid arthritis synoviocyte proliferation in a dose-dependent manner and through its 130 kDa receptor. This antiproliferative effect of IL-4 directly correlated with a blockade of the synoviocyte cell cycle at the G0 + G1 phases. We also observed that IL-4 induced striking morphologic changes in IL-1 beta or PDGF-stimulated synoviocytes, including increased volume and granulosity. These changes led to major perturbations of the cell monolayer, associated with a marked decrease of synoviocyte viability. Taken together, these data indicate that IL-4 inhibits growth factor-induced proliferation of synoviocytes by interfering with the cell cycle, and by decreasing cell survival.
GM-CSF regulates human eosinophil responses to F-Met peptide and platelet activating factor.
Authors: Tomioka K , MacGlashan D W , Lichtenstein L M , Bochner B S , Schleimer R P 
Published: January 2023

Abstract
Evidence is accumulating that suggests that granulocyte macrophage CSF (GM-CSF) may have inflammatory actions in addition to its effects as a hematopoietic growth factor. In these studies, the effects of culture of purified human eosinophils with GM-CSF on cellular responses, including intracellular calcium responses, the expression of adherence molecules, and adhesion, were examined. In freshly isolated eosinophils expression of the adhesion molecule CD11b was only weakly increased by a 10-min incubation with platelet-activating factor (PAF) (118 +/- 3, 121 +/- 4, 117 +/- 2, n = 8) and FMLP (100 +/- 1, 106 +/- 6, and 105 +/- 4% of control for 10(-8), 10(-7), and 10(-6) M, respectively, n = 4). Lyso PAF never increased CD11b expression. Exposure of eosinophils to GM-CSF (0.5 ng/ml for 2 days) induced an increase in CD11b responses to PAF (132 +/- 3, 144 +/- 4, and 140 +/- 7) and FMLP (123 +/- 8, 145 +/- 10, and 137 +/- 4% of control for 10(-8), 10(-7), and 10(-6) M concentrations, respectively, n = 4). In 3-day culture studies, responses were greatest on days 2 and 3. The half-maximal GM-CSF concentration for the increase in the response to FMLP (10(-7) M, day 2) was approximately 100 pg/ml. GM-CSF (0.5 ng/ml) induced an increase in basal CD11b expression by day 1, which declined toward the initial baseline on days 2 and 3. Dexamethasone (10(-7) M) hastened the decline in baseline CD11b expression but did not inhibit the increase in the response to either PAF or FMLP. After 3 days of culture with GM-CSF (0.08 ng/ml), FMLP (10(-6) M)-induced elevations of intracellular calcium were increased (277 +/- 27% of day 0 control, n = 4, p &lt; 0.01), whereas the response induced by PAF was not (70 +/- 36% of day 0 control, p = NS). A 30-min exposure to GM-CSF caused a potentiation of both PAF- and FMLP-induced adherence of eosinophils to gelatin-coated plastic. Longer incubation with GM-CSF (3 days) potentiated only FMLP-induced adherence. We conclude that expression of adherence molecules, transmembrane signaling, and adherence responses of eosinophils are enhanced by exposure to GM-CSF. These effects of GM-CSF could potentiate the adherence to endothelium and subsequent migration of eosinophils to inflammatory sites in vivo.
Degenerate recognition of a dissimilar antigenic peptide by myelin basic protein-reactive T cells. Implications for thymic education and autoimmunity.
Authors: Bhardwaj V , Kumar V , Geysen H M , Sercarz E E 
Published: January 2023

Abstract
The key event in the induction of an immune response is the recognition by a T lymphocyte of an antigenic peptide bound to a MHC molecule. In the absence of structural coordinates of the TCR and class II MHC molecules, various models of T cell recognition have been proposed, with the emerging dogma that T cell recognition is exquisitely specific. We show here that T cell clones specific for the N-terminal fragment of myelin basic protein, acetylated Ac1-11, recognize a set of unrelated peptides in the context of the same I-Au molecule. Moreover, immunization with the peptide mimic is sufficiently cross-reactive with Ac1-9 to either induce the Ac1-9-reactive clones or to induce tolerance as well as protection against Ac1-9-induced EAE. This observed degeneracy in T cell recognition has important implications for thymic selection and induction of autoimmune disease states by "molecular mimicry."
Elevated IFN-gamma and decreased IL-2 gene expression are associated with HIV infection.
Authors: Fan J , Bass H Z , Fahey J L 
Published: January 2023

Abstract
Because cytokines have a central role in the regulation and function of the human immune system, expression of several key cytokine genes in HIV infection was compared by quantitative polymerase chain reaction studies in lymphocytes from HIV-seronegative and -seropositive subjects. Elevated levels of IFN-gamma mRNA and lowered IL-2 mRNA were found in the PBMC of eight seropositive men with CD4 T cells over 500/mm3 (mean, 647/mm3), whereas IL-4 and IL-10 mRNA were not changed significantly. PBMC obtained 2 yr later from four of these patients with stable disease status (unchanged CD4 T cell number) showed median mRNA levels that were nearer normal for IFN-gamma and for IL-2. Four other men whose CD4 levels fell more than 200/mm3 in the following 2 yr, however, showed increased IFN-gamma and lowered IL-2. Purified CD4 and CD8 T cells from 10 HIV-seropositive and 10 -seronegative homosexual men were compared. Cytokine gene expression was found to be markedly different in CD4 and CD8 T cells from HIV-seropositive men. In CD8 T cells on a per-cell basis, the levels of cytokine mRNA were substantially lower than in CD4 T cells and were not markedly changed in HIV infection. In the CD4 T cells, on a per-cell basis, the mean mRNA levels of IFN-gamma, IL-10, and TNF-alpha were increased substantially (p &lt; 0.001) in HIV infection. IL-2 gene expression was not increased significantly. Thus, the low IL-2 mRNA expression seen in PBMC is primarily due to the reduced CD4 T cell numbers. Increased expression of IFN-gamma genes in CD4 T cells, however, indicates that these cells may be responsible for substantial amounts of circulating IFN-gamma that occur in HIV infection. The striking difference in the effect of HIV infection on the expression of IFN-gamma and IL-2 genes indicates that these cytokines are under separate control. IL-4 mRNA levels were not changed. IL-10 gene expression, however, was increased more in early HIV infection, with less of an increase later. Expression of all cytokines in CD4 T cells appeared to subside late in HIV infection. However, the balance of cytokine expression was altered in all stages of HIV infection.
Induction of peri-insulitis but not diabetes in islet transplants expressing a single foreign antigen. A multi-stage model of disease.
Authors: Holers V M , Hollis G F , Schwartz B D , Evans R J , Strauss-Schoenberger J , Carel J C , Barney D L , Li B , Stafford-Hollis J , Lacy P E 
Published: January 2023

Abstract
We have created a new transgenic model in which the human Epstein-Barr virus receptor, CR2 (CD21), has been expressed in pancreatic beta-cells. Mice derived from three transgenic founders bred into H-2b (C57BL/6) or H-2k (CBA) genetic backgrounds did not become spontaneously diabetic. After transplantation of CR2-expressing islets under the kidney capsule of genetically matched recipients, a histologic picture of peri-insulitis was found. However, animals did not manifest cellular invasion of the islets, destruction of the islets, or diabetes for at least 230 days. Significant numbers of both T and B lymphocytes were found in the cell population surrounding the islets. A pronounced serologic response to CR2 was also present and appeared to precede the onset of peri-insulitis. Thus, in this model, we have separated the process of diabetes induction into at least two phases. One is associated with peri-islet infiltration and an antibody response. However, at least one second signal is likely necessary for the process of islet destruction to follow.
Inhibition of inflammatory liver injury by a monoclonal antibody against lymphocyte function-associated antigen-1.
Authors: Tanaka Y , Kobayashi K , Takahashi A , Arai I , Higuchi S , Otomo S , Habu S , Nishimura T 
Published: January 2023

Abstract
When mice were given an i.v. injection of LPS 7 days after an i.v. injection of Propionibacterium acnes, liver injury and a rapid increase of serum alanine aminotransferase and asparagine acid aminotransferase occurred. The in vivo administration of mAb against LFA-1 on days 1, 2, and 3 after the i.v. injection of P. acnes resulted in a potent inhibition of all these dysfunctions. Using P. acnes and the LPS model, we found that anti-LFA-1 mAb protected the mice from P. acnes and LPS-induced lethal shock. During the course of P. acnes and LPS-induced liver injury, inflammatory cells infiltrated the liver and caused a massive hepatic cell necrosis. Flow cytometry revealed that the liver-infiltrating cells were mainly leukocytes expressing a higher level of LFA-1 antigen than that seen in the normal liver. These results suggested that the LFA-1 molecule on liver-infiltrating leukocytes may play an important role in the induction of inflammatory liver injury.
Polyclonal B cell activation induced by herpesvirus saimiri-transformed human CD4+ T cell clones. Role for membrane TNF-alpha/TNF-alpha receptors and CD2/CD58 interactions.
Authors: Del Prete G , De Carli M , D'Elios M M , Fleckenstein I M , Fickenscher H , Fleckenstein B , Almerigogna F , Romagnani S 
Published: January 2023

Abstract
We have shown that in vitro infection herpesvirus saimiri (HVS) can transform human CD4+ T cell clones with defined Th1 or Th2 cytokine profiles to continuous growth. We report here that transformation with HVS enabled both Th1 and Th2 clones to stimulate proliferation and Ig production by autologous or allogeneic B cells in the absence of stimulants. The polyclonal B cell-activating property of HVS-transformed clones was not related to free virus or soluble cytokines, but rather was dependent on an Ag-nonspecific, MHC-unrestricted, contact-dependent mechanism. T blasts from unstimulated HVS-transformed clones did not express CD40 ligand (CD40L) mRNA or CD40L protein, whereas a proportion of them constitutively expressed membrane TNF (mTNF)-alpha. Both CD40L and mTNF-alpha were detectable on either uninfected or HVS-transformed clones upon mitogen stimulation. The activation of high-density B cells by unstimulated HVS-transformed clones was not inhibited by soluble CD40-Ig fusion protein, but was strongly reduced by either anti-TNF-alpha or anti-TNF-alpha receptor (TNF-alpha R) mAbs. Addition of anti-CD2 and/or anti-CD58 mAbs was also inhibitory, but no additive effect with anti-TNF-alpha and/or anti-TNF-alpha R mAbs was observed. Neither anti-IL-2 nor CD40-Ig inhibited the proliferation of naive IgD+ B cells cocultured with fixed unstimulated HVS-transformed clones, whereas a combination of anti-TNF-alpha and anti-TNF-alpha R mAbs was inhibitory. In addition, fixed unstimulated HVS-transformed clones induced Ig synthesis in IgD+ naive B cells even in the absence of exogenous IL-2. Data suggest that both the mTNF-alpha/TNF-alpha R and the CD2/CD58 pathways, but not the CD40L-CD40 interaction plus secreted cytokines, are involved in the unusual mode of B cell activation exerted by CD4+ HVS-transformed clones.
Histaminergic regulation of NK cells. Role of monocyte-derived reactive oxygen metabolites.
Authors: Hellstrand K , Asea A , Dahlgren C , Hermodsson S 
Published: January 2023

Abstract
Monocytes, recovered by centrifugal elutriation, effectively inhibit functions of human NK cells in vitro. Histamine, acting via monocyte H2-type histamine receptors, abrogates the inhibitory signal. The aim of this study was to define the histamine-reversible mechanism by which monocytes inhibit NK cells with special reference to the respiratory burst activity of monocytes. Monocytes recovered from patients with chronic granulomatous disease did not suppress NK cell function, indicating the requirement of intact nicotinamide-adenine dinucleotide phosphate (NAPDH) oxidase activity of monocytes to inhibit NK cells. Furthermore, catalase, a scavenger of hydrogen peroxide (H2O2), was found to potently reverse the monocyte-induced inhibition of NK cell function; on the other hand, superoxide dismutase (a scavenger of superoxide anion), hydroxyl radical scavengers such as mannitol and deferoxamine, the hypochlorous acid scavenger taurin, or the nitric oxide synthetase inhibitor NG-monomethyl-L-arginine (L-NMMA) did not affect the monocyte-derived, suppressive signal. H2O2, at micromolar concentrations, reconstituted the inhibitory effects of monocytes on NK cell function. Histamine had no scavenger activity but effectively suppressed the generation of H2O2 in isolated monocytes. This effect of histamine was transduced by H2-type histamine receptors. We conclude that the histamine-reversible, inhibitory effect of elutriated monocytes on NK cells is dependent on the formation of reactive oxygen metabolites by monocytes and that H2O2 is a pivotal mediator of the suppressive signal.
Coculture of TCR peptide-specific T cells with basic protein-specific T cells inhibits proliferation, IL-3 mRNA, and transfer of experimental autoimmune encephalomyelitis.
Authors: Offner H , Vainiene M , Celnik B , Weinberg A D , Buenafe A , Vandenbark A A 
Published: January 2023

Abstract
TCR peptides, namely V beta 8.2-39-59 or the minimal idiotope, V beta 8-44-54, can treat experimental autoimmune encephalomyelitis (EAE) in Lewis rats, presumably by activating naturally induced TCR peptide-specific T cells that arise in response to the focused appearance of V beta 8.2+ encephalitogenic T cells. The purpose of the present study was to evaluate the mechanisms by which TCR peptides inhibit EAE. We found that treatment of EAE with the V beta 8.2-39-59 peptide did not induce any evidence of DNA fragmentation (apoptosis) in spinal cord cells isolated from clinically well rats, implicating a regulatory rather than a deletional mechanism. TCR peptide-specific T cell lines failed to inhibit EAE induced by already activated BP-specific T cells when the two T cell specificities were co-injected. However, coculturing the encephalitogenic T cells in the presence of the regulatory T cells during the activation step before transfer almost completely inhibited the induction of EAE. Inhibition could be induced by direct contact between the two cell types or by soluble factors produced in a transwell system, but was greatly enhanced when soluble V beta 8.2-39-59 peptide was used to optimally activate the regulatory T cells. The inhibition was regulatory cell dose dependent, and was reflected in vitro by reduced proliferation response and mRNA production for IL-3, and to a lesser extent, IFN-gamma and IL-2. These results indicate that regulation induced by TCR peptides involves cell-cell interactions that lead to the production and release of soluble factors that locally inhibit the activation of encephalitogenic T cells expressing MHC-bound idiotopes of the target V beta-chain, and possibly "bystander" specificities expressing different V beta-chains.
Signal transduction for nuclear factor-kappa B activation. Proposed location of antioxidant-inhibitable step.
Authors: Suzuki Y J , Mizuno M , Packer L 
Published: January 2023

Abstract
Reactive oxygen species are thought to be messengers for nuclear factor (NF)-kappa B activation because its activation can be abrogated by antioxidants. However, this study identifies, for the first time, NF-kappa B activators that are insensitive to antioxidants. NF-kappa B activation that is induced by either calyculin A or okadaic acid (inhibitors of serine/threonine protein phosphatases 1 and 2A) is not blocked by N-acetylcysteine or dihydrolipoate in Jurkat and U937 cells. Nonetheless, these antioxidants block induction by TNF-alpha, lymphotoxin, and PMA. Unlike okadaic acid and calyculin A, neither TNF-alpha, lymphotoxin, nor PMA inhibited activities of phosphatases 1 and 2A. NF-kappa B activation induced by okadaic acid or calyculin A was not blocked by a myosin light chain kinase inhibitor, but was prevented by a protease inhibitor. The mitochondrial inhibitor, rotenone, also inhibited NF-kappa B activation by calyculin A; however, this inhibition was accompanied by a depletion of cellular ATP. These results suggest that 1) phosphatase inhibitors either target a component of signal transduction, which occurs downstream to an antioxidant-sensitive step or use distinct signaling pathways; 2) inhibition of phosphatases 1 and 2A is not a step in the pathway of TNF-alpha-, lymphotoxin-, or PMA-induced NF-kappa B activation; 3) myosin light chain kinase does not participate in NF-kappa B activation; and 4) activation of NF-kappa B by phosphatase inhibitors is controlled by proteases.
Chymase-directed serine protease inhibitor that reacts with a single 30-kDa granzyme and blocks NK-mediated cytotoxicity.
Authors: Woodard S L , Jackson D S , Abuelyaman A S , Powers J C , Winkler U , Hudig D 
Published: January 2023

Abstract
Cytotoxic NK and T lymphocytes kill virally infected cells within minutes without causing damage to themselves or bystander cells. One mechanism of killing involves exocytosis of granules containing serine proteases and perforin. Serine protease inhibitors block killing of target cells mediated by the cytotoxic lymphocytes. There are at least five different serine protease activities in cytolytic granules. Ten different serine protease sequences have been identified with the use of cDNA-specific clones. It is not known whether only one or several of these serine proteases are essential for cytolytic activity. In this study we show that an irreversible serine protease inhibitor, biotinyl-Aca-Aca-Phe-Leu-PheP(OPh)2, selectively inhibits a chymotrypsin-like (chymase) serine protease activity of rat RNK-16 granule extracts. Under the same conditions, only one 30-kDa (reduced) band was detected on protein blots. Furthermore, only one of three chymase peaks separated by hydrophobic interaction chromatography was inhibited. When this granzyme was inhibited, granule-mediated lysis of erythrocytes was diminished. NK cell killing was completely blocked when biotinyl-Aca-Aca-Phe-Leu-PheP(OPh)2 was added to cytotoxicity assays at 200 microM with rat splenocytes as effectors. By confocal fluorescence microscopy, we show that this inhibitor localizes to distinct regions within RNK-16 cells and rat NK cells. Inhibitor treatment of intact cells inactivated the chymase activity and reduced lysis found in their dense organelles. Together these data indicate that biotinyl-Aca-Aca-Phe-Leu-PheP(OPh)2 inhibits a granule chymase that is essential to cytolytic activity of NK cells.
Characterization of the murine B7-1 genomic locus reveals an additional exon encoding an alternative cytoplasmic domain and a chromosomal location of chromosome 16, band B5.
Authors: Borriello F , Freeman G J , Edelhoff S , Disteche C M , Nadler L M , Sharpe A H 
Published: January 2023

Abstract
The murine B7-1 (mB7-1) molecule expressed on APCs delivers a costimulatory signal for T cell activation through its T cell counter-receptor CD28, resulting in T cell proliferation and IL-2 production. Signaling through the TCR in the absence of CD28 signaling results in T cell anergy. We have analyzed the genomic structure of mB7-1 and here describe the identification of a previously unrecognized sixth exon at the far 3' end of the locus, which encodes an alternative cytoplasmic domain. Reverse transcriptase-PCR amplification of mB7-1 transcripts demonstrates that exon 6 is functionally spliced to the transmembrane-encoding exon 4. Furthermore, using 5' rapid amplification of cDNA ends, we determined that the 5'-untranslated region extends over 1505 bp beyond the previously reported transcriptional start site. In addition, we report the chromosomal location of mB7-1 to chromosome 16, band B5.
Limited expression of C/EBP family proteins during B lymphocyte development. Negative regulator Ig/EBP predominates early and activator NF-IL-6 is induced later.
Authors: Cooper C L , Berrier A L , Roman C , Calame K L 
Published: January 2023

Abstract
The importance of C/EBP proteins in B cell biology is suggested by the occurrence of functionally important C/EBP binding sites in Ig gene enhancers and promoters, and the knowledge that family member NF-IL-6 is induced in other systems in response to regulators of B cell differentiation. We have studied the expression pattern and activity of C/EBP family transcriptional regulators in B cells at different developmental stages by using B cell lines and normal splenic B cells. Two family members, Ig/EBP and NF-IL-6, seem to be the major regulators of C/EBP site-dependent transcriptional activity in B cells. Negative regulator Ig/EBP is predominantly present in early B cells; activator NF-IL-6 increases in more mature B cells and is induced by LPS activation of splenic B cells. LIP, an N-terminally truncated form of NF-IL-6, was found in most B cell lines tested; LIP can act as a weak transcriptional activator in B cell lines. Partly as a result of the differential amounts of C/EBP family proteins, C/EBP sites do not function as activator sites in early B cells but are activator sites in terminally differentiated B cells.