bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different subsets of T cells in the adult mouse bone marrow and spleen induce or suppress acute graft-versus-host disease.
Authors: Palathumpat V , Dejbakhsh-Jones S , Holm B , Strober S 
Published: December 2022

Abstract
Fractionation of normal adult mouse spleen and bone marrow cells (C57BL/Ka) was performed by discontinuous Percoll density gradients. The fractionated low density (1.050-1.060 g/ml) C57BL/Ka spleen cells completely suppressed acute lethal graft vs host disease (GVHD) when coinjected with unfractionated C57BL/Ka spleen cells into sublethally irradiated (400 rad) BALB/c mice. In dose response experiments, as few as 0.5 x 10(6) low density cells from the spleen fractions suppressed acute GVHD induced by 2.5 x 10(6) unfractionated allogeneic spleen cells. Although the low density spleen fractions inhibited acute GVHD, the high density (1.075-1.090 g/ml) spleen fractions induced acute GVHD in sublethally irradiated BALB/c recipients. Fractionation of C57BL/Ka bone marrow cells showed that none of the high or low density fractions or unfractionated cells induced lethal GVHD. When these fractions were tested for their capacity to suppress GVHD by coinjection with C57BL/Ka unfractionated spleen cells, all fractions protected the BALB/c recipients. Unfractionated bone marrow cells showed modest protection. Evaluation of the dose response characteristics of the suppressive activity of the low and middle density (1.060-1.068 g/ml) bone marrow cell fraction showed that reproducible protection could be achieved at a 5:1 ratio of inducing to suppressing cells. The low density fractions of both bone marrow and spleen cells had a marked depletion of typical TCR(+)-alpha beta CD4+ or CD8+ T cells, and a predominant population of TCR(+)-alpha beta CD4- CD8- T cells. Purified populations of the latter cells suppressed GVHD. Recipients given unfractionated C57BL/Ka spleen cells and protected with low-density bone marrow or spleen cells were chimeras.
Extensive polymorphism in the extracellular domain of the mouse B cell differentiation antigen Lyb-2/CD72.
Authors: Robinson W H , Ying H , Miceli M C , Parnes J R 
Published: December 2022

Abstract
Lyb-2/CD72 is a 45-kDa mouse B cell surface protein that binds CD5 and has been shown to play a role in B cell proliferation and differentiation. Using the polymerase chain reaction we have isolated and sequenced cDNA clones encoding the serologically defined mouse Lyb-2a, Lyb-2b, and Lyb-2c alleles. We confirmed that our full length cDNA clones encode the Lyb-2a, -2b, and -2c alleles, respectively, by transfecting the isolated Lyb-2/CD72 cDNA clones into L cells and demonstrating that the transfectants bind only the appropriate allele specific anti-Lyb-2/CD72 antibodies. Sequence comparisons demonstrate that the Lyb-2/CD72 allels are highly conserved in their cytoplasmic and transmembrane domains but exhibit a high degree of polymorphism in their extracellular domains. This polymorphism in the extracellular region involves amino acid substitutions at a minimum of 20 residues and is concentrated primarily in the membrane distal region. cDNA sequence comparisons also demonstrate two distinct seven amino acid insertion/deletions among these allelic variants. A form of Lyb-2b cDNA lacking the sequence encoding the transmembrane region was isolated from a C57B1/6 mouse and a CH12.LX subline. The Lyb-2/CD72 PCR products from mRNA of mice expressing Lyb-2a and Lyb-2c contain a DNA fragment that corresponds in size to the transmembraneless form, suggesting that these mouse strains also express this mRNA.
Altered IFN-gamma and IL-4 pattern lymphokine secretion in mice partially depleted of CD4 T cells by anti-CD4 monoclonal antibody.
Authors: Field E H , Rouse T M , Fleming A L , Jamali I , Cowdery J S 
Published: December 2022

Abstract
Complete elimination of CD4 cells by in vivo treatment with anti-CD4 mAb may result in B cell polyclonal activation. Additionally, mice treated with doses of anti-CD4 that eliminate half the CD4 cells produced higher anti-SRBC antibody responses than controls. This suggests that partial CD4 depletion enhances Th2-like function. To test this hypothesis we examined Th1 and Th2 lymphokine potential in mice partially depleted of CD4 cells. We measured IL-4 and IFN-gamma secretion by stimulated unfractionated spleen cells and analyzed activated, purified CD4 cells by RNA in situ hybridization to determine the percentage of IFN-gamma- or IL-4-producing cells. Unfractionated splenocytes from partially CD4-depleted mice secreted more IL-4 and less IFN-gamma than splenocytes from control mice. In situ hybridization proved that CD4 cells from partially depleted mice contained a higher percentage of IL-4 and a lower percentage of IFN-gamma-producing cells than controls. These results indicate that treatment with a dose of mAb resulting in partial CD4 depletion may permit increased Th2-like lymphokine expression. This study also provides evidence that cells committed to Th2-like function exist in vivo in mice.
Oncostatin M is a differentiation factor for myeloid leukemia cells.
Authors: Bruce A G , Hoggatt I H , Rose T M 
Published: December 2022

Abstract
Oncostatin M (OSM) is a 28-kDa glycoprotein produced by stimulated macrophages and T lymphocytes that inhibits the proliferation of a number of different cell lines derived from solid tumors. Analysis of both amino acid sequence and gene structure has demonstrated that OSM is a member of a cytokine family that includes leukemia inhibitory factor (LIF), IL-6, and granulocyte colony-stimulating factor (G-CSF). We demonstrate that, like LIF, IL-6 and G-CSF, OSM can induce the differentiation of the myeloblastic M1 murine leukemia cells into macrophage-like cells. The morphologic and functional changes induced by OSM are more similar to those observed with LIF and IL-6 than those induced with G-CSF. OSM can also induce the differentiation of the histiocytic U937 human leukemia cells in the presence of granulocyte-macrophage CSF, a property shared with LIF and IL-6. In murine M1 cells, binding of labeled OSM is completely inhibited by excess LIF or OSM, reflecting the binding of OSM to the high affinity form of the murine LIF receptor. In contrast, the binding of labeled OSM to human U937 leukemia cells is inhibited by OSM, but the inhibition by LIF is significantly less. These results suggest that, in human leukemia cells, OSM may act through the LIF receptor and an OSM-specific receptor. The existence of an OSM-specific receptor was confirmed by both growth inhibition and competition binding assays on A375 human melanoma cells. The growth of human A375 cells was inhibited by OSM and IL-6 but not LIF or G-CSF. Neither LIF, G-CSF, nor IL-6 could compete with the binding of labeled OSM to A375 cells.
CD2 triggering stimulates the formation of platelet-activating factor-acether from alkyl-arachidonoyl-glycerophosphocholine in a human CD4+ T lymphocyte clone.
Authors: Le Gouvello S , Vivier E , Debre P , Thomas Y , Colard O 
Published: December 2022

Abstract
A human CD4+ T lymphocyte clone synthesized platelet-activating factor (PAF) acether when stimulated via the CD2 pathway. PAF-acether was characterized by biochemical and biophysical properties and precursor-product relationships (alkyl-acyl-sn-glycero-3-phosphocholine (GPC)----alkyl-lyso-GPC (lyso-PAF)----PAF-acether) were demonstrated. The clone contained substantial amounts of alkyl-acyl-GPC. i) Hydrolysis of alkyl-acyl-GPC upon CD2 stimulation was evidenced: [3H]alkyl-lyso-GPC was formed from [3H]alkyl-acyl-GPC in [3H] alkyl-labeled cells; alkyl-lyso-GPC production was also bioassayed after CD2 triggering. ii) The rate of arachidonate transfer from diacyl-GPC to alkyl-acyl-GPC increased after CD2 stimulation of the [3H]arachidonate-labeled P28D T cells, demonstrating alkyl-lyso-GPC formation. iii) Comparison of the molecular species of the produced PAF-acether with those of arachidonate-containing alkyl-acyl-GPC raises the possibility that the produced PAF-acether is related to alkyl-arachidonoyl-GPC.
Components of the protein kinase C pathway induce Ia expression after injection into macrophages.
Authors: Smith M R , Ramsburg E A , Kung H F , Durum S K 
Published: December 2022

Abstract
Macrophages are activated by a variety of microbial and cytokine stimuli. One feature of activation is the induction of class II Ag (Ia) on the cell surface. To understand the intracellular events that occur during activation, we investigated various agents with intracellular activities, and examined their effects on the induction of Ia. We first noted that several agents that activate protein kinase C (PKC) induced Ia, and that several inhibitors of PKC inhibited Ia induction by IFN-gamma. To directly test whether PKC induced Ia, we microinjected normal peritoneal macrophages with this enzyme and other intracellular mediators, then examined Ia expression. We observed that injection of PKC itself, or of other intracellular proteins thought to participate in the PKC pathway (Ras or phospholipase C gamma) strongly induced Ia expression. The Ia-inducing activity of transforming Ras protein was blocked by kinase inhibitor treatment of cells, suggesting that Ras signal transduction requires kinase activity. On the other hand, components of the protein kinase A pathway (phospholipase A2 and protein kinase A itself) did not induce Ia. Thus, the PKC pathway can control expression of macrophage surface Ia, possibly by regulating the genes of the MHC, and may play many other roles in the activation of macrophages.
A recombinant malaria protein that can induce Th1 and CD8+ T cell responses without antibody formation.
Authors: Süss G , Pink J R 
Published: December 2022

Abstract
Inbred strains of mice were immunized with p190-3, a 38-kDa recombinant protein derived from p190, a major merozoite surface Ag of the malaria parasite Plasmodium falciparum. Ag-specific proliferative T cell responses were obtained in H-2b, H-2d, and H-2k mouse strains. Surprisingly, mice of the H-2b haplotype (e.g., C57BL/6) did not give a measurable antibody response to the recombinant protein administered in Freund's adjuvant, but CD8+/CD4- as well as CD4+/CD8- T cells specific for p190-3 could be obtained after in vivo priming and in vitro selection with Ag. Distinct epitopes of p190-3 recognized by the CD8+ and CD4+ T cells from C57BL/6 mice were identified. The CD8+ T cells could kill H-2b APC in the presence of the appropriate epitope-containing peptide. The p190-3-specific CD4+ cells isolated from C57BL/6 mice were of the Th1 type. In contrast, Th2 cells, but no CD8+ T cells were present in a p190-3-specific line from BALB/c mice, which give good antibody responses to p190-3.
Divalent cation substitution reveals CD18- and very late antigen-dependent pathways that mediate human neutrophil adherence to fibronectin.
Authors: Bohnsack J F , Zhou X N 
Published: December 2022

Abstract
We investigated the mechanisms by which Mn2+ alters human neutrophil (PMN) adherence to various connective tissue proteins. Substitution of Mn2+ for Ca2+ and Mg2+ significantly increased adhesion of human PMN to plastic well coated with fibronectin, fibrinogen, and laminin but not gelatin. Anti-CD18 mAb almost completely blocked adherence to laminin, partly blocked adherence to fibrinogen, but did not inhibit adhesion to fibronectin at all. In contrast, anti-very late antigen (VLA)-5 mAb antibodies significantly reduced Mn(2+)-mediated PMN adherence to fibronectin, but not to laminin or fibrinogen, demonstrating that VLA-5-mediated PMN adherence to fibronectin, but not to fibrinogen or laminin. This was supported by experiments in which synthetic GRGDSP peptide significantly inhibited Mn(2+)-mediated adherence to fibronectin, but not to laminin or fibrinogen. Activation of PMN with phorbol ester or C5a stimulated VLA-5-mediated adhesion to fibronectin, but the contribution of VLA-5 to the forces mediating adherence could only be detected when CD18 function was either blocked with mAb, or when CD18 was congenitally absent. VLA-5 mediated adhesion was also more transient than CD18-dependent adhesion. These data further confirm the presence of PMN VLA integrins and demonstrate that PMN VLA-5 contributes to stimulated PMN adherence to fibronectin.
Biosynthesis and secretion of complement component (C3) by activated human polymorphonuclear leukocytes.
Authors: Botto M , Lissandrini D , Sorio C , Walport M J 
Published: December 2022

Abstract
We tested the hypothesis that human polymorphonuclear leukocytes (PMN), bearing complement receptors CR1 and CR3, might also synthesize C3, particularly when activated by LPS or cytokines. Northern blot analysis of total RNA, obtained from purified PMN stimulated overnight with LPS or cytokines (IFN-gamma, TNF-alpha, and IL-1) showed the 5.3-kb RNA transcript reported for C3 in hepatocytes and monocytes. No transcripts for C4 and factor B were detected. Time course studies of C3 mRNA expression in PMN treated with LPS or TNF-alpha demonstrated a steady increase with a plateau at 24 h that correlated with secretion of C3, determined by ELISA. In contrast, IFN-gamma and IL-1 induced a transient increase in C3 transcript with a peak around 8 h after stimulation, which was not reflected in an increased rate of C3 secretion. The content of C3 protein in PMN culture media, measured by ELISA, was about 4 ng/ml/10(7) cells after overnight stimulation with LPS or TNF-alpha. A very small amount of C3 (about 0.7 ng/ml/10(7) cells) was detected in supernatants from unstimulated and IFN-gamma- or IL-1-induced PMN. Immunoprecipitation with a polyclonal anti-human C3, followed by SDS-PAGE analysis, from [35S]methionine labeled PMN, revealed the presence in culture supernatants of three major bands at 185, 115 and 70 kDa, corresponding to pro-C3, alpha and beta chains, respectively. Analysis of [14C]methylamine incorporation and of autolytic cleavage showed that the C3 produced in tissue culture by PMN contained an intact thiolester bond. The capacity of PMN to secrete functional C3 in response to LPS and TNF-alpha might be an important mechanism of host defense at sites of inflammation.
Antineutrophil cytoplasmic autoantibodies in Wegener's granulomatosis recognize conformational epitope(s) on proteinase 3.
Authors: Bini P , Gabay J E , Teitel A , Melchior M , Zhou J L , Elkon K B 
Published: December 2022

Abstract
Although proteinase 3 (PR3) has been identified as a major autoantigen in Wegener's granulomatosis, the precise antibody specificity(ies) and requirements for epitope recognition have not been characterized. We analyzed 11 sera containing antineutrophil cytoplasmic antibodies (cANCA) for binding to azurophilic granule proteins extracted from neutrophils under various conditions and for binding to native or rPR3. Ten of 11 (91%) of the cANCA sera bound to PR3 extracted by nonionic detergents when tested by immunoprecipitation or by IEF followed by capillary immunoblotting. Antibody binding to PR3 was retained when IEF was performed under dissociating conditions (8 M urea) indicating that PR3 is the major autoantigen in azurophilic granules and that association with other proteins is not required for antigenicity. In contrast, antigenicity was totally destroyed by exposure of PR3 to reducing agents or to low pH (less than 3.0) and was either lost or considerably diminished after boiling in SDS. cANCA sera also showed little or no binding to rPR3 expressed as a fusion protein in Escherichia coli or synthesized by wheat germ ribosomes in vitro. Inasmuch as PR3 enzymatic activity was partially retained after acid extraction, these findings indicate that cANCA bind to a limited number of conformational epitopes on PR3. In addition, IEF followed by capillary immunoblotting appears to be a sensitive and specific method to detect anti-PR3 antibodies in Wegener's granulomatosis.
The immunopathology of acute experimental allergic encephalomyelitis induced with myelin proteolipid protein. T cell receptors in inflammatory lesions.
Authors: Sobel R A , Kuchroo V K 
Published: December 2022

Abstract
To determine whether there is predominance of T cells expressing a particular TCR V beta chain in the inflammatory lesions of an autoimmune disease model, TCR expression was analyzed in central nervous system (CNS) tissues of mice with experimental allergic encephalomyelitis (EAE). Acute EAE was induced in SJL/J mice either by sensitization with a synthetic peptide corresponding to myelin proteolipid protein residues 139-151 or by adoptive transfer of myelin proteolipid protein peptide 139-151-specific encephalitogenic T cell clones. Mice were killed when they showed clinical signs of EAE or by 40 days after sensitization or T cell transfer. Cryostat CNS and lymphoid tissue sections were immunostained with a panel of mAb to T cell markers and proportions of stained cells were counted in inflammatory foci. In mice with both actively induced and adoptively transferred EAE, infiltrates consisted of many CD3+, TCR alpha beta+, and CD4+ cells, fewer CD8+ cells, and small numbers of TCR gamma delta+ cells. Approximately 30% of CD45+ leukocytes in the inflammatory foci were T cells. Cells expressing TCR V beta 2, 3, 4, 6, 7 and 14 were detected in the infiltrates, whereas TCR V beta 8 and 11, which that are deleted in SJL mice, were absent. When EAE was induced by transfer of T cell clones that use either V beta 2, 6, 10, or 17, there was also a heterogeneous accumulation of T cells in the lesions. Similar proportions of TCR V beta+ and gamma delta+ cells were detected in EAE lesions and in the spleens of the mice. Thus, at the time that clinical signs are present in acute EAE, peripherally derived, heterogeneous TCR V beta+ cells are found in CNS lesions, even when the immune response is initiated to a short peptide Ag or by a T cell clone using a single TCR V beta.
Generation and characterization of IL-2-activated veto cells.
Authors: Fast L D 
Published: December 2022

Abstract
The regulation of in vivo cytolytic response is important in a model of murine graft-vs-host disease induced by the injection of parental splenocytes into unirradiated B6D2F1 recipients. Injection of C57BL/6J spleen cells into B6D2F1 recipients results in an acute form of graft-vs-host disease that is characterized by the presence of CTL and suppressor cells, runting, and occasionally death. In contrast, injection of DBA/2J spleen cells into B6D2F1 recipients results in a chronic form of graft-vs-host disease that is characterized by the lack of in vivo CTL and hyperproduction of Ig and autoantibodies that results in an SLE-like syndrome. One reason for the lack of donor antirecipient CTL after injection of DBA/2J donor cells is that B6D2F1 recipient cells functionally inactivate the donor DBA/2J CTL precursor cells by expressing veto activity. These B6D2F1 veto cells are radiosensitive, inhibited by anti-CD8 antibodies, found primarily in lymph nodes, and were further characterized by testing the response of these inhibitory cells to lymphokines. These studies indicate that IL-2 can potentiate the activity of the veto cells induced in vivo and veto cells with a similar phenotype can be generated by in vitro incubation of naive lymph node cells with IL-2. These cells have been designated as IL-2-activated veto cells or LAV cells. IL-2 did not increase inhibitory activity by increasing the number of CD8+ cells or the number of CD8 molecules on the LAV cell surface but by altering the activation state of the LAV cell. The inhibitory capabilities of antibodies binding various cell surface molecules indicated that CD2 and intercellular adhesion molecule-1 molecules in addition to CD8 molecules played a role in the function of LAV cells.
Role of complement in endotoxin/platelet-activating factor-induced lung injury.
Authors: Rabinovici R , Yeh C G , Hillegass L M , Griswold D E , DiMartino M J , Vernick J , Fong K L , Feuerstein G 
Published: December 2022

Abstract
C receptor-1 is a protein involved in the regulation of C3 and C5-convertases. Recombinant human soluble C receptor-1 has recently been produced and shown to reduce infarct size in a rat model of myocardial ischemia/reperfusion injury. The present study aimed to investigate whether recombinant human soluble C receptor-1 exerts any protective effect on pulmonary injury produced in a rodent model of adult respiratory distress syndrome. In this model, Escherichia coli endotoxin (LPS, 0.1 microgram/kg) combined with platelet-activating factor (1 pmol/kg/min over 60 min, n = 10) caused microvascular lung injury characterized by elevation of myeloperoxidase activity, deposition of C3 and C5b-9 on the endothelium of pulmonary vessels, and pulmonary edema. Furthermore, bronchoalveolar lavage revealed increased neutrophil count and elevated protein concentration. These pulmonary responses were associated with elevated serum TNF-alpha. Pretreatment (10 min, i.v.) with recombinant human soluble C receptor-1 at 10 mg/kg (n = 13), but not at 1 mg/kg, prevented the LPS/platelet-activating factor-induced pulmonary edema (p less than 0.01) and changes in the bronchoalveolar lavage fluid cell count (p less than 0.01) and protein concentration (p less than 0.05), and attenuated the deposition of C3 and C5b-9 to lung vessels. There was no effect on lung myeloperoxidase activity and serum TNF-alpha. Also, C depletion by cobra venom factor (500 U/kg, i.v.) eliminated the pulmonary edema and elevated leukocyte count in bronchoalveolar lavage fluid, but had no effect on lung myeloperoxidase activity and serum TNF-alpha. These data suggest that C factors may play an important role in the pathophysiology of adult respiratory distress syndrome.
Inhibition of HIV infection by a novel CD4 domain 2-specific monoclonal antibody. Dissecting the basis for its inhibitory effect on HIV-induced cell fusion.
Authors: Burkly L C , Olson D , Shapiro R , Winkler G , Rosa J J , Thomas D W , Williams C , Chisholm P 
Published: December 2022

Abstract
HIV use the CD4 molecule as their primary cellular receptor. Residues in the N-terminal domain (D1) of CD4 are crucial to HIV attachment through the gp120 envelope component. However, other regions of CD4 appear to be required subsequently for virus- and cell-cell fusion. Little is understood of the post-binding steps which may differ between HIV variants. We report a novel anti-CD4 mAb that does not block CD4/gp120 binding, but that does efficiently block both viral infection and cell-cell syncytia formation, and define its contact site as residues in CD4 D2 using both mouse/human CD4 chimeras and CD4 substitution mutants. We also investigated the basis for its antiviral effect. Using the CD4 D2 specific mAb, we identify another conserved step in HIV infection, as evidenced by its ability to neutralize a broad range of primary isolates and T cell-line passaged strains. Monovalent forms of the mAb were used to determine if its activity was due to masking of the D2 epitope, to steric inhibition, or bivalency. Our data indicate that both binding site and bivalency of the mAb underlie its potency. The need for bivalency is not simply explained by affinity, because monovalent forms can displace the intact mAb and reverse its protective effect. These results provide evidence that binding of the D2-specific mAb prevents structural alterations necessary for membrane fusion.