bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leukotriene C4 production from human eosinophils in vitro. Role of eosinophil chemotactic factors on eosinophil activation.
Authors: Tamura N , Agrawal D K , Townley R G 
Published: December 2022

Abstract
We studied the role of naturally occurring eosinophil chemotactic factors on leukotriene (LT)C4 production from highly purified (87.1 +/- 2.4%) normodense eosinophils. Platelet activating factor (PAF) directly induced LTC4 production from eosinophils in a dose (10(-9) to 10(-5) M) and a time-dependent manner. PAF (10(-5) M) induced 0.74 +/- 0.08 ng of LTC4 production/10(6) eosinophils. However, lyso-PAF, eosinophil chemotactic factor of anaphylaxis, and LTB4 failed to induce LTC4 production within the tested range. Furthermore, the pre-incubation of eosinophils with 5 micrograms/ml of cytochalasin B did not alter the chemotactic factor-induced LTC4 production. When eosinophils were stimulated by the submaximal concentration (1 microgram/ml) of calcium ionophore A23187, the pre-incubation of eosinophils with 10(-6) M or 10(-5) M of PAF, or 10(-5) M of eosinophil chemotactic factor of anaphylaxis significantly enhanced LTC4 production up to 163.9 +/- 17.5% (p less than 0.05), 279.2 +/- 32.9% (p less than 0.01) and 165.2 +/- 21.2% (p less than 0.05) of the control, respectively. However, the pre-incubation with lyso-PAF or LTB4 failed to enhance A23187-induced LTC4 production. The pre-incubation of eosinophils with phosphatidyl serine also failed to enhance A23187-induced LTC4 production. However, the direct stimulation of protein kinase C by PMA enhanced the submaximal concentration of A23187-induced LTC4 production from eosinophils up to 179.5 +/- 20.9% (p less than 0.05) of the control. Our findings indicate that PAF and ECF-A work not only as chemotactic factors but also induce a functionally active state of eosinophils probably through their post-receptor mechanisms, and contribute to the inflammatory processes.
Mechanism of human monocyte activation via the 40-kDa Fc receptor for IgG.
Authors: MacIntyre E A , Roberts P J , Abdul-Gaffar R , O'Flynn K , Pilkington G R , Farace F , Morgan J , Linch D C 
Published: December 2022

Abstract
It is shown that a mAb specific for the human 40-kDa FcR (FcRII) leads to activation of human monocytic cells but that extensive cross-linking of the receptor is required. Calcium mobilization can be induced in immature monocytic cells (undifferentiated U937 cells) and peripheral blood monocytes with an intact IgG1 anti-FcRII antibody (CIKM5) but not by F(ab')2 fragments of this antibody. The intact antibody can bind in a tripartite manner by its two F(ab') sites and its Fc-binding site whereas the F(ab')2 fragments of this antibody can only bind in a divalent fashion. A rise in intracellular free calcium ion concentration occurs when F(ab')2 fragments are cross-linked with F(ab')2 anti-mouse Ig indicating that more extensive cross-linking of FcRII is required rather than an obligatory requirement for an Fc-FcRII interaction. Calcium mobilization in response to intact or cross-linked F(ab')2 fragments of CIKM5 is associated with superoxide production only in IFN-gamma-primed peripheral blood monocytes and IFN-gamma differentiated U937 cells indicating that the activation signal produced via FcRII is inadequate to fully stimulate non-"primed" cells. A second mAb reactive with FcRII (2E1) does not cause calcium mobilization in monocytes or U937 cells, and partially blocks the effects of CIKM5. 2E1 also blocks CIKM5 superoxide production in IFN-gamma-primed monocytes and differentiated U937 cells. This may be explained in part by the fact that 2E1 is an IgG2a antibody and can only participate in bipartite binding with FcRII. When 2E1 is cross-linked with F(ab')2 anti-mouse Ig there is a small calcium response. This does not cause superoxide generation in IFN-primed monocytes but does do so in IFN-gamma differentiated U937 cells. FcRII is also expressed on granulocytes and some B cells but the effects of cross-linking the receptor on these cells differ from those seen in monocytes.
Defective thymic education of L3T4+ T helper cell function in graft-vs-host mice.
Authors: Fukuzawa M , Via C S , Shearer G M 
Published: December 2022

Abstract
Our study investigates the effect of a prior graft-vs-host (GVH) reaction on the subsequent ability of irradiated, bone marrow-re-populated mice to develop T cell function. The results indicate that such GVH-bone marrow transplanted (BMT) mice do not generate CTL responses to trinitrophenyl-modified syngeneic cells (TNP-self), but do generate strong CTL activity to H-2 alloantigens. This selective deficiency in TNP-self CTL response potential appeared as early as 10 days after GVH, and required both L3T4+ and Lyt-2+ donor T cells. The in vitro addition of either soluble Th factors or L3T4-enriched spleen cells from normal mice circumvented the defect in the TNP-self response in GVH-BMT mice. These results indicate that T effector function was not defective, and instead suggest a Th defect. Cell depletion and antibody-blocking, as well as IL-2 production experiments, indicate that the Th defect was selective for L3T4+ Th population and not for Lyt-2+ Th population. This defect in L3T4 Th function is not accounted for by the approximate twofold reduction in L3T4 cell numbers in GVH-BMT mice, because IL-2 production and CTL generation to L3T4-dependent Ag were at least eightfold below control levels. Rather, defective L3T4 Th function appears to be the consequence of a GVH-induced defect in thymic maturation because the defect was corrected in vivo by a neonatal parental thymus graft before irradiation and bone marrow transplantation. This system may be useful for elucidating the role of the thymus in the maturation of Th cells. Our findings raise the possibility that impaired development of T cell function occurring in marrow grafted patients who have undergone a GVH reaction could be partly due to a GVH-induced thymic defect.
The involvement of human tumor necrosis factors-alpha and -beta in the mixed lymphocyte reaction.
Authors: Shalaby M R , Espevik T , Rice G C , Ammann A J , Figari I S , Ranges G E , Palladino M A 
Published: December 2022

Abstract
The influence of recombinant human TNF-alpha and -beta (rHuTNF-alpha and -beta) in a human mixed lymphocyte reaction (MLR) was investigated. The addition of 1000 U/ml of either cytokine at the initiation of culture caused up to a sixfold increase in [3H]thymidine incorporation by responder cells. Furthermore, it was found that endogenous HuTNF-alpha is produced after allogeneic cell interaction and can be detected in the MLR supernatant within 1 h of culture initiation. The results also show that, in the absence of exogenous HuTNF-alpha, antibodies to rHuTNF-alpha can cause a significant inhibition of the MLR. These observations indicate the importance of TNF-alpha in allogeneic cell interaction and raise considerations for the use of antibodies, or other antagonists, to TNF-alpha as regulators of disease states associated with cell-mediated immune reactions.
Modulation of stimulus-dependent human platelet activation by C-reactive protein modified with active oxygen species.
Authors: Miyazawa K , Kiyono S , Inoue K 
Published: December 2022

Abstract
C-reactive protein (CRP) is one of the most characteristic acute phase proteins which appear in the serum during certain inflammatory diseases. We report here that human CRP acquired the ability to augment platelet reactivity when treated with an Fe2+ (Cu2+)-ascorbate system. CRP modified by such treatment showed no appreciable activation of platelets in the absence of platelet activators such as platelet-activating factor, thrombin, or ADP. However, in the presence of the modified-CRP, irreversible activation of platelets occurred with sub-optimal doses of platelet-activating factor and other stimulatory agents for platelets. CRP without any treatment did not show any modulating activity. Each component of the Fe2+-ascorbate system was required for modification of CRP, suggesting that CRP was modified through an oxidative process. The modification of the CRP structure was confirmed by the change in the fluorescence spectrum of 8-anilino-1-naphthalene sulfonate complexed with CRP, the increased susceptibility of CRP to proteolytic enzymes and the altered reactivity to anti-CRP mAb. We also found an inactivating system for the modified CRP in plasma. The modified human CRP did not show any modulating activity toward rabbit platelets, suggesting that the activity is species specific.
Human IFN-gamma production is inhibited by a synthetic peptide homologous to retroviral envelope protein.
Authors: Ogasawara M , Cianciolo G J , Snyderman R , Mitani M , Good R A , Day N K 
Published: December 2022

Abstract
A synthetic 17 amino acid peptide (CKS-17) homologous to a highly conserved region of human and animal retroviral transmembrane proteins was investigated for its influence on the in vitro production of IFN-gamma from human peripheral mononuclear cells. The results showed that CKS-17 coupled to a carrier protein, BSA, inhibited production of IFN-gamma in a dose-dependent manner. Controls, consisting of BSA, which had undergone the coupling procedure or neurotensin coupled to BSA in an identical manner as CKS-17, showed no such inhibition. Reduction in IFN-gamma production could not be attributed to decreased viability of cells, delay of IFN-gamma production or to involvement of suppressor cells. Moreover, inhibition of IFN-gamma production was not related to the inhibition of DNA synthesis. The inhibition appeared to be a direct effect of CKS-17 on IFN-gamma-producing cells. Kinetic studies revealed that this suppression occurred when CKS-17 was introduced to the culture concurrent with or within 48 h after introduction of IFN inducers. Preincubation experiments showed that the presence of CKS-17 in the culture medium was not necessary to exert its inhibitory effect. These results suggest that a portion of retroviral envelope proteins possess important immunomodulatory actions.
Two regions within the human IL-2 gene promoter are important for inducible IL-2 expression.
Authors: Williams T M , Eisenberg L , Burlein J E , Norris C A , Pancer S , Yao D , Burger S , Kamoun M , Kant J A 
Published: December 2022

Abstract
We have examined regulatory domains of the human IL-2 gene promoter by transfection and transient expression of rDNA constructs in which the chloramphenicol acetyl transferase gene shows T cell-specific inducible expression and cyclosporin A-mediated inhibition when placed downstream of 587 bp of the human IL-2 5'-flanking region. A series of 5'-deletion constructs transfected into the Jurkat T lymphoid line demonstrates that a region encompassing 370 bp 5' of the transcription start site is sufficient for inducible chloramphenicol acetyl-transferase expression. Further dissection of this region with internal deletion (linker-scanner) mutants revealed that portions of at least two discrete regions from -42 to -169 and -289 to -361 bp relative to the transcription start site are critical for inducible expression of the IL-2 gene. T cell-specific expression of wild-type and mutant IL-2 promoter constructs could be increased severalfold by the insertion of an upstream SV40 enhancer. With use of a battery of IL-2 promoter constructs, we could not identify subregions within IL-2 5'-flanking sequences which are crucial for cyclosporin A inhibition of the IL-2 gene or deletion of which resulted in loss of T cell-specific expression, suggesting that such functions may be mediated at pre-transcriptional levels.
Biochemical and structural properties of a Hodgkin's disease-related membrane protein.
Authors: Nawrocki J F , Kirsten E S , Fisher R I 
Published: December 2022

Abstract
The HeFi-1 mAb recognizes a membrane protein on Hodgkin's disease cells and on a limited number of other human cells that are either tumorigenically transformed or virally activated. Herein biochemical and structural analyses of the HeFi-1 reactive membrane protein (HRMP) were done to identify its potential importance in cellular transformation in the Hodgkin's disease cell line L428, in the T cell lymphoma line HuT 78, and in several EBV-transformed lymphoblastoid cell lines. Immunoprecipitation studies demonstrated that the mature form of the HRMP had an apparent Mr of 120 kDa in tumor cells and 116 kDa in the EBV-transformed cell lines and that it was phosphorylated at both serine and tyrosine residues in all cell lines tested. The precursor to the HRMP is an 86-kDa core protein that, after processing by high mannose N-linked glycosylation, migrates with an apparent Mr of 90 kDa. This protein is then further processed to the mature 120-kDa HRMP in part by O-linked glycosylation, the addition of sialic acid residues, and by the conversion of N-linked oligosaccharides from the high mannose to the complex type. Detectable amounts of the 90-kDa molecule can be found in the membrane and, although this protein can be phosphorylated in vitro, it is not phosphorylated in intact cells. The combined results of this study suggest that the HRMP is involved in cellular metabolism and show that an unusual amount of post-translational processing of the 90-kDa precursor results in the formation, and perhaps phosphorylation, of the mature 120-kDa HRMP.
Specific endotoxic lipopolysaccharide-binding proteins on murine splenocytes. II. Membrane localization and binding characteristics.
Authors: Lei M G , Morrison D C 
Published: December 2022

Abstract
We have characterized the binding of LPS to an 80-kDa LPS-binding protein detected by an LPS photoaffinity probe to be present on murine splenocytes. Specific binding of LPS to the 80-kDa protein is directly proportional to LPS concentration at low concentrations of LPS and is saturable at high concentrations of LPS. Binding is inhibited by both homologous and heterologous underivatized LPS as well as by polysaccharide-free lipid A, indicating a specificity for the biologically active component of LPS. Analysis of the kinetics of binding indicate a time-dependent increase over the first 15 min, but increases are not detected after this time. Binding of LPS to the 80-kDa LPS-binding protein is reduced but still readily detectable at 4 degrees C in the presence of azide. The presence of the 80-kDa LPS-binding protein in an isolated cytoplasmic membrane fraction of murine splenocytes as well as its release from intact splenocytes by octylglucoside suggest that this LPS-binding protein is membrane localized. The results are consistent with, but do not establish unequivocally, the identity of the 80-kDa LPS-binding protein as a specific membrane receptor for lipid A.
Methylation in the 5' region of the murine beta Fc gamma R gene regulates the expression of Fc gamma receptor II.
Authors: Bonnerot C , Daëron M , Varin N , Amigorena S , Hogarth P M , Even J , Fridman W H 
Published: December 2022

Abstract
In order to identify possible mechanisms regulating the expression of Fc gamma RII, we have examined the methylation status of the beta Fc gamma R gene in a panel of Fc gamma RII (+) and (-) cells belonging to several different lineages. We used beta 1 cDNA probes, derived from beta Fc gamma R gene transcripts which encode murine Fc gamma RII molecules. We found that all CCGG sequences detected with these probes were methylated in the genomic DNA of the Fc gamma RII-(-) cells. By contrast, two CCGG sites were found to be selectively unmethylated in the DNA of all Fc gamma RII(+) cells tested. These sites could be assigned to the region of the 5' end of the beta Fc gamma R gene. Besides, the treatment of Fc gamma RII(-) thymoma cells BW5147 with 5-azacytidine induced a hypomethylation of the beta Fc gamma R gene concomitantly with the transcription of that gene as seen by Northern blotting and the expression of functional Fc gamma RII. Conversely, the DNA-methylating agent ethyl methanesulfonate completely reversed the phenotype of the 5-azacytidine-treated cells to that of the Fc gamma RII(-) BW5147 parent cells. In ethyl methanesulfonate-treated cells, the beta Fc gamma R gene was remethylated and the corresponding transcript was no more detectable. We conclude that the methylation of a specific 5' segment of the beta Fc gamma R gene regulates the expression of Fc gamma RII in murine T cells, B cells, mast cells, and macrophages, possibly by controlling the gene transcription.
Cloning and expression of the H chain V region of antibody OVB3 that reacts with human ovarian cancer.
Authors: Gallo M G , Chaudhary V K , Fitzgerald D J , Willingham M C , Pastan I 
Published: December 2022

Abstract
Hybridoma OVB3 produces an antibody (IgG2b kappa) that reacts with an Ag present on the surface of almost all human ovarian carcinomas. An EcoRI fragment of genomic DNA containing the rearranged H chain V region of monoclonal OVB3 was cloned from a lambda gtWES library and then sub-cloned into a pGEM4 vector. To show that the cloned DNA sequence did encode the V region of a functional antibody, the DNA fragment was inserted into plasmid pSV-VNP gamma SNase in place of VNp to produce pSV-VOVB3 gamma SNase. This plasmid was then transfected into variant OVB3 hybridoma cells, which no longer produced the H chain of antibody OVB3, and functional antibody was secreted by the recipient cells. The recombinant chimeric antibody bound to ovarian cancer cells and contained Staphylococcus aureus nuclease activity, proving that a functional V region gene had been cloned.
Acquisition of Ig isotype diversity after bone marrow transplantation in adults. A recapitulation of normal B cell ontogeny.
Authors: Velardi A , Cucciaioni S , Terenzi A , Quinti I , Aversa F , Grossi C E , Grignani F , Martelli M F 
Published: December 2022

Abstract
To gain insight into the prolonged susceptibility to infections noted after allogeneic bone marrow transplantation (BMT), multiple parameters of the humoral immune system were serially monitored in ten bone marrow recipients. IgM B cells appeared in the circulation 2 to 4 mo after engraftment. During the first 6 mo, the IgM B cells expressed low levels of CD21 (C3d/EBV receptors) and were largely CD38+. IgG and IgA B cells were also found to coexpress surface IgM and IgD, indicating that they may be involved in a process of isotype switch. These features are characteristic of neonatal B cells. To explore the pattern of Ig isotype switch, the emergence of plasma cell precursors for each of the four IgG subclasses was examined by culturing blood lymphocytes with PWM or LPS and enumerating bone marrow plasma cells. A marked IgG2 and IgG4 plasma cell deficiency and a relative increase in IgG1 and IgG3 plasma cells were detected both in vitro and in vivo. Serum IgG2 and IgG4 levels were deficient for more than 18 mo after BMT, elevated IgG1 levels accounting for the normal or increased levels of total IgG. The data suggest that a selective unresponsiveness to polysaccharide Ag and IgG2 subclass deficiency may contribute to the late bacterial infections in BMT recipients. These features of gradual development of the humoral immune system in adults undergoing successful marrow engraftment reproduce some of the maturational steps that occur during normal B cell ontogeny over the first 1 to 2 yr of life.
Specific endotoxic lipopolysaccharide-binding proteins on murine splenocytes. I. Detection of lipopolysaccharide-binding sites on splenocytes and splenocyte subpopulations.
Authors: Lei M G , Morrison D C 
Published: December 2022

Abstract
Experiments have been carried out using a unique radio-iodinated, disulfide-reducible, photoactivatable LPS derivative (ASD-LPS) to detect specific LPS-binding proteins on murine splenocytes. Fractionation of LPS-photo-cross-linked, reduced, and solubilized splenocyte extracts on two-dimensional polyacrylamide gels has allowed the identification of an 80-kDa LPS-binding protein with approximate pI of 6.5. This LPS-binding protein is present on partially purified populations of splenic B lymphocytes, T lymphocytes, and macrophages. It is also the dominant LPS-binding protein on the murine 70Z/3 B cell line and the YAC-1 and EL4 T cell lines but is not detectable on the undifferentiated murine Sp2/0 myeloma cell line. Of potential importance is the fact that the 80-kDa protein appears to be indistinguishable when photolabeled extracts of splenocytes from the C3HeB/FeJ (lpsn) and LPS-nonresponder C3H/HeJ (lpsd) mice are compared.
Triggering of cytotoxic T lymphocytes and NK cells via the Tp103 pathway is dependent on the expression of the T cell receptor/CD3 complex.
Authors: Fleischer B , Sturm E , De Vries J E , Spits H 
Published: December 2022

Abstract
The expression and function of the T cell activation molecule Tp103 on human cloned cytotoxic CD3+ and CD3- cells were studied. All in vitro growing CD3+ and CD3- clones expressed Tp103 regardless of their phenotype and the expression of a CD3-associated TCR complex. Whereas the CD2 pathway was functional in all these clones, only CD3-expressing clones could be triggered via Tp103 to kill target cells. In contrast, both CD2 and Tp103 pathways were suppressed after modulation of the TCR complex with anti-CD3 mAb. This indicates that the function of Tp103 but not of CD2 is dependent on the expression of a functional Ag receptor on cytotoxic T cells. Furthermore, modulation of the Ag receptor induces a state of unresponsiveness in cytotoxic T cells that cannot be attributed to just the removal of the CD3/TCR complex from the cell membrane.
Analysis of the molecular basis of HLA-A3 recognition by cytotoxic T cells using defined mutants of the HLA-A3 molecule.
Authors: Jelachich M L , Cowan E P , Turner R V , Coligan J E , Biddison W E 
Published: December 2022

Abstract
The structure-function relationships in human class I HLA molecules have been examined by the analysis of two T cell-defined subtypes of HLA-A3 (A3.1 and A3.2). These subtypes differ by two amino acid residues that are located at positions 152 (GluA3.1 vs ValA3.2) and 156 (LeuA3.1 vs GlnA3.2). By the methods of site-directed mutagenesis and DNA-mediated gene transfer, mammalian cell transfectants have been produced that express only one of the above A3.2 amino acid residues at either position 152 or position 156. Previous studies using murine transfectants have shown that A3.1- and A3.2-expressing cells can be distinguished by A3.1-restricted type A influenza virus-specific CTL and A3.2-allospecific CTL and have implied that amino acid position 152 plays a key role in this specificity. To test whether these results were a function of the virus specificity, the alloantigen, or the cell type expressing the class I molecules, we have tested the recognition of human and murine cell transfectants by A3.1-restricted, A/JAP/305/57 and B/Ann Arbor-specific CTL and by A3.1- and A3.2-allospecific CTL. The results indicate that the Glu at position 152 is critical for recognition by all of the A3.1-restricted CTL populations tested and 15 of 16 of the A3.1-allospecific CTL populations tested. The A3.1 Leu at position 156 was sufficient for recognition by only one A3.1-allospecific CTL line. Substitution of the charged Glu residue for the polar Gln at position 156 of A3.2 affected recognition of some but not all A3.2-alloreactive CTL. These data demonstrate that the structural basis for epitopes that are recognized by almost all CTL that discriminate between A3.1 and A3.2 is primarily the amino acid at position 152. The implications of these data for Ag presentation and CTL recognition are discussed.