bluuebunny/crossref_metadata_2025_split huggingface dataset:
Granulocyte-macrophage colony-stimulating factor modulates the excitation-response coupling sequence in human neutrophils.
Authors: Naccache P H , Faucher N , Borgeat P , Gasson J C , DiPersio J F 
Published: December 2022

Abstract
We have investigated the effects of granulocyte-macrophage (GM) CSF on two biochemical responses thought to play internal signaling roles in the neutrophils, namely the increase in the concentration of free calcium and the changes in the internal pH. The changes in the right-angle light scatter of the cell suspensions were also examined. GM-CSF was found not to affect the resting levels of calcium or the internal pH of the cells. However, pre-incubation of the neutrophils with the growth factor resulted in an increase in the magnitude of the calcium transients that follow the stimulation of the cells with chemotactic factors as well as a profound depression of the cell alkalinization that is induced by fMet-Leu-Phe, leukotriene B4, and platelet-activating factor, as well as by phorbol esters. The rapid cytoplasmic acidification elicited by these agents was apparently magnified. GM-CSF did not directly affect the Na+/H+ antiport as GM-CSF-treated cells were as capable as untreated cells of recovering from an acid load. The right-angle light scatter responses of the cells to the chemotactic factors were found not to be affected by GM-CSF. These results provide an initial description of the effects of GM-CSF on the cellular physiology of the neutrophils and insights into the mechanism of action of this factor as well as into the excitation-response coupling sequence activated by chemotactic factors.
The priming of neutrophils by lipopolysaccharide for production of intracellular platelet-activating factor. Potential role in mediation of enhanced superoxide secretion.
Authors: Worthen G S , Seccombe J F , Clay K L , Guthrie L A , Johnston R B 
Published: December 2022

Abstract
LPS priming of the neutrophil results in enhanced release of superoxide upon subsequent stimulation, but the mechanism of this effect remains obscure. The recent recognition that neutrophils synthesize and retain platelet-activating factor within the cell led us to hypothesize that enhanced synthesis of platelet-activating factor in the LPS-primed cell might account for the observed effects of lipopolysaccharide. Using human neutrophils isolated on plasma-Percoll gradients, we found that incubation with 100 ng/ml LPS for 60 min resulted in a small but significant increase in intracellular platelet-activating factor assessed after lipid extraction, TLC, and bioassay. The further stimulation of primed neutrophils with FMLP resulted in a marked increase in neutrophil platelet-activating factor compared with non-LPS-treated controls. The priming effect of LPS was time dependent (30 to 60 min), dose dependent, and inhibited at 0 degree C and did not require protein synthesis. Platelet-activating factor so generated was not released but rather retained within the neutrophil, and the molecular species of platelet-activating factor produced was predominantly 1-O-hexadecyl-2-acetyl-sn-3-phosphorylcholine. Platelet-activating factor production in LPS-treated neutrophils was also enhanced by PMA, suggesting that receptor-mediated events could not account exclusively for the enhancement. Considering the ability of nanomolar concentrations of exogenously added platelet-activating factor to prime the neutrophil for enhanced release of superoxide, the rapid intracellular accumulation of platelet-activating factor that accompanies stimulation of an LPS-primed cell by FMLP may modulate the secretory events that accompany such stimulation.
Characteristics and specificity of acquired immunologic memory to Mycobacterium tuberculosis infection.
Authors: Orme I M 
Published: December 2022

Abstract
The results herein show that mice infected with Mycobacterium tuberculosis and then exposed to a protracted course of isoniazid chemotherapy possess a heightened state of acquired resistance to subsequent challenge with the homologous organism. Our results provide the first evidence, moreover, that this resistance is mediated by a long-lived, cyclophosphamide- and irradiation-resistant L3T4+ Lyt-2- lymphocyte capable of giving rise to an accelerated re-emergence of resistance in the animal upon rechallenge. Evidence is also provided to show that triggering of this memory-immune T cell population in the re-challenged host was associated with the rapid emergence of non-specific resistance to secondary bacterial infection; however, the accelerated emergence of this population was only observed if the challenge inoculum consisted of the living organism. The relevance of this latter finding to strategies for vaccine development is discussed.
Modulation of Ig gene expression by Ig binding factors. Suppression of alpha-H chain and lambda-2-L chain mRNA accumulation in MOPC-315 by IgA-binding factor.
Authors: Roman S , Moore J S , Darby C , Müller S , Hoover R G 
Published: December 2022

Abstract
Previous reports by a number of laboratories have shown that Ig-binding factors may play a role in the regulation of Ig production by B cells. Although numerous studies have addressed the specificity and biologic function of Ig-binding factors at the cellular level, little information is available regarding the mechanism whereby Ig-binding factor modulates Ig production by B cells at the molecular level. Herein we have examined the specificity and molecular mechanism of the suppression of IgA production mediated by IgA-binding factor. Using the IgA-secreting plasmacytoma, MOPC-315, as a target cell, we have demonstrated that: 1) IgA-binding factor binds to IgA, but not to IgG, IgM, or BSA; 2) IgA-binding factor can suppress proliferation as well as IgA production by MOPC-315; 3) soluble IgA, but not IgG or IgM can inhibit the action of IgA-binding factor; 4) suppression of Ig production by IgA-binding factor is maximal within 8 to 12 h after exposure to the factor and is reversible; 5) IgA-binding factor suppresses IgA production by selectively down-regulating synthesis of IgA H and L chain proteins; 6) IgA-binding factor selectively suppresses transcription of alpha-H chain and lambda-2-L chain genes; 7) IgA-binding factor suppresses accumulation of c-myc mRNA. These findings suggest that IgA-binding factor binds selectively to surface IgA on MOPC-315 and suppresses IgA production by down-regulating transcription of H and L chain genes. Suppression of MOPC-315 proliferation by IgA-binding factor may be related to the concomitant down-regulation of the expression of the c-myc gene. c-myc is deregulated in MOPC-315 by virtue of the reciprocal 15:12 chromosomal translocation present in MOPC-315 where the c-myc gene is translocated and rearranged into the alpha-H chain gene complex. Simultaneous suppression of the expression of c-myc and alpha-H chain genes suggests that these two genes may be coordinately modulated, in plasmacytomas, by IgA-binding factor.
A flexible peptide spacer increases the efficacy of holoricin anti-T cell immunotoxins.
Authors: Marsh J W , Neville D M 
Published: December 2022

Abstract
Immunotoxins, constructed by chemically cross-linking an antibody and protein toxin, do not possess the high efficacy of the native toxin. Decreases in toxicity are due in part to the steric constraints imposed on the two macromolecules, which result in both decreased antibody binding and toxin function. In examining the structural features that influence efficacy in holotoxin-antibody conjugates, it was found that the incorporation of a 29-residue polypeptide, derived from the insulin B chain between the antibody and ricin moiety, resulted in an increase in both potency and efficacy. In a murine model system, potency of the peptide spacer conjugate was increased nearly 10-fold; however, when examined by the procedure used to purge bone marrow, the peptide spacer conjugate was not demonstrably more toxic to nontarget cells than the nonspacer conjugate. Thus, in addition to increases of efficacy and potency, this novel immunotoxin demonstrated increased specificity by approximately 10-fold. To test the general utility of peptide spacer inclusion, a T101-ricin conjugate was constructed with the peptide spacer. It yielded a protein synthesis inhibition rate of -0.6 log/h on MOLT-3 cells, greater than 10-fold more efficacious than a previously constructed nonspacer T101-ricin conjugate examined under similar conditions.
Role of phosphoinositide-derived second messengers in mediating anti-IgM-induced growth arrest of WEHI-231 B lymphoma cells.
Authors: Page D M , DeFranco A L 
Published: December 2022

Abstract
Anti-IgM irreversibly inhibits the growth of WEHI-231 B lymphoma cells and induces phosphoinositide hydrolysis--producing diacylglycerol, which activates protein kinase C, inositol 1,4,5-trisphosphate, which induces the release of calcium from intracellular storage sites into the cytoplasm, and other inositol polyphosphates. The roles of two of the possible second messengers, cytoplasmic free calcium and diacylglycerol, in mediating the action of anti-IgM on WEHI-231 cells were assessed by elevating [Ca2+]i with ionomycin and by activating protein kinase C with phorbol 12,13-dibutyrate (PdBu). The combination of 250 nM ionomycin and 4 to 7 nM PdBu was found to cause growth arrest and cell volume decrease responses in WEHI-231 cells which were similar to those caused by anti-IgM, although clearly slower. Both anti-IgM and the combination of mimicking reagents induced growth arrest of WEHI-231 cells in the G1 phase of the cell cycle. In both cases, this growth arrest was mitigated by addition of bacterial LPS. Moreover, 250 nM ionomycin plus 4 to 7 nM PdBu did not inhibit the growth of two other murine B lymphoma cell lines, each of which did exhibit increased phosphoinositide hydrolysis but not growth arrest in response to anti-Ig. Taken together, these results suggest that ionomycin and PdBu, at the concentrations used, did not inhibit WEHI-231 growth by general toxicity, but rather by mimicking the effects of the natural second messengers generated from Ag receptor cross-linking. Thus, the phosphoinositide-derived second messengers Ca2+i and diacylglycerol are capable of playing important roles in mediating the action of anti-IgM on WEHI-231 B lymphoma cells. However, the response of WEHI-231 cells to anti-IgM could not be fully reproduced with ionomycin and phorbol diester. These results suggest that another second messenger induced by anti-IgM may also play an important role in mediating the growth arrest of these cells.
A novel pathway of human T lymphocyte activation. Identification by a monoclonal antibody generated against a rheumatoid synovial T cell line.
Authors: Higgs J B , Zeldes W , Kozarsky K , Schteingart M , Kan L , Bohlke P , Krieger K , Davis W , Fox D A 
Published: December 2022

Abstract
Substantial evidence indicates that compartmentalized infiltrates of T lymphocytes are central to the pathogenesis of autoimmune diseases such as rheumatoid arthritis, but the mechanisms by which such cells become activated remain unknown. To define surface components of activation pathways important in the function of these cells, we have generated mAb against a rheumatoid synovial T cell line. One such antibody, termed anti-UM4D4, reacts with an Ag, termed UM4D4, which is strongly expressed on most rheumatoid synovial T cell lines and clones, and on a subset of peripheral blood T cells, resting or activated. Anti-UM4D4 is mitogenic in soluble form for PBMC and certain T cell clones, and is comitogenic with the phorbol ester PMA for purified resting T lymphocytes. These functional effects are similar to those previously observed with antibodies to epitopes of CD2 and CD3, surface Ag involved in two well defined pathways of human T cell activation. Binding of anti-UM4D4 to T cells is not, however, blocked by antibodies directed at various epitopes of CD2 and CD3. Moreover, UM4D4 does not comodulate with CD3, and is expressed on a T cell line that lacks CD2, CD3, and CD28. The data, therefore, indicate that anti-UM4D4 identifies a T cell activation pathway, distinct from those previously described, that could play a role in the pathogenesis of T cell-mediated autoimmune diseases.
Characterization of murine IL-1 beta. Isolation, expression, and purification.
Authors: Huang J J , Newton R C , Rutledge S J , Horuk R , Matthew J B , Covington M , Lin Y 
Published: December 2022

Abstract
One cDNA clone encoding a truncated murine IL-1 beta (M IL-1 beta) sequence was isolated from a murine macrophage cDNA library. We reconstituted the coding sequence of the 152-residue mature protein and expressed it in Escherichia coli. rM IL-1 beta was purified to homogeneity and characterized by oligonucleotide and NH2-terminal sequence analysis. Purified rM IL-1 beta exhibited biologic activity equivalent to 7.8 x 10(7) units/mg in the murine thymocyte proliferation assay and 9.9 x 10(3) units/mg in the human gingival fibroblast PGE2 production assay, indicative of species specificity. The isoelectric point of rM IL-1 was found to be 8.85. The circular dichroism spectrum revealed that the secondary structure of M IL-1 is indistinguishable from that of the human protein. Receptor binding studies indicated the rM IL-1 bound to murine EL-4.1 thymoma cells in a specific and dose-dependent fashion with an affinity of 32 pM. Competition binding data suggested that murine and human IL-1 compete for a single class of receptor. Antisera were generated in rabbits against both murine and human IL-1. Results of ELISA binding and antisera neutralization assays indicated that there are common antigenic sites between the two IL-1 beta molecules. These domains are of functional importance because they are capable of mediating the neutralization of biologic activity.
Analysis of a common inheritable idiotype in IgA-deficient sera using monoclonal antibodies.
Authors: Cunningham-Rundles C , Feng Z K 
Published: December 2022

Abstract
In these studies we describe the production of three mAb raised to an idiotype on an IgG anticasein antibody isolated from the serum of one IgA-deficient blood donor. These are IgM kappa and block the binding of casein Ag to anticasein antibody. Sera of unrelated IgA-deficient donors were tested for the presence of the idiotype; 15 of 56 IgA-deficient sera (25%) contain the anticasein idiotype, whereas 1 of 45 normal sera was positive. Anticasein antibodies as a whole were predominantly of the IgG1 and IgG3 subclass; idiotype-positive anticaseins are predominantly of the IgG1 subclass. For IgA-deficient donors, the relative amount of idiotype-positive anticasein antibody was correlated with the level of anticasein present in the serum. Studies were done to investigate the potential inheritance of the idiotype in families; in three of four families the idiotype was inherited in an apparent autosomal dominant pattern. Our data show that a common cross-reactive idiotype can be detected in the sera of IgA-deficient individuals and their family members. This suggests that V region markers may be conserved in this humoral immunodeficiency disease.
Dual stimulation of phospholipase activity in human monocytes. Role of calcium-dependent and calcium-independent pathways in arachidonic acid release and eicosanoid formation.
Authors: Hoffman T , Lizzio E F , Suissa J , Rotrosen D , Sullivan J A , Mandell G L , Bonvini E 
Published: December 2022

Abstract
Human peripheral blood monocytes, prelabeled with [3H]arachidonic acid (AA), release labeled eicosanoids in response to soluble or particulate stimuli. Treatment with 12-O-tetradecanoate phorbol-13 acetate (20 nM), calcium ionophores, A23187 (2 microM) or ionomycin (1 microM), or serum-treated zymosan (300 micrograms) resulted in production of cyclooxygenase (CO) metabolites, 6-keto-PG-F1 alpha, thromboxane-B2, PGE2, PGF2 alpha, PGD2, PGB2, 12-L-hydroxy-5,8,10-heptadecatrienoic acid; 15-lipoxygenase products, including 15-hydroxyeicosatetraenoic acid (HETE); and unmetabolized AA. Labeled 5-lipoxygenase (LO) products, 5-HETE, and leukotriene-B4 were detected only after exposure to ionophore or serum-treated zymosan. The calcium dependence of 5-LO activation was confirmed in experiments where calcium was omitted from the incubation medium, and EGTA (0.5 mM) was added, as well as by direct measurement of increased intracellular calcium in phagocytosing monocytes. Combined or sequential treatment with two stimuli increased the release of unmetabolized AA without a commensurate augmentation of labeled metabolites, indicating that release of CO and LO metabolites does not necessarily reflect the extent of phospholipase activation. Quantitation of individual eicosanoids by RIA confirmed results by using radionuclides. These studies show the following. Activation of human monocyte phospholipase may be regulated by at least two pathways, one "12-O-tetradecanoate phorbol-13 acetate-like," which is largely independent of calcium, and another which is mediated by increased intracellular Ca2+ ("ionophore-like"). "Physiologic" stimulation of monocyte arachidonate release, such as that seen accompanying phagocytosis of opsonized particles, may occur via either a calcium-sensitive or calcium-insensitive pathway or both. Calcium may regulate eicosanoid formation at the level of phospholipase or 5-LO. Free AA, CO products, and 12- or 15-LO products are ordinarily released after phagocytosis, but leukotriene-B4, 5-HETE, or other 5-LO metabolites are produced only under conditions where calcium concentrations are optimal.
The intrinsic affinity constant (K) of anticapsular antibody to oligosaccharides of Haemophilus influenzae type b.
Authors: Hetherington S V 
Published: December 2022

Abstract
Antibody to the polyribosylribitol phosphate (PRP) capsular polysaccharide of Haemophilus influenzae type b is crucial to host defense. Affinities of antibody elicited by vaccination with PRP and PRP-diphtheria toxoid conjugate were determined using oligosaccharides (OS) from PRP. The affinities of antibody induced by vaccination with PRP to OS of three and four repeat units were similar but greater than the affinity to the two-unit OS. NaBH4 reduction of the three-unit OS did not alter the binding affinity, indicating that the reducing end of the OS did not participate in antibody binding. Over the range of OS concentrations tested, antibody affinity appeared to be homogeneous. Antibody concentration could be determined from binding experiments independently from affinity. Whole serum had 8- to 40-fold less antibody detected by binding analysis than by RIA, but the antibody concentration of an IgG fraction measured by the two methods agreed within a factor of two. We could not account for the discrepancy in concentrations found with whole serum by the presence of IgM or IgA antibody. The average affinity of antibodies of 10 adults vaccinated with PRP was similar to that of antibodies elicited in 14 adults vaccinated with a PRP-diphtheria toxoid conjugate (10.7 x 10(5) vs 7.6 x 10(5) liter/mol, respectively, p greater than 0.05). We conclude that the intrinsic affinity of antibody after vaccination with PRP is low and is not different from that of antibody elicited by PRP diphtheria toxoid conjugate.
Identification of a nuclear factor that binds to a conserved sequence of the I-A beta gene.
Authors: Celada A , Shiga M , Imagawa M , Kop J , Maki R A 
Published: December 2022

Abstract
Human and murine class II genes of the MHC show a striking homology 50 to 120 bp upstream of the transcription start site. This area is composed of two conserved sequences (a 13-mer and an 8-mer separated by 19 to 20 bp). Recently, these conserved sequences have been identified as cis-acting transcriptional regulatory elements. We have sought nuclear factors that bind specifically to an upstream fragment (-245 to +75 bp) of the murine I-A beta chain gene that contains the conserved sequences by application of a modified gel electrophoresis DNA binding assay. We report here the identification of a nuclear factor whose binding site overlaps the 8-mer conserved sequence. This factor is present in murine B and T lymphocytes, macrophages, mastocytes, fibroblasts, and human B lymphocytes and macrophages. The binding site was defined by using DNase I and dimethylsulfate protection assays. The putative binding sequence is closely related to the sequence, CCAAT, which is often found associated with the promoter of a gene and is recognized by the transcriptional factors CCAAT-binding transcription factor and nuclear factor I. Oligonucleotides that contain the binding site sequences for nuclear factor I and the alpha-globin CCAAT element, however, do not compete for binding of the nuclear factor to the sequence identified here, suggesting that, in spite of the similarity of the binding sequence, the nuclear factor identified in this report may be different. This nuclear protein may be one of the trans-acting factors that mediate transcription of class II genes.
1,25-Dihydroxyvitamin D3 decreases expression of HLA class II molecules in a melanoma cell line.
Authors: Carrington M N , Tharp-Hiltbold B , Knoth J , Ward F E 
Published: December 2022

Abstract
An HLA class II-positive melanoma cell line, DU-Mel 17, was treated with three compounds known to induce differentiation in various cell lines. Neither retinoic acid nor dibutyryl cAMP altered levels of DR alpha mRNA, but 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) significantly decreased the level of DR alpha mRNA 48 h after treatment. Optimal effect of the hormone on DR alpha mRNA was reached by 72 h. DU-Mel 17 cells were responsive to 1,25(OH)2D3 in a dose-dependent manner, and a reduction in DR alpha mRNA was seen at concentrations as low as 5 x 10(-13) M. The action of 1,25(OH)2D3 on DR alpha mRNA levels was dependent on protein synthesis as evidenced by inhibition of its effect upon addition of cycloheximide. Both DR and DQ protein levels on the surface of DU-Mel 17 were beginning to decline by 72 h after 1,25(OH)2D3 treatment, and by 96 h these proteins were decreased by 65%. 1,25(OH)2D3 was not capable of altering expression of class II molecules on three different class II-positive B lymphoblastoid cell lines, although one of these lines was shown to express the receptor for 1,25(OH)2D3. These findings are important because 1) there is no known physiologic regulator that actively down-regulates class II molecules that are present in and/or on cells, 2) levels of mRNA derived from a very limited number of genes are known to be altered by 1,25(OH)2D3, and 3) they support the contention that 1,25(OH)2D3 may alter the differentiation state of these cells and the activity of the normal counterpart of these cells in an immune response.
Retroviral protein P15E and tumorigenesis. Expression is neither required nor sufficient for tumor development.
Authors: Schmidt D M , Snyderman R 
Published: December 2022

Abstract
Murine tumor cells frequently express retroviral protein p15E, a protein with antiinflammatory activity. This has led to the hypothesis that p15E expression allows nascent tumor cells to escape host immunologic defenses. To evaluate the role of p15E expression in tumorigenesis, NIH3T3 cells transformed by various oncogenes and BALB/c lines transformed by carcinogens or SV40 were examined for p15E expression and tumorigenicity. All of the NIH3T3 transformants and most of the BALB/c transformants did not express p15E, indicating that transformation per se does not inevitably induce the expression of p15E. Although not expressing p15E, some of these transformants were capable of forming tumors in immune competent hosts, indicating that p15E is not universally required for tumor growth. Four of the transformed cell lines negative for p15E expression and deficient in tumor-forming capacity were transfected with a gene coding for Moloney retroviral p15E. Despite the expression of p15E, there was no augmentation of their tumorigenic capacity, showing that p15E is not sufficient to ensure tumor formation by a transformed cell. These results argue against a general role for retroviral p15E expression in tumorigenesis.