bluuebunny/crossref_metadata_2025_split huggingface dataset:
C3b binding, but not its breakdown, is affected by the structure of the O-antigen polysaccharide in lipopolysaccharide from Salmonellae.
Authors: Grossman N , Joiner K A , Frank M M , Leive L 
Published: January 2023

Abstract
Bacteria whose lipopolysaccharide contains O-antigen side chains activate complement via the alternative pathway. We have shown previously that three strains of Salmonella, differing in the chemical structure of their O-antigens, consumed C3 to different extents when incubated in C4-deficient guinea pig serum. Moreover, sheep erythrocytes coated with lipopolysaccharide purified from these strains mimicked whole cells in C3 consumption, proving that lipopolysaccharide alone could account for these results. We have now measured the deposition of 125I-C3 in this system, and found that C3 deposition parallels C3 consumption in rate and extent, and differs for surfaces bearing different O-antigens, whether tested with bacteria or with erythrocytes coated with purified lipopolysaccharide. We have also examined the fate of C3 on these Salmonellae by measuring the size and quantity of 125I-C3 breakdown fragments by SDS-PAGE, and have determined the kinetics of conversion of C3b to iC3b by using conglutinin, a molecule that binds specifically to iC3b. There is no difference in breakdown of C3b deposited on cells with different O-antigens: all show partial conversion to iC3b and C3dg as indicated by 68,000, 44,000, and 41,000 m.w. bands on reduced SDS gels. Furthermore, for all strains, the Ka of conglutinin binding to iC3b is similar (0.49 to 0.69 X 10(8) M-1), as is the rate of generation of iC3b and the final ratio of iC3b:C3b + iC3b (0.62 to 0.72). We therefore postulate that the fine structure of the O-antigen in lipopolysaccharide determines the magnitude of alternative pathway activation on the bacterial surface by affecting the rate and extent of C3b deposition, but not the rate and extent of breakdown of C3b.
Basophil histamine release induced by a substance from stimulated human platelets.
Authors: Orchard M A , Kagey-Sobotka A , Proud D , Lichtenstein L M 
Published: January 2023

Abstract
Platelet activation may occur during immunoglobulin E antibody (IgE)-mediated reactions. In these studies, we confirm that platelet-derived supernatants (PDS) induce histamine release from human mixed leukocytes containing basophils, one of the initial target cells in IgE-mediated reactions. In extending this observation, we have shown that this PDS-induced histamine release is both temperature- and calcium-dependent. Kinetic studies of release induced by PDS indicate that release is more rapid than that associated with IgE-dependent mechanisms. This platelet-derived, histamine-releasing activity is produced by platelet stimulation with collagen (5 micrograms/ml) and acetylglyceryl ether phosphorylcholine (10(-7)), as well as thrombin (1 U/ml). Initial characterization has shown that it is stable to acid and to freeze-thawing but not to boiling for 10 min. In addition, although this histamine-releasing activity is nondialyzable (i.e., greater than 3500 m.w.), it cannot be attributed to platelet factor 4. Thus, platelets, once activated, can produce a soluble substance or substances which can initiate basophil-mediated reactions, further suggesting that platelet activation can enhance allergic and inflammatory reactions.
Plasmodium falciparum antigens synthesized by schizonts and stabilized at the merozoite surface when schizonts mature in the presence of protease inhibitors.
Authors: Lyon J A , Haynes J D 
Published: January 2023

Abstract
Schizonts of Plasmodium falciparum were cultured in medium containing a mixture of 10 micrograms/ml each of leupeptin, chymostatin, pepstatin, and antipain. The protease inhibitors did not inhibit macromolecular synthesis but were associated with decreased reinvasion of red cells and the accumulation of well preserved merozoites clustered around pigment granules (PCM, protease inhibitor clusters of merozoites). The parasite pellet from PCM cultures contained increased amounts of merozoite antigens, particularly at Mr 83, 73, 66, 45, and 17 kDa. The increases of the Mr 83, 73, and 45 kDa surface antigens observed in PCM had been observed also in similar merozoite clusters obtained by culturing schizonts in the presence of inhibitory antibodies. These three antigens are processed products of the abundant Mr 195 kDa schizont surface antigen. Liquid-phase double immunofluorescence of PCM demonstrated a residual red cell membrane through which monoclonal antibodies passed and reacted with the Mr 83, 73, and 45 kDa merozoite surface antigens or their precursors. The processes associated with normal reinvasion apparently involve protease(s), which plays a role(s) in the breakdown of the red cell membrane and the shedding of merozoite surface antigens. Interference with these processes by protease inhibitors is useful in increasing recoveries of merozoite antigens, as well as in elucidating mechanisms of reinvasion.
Translocation of protein kinase C during membrane immunoglobulin-mediated transmembrane signaling in B lymphocytes.
Authors: Chen Z Z , Coggeshall K M , Cambier J C 
Published: January 2023

Abstract
Previous studies have implicated a role for protein kinase C (PKC) in transmembrane signal transduction by B cell surface immunoglobulin (Ig). Specifically, the pharmacologic PKC activator phorbol myristate acetate mimics the biologic effects of mIg cross-linking ligands, and cross-linking of membrane Ig (mIg) induces polyphosphoinositide hydrolysis generating diacylglycerol, a potent activator of PKC. Studies described here additionally implicate PKC in mIg-mediated signaling by demonstrating rapid translocation of activatable PKC (PKCa) from cytosol to Triton-soluble membrane fractions after cross-linking of cell surface IgM or IgD. This response, which is also induced by phorbol myristate acetate and lipolysaccharide, is detectable within 1 min of mIg cross-linking and is followed within 4 min by additional translocation of PKCa to a Triton-insoluble particulate compartment. The ability of dbcAMP plus theophylline to inhibit polyphosphoinositide hydrolysis, PKCa translocation, and the B cell's subsequent biological response suggests that these events may be causally related.
B cell stimulatory factor 1 induces lobster agglutinin 1-separated mouse thymocytes to express cytotoxic T lymphocyte activity.
Authors: Collins J M , Justement L B , Stedman K E , Zlotnik A , Campbell P A 
Published: January 2023

Abstract
Mouse thymocytes low in surface sialic acid were prepared by using the lectin lobster agglutinin 1 (LAg1). These LAg1-thymocytes do not become CTL when incubated with Con A or Con A plus mouse rIL-2, whereas unseparated thymocytes and thymocytes with high levels of surface sialic acid develop good levels of polyclonal CTL activity under these conditions. However, LAg1- thymocytes developed high levels of CTL activity when incubated with B cell stimulatory factor-1 (BSF-1), provided as the supernatant of the rBSF-1-secreting T cell hybridoma D9-C1.12.17. Affinity-purified BSF-1 from D9-C1 supernatant and rBSF-1 also stimulated these cells to become CTL, but they were not as active as the D9-C1 supernatant. The ability of D9-C1 supernatant and of affinity-purified BSF-1 to induce CTL activity was inhibited by the anti-BSF-1 mAb 11B11. Moreover, this mAb inhibited the ability of 24-h Con A-stimulated spleen cell supernatant to induce these cells to express CTL activity. 11B11 also inhibited LAg1+ thymocytes from becoming CTL when stimulated with Con A alone. These experiments suggest that BSF-1 is required for LAg1- and LAg1+ thymocytes to become CTL.
The sites of catabolism of murine monomeric IgA.
Authors: Moldoveanu Z , Epps J M , Thorpe S R , Mestecky J 
Published: January 2023

Abstract
The tissue sites of monomeric IgA (mIgA) catabolism were determined in a BALB/c mouse model. Mouse mIgA myeloma proteins were labeled either by direct iodination or by coupling the residualizing label, dilactitol-125I-tyramine (125I-DLT) to the proteins; catabolites from protein labeled with 125I-DLT accumulate at the site of protein degradation, allowing identification of the tissue and cellular sites involved in catabolism of the protein. The circulating half-lives of 125I- and 125I-DLT-mIgA were the same. The distribution of radioactivity in tissues was measured at 1, 3, 24, and 96 h after iv. injection of 125I-DLT-labeled mIgA, dimeric IgA (dIgA), IgG, or mouse serum albumin. The greatest uptake of 125I-DLT-mIgA was attributable to the liver. This organ accounted for more internal catabolism of mIgA than all other tissues combined. In contrast, 125I-DLT-IgG was catabolized equally in skin, muscle, and liver. These data indicate that, in mice, the liver is the major site of mIgA catabolism. To determine the cell types involved, collagenase digestion was used to isolate parenchymal and non-parenchymal cells from perfused liver of animals injected with 125-DLT-mIgA. Most of the radioactivity was associated with the hepatocyte fraction, even though both cell types showed uptake of 125I-DLT-mIgA. Inhibition studies, with asialofetuin and mouse IgA demonstrated that the uptake of mIgA by liver cells was mediated primarily by the asialoglycoprotein receptor.
Pertussis toxin inhibits human neutrophil responses mediated by the 42-kilodalton IgG Fc receptor.
Authors: Feister A J , Browder B , Willis H E , Mohanakumar T , Ruddy S 
Published: January 2023

Abstract
The effects of pertussis toxin (PT) on human neutrophil responses mediated by the 42-kDa IgG Fc R (Fc gamma R42) were compared with its effects on responses mediated by the FMLP receptor. Pre-treatment of neutrophils with PT completely inhibited FMLP stimulation of superoxide production and blocked over 95% of FMLP-stimulated degranulation. PT inhibited superoxide production stimulated by Fc gamma R42 cross-linking by 92%. In contrast, degranulation stimulated by Fc gamma R42 was only partially inhibited, with beta-glucuronidase release inhibited by 54%, lysozyme by 33%, and lactoferrin by 78%. With either stimulus, PT inhibition was maximal in the range from 1.8 to 2 micrograms/ml. Responses to both stimuli declined in a parallel fashion with increasing time of exposure to PT with maximal inhibition occurring after 2 h of exposure. Inhibition of FMLP responses and Fc gamma R42-mediated superoxide production, but not degranulation, correlated with ADP-ribosylation of a 45-kDa membrane protein. Inhibition by PT of Fc gamma R42-mediated responses was not due to a change in receptor number. These data suggest that activation of polymorphonuclear neutrophils via Fc gamma R42 proceeds through two pathways, only one of which is regulated by a PT-sensitive G protein.
IgE formation and Fc receptor-positive lymphocytes in normal, immuno-deficient, and auto-immune mice infected with Nippostrongylus brasiliensis.
Authors: Lebrun P , Sidman C L , Spiegelberg H L 
Published: January 2023

Abstract
The IgE serum levels and IgE FcR-positive lymphocytes (Fc epsilon R) in the spleen and mesenteric lymph nodes (MLN) of normal and immunologically mutant strains of mice were determined before and 14 days after infection with Nippostrongylus brasiliensis (Nbr) parasites. By IgE rosetting of cells immunofluorescently stained for sIg. Thy-1.2, Lyt-2, and L3T4, only sIg+ IgE rosetting lymphocytes were detected in both normal and Nbr-infected mice. IgE high responder mice had the same percentage of Fc epsilon R+ spleen and MLN lymphocytes as low responder mice. After Nbr infection, the percentages of splenic and MLN Fc epsilon R+ cells increased in parallel to a similar increase of sIg+ B cells. Athymic C57BL/6J-nu mice had 62% Fc epsilon R+ spleen and 85% Fc epsilon R+ MLN cells before and after Nbr infection, but IgE serum levels were less than 5 ng IgE/ml. C57BL/6J mice with the viable moth-eaten mutation mev which have almost exclusively Ly-1+ B cells, had less than 1% Fc epsilon R+ lymphocytes and formed only small amounts of IgE. C57BL/6J mice with the lymphoproliferation (lpr) or generalized lymphoproliferative disease (gld) mutations had low numbers of Fc epsilon R+ cells but formed 15 to 30 times more IgE after Nbr infection than control C57BL/6J mice. The IgE response of mice with the beige mutation (bg) did not differ from control mice. Mice with the xid mutation had few Fc epsilon R+ and sIg+ cells but showed high IgE responses. These data demonstrate that Fc epsilon R are typical cell surface markers for approximately 90% of murine Ly-1-, sIg+ B cells and that the number of Fc epsilon R+ cells does not correlate with the capacity of the mice to form IgE. The IgE response to Nbr infection is normal in mice homozygous for the bg mutation, elevated in mice homozygous for the xid, lpr, and gld mutations, and decreased in mice homozygous for the mev and nu mutations.
Tracing the evolution of H-2 D region genes using sequences associated with a repetitive element.
Authors: Duran L W , Pease L R 
Published: January 2023

Abstract
The class I genes in the murine MHC are genetically divided into the K, D, Qa, and T1a region subfamilies. These genes presumably arose by duplication from a common class I ancestor. Oligonucleotide probes specific for sequences associated with a moderately repetitive B2 SINE element, which is inserted into the 3' untranslated region of the H-2D and H-2L genes, were used to examine the evolutionary relationship between these classically defined D region genes (H-2D and H-2L) and the other members of the class I gene family. Hybridization analyses of recombinant cosmid and genomic DNA indicated that the D region genes separated genetically from the other members of the class I gene family 12 to 14 million years ago. The evidence suggests that during this time frame the chromosomal segment harboring the characteristic insertion became fixed in the ancestral population which gave rise to Mus domesticus. Previous studies have shown that the number of genes present in the Qa and T1a regions varies among inbred strains and among laboratory stocks of wild mice derived from more distant species on the genus Mus. No evidence was found in this study to support the hypothesis that variation in class I gene number is the result of recent duplications of the functionally defined class I genes of the D region, H-2D and H-2L.
Cloning of a gamma 2b gene encoding anti-Pseudomonas aeruginosa H chains and its introduction into the germ line of mice.
Authors: Tsang H , Pinkert C , Hagman J , Lostrum M , Brinster R L , Storb U 
Published: January 2023

Abstract
A complete, functional gamma 2b gene (pVCM) was cloned from a mouse hybridoma (VD93) with antibody activity to Pseudomonas aeruginosa. DNA sequencing of the VDJ region of pVCM determined that the VH gene was a member of the J558 family rearranged to JH2. Upon transfection into myeloma cells the gamma 2b gene gave rise to high levels of gamma 2b mRNA and gamma 2b protein. The gamma 2b protein had the same IEF pattern as the parent hybridoma protein VD93 and the antibodies formed from a combination of the pVCM gamma 2b chains and the myeloma lambda-chains bound weakly to P. aeruginosa. However, the hybrid antibodies did not discriminate between the serotypes 2 and 3, whereas the parent protein was specific for serotype 3. Transgenic mice were produced with the pVCM gamma 2b gene which expressed the gamma 2b mRNA (both membrane and secreted forms) only in lymphoid organs. However, contrary to expectations, the gamma 2b mRNA levels were higher in T cells than in B cells in three different transgenic lines. The serum of the transgenic mice had no activity to P. aeruginosa indicating the importance of L chains for the conformation of the Ag binding site. These gamma 2b transgenic mice provide a convenient tool for the study of feedback inhibition of Ig gene rearrangement.
Regulation of an idiotype+ B cell lymphoma. Effects of antigen and anti-idiotopic antibodies on proliferation and Ig secretion.
Authors: Ward R E , McNamara-Ward M , Webb C F , Altman D , Lim P L , Tucker P W , Kohler H 
Published: January 2023

Abstract
The B cell surface Ig molecule plays an important regulatory role in delivering inductive/tolerogenic signals to the cell. In this paper, the effect of Ag and anti-idiotopic antibodies on the in vitro proliferation and Ig secretion of a B cell tumor was studied. The tumor (BCL1), which had been transfected with the TEPC-15 VH and VL Ig genes, expresses surface Ig and secretes antibody that binds the hapten phosphorylcholine. We found that Ag (C polysaccharide and phosphorylcholine carrier Ag) and two different anti-idiotopic antibodies, in the absence of T cells, all inhibited the proliferation of the T15+ transfectant cell line. The anti-idiotopic antibodies, but not Ag, also inhibited the secretion of T15 Ig by this cell line, suggesting different functional roles for Ag vs anti-Id in the regulation of B cell inactivation. The inhibition of secretion and proliferation appears to be cell cycle phase related. In addition, mouse rIL-4 could override the inhibition of proliferation induced in these studies. These phenomena, demonstrating that binding of surface Ig can result in the transduction of negative growth signals to a B cell tumor, can be viewed as a manifestation of immunologic tolerance. These findings collectively demonstrate that Ag and anti-Id mediate different signals to B cells via interaction with the surface Ig. Because of the monoclonal nature of the T15 transfectant and the anti-idiotypic antibodies, this system can be used to investigate the underlying molecular reactions involved in the B cell response and induction of tolerance.
Quantitative analysis of cytokine gene expression in rheumatoid arthritis.
Authors: Firestein G S , Alvaro-Gracia J M , Maki R , Alvaro-Garcia J M 
Published: January 2023

Abstract
Previous studies of the cytokine profile of rheumatoid arthritis (RA) have been primarily limited to the assessment of the levels of these mediators in synovial fluid (SF) or synovial tissues (ST) by biologic or immunologic assays. We have studied cytokine gene expression in RA by in situ hybridization of SF cells, enzymatically dispersed ST cells, and frozen sections of ST. RA ST cells (n = 7) were studied and a high percentage of cells hybridized to the following anti-sense probes: IL-6 = 19 +/- 3.3%; IL-1 beta = 9.9 +/- 1.7%; TNF-alpha = 5.8 +/- 1.4%; granulocyte-macrophage-CSF = 2.2 +/- 0.8%; transforming growth factor-beta 1 = 1.3 +/- 0.2% (p less than 0.05 for each compared to sense probes). Similar results were found using osteoarthritis ST cells, although the percentage of cells expressing the IL-6 gene (7.1 +/- 2.5%) was significantly less in osteoarthritis compared to RA. RA ST cells did not significantly bind the IFN-gamma probe (0.2 +/- 0.1% positive), although they were capable of expressing the IFN-gamma gene if stimulated with PHA. The OKM1+ population of ST cells (i.e., macrophage lineage cells) was greatly enriched for IL-1 beta and TNF-alpha, whereas the OKM1- population (lymphocytes, fibroblasts, and type B synoviocytes) was enriched for IL-6. The vast majority of cells expressing the IL-6 gene were non-T cells. Furthermore, hybridization to RA ST frozen sections localized IL-6 mRNA to the synovial lining layer, which is comprised of type A and type B synoviocytes. In contrast to the high level of cytokine gene expression observed in ST, SF cells did not hybridize significantly to any of the cytokine probes. If stimulated with LPS or PHA, SF cells expressed IL-1 beta or IFN-gamma genes, respectively.
Transforming growth factor-beta 1 is a costimulator for IgA production.
Authors: Kim P H , Kagnoff M F 
Published: January 2023

Abstract
Transforming growth factor-beta 1 (TGF-beta 1) belongs to a family of polypeptides involved in the regulation of cell growth and differentiation. We have examined the ability of TGF-beta 1 to regulate isotype specific Ig secretion by murine spleen B cells. TGF-beta 1, in the presence of rIL-2, induced a synergistic 10-fold or greater increase in IgA secretion by LPS-stimulated spleen B cells. TGF-beta 1 alone had little to no effect on IgA secretion. In contrast, TGF-beta 1, with or without rIL-2, markedly inhibited IgG1 and IgM secretion under the same conditions. The costimulatory activity of TGF-beta 1 and rIL-2 on IgA secretion was seen in cultures of surface IgA negative B cells and was inhibited by anti-TGF-beta 1 antibody in a dose dependent manner. Vicia villosa agglutinin non-adherent Peyer's patch T cells, which secrete IL-2, also synergized with TGF-beta 1 and could substitute for the activity of LPS and rIL-2 on the IgA response. Finally, IL-5 added after 2 days of culture, but not at the beginning of culture, synergized with TGF-beta 1 on the IgA response. These studies indicate that TGF-beta 1 can interact with other lymphokines and selectively modulate the IgA response.
Production of tumor necrosis factor (TNF-alpha) and lymphotoxin (TNF-beta) by murine pre-B and B cell lymphomas.
Authors: Laskov R , Lancz G , Ruddle N H , McGrath K M , Specter S , Klein T , Djeu J Y , Friedman H 
Published: January 2023

Abstract
Media from murine pre-B and B lymphoma cell cultures, but not from myeloma cell cultures, was cytotoxic to WEHI 164 cells, causing these TNF-sensitive targets to release 51Cr. The cytotoxic activity in the culture medium reached maximum levels approximately 4 days after the cell culture was initiated. The constitutive production of the factors was not influenced by depletion of serum from the medium or by the addition of either phorbol ester or bacterial endotoxin. The factor has a Mr greater than 10 kDa, and its cytotoxicity was abolished by anti-serum against murine TNF. Northern blot analysis with the use of cDNA probes to murine tumor necrosis factor (TNF-alpha) and lymphotoxin (LT, TNF-beta) showed high levels of TNF-mRNA in the pre-B cell lines, lower levels in the mature B cell lines and no TNF-mRNA in the myeloma cell lines. LT mRNA was present in pre-B cell lines, at a much lower concentration in only one of the B cell lines, and was not present in three other B lymphomas or in the myelomas tested. The results show a positive correlation between the presence of TNF and/or LT mRNA and the 51Cr-releasing activity present in the cell culture medium. Our data indicate that TNF and LT can be produced by murine B cells and that the synthesis of these cytokines may be restricted to certain differentiation stages of the B cell lineage.
Selective induction of Fc gamma RIII on human monocytes by transforming growth factor-beta.
Authors: Welch G R , Wong H L , Wahl S M 
Published: January 2023

Abstract
Transforming growth factor-beta (TGF-beta) is a polypeptide that participates in morphogenesis, inflammation, and would repair. Emerging as an important immunomodulatory molecule, TGF-beta may also regulate the phenotype and function of mononuclear cells within an inflammatory site. In this study TGF-beta is shown to induce expression of the gp50-65 receptor for Fc gamma RIII on otherwise negative peripheral blood monocytes. Circulating monocytes express Fc gamma RI and Fc gamma RII, but not Fc gamma RIII, and no inducing agent for Fc gamma RIII has previously been identified. Within hours after exposure of freshly isolated peripheral blood monocytes to picomolar concentrations of TGF-beta 1 or TGF-beta 2, mRNA specific for Fc gamma RIII is detectable followed by expression of the receptors on the cell surface. Neutralizing antibodies to TGF-beta completely inhibit the TGF-beta-induced up-regulation of Fc gamma RIII. In contrast to TGF-beta, other cytokines involved in the inflammatory response are ineffective in regulating Fc gamma RIII expression on human monocytes. Thus, the early release of TGF-beta by platelets in an inflammatory site may foster enhanced immunophagocytosis and contribute to host defense by inducing monocyte Fc gamma RIII expression.