bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipocortin-1 fragments inhibit neutrophil accumulation and neutrophil-dependent edema in the mouse. A qualitative comparison with an anti-CD11b monoclonal antibody.
Authors: Perretti M , Ahluwalia A , Harris J G , Goulding N J , Flower R J 
Published: December 2022

Abstract
The activity of the steroid-inducible protein lipocortin-1 (LC1; with a primary sequence of 346 amino acids; also called annexin 1), a fragment corresponding to amino acids 1-188 and a short peptide from the N-terminus (amino acid 2-26) were tested for anti-inflammatory actions in three models of acute inflammation in the mouse in comparison with a mAb anti-CD11b (alpha CD11b). In the mouse air-pouch model LC1, fragment 1-188 and peptide Ac2-26 exhibited powerful inhibitory effects (ED50 approximately 5.2, 38 and 88 micrograms/mouse, respectively) on leukocyte migration elicited by IL-1. LC1 was approximately 200 times more potent than Ac2-26 on a molar basis although both gave maximal inhibitions, in contrast fragment 1-188 only produced a partial dose-response curve. LC1 was approximately 20 times more potent on a molar basis in this assay than the alpha CD11b mAb. Peptide Ac2-26 and the mAb alpha CD11b also blocked cell migration into the air-pouch induced by IL-8 with approximately the same potency. In the mouse skin edema and zymosan peritonitis assays Ac2-26 was inhibitory (ED50 of 200 micrograms/mouse) but less so than the alpha CD11b antibody (ED50 approximately 0.5 mg/mouse). Both LC1 (10 micrograms) and Ac2-26 (200 micrograms) completely blocked FMLP-induced neutropenia in the mouse. Studies using an inactivated LC1 preparation, which binds to the same high affinity binding sites as the biologically active material, indicated that the short peptide acts on the same sites as the native LC1. This study confirms the activity of LC1 in another model of experimental inflammation and suggests that it acts partly through inhibition of leukocyte activation with an overall effect qualitatively comparable to the blocking of CD11b portion of a beta 2-integrin complex. It also shows that peptides derived from the N-terminal domain of LC1 may mimic the activity of the full length molecule and points the way for a new family of anti-inflammatory substances that inhibit leukocyte trafficking.
Visualization of the endogenous NF-kappa B p50 subunit in the nucleus of follicular dendritic cells in germinal centers.
Authors: Feuillard J , Körner M , Fourcade C , Costa A , Binet J L , Debré P , Raphael M 
Published: December 2022

Abstract
NF-kappa B, a 50 kDa/65 kDa (p50/p65) heterodimer, is a ubiquitous transcription factor involved in the positive regulation of various immune genes. The aim of this study was to determine whether NF-kappa B is related to a particular cell type and/or differentiation step during immunopoiesis. Using in situ hybridization on sections from non HIV hyperplastic lymph nodes, we found that the gene of the 105 kDa precursor of p50 was overexpressed in the light zone of germinal centers, with a network aspect, which suggested the involvement of follicular dendritic cells (FDC). By immunohistochemistry, p50 protein was detected in the cytoplasm and nucleus of FDC, confirming the involvement of FDC. Furthermore, p50 protein was detected in the cytoplasm of all lymphocytes. Thus, we focused our study on isolated FDC clusters from normal tonsils. As showed on tissue sections, we detected the p50 in both cytoplasm and nucleus of FDC. Nuclei of lymphocytes from FDC clusters were negative. We next studied p65 and c-Rel protein expression in FDC clusters. p65 was detected in the cytoplasm of FDC, whereas nuclei were negative. Furthermore, p65 was detected in the nuclei of some lymphocytes. c-Rel protein was detected only in the cytoplasm of lymphocytes and not in the nucleus and cytoplasm of FDC. Our results indicated that, in the context of T cell-dependent B cell immunopoiesis occurring in FDC clusters, p50 is mainly related to FDC with a massive overexpression in the nuclei, whereas p65 is expressed in a scattered manner in the nuclei of lymphocytes and c-Rel protein exclusively in the cytoplasm of lymphocytes from FDC clusters. These results suggested that the two subunits of NF-kappa B and the c-Rel protein have different roles in different cell types during B cell immunopoiesis.
Structural and immunologic analysis of gene triplications in the Ig heavy chain constant region locus.
Authors: Brusco A , Cariota U , Bottaro A , Boccazzi C , Plebani A , Ugazio A G , Galanello R , van Leeuwen A M , DeLange G G , Depelchin S 
Published: December 2022

Abstract
The Ig H chain C region is a multigene family often involved in genomic rearrangements leading to deleted and duplicated haplotypes, most probably through unequal crossing over between homologous regions within the locus. The frequency of these haplotypes in Italy is around 2.7% each. Using PFGE analysis in two unrelated Italian families we found an abnormal high m.w. band, inherited in a Mendelian fashion. To assess the extension of the haplotype we performed Southern blot analysis using several specific Ig H chain C probes. In both cases, the haplotype turned out to be triplicated, with three copies of the genes from A1 to E. In one family segregation of a duplication from EP to G4 was also observed. Analysis of polymorphic loci suggests that the two triplications are of independent origin. Serological detection of IgA2 allotypes demonstrated the functional activity of the genes at the 3' end of the triplicated locus, ruling out any major effect of these large genomic rearrangements on Ig class switching. Furthermore, the triplicated haplotype does not seem to give rise to any clinically significant immunological impairment or increase in Ig serum concentrations.
A single engineered amino acid substitution changes antibody fine specificity.
Authors: Kussie P H , Parhami-Seren B , Wysocki L J , Margolies M N 
Published: December 2022

Abstract
During the acquisition of humoral immunity, the process of somatic hypermutation introduces nucleotide substitutions into expressed antibody (Ab) V region genes. Studies employing in vitro mutagenesis have shown that recurrent mutations observed in vivo often enhance the affinity of the target Ab for Ag. Here we show that a single amino acid replacement at position 35 in the H chain of an unmutated Ab with specificity for p-azophenylarsonate (Ars) confers specificity for the structurally related hapten p-azophenylsulfonate (Sulf) while abolishing specificity for Ars. The mutant Ab binds Sulf with an affinity characteristic of Ab produced by memory B cells. The same mutation in the somatically mutated anti-Ars Ab 36-71, for which the Fab crystal structure is known, resulted in a significant shift in fine specificity from Ars to Sulf. Examination of the crystal structure suggests that the specificity change is caused by a decrease in binding site size and/or new hydrogen bond geometry. Because the mutation at position 35 had been observed in somatically mutated Ab elicited by immunization with Ars followed by Sulf, the results confirm that somatic mutation in vivo can alter Ab specificity. The results also support the potential of Ab engineering to alter antigenic specificity.
Normal V(D)J coding junction formation in DNA ligase I deficiency syndromes.
Authors: Petrini J H , Donovan J W , Dimare C , Weaver D T 
Published: December 2022

Abstract
Bloom syndrome and a clinically related syndrome represented by the cell line 46BR have been associated with reduction in DNA ligase I activity. In these syndromes, DNA ligase I deficiency severely impairs the development and function of the immune system. We undertook analysis of DNA ligase I-deficient cells to determine whether the observed immune deficiency is attributable to a perturbation in the process of V(D)J recombination. V(D)J recombination in Bloom syndrome cell lines and 46BR was examined by a transient transfection assay. No effect on the fidelity of coding and signal junction formation in DNA ligase I-deficient cells was observed. The frequency of V(D)J recombination in DNA ligase I-deficient cells was also examined using recombination substrates modified to function in human cells. Similar recombination frequencies were observed in normal and DNA ligase I-deficient cells, demonstrating that the efficiency of the V(D)J recombination process is unaffected by alterations in DNA ligase I activity. Rearranged immunoglobulin loci from Bloom syndrome cell lines and patient material were molecularly cloned by an inverse polymerase chain reaction strategy which should be applicable to a variety of human immunodeficiency syndromes and were indistinguishable from those found in normal bone marrow samples. Our data argue that the immune system defects associated with DNA ligase I deficiency do not result from perturbation of the V(D)J recombination pathway.
T and B epitope determination and analysis of multiple antigenic peptides for the Schistosoma mansoni experimental vaccine triose-phosphate isomerase.
Authors: Reynolds S R , Dahl C E , Harn D A 
Published: December 2022

Abstract
Schistosoma mansoni triose-phosphate isomerase (TPI), a glycolytic enzyme, was originally identified as the target of the mAb M.1 that conferred protection when the antibody was administered in vivo. In this study we increase the evidence that schistosome TPI is a potential vaccine Ag by showing that it also a potent inducer of IL-2 and IFN-gamma production (Th1 responses), driving production of these cytokines in the same cell populations of infected animals that have high Th2 responses directed at other parasite egg Ag. With the goal of synthetic peptide vaccine design, rTPI was used to determine specific T and B cell epitopes recognized by two strains of mice representing high and moderate responders (C57Bl/6J and CBA/J). All selected epitopes were from nonconserved regions of TPI and thus parasite-specific. We then defined minimal size immunoreactive epitopes and synthesized four-armed multiple antigenic peptides (MAP) consisting of T and B cell epitopes that could be recognized by both strains of mice in the same molecule. Characterization of the immunoreactivity of the MAP showed that higher antibody recognition of the MAP was attained when the B cell epitope was placed on the amino termini relative to the T cell epitope, whereas equivalent immunoreactivity occurred for the T cell epitopes when located at either position. Most interesting was the finding that one of the minimal T cell epitopes, when incorporated into the MAP, required enlarging to retain immunoreactivity. Finally we showed that both the full-length TPI molecule and the final version of the MAP were immunogenic to T cells in naive animals and induced cross-recognition in the form of IL-2 and IFN-gamma production.
CD40-activated surface IgD-positive lymphocytes constitute the long term IL-4-dependent proliferating B cell pool.
Authors: Galibert L , Durand I , Banchereau J , Rousset F 
Published: December 2022

Abstract
In vitro, B cells undergo long term proliferation when triggered through their CD40 surface molecule and in the presence of IL-4. Here, we show that cells that proliferate in this culture system lose their germinal center (GC) features and acquire or maintain non-GC markers. When separated by the magnetic cell separation system, both sIgD+ and sIgD- B cells can proliferate in this culture system, sIgD+ B cells exhibiting a higher rate of growth than sIgD- cells. Simultaneous flow cytometric measurement of sIgD and DNA content revealed that B lymphocytes can keep their sIgD after entry into cell cycle. Experiments using G8 Id-positive B lymphocytes allowed us to follow the evolution of sIgD+ and sIgD- cells in a reconstituted B cell population. Long term proliferating cells are sIgD+/sIgM(+)-derived B lymphocytes whereas the initial sIgD-/sIgM- cells are lost. Taken together, these data show that anti-CD40 + IL-4 activated sIgD+ B blasts express non-GC characteristics and that sIgD+ B cells preferentially proliferate in the CD40 system. The possible in vivo role of IL-4 + CD40 signaling is discussed.
CD11b/CD18 integrin and a beta-glucan receptor act in concert to induce the synthesis of platelet-activating factor by monocytes.
Authors: Elstad M R , Parker C J , Cowley F S , Wilcox L A , McIntyre T M , Prescott S M , Zimmerman G A 
Published: December 2022

Abstract
We determined the mechanism by which opsonized zymosan particles, which are derived from yeast and composed of carbohydrate polymers, stimulate platelet-activating factor (PAF) synthesis by monocytes. A role for CD11b/CD18 was demonstrated because antibodies to this integrin decreased PAF synthesis, zymosan bearing only a ligand for CD11b/CD18 (iC3b) induced the synthesis of PAF, and monocytes that did not express CD11b/CD18 produced much less PAF than control monocytes. Ligation of CD11b/CD18 was not sufficient for PAF synthesis suggesting that an additional receptor was involved. Monocytes are known to bind beta-glucan which is a major component of zymosan. Opsonized beta-glucan particles stimulated the synthesis of PAF, and a soluble form of beta-glucan partially inhibited PAF synthesis in response to opsonized zymosan. Two lines of evidence suggested that the beta-glucan receptor mediating this response was distinct from CD11b/CD18. First, CD11b/CD18-deficient monocytes produced PAF when stimulated by zymosan opsonized with isolated C3b, a molecule that binds to complement receptor type 1 (CD35). Second, inducing contact of monocytes with zymosan by centrifugation resulted in PAF synthesis that was not inhibited by antibodies to CD11b/CD18. The combination of soluble beta-glucan and antibodies to CD11b/CD18 completely blocked PAF synthesis in response to opsonized zymosan. Together, these results demonstrate that induction of maximal PAF synthesis by serum-opsonized zymosan requires the concerted interactions of monocyte receptors for iC3b and beta-glucan. Additionally, they suggest that CD11b/CD18 facilitates binding of the particle and that a beta-glucan receptor transduces the activation signal.
Production of IL-8 and monocyte chemotactic peptide-1 by peripheral blood monocytes. Disparate responses to phytohemagglutinin and lipopolysaccharide.
Authors: Liebler J M , Kunkel S L , Burdick M D , Standiford T J , Rolfe M W , Strieter R M 
Published: December 2022

Abstract
The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of soluble mediators. Recently, two families of chemotactic cytokines have been discovered. The -C-X-C-family, which includes IL-8, appears to recruit neutrophils and lymphocytes. In contrast, the -C-C-family, which includes monocyte chemotactic peptide-1 (MCP-1), appears to recruit predominantly monocytes. Monocytes, after their arrival at a site of inflammation, could further amplify the immune response by secreting IL-8 and MCP-1. We sought to define conditions under which human peripheral blood monocytes produce IL-8 and MCP-1. Using serum-free media, we found that PHA-stimulated monocytes expressed MCP-1 and IL-8 protein and mRNA in a dose-dependent manner. However, the onset of mRNA expression for MCP-1 occurred at least 3 h later than did the onset of IL-8 mRNA expression. IL-8 and MCP-1 gene expression by monocytes appeared to require de novo protein synthesis, in that cycloheximide blocked the expression of mRNA for both IL-8 and MCP-1 in PHA-stimulated cells. However, treatment of monocytes with cycloheximide resulted in the superinduction of IL-8 compared with control monocytes. Monocytes costimulated with PHA and LPS demonstrated enhanced amounts of IL-8 mRNA and protein, but sharply decreased amounts of MCP-1 mRNA and protein. The addition of serum to culture media increased both the constitutive and PHA-induced production of monocyte-derived MCP-1 and IL-8, but had no effect on the inhibition of PHA-stimulated MCP-1 production by LPS. These findings suggest that distinct pathways of activation exist for the production of monocyte-derived IL-8 and MCP-1. The differential expression of these different but related polypeptides may offer a means of control of the type of immune cells that are recruited to a site of inflammation.
Characterization of a high molecular weight tumor necrosis factor-alpha mRNA in influenza A virus-infected macrophages.
Authors: Sprenger H , Bacher M , Rischkowsky E , Bender A , Nain M , Gemsa D 
Published: December 2022

Abstract
Infection by influenza A virus has previously been shown to prime macrophages for a high TNF-alpha production. Influenza A virus induced a TNF-alpha mRNA accumulation that consisted of two types: a regular 1.7 kb and an additional high m.w. 2.4 kb species in murine macrophages, and a high m.w. 3.6 kb species in human monocytes. In this study, we further characterized this virus-induced, novel high m.w. TNF-alpha mRNA. The additional high m.w. TNF-alpha mRNA represented a true polyadenylated mRNA and its induction required exposure to infectious viruses. The regular and the high m.w. TNF-alpha mRNA were both found in the nuclear fraction and the cytoplasm. We excluded that the novel high m.w. TNF-alpha mRNA was an intron-containing precursor TNF-alpha mRNA that could have persisted in virus-infected macrophages. When TNF-alpha exons 1 to 4 and TNF-alpha exons 2 to 4 were amplified by polymerase chain reaction, only regular and no high m.w. bands were detected. By use of specific TNF-alpha intron I and intron III cDNA we could definitely demonstrate the absence of introns in the high m.w. TNF-alpha mRNA. The high m.w. TNF-alpha mRNA was free of TNF-beta and TNF intergenic region elements but contained the 5' and 3' untranslated region of TNF-alpha. Influenza A virus infection also induced a double band of IL-1 beta and IL-6 mRNA. Whether this novel high m.w. TNF-alpha mRNA represents a virus-induced abnormality or a superinduction of an otherwise normal but minor TNF-alpha transcript, and whether this high m.w. TNF-alpha mRNA species codes for a biologically active product, remains to be examined.
Exocytosis of a subpopulation of specific granules coincides with H2O2 production in adherent human neutrophils.
Authors: Suchard S J , Boxer L A 
Published: December 2022

Abstract
Unlike polymorphonuclear leukocytes (PMN) that are activated in suspension, PMN plated onto extracellular matrix (ECM) proteins exhibited a prolonged delay in the onset of the respiratory burst in response to PMA, FMLP, A23187, or GM-CSF. The present study was focused on examining the events leading to H2O2 release in adherent PMN. The time course of stimulated H2O2 release from PMN plated on fibrinogen (FG) kinetically paralleled cell spreading and lactoferrin release. In contrast, the release of another specific granule component, vitamin B12-binding protein, preceded H2O2 generation by at least 20 min, suggesting the differential mobilization of subpopulations of specific granules. FMLP-stimulated PMN from a patient with leukocyte adhesion deficiency (LAD), lacking CD11/CD18 integrins and unable to adhere to FG, attached and spread on thrombospondin (TSP) and generated substantial amounts of H2O2. However, PMN from a second LAD patient, able to attach but not spread on TSP, failed to generate oxidant. These data indicated that PMN spreading might be a prerequisite for H2O2 generation and that CD11/CD18 integrins are likely not the only surface receptors involved in this response. Exposing PMN to the intracellular Ca2+ chelators MAPTAM or BAPTA significantly reduced H2O2 generation in response to the receptor-mediated agonists, FMLP or GM-CSF, but did not affect PMA-stimulated H2O2 generation. Under conditions that resulted in reduced H2O2 generation (i.e., MAPTAM or BAPTA plus FMLP or GM-CSF), lactoferrin, but not vitamin B12-binding protein, release was also reduced, suggesting a link between the secretion of lactoferrin-containing specific granules and H2O2 production. Since neither MAPTAM or BAPTA blocked PMN spreading, it appeared that cell spreading alone was not sufficient for H2O2 production. Thus, the major requirement for H2O2 generation appeared to be the exocytosis of a distinct population of lactoferrin-containing specific granules. In support of this observation, PMN-like HL-60 cells, which lack specific granules, attached and spread on FG but failed to release H2O2. Thus, we postulate that the delivery of cytochrome b from lactoferrin-containing specific granules to the plasma membrane during activation contributes to oxidant production in PMN adherent to ECM proteins.
The suppressor factor of T suppressor cells induced by tolerogenic conjugates of ovalbumin and monomethoxypolyethylene glycol is serologically and physicochemically related to the alpha beta heterodimer of the T cell receptor.
Authors: Chen Y , Takata M , Maiti P K , Mohapatra S , Mohapatra S S , Sehon A H 
Published: December 2022

Abstract
Ovalbumin-specific, H-2Kd restricted, CD8+ Ts cells of clone 17.2 were shown to produce an OVA-specific Ts cell factor (TsF17.2) possessing the same Ag specificity and MHC restriction as those of the intact Ts cells. The Ts cell clone was generated from a single cell of the spleen of a mouse which had been immunosuppressed by injection of tolerogenic OVA(mPEG)12 conjugate. For the elucidation of the nature of TsF17.2, it was characterized by serologic, physicochemical, and Western blot analyses. It was found that 1) the OVA-specific suppression of in vitro antibody production by TsF17.2 could be blocked by mAb H28-710 which binds to an epitope of the constant region of the alpha-chain of TCR; 2) the TsF17.2 could be sequestered by, and eluted from, immunosorbents prepared by coupling to Affi-Gel Hz the H28-710 mAb or the mAb H57-597 and F23.1 which are specific, respectively, for an epitope of the constant region of the beta-chain and an epitope of the V beta 8 region of the TCR; and 3) the TsF17.2 had a pl of 7.0, m.w. of 84,000, and consisted of two disulfide-linked subunits of 42,000 each. After electroelution from the SDS-PAGE gel, the m.w. 84,000 molecule retained its capacity to suppress in vitro antibody production in an OVA-specific manner. From all these results it was concluded that this Ts cell factor may represent a soluble form of the alpha beta heterodimer of TCR of cloned Ts cells.
T cell receptor V beta gene expression in monozygotic twins. Discordance in CD8 subset and in disease states.
Authors: Davey M P , Meyer M M , Bakke A C 
Published: December 2022

Abstract
The peripheral T cell repertoire is shaped by positive and negative selection. These intrathymic events are dependent on the direct interaction of MHC and TCR molecules. Inasmuch as one possible mechanism for HLA-linked disease involves the role that these molecules play in shaping the peripheral T cell repertoire, an understanding of how stable the repertoire remains is an important question that will influence future studies. The purpose of this study was to analyze the stability of the T cell repertoire in monozygotic twins. To investigate this question the percentage of CD4 and CD8 T cells expressing TCR V beta gene products was determined for seven sets of healthy monozygotic twins ages 2 through 44. V beta expression was determined by three-color flow cytometric analysis using antibodies to V beta-5.1, -5.2, -5.3, -6.7, -8, and -12. The percentage of CD4 cells expressing each V beta gene was highly concordant between twins. In contrast, differences were noted for V beta expression within the CD8 subset. This was especially marked when sets of twins were studied (n = 3) where one individual had an underlying disease. Although expression in the CD4 subset was again concordant, significant differences were noted within the CD8 subset compared to the healthy twin. These data indicate that in both health and disease, the CD4 T cell repertoire is tightly regulated although often sizable differences have developed in the CD8 compartment.