bluuebunny/crossref_metadata_2025_split huggingface dataset:
Backcross analysis of genes linked to autoantibody production in New Zealand White mice.
Authors: Vyse T J , Morel L , Tanner F J , Wakeland E K , Kotzin B L 
Published: December 2022

Abstract
F1 hybrids of New Zealand Black (NZB) and New Zealand White (NZW) mice are genetically predisposed to develop a lupus-like autoimmune disease characterized by IgG autoantibody production and an immune complex glomerulonephritis. Genes from both parental strains contribute to autoimmunity in the F1 animal. NZW mice produce mostly non-pathogenic autoantibodies to ssDNA and histones as their major autoimmune trait. We studied the genetics of this trait in order to gain insight into the NZW contribution to F1 disease. Genome-wide mapping of (NZW x BALB/c)F1 x NZW backcross mice showed that four NZW non-MHC loci on chromosomes 1, 11, 16, and 19 were linked with IgG autoantibody production. Another NZW locus on chromosome 14 appeared to be selectively linked with IgG anti-histone Abs. In this backcross, contributions from the nonautoimmune BALB/c strain were also apparent. Heterozygosity for the BALB/c MHC (H2d) was linked with IgG autoantibody production. This influence of H2d is therefore similar to that seen in (NZW x NZB)F1 mice, in which heterozygosity for H2d enhances autoantibody production and disease. Surprisingly, two non-MHC BALB/c loci were linked with IgM autoantibody levels, whereas no NZW loci had such an effect. Neither of these two loci have been previously linked with autoimmunity in lupus-prone mice. These data show that autoantibody production in NZW mice is a polygenic trait that is influenced by contributions from MHC and non-MHC genes. The results also support the hypothesis that NZW genes act to class-switch the autoantibody response, an effect that appears to contribute to disease in (NZB x NZW)F1 mice.
Activation of the Ras signaling pathway by the CD40 receptor.
Authors: Gulbins E , Brenner B , Schlottmann K , Koppenhoefer U , Linderkamp O , Coggeshall K M , Lang F 
Published: December 2022

Abstract
The CD40 receptor is an important molecule regulating B lymphocyte proliferation, maturation, Ab class switching, and cell survival. In the present study, we identified signal transduction events triggered by cross-linking the CD40 receptor. Stimulation of Daudi B cells with anti-CD40 resulted in activation of p21ras, an important switch point in the regulation of cell growth and differentiation. Ras activation correlated with a stimulation of Rac1 and MEK-1 as well as tyrosine phosphorylation of phosphatidylinositol 3-kinase. Inhibition of endogenous Ras by transfection of transdominant inhibitory Ras prevented tyrosine phosphorylation or stimulation of phosphatidylinositol 3-kinase, Rac1, or MEK-1 upon CD40 receptor triggering, proving an activation of the Ras pathway by CD40. Ras activation was partially inhibited by either herbimycin A or calphostin pretreatment and completely inhibited by preincubation with a combination of both inhibitors, indicating a synergistic role for protein tyrosine kinases and diglycerides in Ras activation after CD40 stimulation. In support of a role for diglycerides, we detected a 30 +/- 5% decrease of cellular phosphatidylcholine content, correlating with a threefold increase of diacylglycerol synthesis induced by CD40. Supporting a role for protein tyrosine kinase, we measured a five- to eightfold stimulation of p56lyn and p58blk kinase activity. These results suggest the activation of the Ras pathway via an additive function of src kinases and phospholipases that may be important in the mediation of biologic effects after CD40 receptor engagement.
Expression of trKB neurotrophin receptor during T cell development. Role of brain derived neurotrophic factor in immature thymocyte survival.
Authors: Maroder M , Bellavia D , Meco D , Napolitano M , Stigliano A , Alesse E , Vacca A , Giannini G , Frati L , Gulino A , Screpanti I 
Published: December 2022

Abstract
The relationships between the nervous and the immune systems raise the question of whether neurotrophic factors, in addition to the regulation of neural cell ontogeny, may influence lymphocyte development. We report in this work that the pattern of neurotrophin receptor expression depends on the developmental stage of T cells. The presence of nerve growth factor receptor trkA could not be detected in any of the thymocyte subsets, whereas brain-derived neurotrophic factor (BDNF) receptor trkB was expressed in all thymocyte subpopulations. Interestingly, both trkB mRNA and protein expression inversely correlated with the maturation stage and the differentiation potential of thymocytes, being more expressed in CD4-8- immature thymocytes and progressively declining in CD8+ and CD4+ single-positive and CD4+8+ more mature thymocytes. The developmentally regulated expression of trkB is further shown by the inhibition or enhancement of trkB expression induced by signals that either trigger or impair the transition from immature to more differentiated stages of the thymocyte developmental pathway. Signals generated following the interaction of BDNF with trkB receptor resulted in the stimulation of trkB autophosphorylation and in the up-regulation of the expression of the c-fos gene in CD4-8- cells and enhanced thymocyte survival. Finally, BDNF is expressed in thymic stroma and is further up-regulated by signals generated by the thymocyte/stromal cell interaction. These data suggest that BDNF may be a novel survival factor for thymocyte precursors and support the presence of developmentally regulated feedback mechanisms based on autocrine/paracrine neurotrophin/receptor interactions that may be involved in the thymocyte differentiation process.
Multivalent antibody fragments with high functional affinity for a tumor-associated carbohydrate antigen.
Authors: Rheinnecker M , Hardt C , Ilag L L , Kufer P , Gruber R , Hoess A , Lupas A , Rottenberger C , Plückthun A , Pack P 
Published: December 2022

Abstract
We report in this work a human-derived self-assembling polypeptide based on the tetramerization domain of the human transcription factor p53, which can be fused to single-chain Fv Ab (scFv) fragments via a long and flexible hinge sequence of human origin, allowing exploitation of the functional affinity increase of binding to a ligand or cell surface with multimeric binding sites. We have demonstrated the use of this polypeptide by applying it to the construction of a tetrameric scFv against the tumor-associated carbohydrate Ag Lewis Y (Fuc alpha 1--&gt;2Gal beta 1--&gt;4[Fuc alpha 1--&gt;3] GlcNAc beta 1--&gt;3R). For comparison purposes, the corresponding scFv and dimeric mini-antibody, comprising the scFv fused via a flexible murine hinge to an artificial dimerization domain, were also created. The recombinant mini-antibody proteins were expressed in functional form in Escherichia coli and showed the expected m.w. of a dimer and tetramer, respectively. Analysis of Lewis Y-binding behavior by surface plasmon resonance revealed specific but very weak binding of the scFv fragment. In contrast, both dimeric and tetrameric scFv fusion proteins exhibited an enormous gain in functional affinity that was greatest in the case of the tetrameric mini-antibody.
A highly variable region in members of the streptococcal M protein family binds the human complement regulator C4BP.
Authors: Johnsson E , Thern A , Dahlbäck B , Hedén L O , Wikström M , Lindahl G 
Published: December 2022

Abstract
Strains of Streptococcus pyogenes express one or more molecules that are members of the M protein family, a group of surface proteins implicated in virulence. A characteristic property of the molecules in this family is the presence of a highly variable N-terminal region, whose function is unknown. Here we show that human C4b-binding protein (C4BP), a regulatory component of the complement system, binds to the highly variable region of many members of the M protein family. Chimeric molecules, in which the N-terminal regions of four different C4BP-binding proteins were combined with the C-terminal part of the non-binding M5 protein, had intact C4BP-binding ability, as judged by binding assays and Scatchard analysis with highly purified molecules. Moreover, work with the C4BP-binding Arp4 protein showed that an N-terminal 52-residue fragment retained binding ability, and that a 21-residue synthetic peptide derived from the variable region completely inhibited the binding of C4BP. Computer-assisted analysis of the four C4BP-binding regions studied here (45-66 amino acid residues) indicated that they lack residue identities that could explain their ability to bind the same ligand, but differ from the nonbinding M5 protein in their lower propensity to form a coiled-coil. Thus, the variable C4BP-binding regions have an extraordinary capacity for sequence variation, while retaining the ability to bind C4BP. These data indicate that an important function of the variable region in members of the M protein family is to bind a host protein that down-regulates the complement system.
Multiple melanoma-associated epitopes recognized by HLA-A3-restricted CTLs and shared by melanomas but not melanocytes.
Authors: Mazzocchi A , Storkus W J , Traversari C , Tarsini P , Maeurer M J , Rivoltini L , Vegetti C , Belli F , Anichini A , Parmiani G , Castelli C 
Published: December 2022

Abstract
The molecular characterization of melanoma-associated Ags allowed the definition of several HLA class I-presented peptides recognized by T cells. However, no HLA-A3.1-restricted melanoma epitopes have been identified to date. To gain insight into the HLA-A3.1-restricted T cell epitope repertoire of human melanoma, we analyzed the immunologic reactivity of CTLs isolated from tumor-involved or tumor-free lymph nodes in two HLA-A3.1+ melanoma patients. Three CTL lines, clonal or highly oligoclonal in their TCR composition, and two CTL clones were selected for HLA class I-restricted lysis of the autologous tumor and then tested for the recognition of HLA-A3+ and HLA-A3- normal or neoplastic cells of the melanocyte lineage. One CTL recognized a unique HLA-A3.1-restricted Ag expressed only by the autologous tumors, while all the other CTLs defined three HLA-A3.1 epitopes shared by melanomas, but not by melanocytes. Moreover, the epitopes of two CTL lines with different specificity were reconstituted by nonoverlapping fractions of HLA-A3+ melanoma-derived peptides resolved by reverse phase-HPLC, indicating that distinct naturally processed peptides were specifically recognized on melanoma cells in association with HLA-A3.1 molecules. These novel lineage-unrelated HLA-A3.1-restricted melanoma epitopes do not derive from MAGE, BAGE, or GAGE gene families, as evaluated by the COS-7 transfection assay. Our data show that CTLs may recognize HLA-A3.1-class 1 complexes presenting melanoma (but not melanocyte)-associated epitopes that are either unique to a given patient's tumor or that are shared between multiple melanomas.
Tumor necrosis factor-alpha modulates the expression of its p60 receptor and several cytokines in rat tracheal epithelial cells.
Authors: Bader T , Nettesheim P 
Published: December 2022

Abstract
The epithelium of the conducting airways is frequently the target of toxic chemical and microbial agents causing inflammation, hypersecretion, and epithelial necrosis. TNF-alpha is a prototypical inflammatory cytokine released by macrophages and other inflammatory cells. The purpose of this study was to characterize TNF-alpha receptors in fully differentiated rat tracheal epithelial (RTE) cells in culture and to examine the effects of TNF-alpha on this epithelium. We demonstrated the presence of approximately 250 TNF-alpha receptors per RTE cell. Both known receptor types, p60 (TNF-RI, CD 120a) and p80 (TNF-RII, CD 120b), were expressed. The level of p80 mRNA was unaffected by TNF-alpha treatment, whereas p60 mRNA was down-regulated, and soluble TNF-RI was shed from cells within 30 min. Treatment of RTE cultures with TNF-alpha (1000 U) caused no cytotoxicity (as determined by lactate dehydrogenase release). However, TNF-alpha exposure of the cultures induced the expression of several inflammatory mediators, as determined by reverse transcription-PCR and ELISA. Low levels of IFN-gamma mRNA became detectable after 4 h. Increased levels of TNF-alpha mRNA and protein were found, which peaked after 6 h of TNF-alpha treatment, but neither IL-1 alpha nor IL-1 beta was detectable. Calcium-independent nitric oxide synthase transcripts were elevated two- to threefold within 2 to 6 h of TNF-alpha treatment. These findings suggest that the airway epithelium may actively participate in the pathogenesis of airway inflammation through the production of mediators similar to those found in a Th1 response.
Diminished production of prostaglandin E2 by monocytes of newborns is due to altered fatty acid membrane content and reduced cyclooxygenase activity.
Authors: Murphy F J , Reen D J 
Published: December 2022

Abstract
To determine the biochemical basis for reduced PGE2 expression by cord blood monocytes relative to adult peripheral blood monocytes, fatty acid composition of cell membranes together with the amount and activity of enzymes involved in the cyclooxygenase pathway were investigated. Gas chromatographic analysis of mononuclear cell fatty acids showed a significant reduction in long chain fatty acids, including arachidonic acid. Acylase and phospholipase A2 activity, together with lipocortin 1 levels, were similar in cord and adult monocytes. No difference in amounts of the 70-kDa cyclooxygenase type 1 enzyme was observed between the monocyte sources. The 74k-Da cyclooxygenase type 2 enzyme was synthesized de novo upon LPS stimulation in comparable amounts in both cord and adult monocytes, with both monocyte types responding with equal sensitivity to LPS. The ability of microsomes, prepared from cord monocytes, to convert arachidonic acid into eicosanoids of the cyclooxygenase pathway was reduced. In contrast, the ability of acetylated microsomes to convert PGG2 to PGE2 was comparable, suggesting that the deficiency in PGE2 production by cord monocytes is due to reduced activity, specifically at the cyclooxygenase-active site rather than the peroxidase active site. In conclusion, it appears that both reduced fatty acid content and diminished cyclooxygenase activity are responsible for diminished eicosanoid production by cord monocytes.
Regulation of sialoadhesin expression on rat macrophages. Induction by glucocorticoids and enhancement by IFN-beta, IFN-gamma, IL-4, and lipopolysaccharide.
Authors: van den Berg T K , van Die I , de Lavalette C R , Döpp E A , Smit L D , van der Meide P H , Tilders F J , Crocker P R , Dijkstra C D 
Published: December 2022

Abstract
Sialoadhesin is a macrophage-restricted member of the Ig superfamily that mediates adhesion with lymphoid and myeloid cells. It is expressed on a subpopulation of macrophages in lymphoid tissues and in chronic inflammation (e.g., during autoimmune diseases). We have studied the regulation of sialoadhesin expression in vitro and show that glucocorticoids (GC) induce sialoadhesin expression on freshly isolated rat macrophages and the rat macrophage cell line R2. The cytokines IFN-beta, IFN-gamma, IL-4, and LPS, although unable to induce sialoadhesin expression by themselves, were able to enhance GC-mediated induction of sialoadhesin. Sialoadhesin expression was functional as shown by cell adhesion assays with human RBCs. Northern blotting experiments indicated that regulation predominantly occurred at the mRNA level. Comparison of the different combinations of GC and cytokines/LPS revealed differences in the level of GC-dependent enhancement of sialoadhesin expression, with IFN-beta and IL-4 being more potent than IFN-gamma and LPS. Moreover, the effects of IFN-gamma and LPS could be reproduced by priming, whereas IFN-beta and IL-4 were required simultaneously with GC. The regulation of sialoadhesin expression was mediated by the GC receptor, and not by mineralocorticoid receptor, as shown by inhibition experiments with specific antagonists. Finally, it is demonstrated that macrophages in the adrenal gland, the major site of endogenous GC production, express sialoadhesin. This study demonstrates that GC act as a primary inducer of sialoadhesin expression on rat macrophages, and that the response can be enhanced by IFN-beta, T cell-derived cytokines, or LPS.
Molecular analysis of stimulatory anti-thyrotropin receptor antibodies (TSAbs) involved in Graves' disease. Isolation and reconstruction of antibody genes, and production of monoclonal TSAbs.
Authors: Akamizu T , Matsuda F , Okuda J , Li H , Kanda H , Watanabe T , Honjo T , Mori T 
Published: December 2022

Abstract
Anti-thyrotropin (TSH) receptor autoantibodies (TRAbs) have been known to be involved in Graves' disease. To understand the molecular mechanism for pathogenesis of TSAbs in Graves' disease, we isolated and reconstituted the Ig genes of EBV-transformed B cell clones producing monoclonal thyroid stimulating Ab (TSAb) obtained from patients with Graves' disease. The V region genes of Ig heavy (H) and light (L) chains of two TSAb clones, IgG clone B6B7 and IgM clone 101-2, were isolated by the PCR. Nucleotide sequencing analysis revealed that germ-line VH and VK segments widely used for autoantibodies including the previously isolated TRAbs were utilized in the two clones. A significant number of somatic mutations were found in V regions of both clones, indicating the involvement of somatic mutations for the TSAb specificity. Reconstituted Ig H and L chain genes of the two clones were stably introduced into myeloma cells for IgG1 production. IgGs purified from cultured supernatants of both transfectants exhibited significant TSAb activities, while they did not inhibit TSH binding to the receptor. The successful expression of recombinant TSAbs in eukaryotic cells will provide opportunities to apply them to various pathophysiologic, diagnostic and therapeutic investigations in autoimmune thyroid diseases.
Anti-CD40 ligand antibody treatment prevents the development of lupus-like nephritis in a subset of New Zealand black x New Zealand white mice. Response correlates with the absence of an anti-antibody response.
Authors: Early G S , Zhao W , Burns C M 
Published: December 2022

Abstract
Systemic lupus erythematosus is characterized by B cell production of pathogenic autoantibodies dependent upon cooperation from CD4+ Th cells. The interaction between CD40 on B cells and CD40 ligand (CD40L) on Th cells is necessary for normal thymus-dependent Ab production. An anti-murine CD40L mAb blocks binding of CD40L to CD40 and prevents primary and secondary immune responses to thymus-dependent Ags. In this study, New Zealand Black x New Zealand White lupus-prone mice treated with this anti-CD40L Ab from ages 4 to 10 mo had reduced anti-DNA autoantibody production and renal disease and significantly prolonged survival compared with control mice. Pathologic examination verified the absence of significant renal damage or immune deposition in responding mice. Mice that responded to treatment did not develop an Ab response to the administered Ab. Long-term survivors mounted a substantial Ab response to keyhole limpet hemocyanin after completion of anti-CD40L Ab treatment, suggesting that some of the immunosuppressive effects of the Ab may be reversible. These results suggest a human form of this Ab may have therapeutic utility in human systemic lupus erythematosus.
Attenuation of collagen-induced arthritis in 55-kDa TNF receptor type 1 (TNFR1)-IgG1-treated and TNFR1-deficient mice.
Authors: Mori L , Iselin S , De Libero G , Lesslauer W 
Published: December 2022

Abstract
The role of TNF and its type 1 receptor (TNFR1) in the pathogenesis of collagen-induced arthritis (CIA) was investigated in mice using two approaches. First, DBA/1 mice were treated after immunization with type II collagen by injecting TNFR1-IgG1 fusion protein to neutralize systemic TNF. CIA was prevented when treatment was administered shortly before the onset of clinical disease, suggesting that TNF is a crucial mediator in the late initiation phase of the arthritic process. In a second approach, TNFR1-deficient mice, generated by gene targeting and crossed to DBA/1, were used. These mice developed CIA with a low incidence and in a milder form. However, once a joint was afflicted, the disease progressed in this joint to the same end stage as that in wild-type mice. These data suggest that TNFR1 is the main transducer of TNF proinflammatory effects establishing CIA, but the progression of arthritis to tissue destruction and ankylosis is independent of TNFR1.
Tyrosines 113, 128, and 145 of SLP-76 are required for optimal augmentation of NFAT promoter activity.
Authors: Fang N , Motto D G , Ross S E , Koretzky G A 
Published: December 2022

Abstract
SLP-76 (SH2 domain leukocyte protein of 76 kDa) is a recently identified substrate of the TCR-stimulated protein tyrosine kinases that functions in the signal transduction cascade linking the TCR with IL-2 gene expression. In this report, we demonstrate that engagement of the TCR results in tyrosine phosphorylation of SLP-76 in its amino-terminal acidic region. Two tyrosines (Y113 and Y128) fall within an identical five amino-acid motif and are shown to be phosphorylated upon TCR ligation. Although mutation of either Y113 and Y128 has a minimal effect on SLP-76 function, mutation of both residues decreases significantly the ability of SLP-76 to promote T cell activation. A third tyrosine within the amino-terminal region (Y145) appears to be the most important for optimal SLP-76 function, as altering it alone to phenylalanine has a potent impact on SLP-76 augmentation of NFAT promoter activity.
Mechanisms of tolerance induction: splenocytes from total lymphoid irradiated mice inhibit the IL-2 pathway in TCR-activated CD4 cells.
Authors: Field E H , Ye Z X , Rouse T M 
Published: December 2022

Abstract
Mice given total lymphoid irradiation (TLI) can be tolerized by an incompletely understood mechanism to foreign Ags given during a brief window of time immediately after completing radiation. We previously showed that splenocytes taken from mice immediately after completing TLI treatment (TLI cells) block the ability of control cells to proliferate or to produce IL-2 in response to alloantigen, suggesting that TLI cells interfere with the IL-2 pathway in responder lymphocytes. To further characterize the mechanism by which TLI cells affect IL-2, we utilized an in vitro system of T cell activation. Adding TLI cells into cultures decreased the ability of TCR-stimulated T cells to proliferate and to secrete IL-2 by 40 to 60%. Exogenous IL-2 did not restore the proliferative response. The inhibition of IL-2 secretion resulted both from a decrease in the number of IL-2-producing cells and a decrease in IL-2 mRNA transcription. TLI cells directly inhibited IL-2 secretion by TCR-stimulated CD4 cells, as determined by ELISPOT. Competitive PCR demonstrated that TLI cells decreased IL-2 transcription of TCR-stimulated CD4 cells by 75%. In situ hybridization confirmed that unfractionated spleen and sorted CD4 cells from TCR-stimulated cultures transcribed less IL-2 RNA in the presence of TLI cells. The results show that TLI cells directly inhibit IL-2 transcription and protein secretion of normal TCR-stimulated CD4 cells.