bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of T cell epitopes restricted by HLA-DP9 in streptococcal M12 protein.
Authors: Dong R P , Kamikawaji N , Toida N , Fujita Y , Kimura A , Sasazuki T 
Published: December 2022

Abstract
Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence. Binding of biotinylated peptides to the HLA-DP9 molecule was inhibited by an excess amount of corresponding nonbiotinylated peptides and other nonbiotinylated peptides, indicating that the peptides were bound to the HLA-DP9 molecule at a single binding site. Seven synthetic peptides containing the T cell epitopes restricted by the HLA-DP9 molecule had high binding affinity to the HLA-DP9 molecule. Comparison of the amino acid sequences of truncated analogues that could bind to the HLA-DP9 molecule and/or activate T cells suggested an HLA-DP9-specific binding motif, composed of a positively charged residue (R or K) at position 1, a hydrophobic residue (A, G, or L) at position 6, and another hydrophobic residue (L or V) at position 9. Analysis of single amino acid-substituted analogues suggested that the positively charged amino acid in the motif served as a key anchor residue for binding to the HLA-DP9 molecule, which differs from the binding motif to the HLA-DR molecules.
A novel octamer regulatory element in the VH11 leader exon of B-1 cells.
Authors: Goodglick L , Felsher D W , Neshat M S , Braun J 
Published: December 2022

Abstract
B-1 cells (CD5 B cells) represent an initial fetal wave of B cell lymphopoiesis. B-1 cells have fundamental properties that are unique from conventional B cells, including a restricted Ab repertoire. We investigated the mechanism for the overrepresentation of one such Ig H chain variable-region gene, VH11, by murine B-1 cells. We postulated that a cis-regulatory element contributed to the use of VH11. We observed that the DNA encoding the leader peptide of VH11 was atypically A/T rich and thus was a candidate for nuclear protein binding. By electrophoretic mobility shift analysis, we found that the VH11 leader DNA specifically bound to three protein complexes present in the nucleus of the B-1 cell line AJ9. Of these bands, one was ubiquitous for all cells examined (lymphoid and nonlymphoid); another band was present only in B cells, and the third band was specific for B-1 cells that expressed VH11 or VH12. In addition to its binding properties, the VH11 leader sequence also displayed modest tissue-specific enhancer activity. By DNA footprint analysis, all three protein complexes were found to bind to an octamer motif embedded within the VH11 leader DNA. To identify the octamer-binding proteins, a panel of octamer-specific Abs was used. We found that the ubiquitous band was Oct-1, and the B cell-specific band was Oct-2. The B-1 cell-specific nuclear binding protein was neither Oct-1 nor Oct-2, but may be a novel POU domain protein. We hypothesize that the VH11 leader octamer site may target this gene for preferential rearrangement and/or expression and therefore would be a contributing factor in the increased use of this gene by B-1 cells.
Identification of porcine endothelial cell membrane antigens recognized by human xenoreactive natural antibodies.
Authors: Holzknecht Z E , Platt J L 
Published: December 2022

Abstract
Rejection of an organ transplanted into a phylogenetically disparate recipient may be initiated by the binding of xenoreactive natural Abs of the recipient to Ags expressed on donor endothelium leading to the activation of the C system. Having previously shown that human xenoreactive Abs bind predominantly to N-linked oligosaccharides on porcine endothelial cell glycoproteins, we sought to identify those glycoproteins to gain insight into the pathogenesis of the rejection reaction and to develop improved methods for depleting those Abs. Based on amino-terminal and internal sequencing of the glycoproteins, reactivity with monospecific rabbit Abs, and functional properties, the porcine endothelial cell targets of human natural Abs were shown to be the von Willebrand factor, integrin alpha 1, alpha v, alpha 3/alpha 5, beta 1, and beta 3 chains and a 95-kDa glycoprotein homologous with chick DM-GRASP. Human and baboon Abs directed against those glycoproteins were shown to be absorbed during perfusion of porcine organs and the binding of human IgM to the isolated glycoproteins to initiate the activation of C leading to formation of iC3b neoantigen. The determinants recognized by human xenoreactive Abs had immunodominant alpha-galactosyl residues based on affinity chromatography, reactivity with anti-Gal alpha(1-3)Gal Abs and sensitivity to alpha-galactosidase. The findings show that members of the integrin family and the von Willebrand factor are major targets of xenoreactive Abs and suggest potential mechanisms by which the binding of Abs to endothelial cells might perturb the physiology of those cells and thus cause aberrant functioning of a tissue or organ.
Cloning of the murine CD5 promoter and its tissue-specific regulation.
Authors: Weichert T R , Schwartz R C 
Published: December 2022

Abstract
A genomic clone containing 1700 bp of the 5'-flanking region and first exon of the murine CD5 gene was isolated by screening a NIH 3T3 fibroblast genomic library with the previously characterized murine CD5 cDNA. The CD5 5'-flanking region lacks a consensus TATA box but contains Sp1, AP-1, IgH muE2, SV40 enhancer core, CCAAT, TCF2 alpha/PEA3/ets, and C/EBP motifs. Transcription is initiated from multiple sites upstream of an Inr-like sequence. When linked to the CAT reporter gene, the CD5 5'-flanking region was an active promoter in transient transfection assays using the EL4 (T), PD36 (pre-B) and M12 (B) cell lines, but was inactive in NIH 3T3 fibroblasts. This pattern of lymphoid-specific expression reflects the pattern of in vivo CD5 expression. Successive 5' to 3' deletions of the CD5 promoter/CAT reporter construct were transfected into T and B cells revealing a succession of positive and negative regulatory elements until promoter activity was eliminated at position -27. This result identified sequences from -125 to -27 (which contain the Inr, IgH muE2, SV40 enhancer core, and AP-1 sites) as sufficient for tissue-specific promotion. Isolation and characterization of the CD5 promoter represents an initial step in elucidating the control over tissue-specific expression of the murine CD5 gene.
Rat mammary adenocarcinoma 13762 expressing IFN-gamma elicits antitumor CD4+ MHC class II-restricted T cells that are cytolytic in vitro and tumoricidal in vivo.
Authors: Frey A B 
Published: December 2022

Abstract
Rat adenocarcinoma 13762 was modified by transfection to express IFN-gamma, and the tumor-forming potential of cytokine-producing cells was found to be dramatically impaired. Animals resistant to inocula of IFN-gamma-modified tumor were resistant to subsequent challenge with unmodified 13762 tumor. Induced immunity was tumor specific in that syngeneic but non-cross-reactive tumor grew with normal kinetics in animals injected with IFN-gamma-producing 13762 tumor. Antitumor T cells were derived from animals primed with IFN-gamma-producing 13762 tumor and expanded into a cell line by coculture in vitro with IFN-gamma-producing 13762 cells. Anti-13762-gamma T cells were cytotoxic in vitro toward IFN-gamma-producing 13762 tumor and were not reactive with other syngeneic tumors or spleen B cells. Anti-13762-gamma T cells were determined to be CD4+ by Ab staining and flow cytometric analysis, and recognition of 13762-gamma in vitro was inhibited by anti-MHC class II Ab. Anti-13762-gamma T cells were not reactive in vitro with wild-type 13762 tumor unless treated with exogenous rIFN-gamma, which induced expression of cell surface MHC class II. However, adoptively transferred anti-13762-gamma T cells could effect regression of wild-type 13762 tumor or dramatically inhibit progressive growth in animals carrying significant tumor burden, and the antitumor phenotype did not require CD8+ T cells in vivo. These experiments demonstrate that although antitumor T cells elicited against cytokine-modified tumor may fail to demonstrate reactivity with unmodified tumor in vitro, antitumor properties may be manifest in vivo.
IL-12 enhances Th1-type responses in human Leishmania donovani infections.
Authors: Ghalib H W , Whittle J A , Kubin M , Hashim F A , el-Hassan A M , Grabstein K H , Trinchieri G , Reed S G 
Published: December 2022

Abstract
IL-12 is a pluripotent cytokine that interacts with NK and T cells to play a central role in the initiation and maintenance of Th1 responses and IFN-gamma production. Because of the interactive relationship between IL-12 and IFN-gamma response to infectious organisms, a study was undertaken to examine the role of IL-12 in the immune regulation of human visceral leishmaniasis (VL). Human (Hu) VL is associated with immune dysfunction and the appearance of IL-10 mRNA, not present in healed individuals. We found that PBMC from treated VL patients produced both IL-12 p40 and IFN-gamma in response to in vitro stimulation with Leishmania donovani. The production of both IL-12 p40 and IFN-gamma were interdependent and were abrogated by the addition of exogenous Hu rIL-10. In contrast, PBMC from active VL patients did not produce IL-12 p40 or IFN-gamma in response to L. donovani lysate. Neutralizing anti-IL-10 mAb led to the enhancement of IFN-gamma production by active VL PBMC cultured with L. donovani lysate, and this enhanced IFN-gamma production was blocked by anti-IL-12 mAb. The addition of exogenous Hu rIL-12 to PBMC from active VL patients resulted in the augmentation of IFN-gamma in response to L. donovani lysate. Therefore, treatment of active VL patient PBMC with anti-IL-10 or IL-12 shifted the response toward a Th1-type response with the production of IFN-gamma. These results indicate that IL-12 may play an important role in the regulation of the cellular immune responses in Hu VL.
Multiple point mutations in an endogenous retroviral gene confer high immunogenicity on a drug-treated murine tumor.
Authors: Grohmann U , Puccetti P , Belladonna M L , Fallarino F , Bianchi R , Binaglia L , Sagakuchi K , Mage M G , Appella E , Fioretti M C 
Published: December 2022

Abstract
Exposure in vivo of murine L5178Y lymphoma cells to cytoreductive triazene derivatives leads to the generation of immunogenic variant lines expressing new transplantation Ags recognized by CTL. In one such clonal variant (clone D), at least one subset of T cell neoepitopes are provided by proteins previously shown by serology to be products of endogenous retroviral env sequences. We report here on characterization of PCR-amplified gp70 env genes in clone D. Relative to known gp70 sequences in parental cells and in current databases, one gp70 sequence presented four distinct nucleotide changes, two of which were apparently unique to clone D DNA and cDNA upon differential hybridization analysis. Transfection experiments with the entire gp70 gene or subgenic fragments encompassing a single putative mutation showed that products of the mutated env gene or fragments may confer immunogenicity in vivo and susceptibility in vitro to lysis by clone D-primed, H-2Kd- or H-2Ld-restricted CTL. By skin test assay of mice primed with either clone D or three mutated synthetic peptides, evidence was obtained that amino acid substitutions at the relevant positions of the gp70 protein may produce immunogenic T cell epitopes and that these epitopes are expressed in vivo by clone D. These data point to the role of mutated retroviral tumor peptides as rejection Ags in histocompatible hosts.
Synthetic oligonucleotide expressed by a recombinant vaccinia virus elicits therapeutic CTL.
Authors: Irvine K R , McCabe B J , Rosenberg S A , Restifo N P 
Published: December 2022

Abstract
P815A is a naturally occurring tumor rejection Ag of the methylcholanthrene-induced murine mastocytoma P815. The gene encoding the Ag P815A, designated P1A, is identical to that encoded in the normal genome of the DBA/2 mouse. A recombinant vaccinia virus (rVV) was constructed that expressed a synthetic oligonucleotide encoding the minimal determinant peptide of the tumor-associated Ag. Although the rVV recombinant expressing this mini-gene was recognized efficiently in vitro, it was an ineffective immunogen in vivo. The addition of an endoplasmic reticulum insertion signal sequence to the NH2 terminus of the minimal determinant resulted in a rVV that elicited CD8+ T cells that could lyse P815 mastocytoma cells in vitro and that were therapeutic in vivo. Recombinant viruses expressing synthetic oligonucleotide sequences preceded by the insertion signal sequences allow the expression of Ag directly into the endoplasmic reticulum, where binding to MHC class I molecules is most efficient. Vaccines based on synthetic oligonucleotides could be constructed with ease and rapidity but, most importantly, such constructs avoid the dangers associated with the expression of full length genes encoding TAA that are potentially oncogenic.
Inducible nitric oxide synthase in cattle. Differential cytokine regulation of nitric oxide synthase in bovine and murine macrophages.
Authors: Adler H , Frech B , Thöny M , Pfister H , Peterhans E , Jungi T W 
Published: December 2022

Abstract
We assessed bovine bone marrow-derived macrophages and monocyte-derived macrophages for expression of inducible nitric oxide synthase (iNOS) activity. Both cell types expressed iNOS activity upon stimulation with Salmonella dublin (S. dublin) or with LPS. A 372-bp fragment of the bovine iNOS mRNA could be amplified by reverse transcription-PCR from mRNA of stimulated macrophages. Cloning and sequencing of the fragment revealed a high degree of homology to human hepatocyte, rat vascular smooth muscle cell, and mouse macrophage iNOS both at the nucleotide (87 to 92%) and amino acid levels (94 to 97%). iNOS mRNA was expressed maximally 6 h after stimulation with S. dublin, whereas maximal nitrite accumulation in supernatants was measured at 24 to 48 h. Significant differences with regard to cytokine regulation of iNOS were observed between murine and bovine macrophages cultured under identical conditions. The most striking difference was the inability of homologous IFN-gamma to induce iNOS both at the level of nitrite production and of mRNA expression in bovine macrophages. TNF-alpha, IL-2, and IL-1 alone or together with IFN-gamma neither induced iNOS nor primed bovine macrophages for enhanced iNOS expression or activity upon stimulation with S. dublin. RhuIL-4, but not rhuTGF-beta, down-regulated S. dublin-induced iNOS activity and mRNA expression in bovine macrophages. Thus, an enzyme with a high degree of homology to rodent iNOS is inducible by stimulation of bovine macrophages with bacteria, but induction and regulation by cytokines occur under more restricted conditions than in rodent macrophages.
Complement expression in human brain. Biosynthesis of terminal pathway components and regulators in human glial cells and cell lines.
Authors: Gasque P , Fontaine M , Morgan B P 
Published: December 2022

Abstract
C biosynthesis at extrahepatic sites remote from plasma C may be important in the protection of tissues against inflammation and infection but may also contribute to tissue injury. This latter possibility is particularly relevant in the central nervous system (CNS), where several cell types are susceptible to damage by C. We have previously shown that human astrocyte-derived tumor cell lines synthesize and secrete all of the components of the activation pathways of C. In this study, we demonstrate that these cells also produce the components (C6, C7, C8, and C9) and regulators (S-protein and clusterin) of the lytic terminal C pathway. The terminal components produced are hemolytically active, and secretion is markedly up-regulated by the inflammatory cytokine IFN-gamma. Primary human fetal astrocytes also expressed C6, C7, S-protein, and clusterin. The human monocyte/macrophage cell line, used here as a model for microglia, also produced all terminal components and regulators when appropriately stimulated. These studies raise the prospect of the intrathecal synthesis of a complete, functional C system and its regulators in the inflamed CNS. Intrathecal C synthesis may be important in the resolution of infection and inflammation but, given the C susceptibility of some CNS cell types, may also exacerbate damage in demyelination and neurodegeneration.
Human polymorphonuclear leukocytes store large amounts of terminal complement components C7 and C6, which may be released on stimulation.
Authors: Høgåsen A K , Würzner R , Abrahamsen T G , Dierich M P 
Published: December 2022

Abstract
Secretion of the C factors C7, C6, and C3 by human polymorphonuclear leukocytes (PMNs) and PBMCs was studied by ELISA and immunoblot. The release of C7 and C6 by PMNs during 24 h of culture was 16-fold and 6-fold higher, respectively, than the C3 release, with median concentrations of 50.2 ng/ml, 18.3 ng/ml, and 3.1 ng/ml, respectively. In PBMC cultures, C release was considerably lower, and there was a different secretory pattern with a 6-fold higher release of C3 compared with C7 and C6. Stimulation with PMA led to a more rapid and complete secretion of the components to the culture media, whereas treatment with unopsonized Candida species did not affect the release. PMN release of C factors was not dependent on protein biosynthesis, and there was no indication of a selective uptake of C7 from serum as demonstrated by incubating PMNs from a subject with allotype C7 N in C7 M serum. Thus, the C components were probably produced by the PMNs or their bone marrow precursors before ex vivo culture. In cell lysates of freshly isolated cells, median C7, C6, and C3 contents of 1 x 10(7) PMNs were 149.7, 60.1, and 10.4 ng/ml, respectively, whereas the corresponding values for 1 x 10(7) PBMCs were 3.2, 2.6, and 14.6 ng/ml, respectively. The C6 and C7 were shown to incorporate into the terminal complement complex, and their molecular integrity was supported by identical m.w. to C6 and C7 present in normal serum. PMNs may represent a major source of C7 and C6 and may be more important than monocytes or macrophages in contributing terminal C components at a site of inflammation. This suggests a new role for the PMN as a C membrane attack modulator.
Prostanoid enhancement of interleukin-6 production by rat peritoneal mast cells.
Authors: Leal-Berumen I , O'Byrne P , Gupta A , Richards C D , Marshall J S 
Published: December 2022

Abstract
Mast cells are traditionally associated with an acute response involving the short-term release of mediators such as histamine. We have shown previously that mast cells can produce IL-6 without prior histamine release. In this study we examined the hypothesis that mast cell IL-6 production can be selectively regulated by PGs. Highly purified rat peritoneal mast cells were cultured in the presence of PGE1, PGE2, or PGD2 alone or in combination with anti-IgE or bacterial LPS. Histamine release was assessed after 10 min; IL-6 and TNF-alpha production was measured in supernatants after 18 h. Mast cell IL-6 production was induced by PGE1 and PGE2 to a similar level to that observed in anti-IgE-activated cells. In contrast, constitutive production of TNF-alpha was inhibited by PGE1 and PGE2, but not by PGD2. PGE2 had a synergistic effect, inducing IL-6 in the presence of LPS, whereas an additive effect was observed in the presence of anti-IgE. None of the prostanoids alone induced significant histamine release at the 10-min time point. However, PGE2 significantly increased histamine release when added concurrently with anti-IgE. Flurbiprofen in the context of anti-IgE or LPS activation did not alter mast cell IL-6 or TNF-alpha production. IL-6 production in response to each of the stimuli was significantly inhibited by the corticosteroid dexamethasone. These observations of selective modulation of mast cell cytokine production are important to understand the mechanisms by which mast cells interact with other cells during an inflammatory process involving prostanoid synthesis.
Periocular inflammation in mice with experimental systemic lupus erythematosus. A new experimental blepharitis and its modulation.
Authors: Chan C C , Gery I , Kohn L D , Nussenblatt R B , Mozes E , Singer D S 
Published: December 2022

Abstract
Experimental systemic lupus erythematosus (SLE) can be induced in mice by immunization with a human monoclonal anti-DNA Ab, bearing a major Id 16/6Id. Immunized mice initially produce Abs to 16/6Id, DNA and nuclear Ags, and subsequently develop various clinical manifestations including leukopenia and renal immune complex disease. MHC class I Ags play a critical role in the induction and progression of experimental SLE. The present study reports that ocular changes also occur in mice with experimental SLE. The ocular disease is characterized by bilateral subacute and chronic inflammation of the eyelids (blepharitis) with immune complex IgG deposition and hypertrophic meibomian glands. The severity of ocular changes was strain dependent: most severe in 129 mice, less intense in BALB/c animals and only minimal in C3H.SW mice. No blepharitis developed in mice deficient in MHC class I expression. Further, the disease was strongly inhibited in BALB/c mice treated with methimazole, an agent that has been shown to repress transcription of MHC class I. In these cases, there was no IgG deposition and a decreased infiltration of inflammatory cells in the eyelids. These observations thus suggest that, similar to the observation with experimental SLE, MHC class I is critical in the onset of this experimental autoimmune blepharitis. The new experimental eye disease described here provides an animal model for chronic blepharitis in humans, a common condition for which such a model has been sought.