bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined diesel exhaust particulate and ragweed allergen challenge markedly enhances human in vivo nasal ragweed-specific IgE and skews cytokine production to a T helper cell 2-type pattern.
Authors: Diaz-Sanchez D , Tsien A , Fleming J , Saxon A 
Published: December 2022

Abstract
We have previously shown that in vivo nasal challenge with diesel exhaust particles (DEP) induces both quantitative and qualitative changes in local IgE production and stimulates generalized local cytokine production. We have now investigated the combined effects of intranasal challenge with DEP plus ragweed allergen on local humoral immune responses. We collected nasal lavages from ragweed sensitized subjects at different times after nasal challenge. As compared with challenge with ragweed alone, challenge with both DEP and ragweed induced markedly higher ragweed-specific IgE but not total IgE levels or IgE-secreting cell numbers. Total and specific IgG4 levels also were enhanced, while total IgG levels were not. Synergy was also observed between the DEP and ragweed in altering the profile of epsilon mRNAs generated by alternative splicing, mRNAs that code for different expressed IgE proteins. Intranasal challenge with ragweed alone induced inconsistent and low levels of mucosal cytokine mRNAs. In contrast, challenge with both ragweed plus DEP resulted in decreased expression for Th1-type cytokines (IFN-gamma and IL-2) but elevated expression of mRNA for other cytokines (IL-4, -5, IL-6, IL-10, IL-13). This synergy between DEP and natural allergen exposure is suggested as a key feature in increasing allergen-induced respiratory allergic disease.
Eosinophils are not required for the rejection of neovascularized fetal pig proislet xenografts in mice.
Authors: Simeonovic C J , Townsend M J , Wilson J D , McKenzie K U , Ramsay A J , Matthaei K I , Mann D A , Young I G 
Published: December 2022

Abstract
The rejection of neovascularized pig proislet (islet precursor) xenografts in mice is a CD4 T cell-dependent process involving invasion of the graft site mainly by host CD4 T cells and eosinophils. We previously identified CD4 T cell-dependent enhancement of intragraft IL-3, IL-4, and IL-5 mRNA expression during acute xeno-rejection in CBA/H recipient mice. In the present study we investigated the role of each cytokine and the involvement of eosinophils in the rejection of pig proislet xenografts using cytokine gene knockout mice (IL-4 -/- and IL-5 -/-) and the treatment of transplant recipients with anti-IL-3 mAb. In IL-4 -/- mice, IL-5 -/- recipient animals, and anti-IL-3 mAb-treated CBA/H mice, eosinophil accumulation at the transplant site was inhibited or ablated, but the kinetics of xenograft rejection was unaltered. Prolonged xenograft survival was only achieved in anti-CD4 mAb-treated mice and consistently correlated with the absence of intragraft IL-3, IL-4, and IL-5 mRNA enhancement. Together these findings indicate that neither IL-3, nor IL-4, nor IL-5 individually plays an obligatory role in the rejection process. The cytokine mRNA profile correlating with the lack of eosinophil recruitment was variable; the data suggest that IL-4 regulates eosinophil involvement in the xeno-rejection reaction indirectly via effects on IL-5 and IL-3 transcript expression. There is also suggestive evidence that IL-5 may influence IL-3 and IL-4 mRNA expression via feedback inhibition. Eosinophils, therefore, do not play an essential role in the rejection of neovascularized pig proislet xenografts in mice.
Actions of IL-1 are selectively controlled by p38 mitogen-activated protein kinase: regulation of prostaglandin H synthase-2, metalloproteinases, and IL-6 at different levels.
Authors: Ridley S H , Sarsfield S J , Lee J C , Bigg H F , Cawston T E , Taylor D J , DeWitt D L , Saklatvala J 
Published: December 2022

Abstract
The role of p38 mitogen-activated protein kinase (MAPK) in responses of human fibroblasts and vascular endothelial cells to IL-1 was investigated by use of a pyridinyl imidazole compound (SB 203580), which specifically inhibits the enzyme. SB 203580 inhibited (50% inhibitory concentration approximately 0.5 microM) IL-1-induced phosphorylation of heat shock protein 27 (an indicator of p38 MAPK activity) in fibroblasts without affecting the other known IL-1-activated protein kinase pathways (p42/p44 MAPK, p54 MAPK/c-Jun N-terminal kinase and beta-casein kinase). SB 203580 significantly inhibited IL-1-stimulated IL-6, (30 to 50% at 1 microM) but not IL-8 production from human fibroblasts (gingival and dermal) and umbilical vein endothelial cells. IL-1 induction of steady state level of IL-6 mRNA was not significantly inhibited, which is consistent with p38 MAPK regulating IL-6 production at the translational level. SB 203580 strongly inhibited IL-1-stimulated PG production by fibroblasts and human umbilical vein endothelial cells. This was associated with the inhibition of the induction of PGH synthase-2 protein and mRNA. SB 203580 also inhibited the stimulation of collagenase-1 and stromelysin-1 production by IL-1 without affecting synthesis of the tissue inhibitor of metalloproteinases (TIMP)-1. SB 203580 prevented the increase in collagenase-1 and stromelysin-1 mRNA stimulated by IL-1. In a model of cartilage breakdown, short-term IL-1-stimulated proteoglycan resorption and inhibition of proteoglycan synthesis were unaffected by SB 203580, while longer term collagen breakdown was prevented. It is concluded that 1) p38 MAPK plays an important role in the regulation of some, but not all, responses to IL-1, and 2) it is involved in the regulation of mRNA levels of some IL-1-responsive genes.
Alterations in the level of CD45 surface expression affect the outcome of thymic selection.
Authors: Wallace V A , Penninger J M , Kishihara K , Timms E , Shahinian A , Pircher H , Kündig T M , Ohashi P S , Mak T W 
Published: December 2022

Abstract
CD45 is a receptor protein tyrosine phosphatase whose activity is required for thymocyte development and TCR-mediated signal transduction. Here we show that positive selection of TCR-alphabeta transgenic thymocytes is completely blocked in CD45 exon 6 -/- gene-deficient (CD45 -/-) mice that express the P14 TCR specific for the lymphocytic choriomeningitis virus. Thymocytes from mice heterozygous for the targeted disruption of the CD45 gene (CD45 +/-) displayed a reduction in both CD45 surface intensity and enzymatic CD45 protein tyrosine phosphatase activity. Surprisingly, positive thymocyte selection was enhanced in CD45 +/- mice as characterized by an up-regulation of the P14 TCR on thymocytes and increased numbers of transgenic T cells. Using a variant of lymphocytic choriomeningitis virus that is impaired in the induction of negative selection of P14 thymocytes, we also show that the reduction of CD45 surface expression in CD45 +/- mice rendered P14 transgene thymocytes susceptible to negative selection. These data demonstrate that changes in the expression level of the receptor protein tyrosine phosphatase CD45 can alter thymic selection.
Point mutation flanking a CTL epitope ablates in vitro and in vivo recognition of a full-length viral protein.
Authors: Yellen-Shaw A J , Wherry E J , Dubois G C , Eisenlohr L C 
Published: December 2022

Abstract
CD8+ T cells (T(CD8+)) recognize viral Ags as short peptides (epitopes) displayed at the cell surface by MHC class I molecules. Using a panel of recombinant vaccinia viruses, we show that single-point mutations flanking either side of an H-2Kd-restricted epitope, residues 147-155, within full-length influenza nucleoprotein (NP) can impact, even ablate, presentation of that epitope, while having no effect on presentation of distal epitopes. The most severe blocking mutation (Ala to Pro at position 146) did not inhibit NP(147-155) presentation in the context of a truncated minigene, implying that this peptide is not a functional processing intermediate. An amino-terminal proline replacement also significantly reduced presentation of NP(50-57) (H-2Kk restricted), while the same mutation did not affect a third NP epitope. Thus, while trends in processing specificity may exist, the epitope itself contributes to flanking sequence effects. These findings were paralleled by in vivo priming experiments in which, depending on viral dose, subtle in vitro blocking effects were absolute. Proteasome/synthetic peptide coincubation studies support a role for enhanced epitope destruction in preventing presentation, as did the effect of the peptide aldehyde, LLnL, which restored presentation of NP(147-155) from the mutated constructs. This reagent did not inhibit epitope presentation, even from wild-type NP, suggesting that its production may be proteasome independent. These results support the notion that point mutation of epitope flanking sequence can serve as a mechanism for viral immune evasion, shed light on the mechanisms involved, and suggest that in vitro assays may not be sensitive indicators of flanking sequence effects.
Virus-mediated delivery of antigenic epitopes into dendritic cells as a means to induce CTL.
Authors: Brossart P , Goldrath A W , Butz E A , Martin S , Bevan M J 
Published: December 2022

Abstract
Dendritic cells (DC) are potent inducers of CD8+ T cells and can stimulate protective antitumor immunity when pulsed with an antigenic peptide or protein. We used a replication-deficient adenovirus containing a Kb-restricted antigenic peptide of chicken OVA to study CTL induction in vitro and in vivo after adenovirus-mediated gene transfer into DC. The efficiency of adenovirus-infected DC in eliciting a specific CTL response was compared with immunizations with a recombinant vaccinia virus and DC pulsed with peptide or protein. An immortalized DC line derived from a C57BL/6 mouse and freshly isolated splenic DC from C57BL/6 mice were used in CTL induction. Virus-infected DC elicited the strongest Ag-specific CTL response in vitro and in vivo and induced protective antitumor immunity to a challenge with EG.7 tumors (EL-4 cell line expressing OVA). Direct immunization of mice with recombinant adenovirus resulted in the induction of high titers of neutralizing Abs, which precluded a boost of a CTL response after repeated inoculations. However, repeated injections of virus-infected DC induced only low titers of neutralizing Abs. Furthermore, the presence of neutralizing Abs specific for the virus did not affect the usefulness of infected DC as repeated applications of virus-infected DC boosted the CTL response even in mice previously infected with the recombinant vector. The use of DC infected with a recombinant virus has advantages over other forms of immunization and could provide an alternative approach for designing vaccination therapies.
Borrelia burgdorferi activates nuclear factor-kappa B and is a potent inducer of chemokine and adhesion molecule gene expression in endothelial cells and fibroblasts.
Authors: Ebnet K , Brown K D , Siebenlist U K , Simon M M , Shaw S 
Published: December 2022

Abstract
Lyme disease, caused by the tick-borne spirochete Borrelia burgdorferi, is a systemic infection with preponderance for the skin, joints, heart, and nervous system. Inflammatory lesions of target organs are characterized by the presence of spirochetes and inflammatory leukocytes. We have analyzed the potential of B. burgdorferi to induce gene expression of chemokines and adhesion molecules in human endothelial cells, keratinocytes, and fibroblasts. We find induction of the chemokines RANTES (regulated upon activation, normal T cells expressed and secreted), monocyte chemoattractant protein-1, IL-8, gro-alpha, IFN-inducible protein-10, and mig (monokine induced by gamma-IFN), and of the adhesion molecules E-selectin, ICAM-1, and VCAM-1 in endothelial cells and induction of the same chemokines and ICAM-1 in fibroblasts. This is mediated by the lipid moiety of the outer surface lipoprotein A. Induction of chemokine and adhesion molecule genes by B. burgdorferi occurs rapidly and does not require new protein synthesis. Induction is blocked by inhibitors of nuclear factor (NF)-kappa B. We also find that B. burgdorferi induces nuclear translocation of NF-kappa B and a transient increase in the expression of its inhibitor I kappa B-alpha. These findings indicate that B. burgdorferi is a potent inducer of molecules required for leukocyte recruitment to inflammatory foci, and the data suggest that this biologic activity is due to the ability of the spirochetes to activate the pleiotropic transcription factor NF-kappa B.
Interleukin-13 induces human monocyte/macrophage fusion and macrophage mannose receptor expression.
Authors: DeFife K M , Jenney C R , McNally A K , Colton E , Anderson J M 
Published: December 2022

Abstract
Inasmuch as we recently demonstrated that IL-4 is a strong inducer of monocyte/macrophage fusion and IL-13 has been observed to mimic many of the biologic effects of IL-4, the ability of IL-13 to promote human macrophage fusion in vitro was tested and compared with IL-4-mediated fusion. IL-13 induced the fusion of monocyte-derived macrophages as potently as IL-4 under identical culture conditions, and resulted in foreign body-type giant cell formation. At optimal concentrations of cytokine added, statistically equal numbers of macrophages participated in IL-13- and IL-4-induced fusion (66.1 +/- 4.6% and 63.9 +/- 4.4%, respectively). However, the effects of IL-13 and IL-4 were not additive or synergistic, and the maximum fusion obtained when both IL-4 and IL-13 were added was 63.8 +/- 3.6%. Only anti-human IL-13 Abs inhibited IL-13-induced foreign body giant cell formation; the fusion-inducing effects of IL-13 continued to be observed in the presence of neutralizing Abs to IL-4 and several other anti-cytokine Abs, including Abs against IFN-gamma, granulocyte-macrophage CSF, IL-3, and TNF-alpha. IL-13 also significantly enhanced the fluorescence intensity detected by anti-human macrophage mannose receptor Abs, indicating that IL-13, like IL-4, up-regulates expression of the receptor that may be an essential participant in macrophage fusion. The results of this study demonstrate that IL-13, like IL-4, is a potent human macrophage fusion factor, and suggest that although IL-13 acts independently of IL-4 to promote foreign body giant cell formation, it may trigger a common mechanism for macrophage fusion.
Requirement for C-X-C chemokines (macrophage inflammatory protein-2 and cytokine-induced neutrophil chemoattractant) in IgG immune complex-induced lung injury.
Authors: Shanley T P , Schmal H , Warner R L , Schmid E , Friedl H P , Ward P A 
Published: December 2022

Abstract
The C-X-C chemokines of the IL-8 family possess potent chemotactic activity for neutrophils, but their in vivo role in inflammatory responses is not well understood. In the IgG immune complex-induced model of acute lung inflammatory injury in the rat we have evaluated the roles of two rat chemokines, macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC). Both mRNA and protein for MIP-2 and CINC appeared in a time-dependent manner after initiation of IgG immune complex deposition in lung. There exists a 69% homology between the amino acid sequences for these proteins, and we found cross-reactivity between polyclonal Abs raised to these chemokines. By purifying the blocking Abs using double affinity methods (with Ag-immobilized beads), this cross-reactivity was removed. Individually, anti-MIP-2 and anti-CINC Ab significantly reduced lung injury (as measured by 125I-labeled albumin leakage from the pulmonary vasculature) and reduced neutrophil accumulation in the lung (as determined by myeloperoxidase (MPO content) and neutrophil counts in bronchoalveolar lavage (BAL) fluids); however, no change in TNF-alpha levels in BAL fluids was found. Chemotactic activity in BAL fluids collected 2 h after injury from animals undergoing immune complex deposition could be shown to be chiefly due to the combined contributions of MIP-2 (39%), CINC (28%), and C5a (21%). When either MIP-2 or CINC was blocked in vivo, up-regulation of Mac-1 expression on neutrophils obtained from BAL fluids was significantly reduced. These data suggest that, in the model studied, both MIP-2 and CINC contribute significantly to the influx of neutrophils and their activation.
Autoreactive T cell clones from patients with systemic lupus erythematosus support polyclonal autoantibody production.
Authors: Takeno M , Nagafuchi H , Kaneko S , Wakisaka S , Oneda K , Takeba Y , Yamashita N , Suzuki N , Kaneoka H , Sakane T 
Published: December 2022

Abstract
This work examines the functional properties and TCRbeta gene utilization of 15 autoreactive T cell clones derived from five patients with systemic lupus erythematosus. All these clones proliferated and secreted cytokine when stimulated in vitro by autologous (but not allogenic) B cells. Individual T cell clones used diverse TCRbeta genes and did not show skewing toward the preferential usage of anionically charged receptors. Autoreactive T cell clones supported polyclonal B cell activation, as characterized by the production of anti-DNA, anti-Sjögren syndrome A, and anti-tetanus toxoid (anti-TT) Abs. This T cell help was mediated through the production of immunostimulatory cytokines, especially IL-6. Although stimulation of the autoreactive clones was blocked by anti-HLA class II Abs, the T cell clones did not proliferate, nor did they support polyclonal IgG production by HLA class II-matched normal B cells. Unlike the autoreactive clones, TT-specific clones derived from the same patients provided help selectively to B cells secreting anti-TT Abs. These findings suggest that autoreactive T cells from systemic lupus erythematosus patients are triggered to provide help following cognate interactions with self-peptides presented in the context of HLA class II molecules expressed on autologous B cells regardless of their specificities.
Thymus-independent generation of NK1+ T cells in vitro from fetal liver precursors.
Authors: Shimamura M , Ohteki T , Launois P , Garcia A M , MacDonald H R 
Published: December 2022

Abstract
NK1.1+TCR alpha beta+ (NK1+) T cells are an unusual subset of mouse TCR alpha beta+ cells found primarily in adult thymus and liver. In contrast to conventional TCR alpha beta+ cells, NK1+ T cells have a TCR repertoire that is highly skewed to V alpha14 and to Vbeta8, -7, and -2. The developmental origin and ligand specificity of NK1+ T cells are controversial. We show here that NK1+ T cells with a typically biased V alpha and V beta repertoire develop in cytokine-supplemented suspension cultures of fetal liver established from either normal or athymic mice. Furthermore, NK1+ T cell development in fetal liver cultures is abrogated in beta2m-deficient mice (which lack MHC class I and other related molecules) and can be partially inhibited by the presence of anti-CD1 mAbs. Moreover, mixing experiments indicate that recombination-deficient SCID fetal liver cells can reconstitute NK1+ T cell development in beta2m-deficient fetal liver cultures. Collectively, our data demonstrate that NK1+ T cells can develop extrathymically from fetal liver precursors and that a beta2m-associated ligand (putatively CD1) present on nonlymphoid cells is essential for their positive selection and/or expansion.
Complement evasion by Echinococcus granulosus: sequestration of host factor H in the hydatid cyst wall.
Authors: Díaz A , Ferreira A , Sim R B 
Published: December 2022

Abstract
Hydatid disease, which affects humans and various livestock species, is caused by the larval stages of the cestode parasite Echinococcus granulosus. The disease involves the growth of a fluid-filled cyst in the host's internal organs. The hydatid cyst wall is generally thought to preclude the access of host immune cells to the cyst, while allowing passage of macromolecules. Thus, evasion of humoral effector mechanisms, in particular the complement system, may be crucial to parasite survival. Evasion of complement might involve inhibition of the C3b deposition step, which can in principle be achieved through parasite-derived or host-derived and parasite-bound regulatory molecules. In this work, extracts from bovine hydatid cysts were analyzed for the presence of factor H-like function, namely the cofactor activity for the breakdown of amidated bovine C3 by bovine factor I. Both this activity and antigenically detectable bovine factor H were found in most extracts. The cofactor activity was retained by an anti-bovine factor H Ab column; as no factor H-cross-reactive parasite molecules were detected in the active extracts, the activity was indeed due to host factor H. The pattern of extraction of host factor H from the parasite tissue indicated that at least part of it was selectively bound to the cyst wall, and that a strong charge component was involved in the binding. Our results indicate that the selective concentration of host factor H from plasma/interstitial fluid may contribute to complement evasion by E. granulosus.
Constitutive shedding of both p55 and p75 murine TNF receptors in vivo.
Authors: Pinckard J K , Sheehan K C , Arthur C D , Schreiber R D 
Published: December 2022

Abstract
Recently, we reported the generation and characterization of hamster mAbs specific for the murine p55 and p75 TNF receptors. Upon characterizing these mAbs in vivo, we discovered that administration of TNF receptor-specific mAb to normal mice resulted in the linear accumulation of the appropriate class of soluble TNF receptor in the circulation. The mechanism underlying soluble receptor accumulation was found to be due to an abrogation of the clearance of constitutively shed soluble receptor by receptor-specific mAb. Levels of p55 or p75 accumulated in the presence of nonblocking, nonagonistic TNF receptor mAb were capable of inhibiting murine TNF-induced responses in vivo. These results document that both p55 and p75 are constitutively shed in substantial amounts in vivo and suggest that the process of constitutive TNF receptor shedding plays an important role in regulating TNF activity under physiologic conditions.
Neutrophil-activating protein ENA-78 and IL-8 exhibit different patterns of expression in lipopolysaccharide- and cytokine-stimulated human monocytes.
Authors: Schnyder-Candrian S , Walz A 
Published: December 2022

Abstract
The production of epithelial neutrophil-activating protein-78 (ENA-78) by normal human monocytes was studied in comparison with IL-8 upon stimulation with various stimuli. LPS at 100 ng/ml was a strong inducer of ENA-78, yielding a delayed up-regulation of steady state mRNA peaking at 24 h and causing a long-lasting ENA-78 protein secretion starting 20 h after induction. As shown by specific ELISA and immunoprecipitation, ENA-78 secretion by monocytes was not down-regulated for up to 72 h. Thus, ENA-78 production becomes effective when IL-8 synthesis is shut off, since IL-8 mRNA peaks at 4 to 12 h and approaches background levels at about 16 h. Induction of steady state ENA-78 mRNA by proinflammatory cytokines IL-1beta (10 ng/ml) and TNF-alpha (100 ng/ml) was weaker than that by LPS and yielded a biphasic kinetic with a first maximum at 8 to 12 h and a second at 20 to 28 h. Steady state IL-8 mRNA induced by LPS, IL-1beta, or TNF-alpha was superinduced or unchanged in the presence of cycloheximide (10 microg/ml). In contrast, ENA-78 mRNA was completely abrogated, suggesting the involvement of a newly synthesized protein intermediate necessary for ENA-78 up-regulation. Dexamethasone treatment reduced ENA-78 mRNA and protein levels by 60% of the LPS control level. This inhibition was identical when dexamethasone was added 8 h after LPS induction. These results demonstrate significant differences in the production of monocyte-derived IL-8 and ENA-78 and thus may suggest different roles for the two chemokines in acute or chronic inflammation.