bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bradykinin Stimulates IL-8 Production in Cultured Human Airway Smooth Muscle Cells: Role of Cyclooxygenase Products
Authors: Pang Linhua , Knox Alan J. 
Published: December 2022

Abstract
IL-8 is an important neutrophil and eosinophil chemoattractant in asthma. A recent report has suggested that bradykinin (BK), an asthmatic mediator, induces the release of IL-8 in nonairway cells. We have recently reported that BK causes cyclooxygenase (COX)-2 induction and PGE2 release in human airway smooth muscle (ASM) cells. In this study, we tested the ability of BK to induce IL-8 from these cells and explored the role of COX products and COX-2 induction in this process. Confluent serum-deprived human ASM cells were studied. IL-8 was assayed by specific ELISA. Unstimulated cells released low levels of IL-8. BK enhanced IL-8 release in a concentration- and time-dependent fashion (maximum 50-fold increase over basal). The nonselective COX inhibitor indomethacin and the selective COX-2 inhibitor NS-398 strongly inhibited BK-stimulated PGE2 and IL-8 production. The COX substrate arachidonic acid also caused PGE2 and IL-8 production, and its effect was inhibited by nonselective COX inhibitors but unaffected by NS-398. Both the BK- and arachidonic acid-induced IL-8 production was inhibited by the protein synthesis inhibitors cycloheximide and actinomycin D and by the steroid dexamethasone. Furthermore, exogenous PGE2 and calcium ionophore A23187 also stimulated IL-8 release. BK-induced IL-8 release was mimicked by the BK B2 receptor agonist (Tyr(Me)8)-BK and was potently inhibited by the selective B2 receptor antagonist HOE-140. These results suggest that human ASM can be a source of IL-8 and also that endogenous prostanoids, involving both COX-1 and COX-2, have a novel role in mediating BK-induced IL-8 production.
Contribution of Endothelial Selectins and α4 Integrins to Eosinophil Trafficking in Allergic and Nonallergic Inflammatory Reactions in Skin
Authors: Teixeira Mauro M. , Hellewell Paul G. 
Published: December 2022

AbstractThe role of endothelial selectins in mediating eosinophil recruitment was assessed using the trafficking of 111In-labeled blood eosinophils in mouse skin. An intradermal injection of chemoattractants (leukotriene B4, macrophage inflammatory protein-1α, and eotaxin) resulted in a rapid accumulation of 111In eosinophils that was reduced 49 to 91% by anti-P-selectin mAb. An anti-E-selectin mAb was ineffective, although a combined E- and P-selectin blockade resulted in &gt;95% inhibition of all responses. The accumulation of a pulse of 111In eosinophils at sites of active cutaneous anaphylaxis (ACA) at 4 to 8 h and at 20 to 24 h after Ag challenge was completely dependent upon E- and P-selectin in combination, but not in isolation. In contrast, at 20 to 24 h after Ag challenge in a delayed-type hypersensitivity (DTH) reaction in skin, 111In eosinophil accumulation was largely independent of endothelial selectins, even when L-selectin was also blocked. An anti-α4 integrin mAb significantly reduced 111In eosinophil trafficking in both allergic reactions but was slightly more effective in the DTH reaction compared with the ACA reaction. These results show that P-selectin and to a lesser extent E-selectin mediate eosinophil recruitment in skin in acute inflammatory reactions. In allergic, late-onset inflammatory reactions, neither P- nor E-selectin alone are sufficient to mediate eosinophil accumulation; when combined, they are essential for trafficking in ACA but are less important in the DTH reaction. Whether α4 integrin-based strategies will be more effective than selectin-based strategies at inhibiting eosinophil recruitment in human disease remains to be determined.
Intracellular Expression of FcγRIII (CD16) and Its Mobilization by Chemoattractants in Human Eosinophils
Authors: Zhu Xiangdong , Hamann Kimm J. , Muñoz Nilda M. , Rubio Noel , Mayer Diane , Hernrreiter Anja , Leff Alan R. 
Published: December 2022

AbstractWe characterized the existence, translocation, and reabsorption during cellular activation of a constitutively expressed intracellular CD16 in the human eosinophil. By two-color flow cytometry, we showed that 6.5 ± 0.3% of nonpurified eosinophils expressed surface CD16. After digestion with phosphotidylinositol-specific phospholipase C, surface CD16 on both neutrophils and eosinophils decreased substantially, suggesting that eosinophil CD16 is a glycosyl-phosphatidylinositol-linked isoform. However, CD16 was substantially expressed intracellularly in human eosinophils. Epitope-specific binding to CLB-gran11 mAb from non-NA2/NA2 donors demonstrated that intracellular eosinophil CD16 also differed from the transmembrane isoform of CD16 expressed on NK cells or macrophages. Western blot analysis performed with 3G8 or DJ130c mAb showed a broad band at ∼65 to 80 kDa, which was the same as neutrophil CD16 from the same NA2/NA2 donors. Upon stimulation by chemoattractants C5a, FMLP, or platelet-activating-factor, eosinophilic intracellular CD16 was rapidly translocated to the eosinophil surface, expressed maximally at 30 s, and then gradually disappeared from the cell surface during the next 10 min. Intracellular flow cytometry of stimulated eosinophils and sandwich ELISA of stimulated eosinophil supernatants demonstrated that the disappearance was due to its rapid release into medium and reabsorption by the cells. Our data identify a CD16B that is consistently expressed intracellularly but only rarely on the surface of nonactivated human eosinophils. This CD16 is transiently expressed during stimulation by chemoattractants.
Histamine Potently Suppresses Human IL-12 and Stimulates IL-10 Production via H2 Receptors
Authors: Elenkov Ilia J. , Webster Elizabeth , Papanicolaou Dimitris A. , Fleisher Thomas A. , Chrousos George P. , Wilder Ronald L. 
Published: December 2022

Abstract
IL-12 and IL-10, respectively, stimulate Th1 and Th2 immune responses. The development of some allergic reactions, infections, and tumors are associated with excessive histamine production and a shift toward Th2 responses. Here we address the possibility that this association is causally linked, at least in part, to modulation of IL-12 and IL-10 production by histamine. We report that histamine dose-dependently inhibited the secretion of human IL-12 (p70) and increased the production of IL-10 in LPS-stimulated whole blood cultures. These effects of histamine were antagonized by cimetidine, an H2 receptor antagonist, but not by selective H1 and H3 receptor blockers, and were mimicked by an H2 receptor agonist. The effects of histamine on IL-12 and IL-10 secretion were independent of endogenous secretion of IL-10 or exogenous addition of IL-12, while Ro 20–1724, a phosphodiesterase inhibitor, potentiated the effects of histamine on IL-12 and IL-10 production, implicating cAMP in its actions. Similar modulatory effects of histamine on IL-12 and IL-10 production, which were reversed by the H2 antagonist cimetidine, were observed in PBMC and isolated monocytes stimulated by Staphylococcus aureus Cowan strain 1 and LPS, respectively. Thus, histamine, via stimulation of H2 receptors on peripheral monocytes and subsequent elevation of cAMP, suppresses IL-12 and stimulates IL-10 secretion, changes that may result in a shift of Th1/Th2 balance toward Th2-dominance. This may represent a novel mechanism by which excessive secretion of histamine potentiates Th2-mediated allergic reactions and contributes to the development of certain infections and tumors normally eliminated by Th1-dependent immune mechanisms.
Impaired Yield, Phenotype, and Function of Monocyte-Derived Dendritic Cells in Humans at Risk for Insulin-Dependent Diabetes
Authors: Takahashi Kazuma , Honeyman Margo C. , Harrison Leonard C. 
Published: December 2022

AbstractDendritic cells (DC) present Ag to naive T cells and are therefore pivotal in shaping immune responses. DC may either immunize or tolerize T cells. Humans with pancreatic islet autoimmunity at high risk for insulin-dependent diabetes mellitus (IDDM) present the opportunity to investigate DC in autoimmune disease. We compared DC phenotype and function in 12 euglycemic, asymptomatic IDDM relatives with islet autoimmunity and controls matched for age, sex, and MHC class II alleles. DC were generated from adherent peripheral blood cells by culture with granulocyte/macrophage-CSF and IL-4. The yield of DC was significantly lower in IDDM relatives than in controls. While the DC phenotype, HLA-DR+CD14−, was expressed by ≥90% of the cells generated from relatives and controls, the proportion of cells that expressed CD1a and the costimulator molecules CD80 (B7-1) and CD86 (B7-2) was significantly lower in IDDM relatives. In addition, B7-1 and B7-2 expression per cell was significantly lower in IDDM relatives. These phenotypic changes were accompanied by reduced stimulation of autologous CD4 cells by DC from IDDM relatives. Similar findings were obtained in three recently diagnosed IDDM patients. These findings indicate that impairment of DC phenotype and function is a marker of islet autoimmunity and are consistent with a role for impaired DC function in the pathogenesis of autoimmune disease.
IA-2 (Islet Cell Antigen 512) Is the Primary Target of Humoral Autoimmunity Against Type 1 Diabetes-Associated Tyrosine Phosphatase Autoantigens
Authors: Bonifacio Ezio , Lampasona Vito , Bingley Polly J. 
Published: December 2022

AbstractIA-2 (islet cell Ag 512) and IA-2β (phogrin/IAR) are related autoantigens associated with type 1 diabetes. To determine the critical regions for autoantibody binding and which of these autoantigens is the primary target, mutant and chimeric constructs were used to characterize Ab epitope binding in sera from 217 new onset patients with type 1 diabetes and sequential samples from 141 islet cell Ab positive first degree relatives of patients. All 22 relatives and 121 of 129 patients with IA-2/IA-2β Abs had reactivity to IA-2-specific epitopes. These epitopes were in the juxtamembrane region (residues 601–682) and the protein tyrosine phosphatase (PTP)-like domain of IA-2. Chimeras showed that IA-2 residues 795–889 were important for IA-2-specific Ab binding in the PTP-like domain, and mutation of IA-2 residues 877 and 911, previously indicated as relevant for phosphatase activity, also reduced Ab binding. In contrast, Ab binding to IA-2β was limited to its PTP-like domain, most IA-2β Abs recognized epitopes shared with IA-2, and only 20 patients and 2 relatives had Abs to IA-2β-specific epitopes. In 4 relatives, IA-2 and/or IA-2β Abs developed in follow-up samples. In each of these, Abs to IA-2-specific epitopes were the first detected. In three, spreading to epitopes shared between IA-2 and IA-2β in subsequent samples was seen. In the 17 relatives who developed type 1 diabetes, progression to disease was associated with reactivity to multiple IA-2/IA-2β epitopes. These data suggest that IA-2 is the primary phosphatase-like autoantigen associated with type 1 diabetes and that studying autoantibody epitope diversity may assist in disease prediction.
Cutting Edge Commentary: Chemokine Regulation of Experimental Autoimmune Encephalomyelitis: Temporal and Spatial Expression Patterns Govern Disease Pathogenesis
Authors: Karpus William J. , Ransohoff Richard M. 
Published: December 2022

AbstractExperimental autoimmune encephalomyelitis (EAE) is a CD4+ Th1-mediated demyelinating disease of the central nervous system that serves as a model for multiple sclerosis (MS). There are several considerations that suggest a role for chemokines in the disease process. First, chemokines are highly expressed in the central nervous system with a tight temporal relationship to disease activity. Second, in vivo neutralization studies showed a distinct role for specific chemokines in the evolution of the process. Third, the selective and differential expression of chemokines in differing models of EAE bears a close relationship to the patterns of inflammatory pathology. Fourth, the spatial distribution of chemokine expression could plausibly contribute to lesion architecture. Finally, preliminary observations in MS material suggest that chemokine expression observed in EAE may provide useful information regarding the pathogenesis of inflammation in MS. We propose that temporal and spatial expression of chemokines are crucial factors, complementing adhesion molecule up-regulation, that regulate EAE disease activity.
HindIII Liposomes Suppress Delayed-Type Hypersensitivity Responses In Vivo and Induce Epidermal IL-10 In Vitro
Authors: Nishigori Chikako , Yarosh Daniel , O’Connor Adrienne , K. Shreedhar Vijay , Ullrich Stephen E. , Cox Patricia , Kripke Margaret L. 
Published: December 2022

AbstractConsiderable evidence suggests that ultraviolet-B (UV-B) radiation suppresses certain immune responses through the induction of cyclobutane pyrimidine dimers in DNA. To determine whether induction of other forms of DNA damage in the skin mimicked the immunosuppressive effects of UV-B radiation, we produced double-strand breaks in the DNA of epidermal cells with HindIII restriction endonuclease encapsulated in liposomes. Application of these liposomes, but not liposomes containing inactive HindIII or an irrelevant endonuclease, to the skin of C3H mice suppressed the induction of delayed-type hypersensitivity responses to Candida albicans and alloantigen and induced IL-10 production in the epidermis. Treatment of the Pam212 murine keratinocyte cell line with these liposomes in vitro induced immunosuppressive activity and IL-10 in culture supernatants. Unlike UV-B irradiation, however, HindIII in liposomes failed to induce suppressor T cell activity in vivo or in vitro. We conclude that double-strand breaks in DNA of epidermal cells can induce immunosuppression and up-regulate the production of immunomodulatory cytokines; however, either DNA damage alone does not account for all the immunosuppressive properties of UV-B irradiation, or cyclobutane pyrimidine dimers differ qualitatively from double-strand breaks in their biologic consequences. These studies raise the possibility that drugs causing DNA damage may induce cytokine dysregulation and immune suppression in addition to cytotoxicity.
B Cell Tolerance to a Minor, But Not to a Major, Antigenic Surface of the Self Antigen, Cytochromec
Authors: Jemmerson Ronald , Minnerath Jeanne M. , Hedrick Stephen M. , Oehen Stephan 
Published: December 2022

AbstractTo study B cell tolerance to the mitochondrial protein cytochrome c (CYT), the B cell response to pigeon CYT (PCC) was examined in mice transgenic for PCC. PCC was coupled to OVA to provide T cell help, since PCC-specific T cells in PCC-transgenic mice are deleted in the thymus. The frequency of secondary B cells responding to the minor antigenic surface around residue 44 on PCC was decreased about 10-fold in native PCC-transgenic mice compared with that in control mice or in transgenic mice expressing an altered form of PCC that lacked the heme and had a different amino acid sequence at the N-terminus. A similar decrease has been observed in the frequency of B cells in normal mice recognizing the site around residue 44 on mouse CYT compared with the frequency of B cells recognizing the corresponding site on foreign CYT. There were no major decreases but apparently were compensatory increases in the frequencies of B cells recognizing other sites on PCC in the native PCC-transgenic mice compared with those in other mice. These results indicate that B cells in mice are only partially tolerant to self CYT. A possible basis for this partial tolerance relating to the fate of CYT in cell death is discussed. This may be the first example of the use of a transgenic system to study B cell tolerance to a homologous self Ag.
IL-13 Suppresses TNF-Induced Activation of Nuclear Factor-κB, Activation Protein-1, and Apoptosis
Authors: Manna Sunil K. , Aggarwal Bharat B. 
Published: December 2022

AbstractIL-13 is known to suppress the production of inflammatory cytokines such as TNF. Whether IL-13 also modulates the biologic effects of TNF is not known. In the present report we examined the effect of IL-13 on TNF-induced activation of nuclear transcription factors NF-κB and activation protein-1 (AP-1) and apoptosis. Pretreatment of cells with IL-13 blocked TNF-induced NF-κB activation, nuclear translocation of p65 subunit, and degradation of IκBα. IL-13 also inhibited NF-κB activation by LPS, okadaic acid, H2O2, and ceramide. TNF-induced NF-κB-dependent gene transcription was also blocked by IL-13. TNF-induced activation of another nuclear transcription factor, AP-1, was suppressed by IL-13. The activation of N-terminal c-Jun kinase and mitogen-activated protein kinase kinase, implicated in the regulation of AP-1 and NF-κB, was also down-regulated by IL-13. TNF-mediated cytotoxicity and activation of caspase-3 were abolished by IL-13. The inhibitory effects of IL-13 on TNF were sensitive to H-7, neomycin, and wortmannin, suggesting that the pathway consisting of protein kinase C, phosphatidylinositol 3-kinase, and phospholipase C must be involved in IL-13 signaling. Thus, overall, these results demonstrate that IL-13 is a potent inhibitor of TNF-mediated activation of NF-κB, AP-1, and apoptosis, which may contribute to its previously described immunosuppressive and anti-inflammatory effects.
HLA-DR4 (DRB1*0401) Transgenic Mice Expressing an Altered CD4-Binding Site: Specificity and Magnitude of DR4-Restricted T Cell Response
Authors: Pan Shuchong , Trejo Theodore , Hansen Julie , Smart Michele , David Chella S. 
Published: December 2022

AbstractOptimum function of HLA-DR molecules in transgenic mice requires efficient interaction between the class II molecules on APCs and CD4 on T cells. Residues 110 and 139 of the second domain of class II molecules are considered to be critical for recognition of CD4. We generated an HLA-DR4β(NT) transgene construct in which positions 110 and 139 were altered to resemble endogenous mouse H2 Aβ molecules. This construct was introduced into (B10 × SWR) embryos, and DR4β(NT) transgenic mice were produced. The transgene was transferred into B10.RFB3 (Eβ0 Eαp) mice. The transgene-encoded DR4β molecules paired with endogenous Eα chains to form stable DR4β/Eα dimers expressed on the cell surface. The hybrid dimers showed similar Ag-binding specificity to HLA-DR4 molecules and positively selected CD4+ T cells in vivo. Immunization of HLA-DR4β(NT) transgenic mice with DR4-restricted peptides induced T cell proliferation in vitro. While the purified T cells from DR4β(NT) transgenic mice responded strongly to the HA(307–319) presented by M12C3 transfectants expressing altered DR4β/Eα heterodimers, the response to the same peptides presented by transfectants expressing wild-type DR4β/Eα molecules was substantially reduced. Taken together, these data confirmed in vitro studies on the importance of these residues in CD4-MHC class II interaction. The altered HLA-DR4β transgenic mice were able to overcome the species barrier and generate efficient HLA-DR4-restricted CD4-specific immune responses. Thus, residues 110 and 139 were critical for the interaction of class II with CD4 T cells during thymic selection as well as peripheral immune responses.
Limited Diversity of Human scFv Fragments Isolated by Panning a Synthetic Phage-Display scFv Library with Cultured Human Melanoma Cells
Authors: Noronha Elvyra J. , Wang Xinhui , Desai Smruti A. , Kageshita Toshiro , Ferrone Soldano 
Published: December 2022

Abstract
To broaden the specificity of the Abs recognizing human melanoma-associated Ags (MAAs), we have isolated human single-chain fragment of the V region (scFv) fragments by panning the synthetic phage Ab library (#1) with the human melanoma cell lines S5 and SK-MEL-28. All of the isolated scFv fragments reacted with the mouse mAb defined high molecular weight melanoma-associated Ag (HMW-MAA). scFv #70 immunoprecipitates the two characteristic subunits of HMW-MAA, while scFv #28 only immunoprecipitates its large subunit. These results challenge the current view regarding the structure of HMW-MAA and indicate that it consists of two independent subunits. The human scFv fragments share some similarities with the mouse anti-HMW-MAA mAb. Like mAb 149.53 and 225.28, scFv #28 reacts with rat B49 neural cells that express a homologue of HMW-MAA. scFv #70 reacts with a determinant that is spatially close to the one identified by mAbs 149.53, VT68.2, and VT86. Besides suggesting similarities in the recognition of human melanoma cells by the mouse and human Ab repertoire, these results indicate that the Abs isolated from synthetic Ab libraries resemble those that are found in natural Ab repertoires. The restricted diversity of the scFv fragments that were isolated by panning synthetic Ab libraries with different melanoma cell lines suggests that certain Ags, like HMW-MAA, are immunodominant in vitro. This phenomenon, which parallels the in vivo immunodominance of certain Ags, implies that the antigenic profile of the cells used for panning determines the specificity of the preponderant population of isolated Abs.
Inducible Nitric Oxide Synthase Is Not Required for Long-Term Vaccine-Based Immunity AgainstToxoplasma gondii
Authors: Khan Imtiaz A. , Matsuura Tadashi , Kasper Lloyd H. 
Published: December 2022

AbstractInduction of reactive nitrogen intermediates by IFN-γ is presumed an important mechanism of host resistance against acute and chronic infection with Toxoplasma gondii. Although nitric oxide (NO) has been shown to be important in the control of parasite replication in vivo, the role of this molecule in vaccine-based immunity against T. gondii is unknown. Mice with a targeted disruption of inducible NO synthase (iNOS) were immunized with an avirulent temperature-sensitive strain of this parasite (ts-4). Both the parental C57BL/6 and the iNOS−/− mice survived infection with the ts-4 mutant. Oral challenge of the vaccinated mice with a lethal dose of cysts containing bradyzoites resulted in reduced parasite burden and increased survival compared with nonvaccinated control mice. Host immunity in the iNOS−/− mice, similar to that observed in the parental strain, appears dependent upon both IFN-γ and CD8+ T cells. These findings suggest that although vaccine-based long-term immunity against T. gondii is dependent upon the induction of IFN-γ, it does not rely upon the anti-microbial effect of NO.
Prostaglandin E2 Protects Against Liver Injury AfterEscherichia coliInfection but Hampers the Resolution of the Infection in Mice
Authors: Takano Manabu , Nishimura Hitoshi , Kimura Yuki , Washizu Junji , Mokuno Yasujii , Nimura Yuji , Yoshikai Yasunobu 
Published: December 2022

AbstractcAMP-increasing agents such as prostaglandin E2 (PGE2) are known to protect against LPS-induced liver injury by down-regulating the production of inflammatory cytokines such as TNF-α. However, the effects of such reagents on host defense against bacterial infection remain unknown. We show here that in vivo administration of PGE2 significantly protected mice against liver injury after Escherichia coli infection but hampered the resolution of the infection. PGE2 significantly suppressed circulating TNF-α and IL-12 levels but increased the IL-10 production after E. coli challenge. PGE2 inhibited the emergence of γδ T cells in the peritoneal cavity, which are important for host defense against E. coli, and deteriorated bacterial exclusion in the peritoneal cavity after E. coli challenge. These results suggested that PGE2 affects host defense mechanisms against E. coli infection through modulation of cytokine production and γδ T cell accumulation.