bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leukocyte transmigration, but not rolling or adhesion, is selectively inhibited by dexamethasone in the hamster post-capillary venule. Involvement of endogenous lipocortin 1.
Authors: Mancuso F , Flower R J , Perretti M 
Published: December 2022

Abstract
This study investigates the effect of dexamethasone on leukocyte extravasation in the post-capillary venules of the hamster cheek pouch, using an intravital microscopy technique, and seeks to clarify the potential involvement of the steroid-inducible protein lipocortin 1. Topical application of FMLP (10 nmol), or substance P (10 nmol), to the superfused cheek pouch induced at the level of the post-capillary venules the three characteristic phenomena of leukocyte rolling, adhesion, and transmigration. Pretreatment of hamsters with an anti-inflammatory dose of dexamethasone (1 mg/kg) increased lipocortin 1 levels in circulating leukocytes as assessed by flow cytometry, but did not modify either leukocyte rolling or the number of adherent cells; however approximately 65% of the adherent leukocytes subsequently detached and returned to the blood stream, whereas those that entered into the diapedesis process exhibited a long latency (approximately three- to fourfold longer than in control animals) before transmigration. In hamsters passively immunized with a polyclonal anti-lipocortin 1 serum, leukocyte diapedesis started at similar times in both control and dexamethasone-treated animals, whereas a significant prolongation was observed in those animals treated with a non-immune sheep serum. These observations indicate that 1) lipocortin 1 is elevated in circulating leukocytes following dexamethasone treatment; 2) the step of leukocyte extravasation affected by dexamethasone in the actual transmigration process, and 3) this specific effect upon leukocyte diapedesis is mediated by endogenous lipocortin 1.
The activation of the Jak-STAT 1 signaling pathway by IL-5 in eosinophils.
Authors: Pazdrak K , Stafford S , Alam R 
Published: December 2022

Abstract
The intracellular signal transduction of IL-5 in eosinophils is unknown. The objective of this study was to investigate the involvement of the newly discovered Jak-STAT pathway in the IL-5 signal transduction mechanism. Eosinophils were purified from peripheral blood by discontinuous Percoll gradients and stimulated with IL-5. The involvement of Jak 2 was investigated by immunoprecipitation followed by immunoblotting for tyrosine phosphorylation. The activation of Jak 2 was studied by autophosphorylation of the immunoprecipitated kinase. Jak 2 was tyrosine phosphorylated within 1 to 3 min after stimulation of eosinophils with IL-5. Further, the immunoprecipitated Jak 2 obtained from IL-5-stimulated cells underwent autophosphorylation. Jak 2 coprecipitated with the beta-subunit of the IL-5 receptor, suggesting a physical association of the kinase with the receptor. The nuclear factor STAT-1 (p91) was investigated by immunoprecipitation followed by immunoblotting for tyrosine phosphorylation. STAT-1 was tyrosine phosphorylated within 15 min of IL-5 stimulation. The presence of STAT-1 in the nuclear extract was studied by electrophoretic mobility shift assay. IL-5 induced two proteins that bound to the gamma-activating sequence. In the presence of an anti-STAT-1 Ab, the band was supershifted. Thus, we demonstrated that IL-5 activated the Jak 2-STAT 1 signaling pathway in eosinophils. We speculate that the Jak 2-STAT 1 pathway may be involved in the activation of IL-5-inducible genes in eosinophils.
IL-2 knockout recipient mice reject islet cell allografts.
Authors: Steiger J , Nickerson P W , Steurer W , Moscovitch-Lopatin M , Strom T B 
Published: December 2022

Abstract
The IL-2 pathway is portrayed often as central to allograft rejection. To test this hypothesis, we studied IL-2-deficient mice as allograft recipients. IL-2 gene knockout (KO) mice reject islet allografts and demonstrate a classical mononuclear leukocytic infiltrate, containing CD4+ and CD8+ T cells, surrounding and invading the islet allografts. Moreover, allograft rejection in the IL-2 KO mouse is associated with intragraft expression of certain cytokine and CTL attack molecule genes (e.g. IFN-gamma, IL-4, IL-7, IL-10, and granzyme B). In separate experiments, IL-2 KO mice generated CTLs in response to in vivo challenge with allogeneic tumor cells. Although IL-2 KO mice reject allografts in vivo, spleen cells from immunologically naive IL-2 KO mice exhibit a diminished proliferative response to mitogens in vitro that could be restored largely by exogenous IL-2, IL-4, or IL-7. The paradoxical ability to execute graft rejection in vivo despite near absent T cell proliferative responses in vitro may result from the expression of IL-7 in vivo, but not in vitro. Con A-stimulated bulk spleen cell cultures derived from IL-2 KO mice were essentially devoid not only of IL-2 but also IL-7 gene transcripts. These data indicate that 1) IL-2 is not the sole T cell growth factor capable of supporting allograft rejection and 2) expression of IL-4, but not IL-2, during the allograft response does not lead inevitably to tolerance.
CD28-B7 costimulatory blockade by CTLA4Ig prevents actively induced experimental autoimmune encephalomyelitis and inhibits Th1 but spares Th2 cytokines in the central nervous system.
Authors: Khoury S J , Akalin E , Chandraker A , Turka L A , Linsley P S , Sayegh M H , Hancock W W 
Published: December 2022

Abstract
We studied the contribution of the CD28-B7 costimulatory T cell activation pathway to the pathogenesis of experimental autoimmune encephalomyelitis in the Lewis rat model. Systemic administration of CTLA4Ig suppressed clinical disease and was effective even when CTLA4Ig was delayed until day 10 postimmunization, a time when pathologic disease is evident. This protection was not reversible by systemic administration of high doses of IL-2. Detailed immunohistologic studies showed that CTLA4Ig therapy resulted in suppression of the inflammatory response with inhibition of Th1 (IL-2 and IFN-gamma) and sparing of Th2 (IL-4, IL-10, and IL-13) cytokines in the central nervous system. These results indicate that the CD28-B7 T cell costimulatory pathway plays an important role in experimental autoimmune encephalomyelitis, a Th1-mediated disease, and suggest that blockade of this costimulatory pathway protects against active disease by causing a state of immune deviation towards Th2 function. The ability of CTLA4Ig to treat animals with pathologically established disease may have important clinical implications for patients with multiple sclerosis.
Prostaglandin E2 at priming of naive CD4+ T cells inhibits acquisition of ability to produce IFN-gamma and IL-2, but not IL-4 and IL-5.
Authors: Katamura K , Shintaku N , Yamauchi Y , Fukui T , Ohshima Y , Mayumi M , Furusho K 
Published: December 2022

Abstract
We investigated the effect of prostaglandin E2 on the acquisition of cytokine-producing ability by naive CD4+ T cells in human cord blood. Naive CD4+ T cells were stimulated for 3 days with mouse monoclonal anti-CD3 Ab, then washed and expanded in IL-2-containing medium for 3 more days. These activated T cells produced IL-2, IL-4, IL-5, and IFN-gamma upon stimulation with PMA and ionomycin. PGE2 added at priming of naive T cells inhibited the production of IL-2 and IFN-gamma, but not of IL-4 and IL-5, in a dose-dependent manner. This change in the cytokine production profile induced by PGE2 was maintained in T cells restimulated with anti-CD3 in the absence of PGE2, expanded by IL-2, and stimulated with PMA and ionomycin. The mRNA expression of IFN-gamma and IL-2, but not that of IL-4, was also decreased in these cells. Forskolin and dibutyryl cAMP had a similar effect. PGE2 must exist at an early stage of T cell activation to inhibit priming for IL-2 and IFN-gamma production. PGE2 also showed this effect, even in the presence of exogenous IFN-gamma, at the primary stimulation. These results indicate that PGE2 inhibits the acquisition of the ability to produce IL-2 and IFN-gamma by acting directly on naive T cells. Our results suggest that PGE2 plays a role in facilitating the development of the Th2-type cytokine production profile.
Alterations in cytokine and antibody production following chemical sympathectomy in two strains of mice.
Authors: Kruszewska B , Felten S Y , Moynihan J A 
Published: December 2022

Abstract
It is becoming clear that immune responses are subject to modulation by the sympathetic nervous system. We examined the effect of chemical sympathectomy (to ablate peripheral sympathetic nerve fibers) on cytokine and Ab production in two strains of mice that are known to differ in their response to a variety of pathogens and in the dominant types of cytokines produced. C57Bl/6J mice produce a strong cell-mediated response, characterized by production of IL-2 and IFN-gamma, whereas BALB/cJ have a dominant humoral response, with production of IL-4 and IL-10. Animals were denervated by injection with 6-hydroxydopamine and immunized with keyhole limpet hemocyanin, and spleens were removed at various times after immunization. Denervation significantly increased the keyhole-limpet-hemocyanin-stimulated in vitro proliferation and IL-2 and IL-4 production by splenocytes from both strains. The increases were prevented by pretreatment with desipramine, which blocks the uptake of 6-hydroxydopamine into the nerve fibers and subsequent nerve fiber destruction. Serum titers of IgM, IgG, IgG1, and IgG2a were also enhanced in the C57Bl/6J strain; BALB/cJ mice had a small increase in IgG1 only. These results suggest that one function of splenic innervation and transmitter release may be to modulate T helper cytokines, thereby partially regulating immune effector function. Our evidence is consistent with a model of immune regulation in which removal of sympathetic nervous system input enhances at least some parameters of immune responses.
Mucosal adjuvant effect of cholera toxin in mice results from induction of T helper 2 (Th2) cells and IL-4.
Authors: Marinaro M , Staats H F , Hiroi T , Jackson R J , Coste M , Boyaka P N , Okahashi N , Yamamoto M , Kiyono H , Bluethmann H , Fujihashi K , McGhee J R 
Published: December 2022

Abstract
Despite pathophysiologic effects including diarrhea, cholera toxin (CT) is a potent mucosal immunogen and adjuvant. We investigated the influence of CT on T helper (Th)-type 1 (Th1) and Th2 cell-regulated Ag-specific B cell isotype and IgG subclass Ab responses elicited when the toxin was co-administered orally with different protein Ags. When mice were orally immunized with tetanus toxoid (TT) and CT as adjuvant, this regimen induced TT-specific secretory IgA responses in the gastrointestinal tract as well as serum IgG, including IgG1 and IgG2b subclasses, and IgA responses. This oral regimen also induced TT- and CT-B-specific IgE responses. In addition, CT also elicited adjuvant effects for Ag-specific IgG1, IgE, and IgA responses when two other protein Ags, OVA and hen egg white lysozyme, were given by the oral route. Quantitative reverse transcriptase-PCR was performed to assess levels of mRNA for Th1 (IFN-gamma) and Th2 (IL-4) cytokine expression in TT-stimulated CD4+ T cell cultures. Both Peyer's patches and splenic CD4+ T cells expressed markedly increased levels of IL-4-specific message, but did not result in changes in IFN-gamma mRNA expression. To determine whether the route of immunization influenced IgE responses, mice were immunized s.c. with TT and CT as adjuvant. Significant increases in total and TT-specific IgE Abs were induced when CT was co-administered. Taken together, these results show that CT acts as a mucosal adjuvant to enhance Th2-type responses and in particular, the IL-4 produced results in a characteristic Ab isotype pattern associated with this cytokine.
Stimulation of thymocytes before and after positive selection results in the induction of different NF-kappa B/Rel protein complexes.
Authors: Moore N C , Girdlestone J , Anderson G , Owen J J , Jenkinson E J 
Published: December 2022

Abstract
Positive selection triggers the differentiation of immature CD4+8+TCRlow thymocytes into TCRhigh single-positive CD4+ or CD8+ cells and is associated with major changes in gene expression. However, little is known about the DNA binding factors controlling these fundamental changes. Here we have examined NF-kappa B/Rel subunit expression and DNA-binding activity in developing thymocytes before and after the induction of positive selection. We show that positive selection is accompanied by the strong up-regulation of c-rel mRNA expression and the constitutive activation of p50/p65 and p50/c-Rel NF-kappa B/Rel complexes, confirming the activation-like status of cells undergoing positive selection. Moreover, CD69+ cells that have initiated positive selection (but not their preselection CD4+8+TCR- precursors) respond to stimulation by the preferential activation of c-Rel-containing DNA-binding complexes. Because the different NF-kappa B/Rel dimers have distinct transcriptional activities and binding site preferences, this preferential activation of c-Rel-containing DNA-binding complexes may well have implications for the changes in gene expression and functional response associated with positive selection.
Differentiation to T helper cells in the thymus. Gradual acquisition of T helper cell function by CD3+CD4+ cells.
Authors: Vanhecke D , Verhasselt B , Debacker V , Leclercq G , Plum J , Vandekerckhove B 
Published: December 2022

Abstract
We investigated at which point during thymocyte differentiation functions were acquired that are characteristic for mature Th cells. Differentiation from CD3+CD69-, CD4+CD8+ double-positive (DP) cells to terminally differentiated CD3+, CD4+CD8- single-positive (SP) cells was broken down into six discrete stages that were purified by four-color sorting: CD69-CD3+DP (stage 0), CD69+CD27-DP (stage 1), CD69+CD27-CD4+SP (stage 2), CD27+CD1+CD4+SP (stage 3), CD1-CD45RO+CD4+SP (stage 4), and CD1-CD45RO-CD4+SP cells (stage 5). Phenotypically, these stages seem to describe consecutive steps in differentiation from immature stage 0 to the terminally matured stage 5. Functionally, the capacity to proliferate on IL-2 after stimulation was absent in CD69- stage 0 cells, but was acquired gradually during stages 1 to 4. Clonal expandability and the capacity to respond to stimulation with the production of cytokines were acquired later and rather abruptly by CD1- stage 4 and 5 cells. Activation markers such as CD69 expression and in vivo IL-2 gene transcription came up simultaneously at the DP stage and peaked at stage 3 to 4. These data suggest that functional maturation of Th cells occurs over an extended period in differentiation, stages 1 to 4, and coincides with a gradual increase in activation markers. After completion of functional differentiation, at stage 5, in vivo IL-2 mRNA transcription and CD69 expression are down-regulated, and the cells become functionally resting naive T cells expressing CD45RA+.
Interference of distinct invariant chain regions with superantigen contact area and antigenic peptide binding groove of HLA-DR.
Authors: Vogt A B , Stern L J , Amshoff C , Dobberstein B , Hämmerling G J , Kropshofer H 
Published: December 2022

Abstract
In the endoplasmic reticulum, MHC class II alpha beta dimers associate with the trimeric invariant chain (li), generating a nine-subunit (alpha beta li)3 complex. In the presence of li, the peptide binding groove is blocked, so that loading with self or antigenic peptides can only occur after proteolytic removal of li in specialized post-Golgi compartments. The class II-associated invariant chain peptide region of li (about residues 81-104) is known to mediate binding to class II molecules and blockade of the groove, but this does not exclude additional contact sites for li. Using a set of overlapping li peptides and recombinant soluble li, we demonstrate here that a large segment of li encompassing approximately residues 71 to 128 interacts with HLA-DR molecules. The N- and C-terminal regions of this li segment appear to bind outside the peptide groove to the contact area for the staphylococcal superantigen Staphylococcus aureus enterotoxin B on the alpha 1 domain. The core region of this segment (residues 95-108) prevents binding of antigenic peptides, probably by interaction with the peptide groove. Occupation of the groove with antigenic peptides abolishes binding not only of the core region, but also that of those li peptides that bind outside the groove. These findings suggest the existence of distinct conformational states of class II molecules, with li binding preferentially to one form.
Identification of an HLA-A11-restricted epitope from the tandem repeat domain of the epithelial tumor antigen mucin.
Authors: Doménech N , Henderson R A , Finn O J 
Published: December 2022

Abstract
Epithelial cell mucin encoded by the MUC-1 gene is overexpressed and aberrantly glycosylated on pancreatic, breast, and ovarian cancers as well as on multiple myelomas. It is recognized by patients' Ab and by T cells derived from tumor-draining lymph nodes. The T cell recognition is not MHC restricted and is specific for an epitope previously localized to the immunodominant tandem repeat region of the native mucin molecule. In search of possible MHC-restricted epitopes in the same immunodominant region, we synthesized a panel of overlapping, nine-amino acid long peptides spanning the MUC-1 tandem repeat and first examined their binding to specific human MHC class I molecules using two independent flow cytometry-based assay systems. This approach identified one peptide, p9-17 (STAPPAHGV), that bound to HLA-A1, -A2.1, -A3, and -A11. Measurements of the affinity of binding to each of these alleles, using a quantitative molecular binding assay, indicated that only the relative binding affinity to HLA-A11 was close to immunogenic values. We tested the immunogenicity of p9-17 in vitro. We detected a secondary T cell response specific for p9-17 in lymph nodes from an HLA-A11 breast cancer patient. Moreover, CTL specific for p9-17 peptide could be generated from PBL in several healthy HLA-A11 donors by primary in vitro stimulation.
The role of monocyte chemotactic protein-1 (MCP-1) in the recruitment of monocytes and CD4+ T cells during a pulmonary Cryptococcus neoformans infection.
Authors: Huffnagle G B , Strieter R M , Standiford T J , McDonald R A , Burdick M D , Kunkel S L , Toews G B 
Published: December 2022

Abstract
Cryptococcus neoformans is acquired via the respiratory tract and is the leading cause of fatal mycosis in AIDS. Development of a T cell-mediated pulmonary inflammatory response is critical for clearance of this pathogen; however, the chemotactic factors that mediate inflammatory cell recruitment into the lungs have not been identified. In the present study, the bronchoalveolar lavage (BAL) fluid levels of the C-C chemokine monocyte chemotactic protein-1 (MCP-1) and the recruitment of inflammatory cells both increased following pulmonary infection with C. neoformans. The kinetics of MCP-1 production in the lungs correlated most closely with the recruitment of CD4+ T cells and monocytes/macrophages. Administration of neutralizing anti-MCP-1 Abs in vivo reduced the BAL fluid levels of MCP-1, decreased the recruitment of both macrophages (&gt; 95%) and CD4+ T cells (76 +/- 9%), and inhibited cryptococcal clearance. Although no in vitro neutrophil or B cell chemotactic activity has been reported for MCP-1, recruitment of these leukocytes was also decreased in anti-MCP-1-treated mice (most likely an indirect effect of reducing the number of CD4+ T cells and macrophages). Neutralization of MCP-1 also resulted in decreased BAL fluid levels of TNF-alpha and IL-6. This is the first demonstration of a role for MCP-1 in clearance of an infection, and provides direct evidence that MCP-1 plays a critical role in the T cell-dependent immune response to C. neoformans.
Increased susceptibility of fas mutant MRL-lpr/lpr mice to staphylococcal enterotoxin B-induced septic shock.
Authors: Mountz J D , Baker T J , Borcherding D R , Bluethmann H , Zhou T , Edwards C K 
Published: December 2022

Abstract
MRL-lpr/lpr mice are defective in the fas Ag/APO-1 apoptosis gene (CD95). Using the hepatotoxin D-galactosamine (D-GalNH2), we demonstrate that MRL-lpr/lpr mice have an increased susceptibility to staphylococcal enterotoxin B (SEB)-induced lethal shock, which causes them to exhibit the septic shock-like behaviors of fur ruffling and listlessness, and death occurs within 8 to 18 h. SEB susceptibility is greater in V beta 8.2 TCR transgenic MRL-lpr/lpr mice than in nontransgenic mice. In studies designed to elucidate the molecular pathways of SEB-induced septic shock, we found that C57Bl/6.Ab0/Ab0, MHC class II-deficient "C2D" mice, but not C57Bl/6-(+/+) mice, are nonresponsive to challenge with SEB. C2D mice, backcrossed with the fas mutation resulting in double-knockout C2D;lpr/lpr mice, are more susceptible to challenge with SEB/D-GalNH2. The LD50s for C57Bl/6.C3H-gld/gld "fas ligand-mutant mice" challenged with SEB/D-GalNH2 were comparable to C57Bl/6.MRL-lpr/lpr and MRL-lpr/lpr mice, suggesting that reciprocal mutations in either fas or fas ligand increases susceptibility to bacterial superantigens (SAGs). SEB-induced lethal shock can be reversed by treatment with Abs to V beta 8 TCR, MHC class II Ia+, IL-2, and TNF-alpha, by the immunosuppressant cyclosporin A, or by treatment with carbocyclic nucleoside analogues. These data indicate that SAG-induced septic shock is dependent on interactions with the TCR and MHC class II Ags, and they also suggest a critical role for a functional fas and/or fas ligand in resistance to SAG-induced septic shock.
High level monocyte chemoattractant protein-1 expression in transgenic mice increases their susceptibility to intracellular pathogens.
Authors: Rutledge B J , Rayburn H , Rosenberg R , North R J , Gladue R P , Corless C L , Rollins B J 
Published: December 2022

Abstract
We have constructed transgenic mice in which the mouse mammary tumor virus long terminal repeat controls the expression of murine monocyte chemoattractant protein-1 (MCP-1). Several independently derived lines of transgenic mice constitutively expressed MCP-1 protein in a variety of organs. Protein extracts from these organs had substantial in vitro monocyte chemoattractant activity that was neutralized by an anti-MCP-1 Ab, indicating that transgenic MCP-1 protein is biologically active. However, no transgenic mouse at any age displayed monocyte infiltrates in MCP-1-expressing organs. Two transgenic lines had circulating MCP-1 levels of 13 to 26 ng/ml, which is a concentration sufficient to induce maximal monocyte chemotaxis in vitro. These transgenic lines showed a 1 to 1.5 log greater sensitivity to infection with Listeria monocytogenes and Mycobacterium tuberculosis. A third transgenic line had lower serum levels of MCP-1 and was resistant to L. monocytogenes. The results suggest that this transgenic model is one of monocyte nonresponsiveness to locally produced MCP-1 due to either receptor desensitization or neutralization of a chemoattractant gradient by high systemic concentrations of MCP-1. Regardless of the mechanism, the data indicate that constitutively high levels of MCP-1 expression do not induce monocytic infiltrates, and that MCP-1 is involved in the host response to intracellular pathogens.