bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD45 Regulates Tyrosine Phosphorylation of CD22 and Its Association with the Protein Tyrosine Phosphatase SHP-1
Authors: Greer Susanna F. , Justement Louis B. 
Published: December 2022

AbstractCross-linking of CD45 induced capping and physical sequestration from CD22 leading to an increase in tyrosine phosphorylation of CD22 and SHP-1 recruitment. Additionally, CD22 isolated from a CD45-deficient B cell line exhibited increased basal/inducible tyrosine phosphorylation and enhanced recruitment of SHP-1 compared with CD22 isolated from CD45-positive parental cells. Subsequent experiments were performed to determine whether enhanced SHP-1 recruitment to CD22 is responsible for attenuation of receptor-mediated Ca2+ responses in CD45-deficient cells. Catalytically inactive SHP-1 expressed in CD45-deficient cells interacted with CD22 and decreased phosphatase activity in CD22 immunoprecipitates to levels that were comparable to those in CD45-positive cells. Expression of catalytically inactive SHP-1 restored intracellular mobilization of Ca2+ in response to MHC class II cross-linking, but did not affect B cell Ag receptor- or class II-mediated Ca2+ influx from the extracellular space. These results indicate that CD45 regulates tyrosine phosphorylation of CD22 and binding of SHP-1. The data further indicate that enhanced recruitment and activation of SHP-1 in CD45-deficient cells affect intracellular mobilization of Ca2+, but are not responsible for abrogation of receptor-mediated Ca2+ influx from the extracellular space.
Mice Deficient in CD4 T Cells Have Only Transiently Diminished Levels of IFN-γ, Yet Succumb to Tuberculosis
Authors: Caruso Amy Myers , Serbina Natalya , Klein Edwin , Triebold Karla , Bloom Barry R. , Flynn JoAnne L. 
Published: December 2022

AbstractCD4 T cells are important in the protective immune response against tuberculosis. Two mouse models deficient in CD4 T cells were used to examine the mechanism by which these cells participate in protection against Mycobacterium tuberculosis challenge. Transgenic mice deficient in either MHC class II or CD4 molecules demonstrated increased susceptibility to M. tuberculosis, compared with wild-type mice. MHC class II−/− mice were more susceptible than CD4−/− mice, as measured by survival following M. tuberculosis challenge, but the relative resistance of CD4−/− mice did not appear to be due to increased numbers of CD4−8− (double-negative) T cells. Analysis of in vivo IFN-γ production in the lungs of infected mice revealed that both mutant mouse strains were only transiently impaired in their ability to produce IFN-γ following infection. At 2 wk postinfection, IFN-γ production, assessed by RT-PCR and intracellular cytokine staining, in the mutant mice was reduced by &gt;50% compared with that in wild-type mice. However, by 4 wk postinfection, both mutant and wild-type mice had similar levels of IFN-γ mRNA and protein production. In CD4 T cell-deficient mice, IFN-γ production was due to CD8 T cells. Thus, the importance of IFN-γ production by CD4 T cells appears to be early in infection, lending support to the hypothesis that early events in M. tuberculosis infection are crucial determinants of the course of infection.
Immune-Stimulating Complexes Induce an IL-12-Dependent Cascade of Innate Immune Responses
Authors: Smith Rosemary E. , Donachie Anne M. , Grdic Dubravka , Lycke Nils , Mowat Allan McI. 
Published: December 2022

AbstractThe development of subunit vaccines requires the use of adjuvants that act by stimulating components of the innate immune response. Immune-stimulating complexes (ISCOMS) containing the saponin adjuvant Quil A are potential vaccine vectors that induce a wide range of Ag-specific responses in vivo encompassing both humoral and CD4 and CD8 cell-mediated immune responses. ISCOMS are active by both parenteral and mucosal routes, but the basis for their adjuvant properties is unknown. Here we have investigated the ability of ISCOMS to recruit and activate innate immune responses as measured in peritoneal exudate cells. The i.p. injection of ISCOMS induced intense local inflammation, with early recruitment of neutrophils and mast cells followed by macrophages, dendritic cells, and lymphocytes. Many of the recruited cells had phenotypic evidence of activation and secreted a number of inflammatory mediators, including nitric oxide, reactive oxygen intermediates, IL-1, IL-6, IL-12, and IFN-γ. Of the factors that we investigated further only IL-12 appeared to be essential for the immunogenicity of ISCOMS, as IL-6- and inducible nitric oxide synthase knockout (KO) mice developed normal immune responses to OVA in ISCOMS, whereas these responses were markedly reduced in IL-12KO mice. The recruitment of peritoneal exudate cells following an injection of ISCOMS was impaired in IL-12KO mice, indicating a role for IL-12 in establishing the proinflammatory cascade. Thus, ISCOMS prime Ag-specific immune responses at least in part by activating IL-12-dependent aspects of the innate immune system.
Regulation of Inflammatory Responses by Oncostatin M
Authors: Wallace Philip M. , MacMaster John F. , Rouleau Katherine A. , Brown T. Joseph , Loy James K. , Donaldson Karen L. , Wahl Alan F. 
Published: December 2022

AbstractOncostatin M (OM) is a pleiotropic cytokine produced late in the activation cycle of T cells and macrophages. In vitro it shares properties with related proteins of the IL-6 family of cytokines; however, its in vivo properties and physiological function are as yet ill defined. We show that administration of OM inhibited bacterial LPS-induced production of TNF-α and lethality in a dose-dependent manner. Consistent with these findings, OM potently suppressed inflammation and tissue destruction in murine models of rheumatoid arthritis and multiple sclerosis. T cell function and Ab production were not impaired by OM treatment. Taken together these data indicate the activities of this cytokine in vivo are antiinflammatory without concordant immunosuppression.
IL-12, IFN-γ, and T Cell Proliferation to Measles in Immunized Infants
Authors: Gans Hayley A. , Maldonado Yvonne , Yasukawa Linda L. , Beeler Judy , Audet Susette , Rinki Mary M. , DeHovitz Ross , Arvin Ann M. 
Published: December 2022

Abstract
Measles infection in infants is associated with severe complications, and secondary infections are attributed to generalized immunosuppression. Measles binding to its monocyte receptor down-regulates IL-12 which is expected to diminish Th1-like cytokine responses, including IFN-γ. Whether young infants can be immunized effectively against measles is an important public health issue. We evaluated Ag-specific IL-12, IFN-γ, and T cell responses of infants at 6 (n = 60), 9 (n = 46), or 12 mo (n = 56) of age and 29 vaccinated adults. IL-12 and IFN-γ release by PBMC stimulated with measles Ag increased significantly after measles immunization in infants. IL-12 and IFN-γ concentrations were equivalent in younger and older infants, but IL-12 concentrations were significantly lower in infants than in adults (p = 0.04). IL-12 production by monocytes was down-regulated by measles; the addition of recombinant human IL-12 enhanced IFN-γ production by PBMC stimulated with measles Ag, but infant T cells released significantly less IFN-γ than adult T cells under this condition. Of particular interest, the presence of passive Abs to measles had no effect on the specific T cell proliferation or IFN-γ production after measles stimulation. Cellular immunity to measles infection and vaccination may be limited in infants compared with adults as a result of less effective IFN-γ and IL-12 production in response to measles Ags. These effects were not exaggerated in younger infants compared with effects in infants who were immunized at 12 mo. In summary, infant T cells were primed with measles Ag despite the presence of passive Abs, but their adaptive immune responses were limited compared with those of adults.
DNA Immunization with HIV-1tatMutated in thetransActivation Domain Induces Humoral and Cellular Immune Responses Against Wild-Type Tat
Authors: Caselli Elisabetta , Betti Monica , Grossi Maria Pia , Balboni Pier Giorgio , Rossi Cristina , Boarini Chiara , Cafaro Aurelio , Barbanti-Brodano Giuseppe , Ensoli Barbara , Caputo Antonella 
Published: December 2022

AbstractIntramuscular immunization of mice with plasmids encoding two transdominant negative mutants of the HIV-1 Tat protein (Tat22 and Tat22/37) elicited a humoral response to wild-type Tat that is comparable to that induced by inoculation of wild-type tat DNA or Tat protein. The percentage of the responders and the Ab titers continued to increase after three additional DNA boosts and pretreatment with bupivacaine at the site of inoculation, without a significant difference (p &gt; 0.05) among the three groups of mice immunized with mutant and wild-type tat genes. By utilizing synthetic peptides representing the amino acid sequence of Tat, one major B cell epitope was defined within the cysteine-rich domain of Tat. Anti-Tat IgG Abs directed against this epitope were found in mice immunized with all tat DNA constructs, whereas different Tat epitopes were detected in mice immunized with the Tat protein. Similarly, IgG2a was the predominant isotype in DNA-immunized mice, with both mutants and wild-type tat genes, as compared with protein immunization, which induced mostly IgG1 and IgG3. Sera from most immunized mice neutralized the effect of extracellular Tat in activating HIV-1 replication. A cellular response was also elicited as indicated by the proliferation of splenocytes when stimulated with wild-type Tat. These results indicate that the wild-type Tat Ag is recognized by Abs and T cells induced by DNA immunization with mutated tat genes, suggesting the possible use of these Tat transdominant mutants, lacking viral trans activation activity and capable of blocking wild-type Tat activity, in the development of an anti-HIV-1 vaccine.
Proteoglycan (Aggrecan)-Induced Arthritis in BALB/c Mice Is a Th1-Type Disease Regulated by Th2 Cytokines
Authors: Finnegan Alison , Mikecz Katalin , Tao Ping , Glant Tibor T. 
Published: December 2022

AbstractIn animal models of arthritis induced with Ags or infectious agents, disease severity correlates with a dominant Th1-type response characterized by a higher ratio of IFN-γ to IL-4. Analysis of BALB/c mice revealed a genetic predisposition toward developing CD4+ Th2-type responses. The bias toward an IL-4-dominant response in BALB/c mice protects mice from severe Lyme-induced arthritis and spontaneous autoimmune disease. Since BALB/c mice immunized with proteoglycan develop severe arthritis, we were interested in testing whether arthritis is associated with a Th2-type response and thus is different from other arthritic models. BALB/c mice immunized with proteoglycan generated a higher ratio of IFN-γ to IL-4 that peaks at the onset of arthritis. We investigated whether when Th1 cells were dominant, disease outcome could be modified with pharmacological amounts of Th2 cytokines. Treatment with IL-4 prevented disease and induced a switch from a Th1-type to a Th2-type response. Proinflammatory cytokine mRNA transcripts were reduced in joints of cytokine-treated mice. Th2 cytokine therapy at the time of maximum joint inflammation also suppressed symptoms of disease. Despite the predisposition of BALB/c mice to a Th2-type response, proteoglycan-induced arthritis is a Th1-type disease. The effectiveness of IL-4 treatment was particularly striking because in other models of arthritis, treatment in a similar manner with IL-4 was not sufficient to inhibit arthritis. The effective control of arthritis and the switch from a Th1 to Th2 response suggest that levels of endogenous IL-4 in BALB/c mice may increase their responsiveness to Th2 cytokine therapy.
Gamma-Irradiation Directly Affects the Formation of Coding Joints in SCID Cell Lines
Authors: Binnie Alexandra , Olson Stacy , Wu Gillian E. , Lewis Susanna M. 
Published: December 2022

Abstract
SCID mice have a defect in the catalytic subunit of the DNA-dependent protein kinase, causing increased sensitivity to ionizing radiation in all tissues and severely limiting the development of B and T cell lineages. SCID T and B cell precursors are unable to undergo normal V(D)J recombination: coding joint and signal joint products are less frequently formed and often will exhibit abnormal structural features. Paradoxically, irradiation of newborn SCID mice effects a limited rescue of T cell development. It is not known whether irradiation has a direct impact on the process of V(D)J joining, or whether irradiation of the thymus allows the outgrowth of rare recombinants. To investigate this issue, we sought to demonstrate an irradiation effect ex vivo. Here we have been able to reproducibly detect low-frequency coding joint products with V(D)J recombination reporter plasmids introduced into SCID cell lines. Exposure of B and T lineage cells to 100 cGy of gamma irradiation made no significant difference with respect to the number of coding joint and signal joint recombination products. However, in the absence of irradiation, the coding joints produced in SCID cells had high levels of P nucleotide insertion. With irradiation, markedly fewer P insertions were seen. The effect on coding joint structure is evident in a transient assay, in cultured cells, establishing that irradiation has an immediate impact on the process of V(D)J recombination. A specific proposal for how the DNA-dependent protein kinase catalytic subunit influences the opening of hairpin DNA intermediates during coding joint formation in V(D)J recombination is presented.
Early B Cell Factor Is an Activator of the B Lymphoid Kinase Promoter in Early B Cell Development
Authors: Åkerblad Peter , Sigvardsson Mikael 
Published: December 2022

AbstractEarly B cell factor (EBF) is a transcription factor suggested to be involved in the transcriptional control of several B cell restricted genes. EBF is also essential for B lymphocyte development because mice carrying a homologous disruption of the EBF gene lack mature B lymphocytes. This makes the identification of genetic targets for EBF important for the understanding of early B cell development. Examination of the nucleotide sequence of the B lymphoid kinase (Blk) promoter suggested the presence of an EBF binding site, and in vivo footprinting analysis showed that the site was protected from methylation in a pre-B cell line. EMSA indicated that recombinant and cellular EBF interact physically with this site; furthermore, transient transfections indicated that ectopic expression of EBF in nonlymphoid HeLa cells activate a Blk promoter-controlled reporter construct 9-fold. The defined EBF binding site was also important for the function of the Blk promoter in pre-B cells, because transient transfections of a reporter construct under the control of an EBF site-mutated Blk promoter displayed only 20–30% of the activity of the wild-type promoter. Furthermore, transient transfections in HeLa cells proposed that EBF and B cell-specific activator protein were able to cooperate in the activation of a Blk promoter-controlled reporter construct. These data indicate that EBF plays an important role in the regulation of the Blk promoter in early B cell development and that EBF and BSAP are capable to act in cooperation to induce a target gene.
Defects in the Generation of IFN-γ Are Overcome to Control Infection withLeishmania donovaniin CC Chemokine Receptor (CCR) 5-, Macrophage Inflammatory Protein-1α-, or CCR2-Deficient Mice
Authors: Sato Naoko , Kuziel William A. , Melby Peter C. , Reddick Robert Lee , Kostecki Vannessa , Zhao Weiguo , Maeda Nobuyo , Ahuja Sunil K. , Ahuja Seema S. 
Published: December 2022

AbstractWe investigated the immune responses in mice lacking CCR2, CCR5, or macrophage inflammatory protein-1α (MIP-1α), a ligand for CCR5, in two situations: following T cell stimulation or after challenge with Leishmania donovani, an intracellular microbe whose control is dependent on a Th1 immune response. Mice deficient in CCR5, MIP-1α, or CCR2 had reduced IFN-γ responses following ligation of the TCR. Reduced IFN-γ responses following PMA and ionomycin were also observed in CD8+ T cells of CCR5−/− and CCR2−/− mice. During the early phases of infection, all three knockout mice had low Ag-specific IFN-γ responses. However, this reduced IFN-γ response was overcome during a state of persistent Ag stimulation (chronic infection), and was not associated with an adverse parasitologic outcome in any of the gene-targeted mouse strains. To the contrary, during the late phase of infection, an exaggerated Ag-specific IFN-γ response was evident in CCR5−/− and MIP-1α−/− mice, and this correlated with an enhanced control of parasite replication. Although granuloma formation was abnormal in each of the knockout mice, there was no correlation between the number or architecture of the granulomas and parasite burden. Collectively, these findings indicate an important role for CCR5, MIP-1α, and CCR2 in granulomatous inflammation, and that CCR5 and MIP-1α, possibly acting through CCR5, might play a deleterious role in the outcome of chronic L. donovani infection. Our data also suggest that there might be cross-talk between TCR and chemokine receptor signaling pathways.
Development of Systemic Immunity to Glioblastoma Multiforme Using Tumor Cells Genetically Engineered to Express the Membrane-Associated Isoform of Macrophage Colony-Stimulating Factor
Authors: Graf Martin R. , Jadus Martin R. , Hiserodt John C. , Wepsic H. Terry , Granger Gale A. 
Published: December 2022

Abstract
We investigated the ability of Fischer rat T9 glioblastoma cells transduced with cDNA genes for the secreted (s) or membrane-associated (m) isoform of M-CSF to elicit an antitumor response when implanted into syngeneic animals. Intracranial (i.c.) implantation of 1 × 105 T9 cells expressing mM-CSF (T9/mM-CSF) resulted in 80% tumor rejection. Electron microscopy of the T9/mM-CSF tumor site, 2–4 days postimplantation, showed marked infiltration by macrophages, many of which were in physical contact with the T9/mM-CSF cells. Animals that rejected T9/mM-CSF cells were resistant to i.c. rechallenge with T9 cells, but not syngeneic MadB106 breast adenocarcinoma cells, suggesting that T9-specific immunity can be generated within the brain via the endogenous APCs. Intracranial injection of parental T9, vector control (T9/LXSN), or T9 cells secreting M-CSF (T9/sM-CSF) was 100% fatal. Subcutaneous injection of 1 × 107 T9/sM-CSF, T9/LXSN, or parental T9 cells resulted in progressive tumors. In contrast, T9/mM-CSF cells injected s.c. were destroyed in 7–10 days and animals developed systemic immunity to parental T9 cells. Passive transfer of CD3+ T cells from the spleens of immune rats into naive recipients transferred T9 glioma-specific immunity. In vitro, splenocytes from T9/mM-CSF-immunized rats specifically proliferated in response to various syngeneic glioma stimulator cells. However, only marginal T cell-mediated cytotoxicity was observed by these splenocytes in a CTL assay against T9 target cells, regardless of restimulation with T9 cells. Subcutaneous immunization with viable T9/mM-CSF cells was effective in eradicating i.c. T9 tumors.
Resistance of Rheumatoid Synovial Dendritic Cells to the Immunosuppressive Effects of IL-10
Authors: MacDonald Kelli P. A. , Pettit Allison R. , Quinn Christopher , Thomas Gregory J. , Thomas Ranjeny 
Published: December 2022

AbstractIL-10 down-regulates the APC function of many dendritic cells (DC), including human peripheral blood (PB) DC. In rheumatoid arthritis (RA), synovial fluid (SF) DC express markers of differentiation and are effective APC despite abundant synovial IL-10. The regulation of DC responsiveness to IL-10 was therefore examined by comparing the effect of IL-10 on normal PB and RA SF DC. Whereas IL-10 down-modulated APC function and MHC class II and B7 expression of PB DC, IL-10 had no such effect on SF DC. Since SF DC have differentiated in vivo in the presence of proinflammatory cytokines, PB DC were cocultured in the presence of IL-10 and either GM-CSF, IL-1β, TNF-α, IL-6, or TGF-β. GM-CSF, IL-1β, and TNF-α were all able to restore APC function. Whereas the effects of IL-10 on PB DC were shown to be mediated by IL-10R1, neither PB nor RA SF DC constitutively expressed IL-10R1 mRNA or detectable surface protein. In contrast, IL-10R1 protein was demonstrated in PB and SF DC whole cell lysates, suggestive of predominant intracellular localization of the receptor. Thus, DC responsiveness to IL-10 may be regulated through modulation of cell surface IL-10R1 expression or signaling.
Differential Regulation of Epithelial-Derived C-C Chemokine Expression by IL-4 and the Glucocorticoid Budesonide
Authors: Stellato Cristiana , Matsukura Satoshi , Fal Andrzej , White John , Beck Lisa A. , Proud David , Schleimer Robert P. 
Published: December 2022

AbstractAirway epithelial cells are a rich source of eosinophil-selective C-C chemokines. We investigated whether cytokines and the topical glucocorticoid budesonide differentially regulate RANTES, monocyte chemoattractant protein-4 (MCP-4), and eotaxin mRNA and protein expression in the human bronchial epithelial cell line BEAS-2B and in primary human bronchial epithelial cells by Northern blot analysis and ELISAs. Eotaxin and MCP-4 mRNA expression induced by TNF-α alone or in combination with IFN-γ was near-maximal after 1 h, peaked at 4 and 8 h, respectively, remained unchanged up to 24 h, and was protein synthesis independent. In contrast, RANTES mRNA was detectable only after 2 h and slowly increased to a peak at 24 h, and was protein synthesis dependent. Induction of eotaxin and MCP-4 mRNA showed a 10- to 100-fold greater sensitivity to TNF-α compared with RANTES mRNA. IL-4 and IFN-γ had selective effects on chemokine expression; IL-4 selectively up-regulated the expression of eotaxin and MCP-4 and potentiated TNF-α-induced eotaxin, while IFN-γ markedly potentiated only the TNF-α-induced expression of RANTES. Although budesonide inhibited the expression of chemokine mRNA to a variable extent, it effectively inhibited production of eotaxin and RANTES protein. Budesonide inhibited both RANTES- and eotaxin promoter-driven reporter gene activity. Budesonide also selectively accelerated the decay of eotaxin and MCP-4 mRNA. These results point to IL-4 as a possible mediator by which Th2 cells may induce selective production of C-C chemokines from epithelium and indicate that glucocorticoid inhibit chemokine expression through multiple mechanisms of action.