bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immobilized IL-8 Triggers Progressive Activation of Neutrophils Rolling In Vitro on P-Selectin and Intercellular Adhesion Molecule-1
Authors: DiVietro Jeffrey A. , Smith McRae J. , Smith Bryan R. E. , Petruzzelli Lilli , Larson Richard S. , Lawrence Michael B. 
Published: April 2014

AbstractThe chemokine IL-8 is found on the luminal side of vascular endothelial cells, where it is postulated to be immobilized during inflammation. In this study, we observed that immobilized IL-8 can stimulate neutrophils to firmly adhere to a substrate containing ICAM-1 in a static adhesion assay. Soluble IL-8 was then perfused over neutrophils rolling on P-selectin (P-sel) and ICAM-1, confirming that IL-8 in solution can quickly cause rolling neutrophils to arrest. To mimic a blood vessel wall with IL-8 expressed on the luminal surface of endothelial cells, IL-8 was immobilized along with P-sel and ICAM-1 at defined site densities to a surface. Neutrophils rolled an average of 200 μm on surfaces of P-sel, ICAM-1, and IL-8 before firmly adhering through ICAM-1-β2 integrin interactions at 2 dynes/cm2 wall shear stress. Increasing the density of IL-8 from 60 to 350 sites/μm2 on the surface decreased by 50% the average distance and time the neutrophils rolled before becoming firmly adherent. Temporal dynamics of ICAM-1-β2 integrin interactions of rolling neutrophils following IL-8 exposure suggest the existence of two classes of β2 integrin-ICAM-1 interactions, a low avidity interaction with a 65% increase in pause times as compared with P-sel-P-sel glycoprotein ligand-1 interactions, and a high avidity interaction with pause times 400% greater than the selectin interactions. Based on the proportionality between IL-8 site density and time to arrest, it appears that neutrophils may need to sample a critical number of IL-8 molecules presented by the vessel wall before forming a sufficient number of high avidity β2 integrin bonds for firm adhesion.
Characterization of Mutations, Including a Novel Regulatory Defect in the First Intron, in Bruton’s Tyrosine Kinase Gene from Seven Korean X-Linked Agammaglobulinemia Families
Authors: Jo Eun-Kyeong , Kanegane Hirokazu , Nonoyama Shigeaki , Tsukada Satoshi , Lee Jae-Ho , Lim Kyu , Shong Minho , Song Chang-Hwa , Kim Hwa-Jung , Park Jeong-Kyu , Miyawaki Toshio 
Published: April 2014

Abstract
In this report, we describe seven mutations, including a novel single base pair substitution in intron 1, of the Bruton’s tyrosine kinase (Btk) gene found in 12 Korean patients with X-linked agammaglobulinemia. Various mutations, including three novel genetic alterations, were discovered using single-strand conformation polymorphism analysis and direct DNA sequencing. The effect of the intron 1 point mutation (intron 1 +5G→A) was further evaluated using reporter constructs. Using luciferase assay experiments, we showed that the transcriptional activity of the mutant was significantly lower than in normal counterparts, indicating that the intronic mutation was functional. In addition, DNase I footprinting analysis showed that a single protected region spanning the position +3 to +15 bp hybridized with a mutant-specific probe, but not with a wild-type probe. EMSA indicated that a distinct nuclear protein has the ability to bind the mutant oligonucleotides to produce a new DNA-protein complex. We also observed decreased expression of Btk proteins in monocytes of patients having the point mutation in intron 1. Taken together with the functional analysis, our results strongly suggest the existence of a novel cis-acting element, which might be involved in the down-regulation of Btk gene transcription. Precise definition of the regulatory defect in the Btk intron 1 may provide valuable clues toward elucidating the pathogenesis of X-linked agammaglobulinemia.
Soluble CD137 (4-1BB) Ligand Is Released Following Leukocyte Activation and Is Found in Sera of Patients with Hematological Malignancies
Authors: Salih Helmut R. , Schmetzer Helga M. , Burke Christine , Starling Gary C. , Dunn Robert , Pelka-Fleischer Renate , Nuessler Volkmar , Kiener Peter A. 
Published: April 2014

Abstract
Expression of CD137 ligand (4-1BBL), a member of the TNF family of proteins, has been reported on several types of APCs, various carcinoma cells, and can be induced on activated T cells. In this study, we report that the soluble ligand was released constitutively at low levels from leukocytes and at higher levels following cellular activation. Release from cells was blocked by addition of a metalloproteinase inhibitor which concomitantly caused the accumulation of 4-1BBL on the cell surface. In addition, we show that a soluble form of 4-1BBL was present at high levels in the sera of some patients with various hematological diseases, but only at low levels in healthy donors. Soluble 4-1BBL was active in that it competed with recombinant 4-1BBL for binding to the 4-1BB receptor and was able to costimulate IL-2 and IFN-γ release from peripheral T cells. These results indicate that the release of soluble 4-1BBL from the cell surface is mediated by one or more sheddases and likely regulates 4-1BB-4-1BBL interactions between cells in vivo. Cleavage of 4-1BBL to an active soluble form would alter both proximal and distal cellular responses, including cell survival and costimulatory or inflammatory responses, that are mediated through the 4-1BB pathway. This, in turn, would likely alter disease progression or outcome.
Role of Cyclin Kinase Inhibitor p21 in Systemic Autoimmunity
Authors: Santiago-Raber Marie-Laure , Lawson Brian R. , Dummer Wolfgang , Barnhouse Marlene , Koundouris Stefanos , Wilson Curtis B. , Kono Dwight H. , Theofilopoulos Argyrios N. 
Published: April 2014

Abstract
The cyclin kinase inhibitor protein p21 affects multiple processes relevant to the immune system, including cell cycle progression, replicative senescence, hemopoietic stem cell quiescence, and apoptosis. Therefore, malfunction of this protein may be a contributor to the pathogenesis of systemic autoimmunity. Here, we report that mixed background p21-deficient 129/Sv × C57BL/6 mice showed increased in vitro and in vivo T cell cycling and activation, moderate hypergammaglobulinemia and, at low penetrance, anti-chromatin autoantibodies. Homeostatic anti-self MHC/peptide ligand-induced proliferation of p21-deficient T cells was also enhanced. However, lymphoid organ enlargement was very mild, presumably due to increased apoptosis of the rapidly dividing cells. Moreover, the older p21-deficient mice had kidney pathology representing a similar, but slightly more advanced, state than that seen in the control mice. The timing and severity of the above serologic, cellular, and histologic manifestations in p21-deficient mice were unaffected by gender. Thus, p21 deficiency significantly enhances T cell activation and homeostatic proliferation, and can induce mild autoimmune manifestations at a low incidence without gender bias, but does not in itself generate the full spectrum of lupus-like disease.
HLA-DR Modulates Autoantibody Repertoire, But Not Mortality, in a Humanized Mouse Model of Systemic Lupus Erythematosus
Authors: Paisansinsup Tawatchai , Vallejo Abbe N. , Luthra Harvinder , David Chella S. 
Published: April 2014

Abstract
To evaluate the disease-modulating role of HLA-DR2 and DR3 molecules, which have been associated with systemic lupus erythematosus, a humanized mouse model was examined. HLA-DR2 (DRB1*1502)- and DR3 (DRB1*0301)-transgenic mice were backcrossed to the New Zealand Mixed 2410 (NZM 2410, H2z) strain. Seventh generation DR2 and DR3 transgene-positive animals along with their transgene-negative littermates and the parental strain NZM2410 were monitored for proteinuria, azotemia, autoantibody production, development of nephritis, and mortality. The results showed no significant differences in proteinuria, azotemia, or mortality between the backcrosses with and without HLA-DR2 or HLA-DR3. However, the genetic analysis of different backcrosses showed that heterozygosity at the endogenous H2-E locus (Ez/Eb) was strongly linked with acceleration of lupus nephritis in both HLA-DR2 and HLA-DR3 transgenics. More importantly, the presence of the HLA-DR2, but not the HLA-DR3, transgene significantly enhanced the production of anti-dsDNA, but not anti-ssDNA, anti-histone-dsDNA complex, or anti-histone, Abs. In contrast, neither HLA-DR2 nor HLA-DR3 influenced the development of glomerulonephritis or the degree of immune complex deposition. Moreover, nephritic kidneys from mice with and without HLA-DR2 or HLA-DR3 transgenes showed similar patterns of cytokine expression. Collectively, these findings provide molecular evidence that the association of HLA-DR2 or HLA-DR3 with lupus susceptibility is related to the type of autoantibody rather than to disease mortality. The use of a humanized mouse model provides a way of dissecting the roles of human MHC genes in systemic lupus erythematosus pathogenesis.
Neutralization of the Chemokine CXCL10 Reduces Inflammatory Cell Invasion and Demyelination and Improves Neurological Function in a Viral Model of Multiple Sclerosis
Authors: Liu Michael T. , Keirstead Hans S. , Lane Thomas E. 
Published: April 2014

Abstract
Intracerebral infection of mice with mouse hepatitis virus (MHV) results in an acute encephalomyelitis followed by a chronic demyelinating disease with clinical and histological similarities with the human demyelinating disease multiple sclerosis (MS). Following MHV infection, chemokines including CXC chemokine ligand (CXCL)10 (IFN inducible protein 10 kDa), CXCL9 (monokine induced by IFN-γ), and CC chemokine ligand 5 (RANTES) are expressed during both acute and chronic stages of disease suggesting a role for these molecules in disease exacerbation. Previous studies have shown that during the acute phase of infection, T lymphocytes are recruited into the CNS by the chemokines CXCL10 and CXCL9. In the present study, MHV-infected mice with established demyelination were treated with antisera against these two chemokines, and disease severity was assessed. Treatment with anti-CXCL10 reduced CD4+ T lymphocyte and macrophage invasion, diminished expression of IFN-γ and CC chemokine ligand 5, inhibited progression of demyelination, and increased remyelination. Anti-CXCL10 treatment also resulted in an impediment of clinical disease progression that was characterized by a dramatic improvement in neurological function. Treatment with antisera against CXCL9 was without effect, demonstrating a critical role for CXCL10 in inflammatory demyelination in this model. These findings document a novel therapeutic strategy using Ab-mediated neutralization of a key chemokine as a possible treatment for chronic human inflammatory demyelinating diseases such as MS.
Up-Regulation of Fas Ligand Expression by Human Cytomegalovirus Immediate-Early Gene Product 2: A Novel Mechanism in Cytomegalovirus-Induced Apoptosis in Human Retina
Authors: Chiou Shih-Hwa , Liu Jorn-Hon , Hsu Wen-Ming , Chen Steve S.-L. , Chang Sui-Yuan , Juan Li-Jung , Lin Jung-Chun , Yang Yu-Ting , Wong Wing-Wai , Liu Cheng-Yi , Lin Young-Sun , Liu Wu-Tse , Wu Cheng-Wen 
Published: April 2014

Abstract
Human CMV (HCMV) is an important pathogen that causes widespread diseases in immunocompromised individuals. Among the opportunistic HCMV infections, HCMV retinitis is most common in transplant recipients and AIDS patients. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis remains unresolved. Here, we report that viral immediate-early gene product 2 (IE2), but not IE1, up-regulates the Fas ligand (FasL) expression in HCMV-infected human retinal pigment epithelium cells. Increased secretion of FasL from virally infected cells into cultured medium was observed upon HCMV infection. The capability of such cell-free medium to induce apoptosis of Fas (CD95)-expressing Jurkat cells further implies that Fas-FasL interaction might mediate cell death in the lesion of HCMV retinitis. To support this idea, we observed augmented soluble FasL levels in vitreous from AIDS patients with HCMV retinitis as compared with that from AIDS patients without HCMV infection. In addition, by in situ hybridization and immunohistochemistry, we detected enhanced signals of FasL, the existence of viral IE Ags and apoptotic cells at the same sites in the lesion of HCMV-infected retina. These results strongly suggest that IE2 induction of FasL expression in human retina might be an important event that takes place in the early stage of infection and finally leads to visual loss in individuals affiliated with HCMV retinitis.
IL-12 Administration Reveals Diabetogenic T Cells in Genetically Resistant I-Eα-Transgenic Nonobese Diabetic Mice: Resistance to Autoimmune Diabetes Is Associated with Binding of Eα-Derived Peptides to the I-Ag7 Molecule
Authors: Trembleau Sylvie , Gregori Silvia , Penna Giuseppe , Gorny Irmina , Adorini Luciano 
Published: April 2014

Abstract
Nonobese diabetic (NOD) and NOD-DRα transgenic (tg) mice, expressing Aαd:Aβg7 and Aαd:Aβg7 plus DRα:Eβg7 class II molecules, respectively, both develop insulin-dependent diabetes mellitus (IDDM), whereas NOD-Eα tg mice expressing Aαd:Aβg7 plus Eα:Eβg7 are protected. We show that IL-12 administration induces rapid IDDM onset in NOD-DRα but fails to provoke insulitis and diabetes in NOD-Eα tg mice. Nevertheless, T cells from IL-12-treated NOD-Eα tg mice secrete IFN-γ and transfer IDDM to NOD-SCID and NOD-Eα-SCID recipients, demonstrating the presence of peripheral diabetogenic Th1 cells in the protected mice. Surprisingly, regulatory cells were undetectable. Moreover, Eα:Eβg7 could substitute for DRα:Eβg7 in Ag presentation, arguing against mechanisms of protection involving capture of diabetogenic I-Ag7-restricted epitopes by Eα:Eβg7molecules. Interestingly, the expression of naturally processed epitopes derived from DRα- and Eα-chains bound to I-Ag7 is different in the two strains of tg mice, and the difference is enhanced by IL-12 administration. I-Ag7 molecules from both NOD-DRα and NOD-Eα tg mice present the conserved DRα/Eα 52-68 sequence, at high and low levels, respectively. In addition, only IDDM-resistant NOD-Eα tg mice possess APCs bearing Eα65-77/I-Ag7 complexes, which tolerize the specific T cells. This is associated with the selective inhibition of the response to insulinoma-associated protein 2 (IA-2), an autoantigen in IDDM. Our results support protective mechanisms based on I-Ag7 blockade by peptides unique to the Eα-chain, such as Eα65-77 and/or tolerance of diabetogenic T cells cross-reactive with Eα-peptide/I-Ag7 complexes.
Distinct Clonal Ig Diversification Patterns in Young Appendix Compared to Antigen-Specific Splenic Clones
Authors: Sehgal Devinder , Obiakor Harold , Mage Rose G. 
Published: April 2014

AbstractThe young rabbit appendix is a dynamic site for primary B cell repertoire development. To study diversification patterns during clonal expansion, we collected single appendix B cells from 3- to 9-wk-old rabbits and sequenced rearranged H and L chain genes. Single cells obtained by hydraulic micromanipulation or laser capture microdissection were lysed, PCR amplified, and products directly sequenced. Gene conversion-like changes occurred in rearranged H and L chain sequences by 3–4 wk of age. Somatic mutations were found in the D regions that lack known conversion donors and probably also occurred in the V genes. A few small sets of clonally related appendix B cells were found at 3–5 wk; by 5.5 wk, some larger clones were recovered. The diversification patterns in the clones from appendix were strikingly different from those found previously in splenic germinal centers where an immunizing Ag was driving the expansion and selection process toward high affinity. Clonally related appendix B cells developed different amino acid sequences in each complementarity-determining region (CDR) including CDR3, whereas dominant clones from spleen underwent few changes in CDR3. The variety of combining sites generated by diversification within individual clones suggests that at least some clonal expansion and selection, known to require normal gut flora, may be driven through indirect effects of microbial components rather than solely by their recognition as specific foreign Ags. This diversity of combining sites within B cell clones supports the proposed role of appendix in generating the preimmune repertoire.
CD40 Ligation Conditions Dendritic Cell Antigen-Presenting Function Through Sustained Activation of NF-κB
Authors: O’Sullivan Brendan John , Thomas Ranjeny 
Published: April 2014

AbstractAn understanding of the biochemical control of dendritic cell (DC) differentiation/activation is essential for improving T cell immunity by various immunotherapeutic approaches, including DC immunization. Ligation of CD40 enhances DC function, including conditioning for CTL priming. NF-κB, and particularly RelB, is an essential control pathway for myeloid DC differentiation. Furthermore, RelB regulates B cell Ag-presenting function. We hypothesized that CD40 ligand (CD40L) and TNF-α, which differ in their capacity to condition DC, would also differ in their capacity to activate NF-κB. DC differentiated for 2 days from monocytes in the presence of GM-CSF and IL-4 were used as a model, as NF-κB activity was constitutively low. The capacity of DC to activate T cells following CD40L treatment was enhanced compared with TNF-α treatment, and this was NF-κB dependent. Whereas RelB/p50 translocation induced by TNF-α was attenuated after 6 h, RelB/p50 nuclear translocation induced by CD40L was sustained for at least 24 h. The mechanism of this difference related to enhanced degradation of IκBα following CD40L stimulation. However, NF-κB activation induced by TNF-α could be sustained by blocking autocrine IL-10. These data indicate that NF-κB activation is essential for T cell activation by DC, and that this function is enhanced if DC NF-κB activation is prolonged. Because IL-10 moderates DC NF-κB activation by TNF-α, sustained NF-κB activation can be achieved by blocking IL-10 in the presence of stimuli that induce TNF-α.
A Rational Strategy to Design Multiepitope Immunogens Based on Multiple Th Lymphocyte Epitopes
Authors: Livingston Brian , Crimi Claire , Newman Mark , Higashimoto Yuichiro , Appella Ettore , Sidney John , Sette Alessandro 
Published: April 2014

AbstractFour HLA-DR-restricted HIV-derived Th lymphocyte (HTL) epitopes cross-reactive with the murine I-Ab class II molecule were used to evaluate different vaccine design strategies to simultaneously induce multiple HTL responses. All four epitopes were immunogenic in H-2b mice, demonstrating the feasibility of murine models to evaluate epitope-based vaccines destined for human use. Immunization with a pool of peptides induced responses against all four epitopes; illustrating immunodominance does not prevent the induction of balanced multispecific responses. When different delivery systems were evaluated, a multiple Ag peptide construct was found to be less efficient than a linear polypeptide encompassing all four epitopes. Further characterization of linear polypeptide revealed that the sequential arrangement of the epitopes created a junctional epitope with high affinity class II binding. Disruption of this junctional epitope through the introduction of a GPGPG spacer restored the immunogenicity against all four epitopes. Finally, we demonstrate that a GPGPG spacer construct can be used to induce HTL responses by either polypeptide or DNA immunization, highlighting the flexibility of the approach.
Id2 Negatively Regulates B Cell Differentiation in the Spleen
Authors: Becker-Herman Shirly , Lantner Frida , Shachar Idit 
Published: April 2014

Abstract
Early stages of B cell development occur in the bone marrow, resulting in formation of immature B cells. These immature cells migrate to the spleen where they differentiate into mature (B2 or marginal zone (MZ)) cells. This final maturation step is crucial for B cells to become responsive to Ags and to participate in the immune response. Id2 is a helix-loop-helix protein that lacks a DNA-binding region; and therefore, inhibits basic helix-loop-helix functions in a dominant negative manner. In this study, we show that Id2 expression is down-regulated during differentiation of immature B cells into mature B2 and MZ B cells. The high levels of Id2 expressed in the immature B cells result in inhibition of E2A binding activity to an E2 box site. Moreover, mice lacking Id2 show an elevation in the proportion of mature B2 cells in the spleen, while the MZ population in these mice is almost absent. Thus, Id2 acts as a regulator of the differentiation of immature B cells occurring in the spleen, it negatively controls differentiation into mature B2 cells while allowing the commitment to MZ B cells. In the absence of Id2 control, the unregulated differentiation is directed toward the mature B2 population.
The Mechanism Underlying T Cell Help for Induction of an Antigen-Specific In Vivo Humoral Immune Response to IntactStreptococcus pneumoniaeIs Dependent on the Type of Antigen
Authors: Wu Zheng-Qi , Shen Yi , Khan Abdul Q. , Chu Ching-Liang , Riese Richard , Chapman Harold A. , Kanagawa Osami , Snapper Clifford M. 
Published: April 2014

AbstractLittle is known concerning the role of T cells in regulating an anti-polysaccharide Ig response to an intact pathogen. We previously reported that the in vivo Ig responses to Streptococcus pneumoniae (strain R36A), specific for pneumococcal surface protein A (PspA) and for the phosphorylcholine (PC) determinant of C-polysaccharide, were both dependent on TCR-αβ+ T cells and B7-dependent costimulation, although only PspA-specific memory was generated. In this report, we show that the T cell help underlying these two Ag-specific Ig responses is distinct. Using H-Y-specific T cell transgenic mice made “nonleaky” by crossing with mice genetically deficient for TCR-α, we demonstrate that the T cell help for the anti-PC, in contrast to the anti-PspA, response is TCR-nonspecific and occurs normally in the absence of germinal center formation, although it is still dependent on B7-dependent costimulation. Consistent with these data, we demonstrate, using cathepsin S−/− mice, that although the anti-PC response is largely dependent on CD4+ T cells, there is a reduced (or lack of) dependence, relative to the anti-PspA response, on the generation of new peptide-MHC class II complexes. In this regard, the T cell help for an optimal anti-PC response is delivered more rapidly than that required for an optimal anti-PspA response. Collectively, these data demonstrate a novel accelerated TCR-nonspecific B7-dependent form of T cell help for augmenting a polysaccharide-specific Ig response to an intact bacterium without the generation of memory.