bluuebunny/crossref_metadata_2025_split huggingface dataset:
E2-2 Regulates the Expansion of Pro-B Cells and Follicular versus Marginal Zone Decisions
Authors: Wikström Ingela , Forssell Johan , Goncalves Mario , Colucci Francesco , Holmberg Dan 
Published: April 2014

Abstract
The E-proteins E2A, HeLa E-box binding protein, and E2-2 constitute a class of basic helix-loop-helix transcription factors that differentially affect B cell development. E2A is by far the most investigated and appears to operate at several levels during B cell ontogeny. Less is known concerning the role of the other E-proteins. To address the role of E2-2, we have performed transfers of fetal liver (FL) cells into irradiated Rag-deficient mice. Although the transfer of E2-2-deficient cells alone can reconstitute all B cell subpopulations, albeit with a moderate reduction in cellularity, E2-2-deficient cells have a disadvantage when transferred together with wild-type cells. Cultivation of E2-2−/− day 14.5 FL cells on stromal cells and IL-7 revealed a reduced frequency of responding B cell progenitors despite normal IL-7Rα surface expression. Real-time PCR analysis revealed that E2-2 mRNA expression is high at the pro-B cell stage and drops sharply at the pre-B cell stage, consistent with a role for E2-2 in pro-B cells. In contrast, E2A mRNA was most abundant in pre-B cells. Analysis of the peripheral repertoire revealed that mice reconstituted with E2-2−/− FL cells had an increased proportion of marginal zone (MZ) B cells. Interestingly, E2-2 mRNA was elevated ∼2-fold (p &lt; 0.01) in follicular compared with MZ B cells. Although E2A mRNA showed a similar tendency, the difference was not significant. Collectively, our findings indicate that E2-2 is required for optimal expansion of pro-B cells, and also influences the follicular vs MZ decision.
Melan-A/MART-1-Specific CD4 T Cells in Melanoma Patients: Identification of New Epitopes and Ex Vivo Visualization of Specific T Cells by MHC Class II Tetramers
Authors: Bioley Gilles , Jandus Camilla , Tuyaerts Sandra , Rimoldi Donata , Kwok William W. , Speiser Daniel E. , Tiercy Jean-Marie , Thielemans Kris , Cerottini Jean-Charles , Romero Pedro 
Published: April 2014

Abstract
Over the past decade, many efforts have been made to identify MHC class II-restricted epitopes from different tumor-associated Ags. Melan-A/MART-126–35 parental or Melan-A/MART-126–35(A27L) analog epitopes have been widely used in melanoma immunotherapy to induce and boost CTL responses, but only one Th epitope is currently known (Melan-A51–73, DRB1*0401 restricted). In this study, we describe two novel Melan-A/MART-1-derived sequences recognized by CD4 T cells from melanoma patients. These epitopes can be mimicked by peptides Melan-A27–40 presented by HLA-DRB1*0101 and HLA-DRB1*0102 and Melan-A25–36 presented by HLA-DQB1*0602 and HLA-DRB1*0301. CD4 T cell clones specific for these epitopes recognize Melan-A/MART-1+ tumor cells and Melan-A/MART-1-transduced EBV-B cells and recognition is reduced by inhibitors of the MHC class II presentation pathway. This suggests that the epitopes are naturally processed and presented by EBV-B cells and melanoma cells. Moreover, Melan-A-specific Abs could be detected in the serum of patients with measurable CD4 T cell responses specific for Melan-A/MART-1. Interestingly, even the short Melan-A/MART-126–35(A27L) peptide was recognized by CD4 T cells from HLA-DQ6+ and HLA-DR3+ melanoma patients. Using Melan-A/MART-125–36/DQ6 tetramers, we could detect Ag-specific CD4 T cells directly ex vivo in circulating lymphocytes of a melanoma patient. Together, these results provide the basis for monitoring of naturally occurring and vaccine-induced Melan-A/MART-1-specific CD4 T cell responses, allowing precise and ex vivo characterization of responding T cells.
TCRα Genes Direct MHC Restriction in the Potent Human T Cell Response to a Class I-Bound Viral Epitope
Authors: Miles John J. , Borg Natalie A. , Brennan Rebekah M. , Tynan Fleur E. , Kjer-Nielsen Lars , Silins Sharon L. , Bell Melissa J. , Burrows Jacqueline M. , McCluskey James , Rossjohn Jamie , Burrows Scott R. 
Published: April 2014

Abstract
The underlying generic properties of αβ TCRs that control MHC restriction remain largely unresolved. To investigate MHC restriction, we have examined the CTL response to a viral epitope that binds promiscuously to two human leukocyte Ags (HLAs) that differ by a single amino acid at position 156. Individuals expressing either HLA-B*3501 (156Leucine) or HLA-B*3508 (156Arginine) showed a potent CTL response to the 407HPVGEADYFEY417 epitope from EBV. Interestingly, the response was characterized by highly restricted TCR β-chain usage in both HLA-B*3501+ and HLA-B*3508+ individuals; however, this conserved TRBV9+ β-chain was associated with distinct TCR α-chains depending upon the HLA-B*35 allele expressed by the virus-exposed host. Functional assays confirmed that TCR α-chain usage determined the HLA restriction of the CTLs. Structural studies revealed significant differences in the mobility of the peptide when bound to HLA-B*3501 or HLA-B*3508. In HLA-B*3501, the bulged section of the peptide was disordered, whereas in HLA-B*3508 the bulged epitope adopted an ordered conformation. Collectively, these data demonstrate not only that mobile MHC-bound peptides can be highly immunogenic but can also stimulate an extremely biased TCR repertoire. In addition, TCR α-chain usage is shown to play a critical role in controlling MHC restriction between closely related allomorphs.
CD8+ IL-17-Producing T Cells Are Important in Effector Functions for the Elicitation of Contact Hypersensitivity Responses
Authors: He Donggou , Wu Lizhi , Kim Hee Kyung , Li Hui , Elmets Craig A. , Xu Hui 
Published: April 2014

AbstractAllergen-induced contact hypersensitivity (CHS) is a T cell-mediated delayed-type immune response which has been considered to be primarily mediated by CD8+ T cytotoxic type I (Tc1) cells. IFN-γ, the prototype Tc1 (Th1) cytokine, has been implicated as the primary inflammatory cytokine for CHS. In this study, we demonstrate that neutralization of IL-17 rather than IFN-γ suppresses the elicitation of CHS. The suppression does not result from inhibition of the proliferation of allergen-activated T cells. Allergen sensitization induces the development of distinct CD8+ T cell subpopulations that produce IFN-γ or IL-17. Although CD8+ IL-17-producing cells are stimulated by IL-23, they are inhibited by IL-12, a prototypical stimulator of IFN-γ-producing Tc1 cells. This indicates that CD8+ IL-17-producing cells are distinct from Tc1 cells and are important in effector functions at the elicitation of CHS. These studies provide insights into a novel mechanism for CHS.
The Study of High-Affinity TCRs Reveals Duality in T Cell Recognition of Antigen: Specificity and Degeneracy
Authors: Donermeyer David L. , Weber K. Scott , Kranz David M. , Allen Paul M. 
Published: April 2014

AbstractTCRs exhibit a high degree of Ag specificity, even though their affinity for the peptide/MHC ligand is in the micromolar range. To explore how Ag specificity is achieved, we studied murine T cells expressing high-affinity TCRs engineered by in vitro evolution for binding to hemoglobin peptide/class II complex (Hb/I-Ek). These TCRs were shown previously to maintain Ag specificity, despite having up to 800-fold higher affinity. We compared the response of the high-affinity TCRs and the low-affinity 3.L2 TCR toward a comprehensive set of peptides containing single substitutions at each TCR contact residue. This specificity analysis revealed that the increase in affinity resulted in a dramatic increase in the number of stimulatory peptides. The apparent discrepancy between observed degeneracy in the recognition of single amino acid-substituted Hb peptides and overall Ag specificity of the high-affinity TCRs was examined by generating chimeric peptides between the stimulatory Hb and nonstimulatory moth cytochrome c peptides. These experiments showed that MHC anchor residues significantly affected TCR recognition of peptide. The high-affinity TCRs allowed us to estimate the affinity, in the millimolar range, of immunologically relevant interactions of the TCR with peptide/MHC ligands that were previously unmeasurable because of their weak nature. Thus, through the study of high-affinity TCRs, we demonstrated that a TCR is more tolerant of single TCR contact residue substitutions than other peptide changes, revealing that recognition of Ag by T cells can exhibit both specificity and degeneracy.
Reversing Tumor Immune Suppression with Intratumoral IL-12: Activation of Tumor-Associated T Effector/Memory Cells, Induction of T Suppressor Apoptosis, and Infiltration of CD8+ T Effectors
Authors: Kilinc Mehmet O. , Aulakh Karanvir S. , Nair Raji E. , Jones Stacy A. , Alard Pascale , Kosiewicz Michele M. , Egilmez Nejat K. 
Published: April 2014

Abstract
A single intratumoral injection of IL-12 and GM-CSF-loaded slow-release microspheres induces T cell-dependent eradication of established primary and metastatic tumors in a murine lung tumor model. To determine how the delivery of cytokines directly to the microenvironment of a tumor nodule induces local and systemic antitumor T cell activity, we characterized therapy-induced phenotypic and functional changes in tumor-infiltrating T cell populations. Analysis of pretherapy tumors demonstrated that advanced primary tumors were infiltrated by CD4+ and CD8+ T cells with an effector/memory phenotype and CD4+CD25+Foxp3+ T suppressor cells. Tumor-associated effector memory CD8+ T cells displayed impaired cytotoxic function, whereas CD4+CD25+Foxp3+ cells effectively inhibited T cell proliferation demonstrating functional integrity. IL-12/GM-CSF treatment promoted a rapid up-regulation of CD43 and CD69 on CD8+ effector/memory T cells, augmented their ability to produce IFN-γ, and restored granzyme B expression. Importantly, treatment also induced a concomitant and progressive loss of T suppressors from the tumor. Further analysis established that activation of pre-existing effector memory T cells was short-lived and that both the effector/memory and the suppressor T cells became apoptotic within 4 days of treatment. Apoptotic death of pre-existing effector/memory and suppressor T cells was followed by infiltration of the tumor with activated, nonapoptotic CD8+ effector T lymphocytes on day 7 posttherapy. Both CD8+ T cell activation and T suppressor cell purge were mediated primarily by IL-12 and required IFN-γ. This study provides important insight into how local IL-12 therapy alters the immunosuppressive tumor milieu to one that is immunologically active, ultimately resulting in tumor regression.
Antibodies to Complement Receptor 3 Treat Established Inflammation in Murine Models of Colitis and a Novel Model of Psoriasiform Dermatitis
Authors: Leon Francisco , Contractor Nikhat , Fuss Ivan , Marth Thomas , Lahey Edward , Iwaki Shoko , la Sala Andrea , Hoffmann Victoria , Strober Warren , Kelsall Brian L. 
Published: April 2014

Abstract
Prior studies indicated the ability of Abs to complement receptor 3 (CR3, CD11b/CD18) to suppress the production of IL-12 from immune cells. Therefore, we tested the ability of an anti-CR3 Ab (clone M1/70) to treat established IL-12-dependent Th1-mediated inflammation in murine models. Systemic administration of anti-CR3 significantly ameliorated established intestinal inflammation following the intrarectal administration of trinitrobenzene sulfonic acid (TNBS-colitis), as well as colitis and skin inflammation in C57BL/10 RAG-2−/− mice reconstituted with CD4+CD45RBhigh T cells. The hyperproliferative skin inflammation in this novel murine model demonstrated many characteristics of human psoriasis, and was prevented by the adoptive transfer of CD45RBlow T cells. In vitro and in vivo studies suggest that anti-CR3 treatment may act, at least in part, by directly inhibiting IL-12 production by APCs. Administration of anti-CR3 may be a useful therapeutic approach to consider for the treatment of inflammatory bowel disease and psoriasis in humans.
CD4+CXCR4highCD69+ T Cells Accumulate in Lung Adenocarcinoma
Authors: Wald Ori , Izhar Uzi , Amir Gail , Avniel Shani , Bar-Shavit Yochai , Wald Hanna , Weiss Ido D. , Galun Eithan , Peled Amnon 
Published: April 2014

Abstract
The chemokine receptor CXCR4 is involved in the growth and metastasis of tumor cells. However, the expression of its ligand, the chemokine CXCL12, in tumors and its role in regulating the accumulation of immune cells within the tumors is not clear. Using ELISA and immunohistochemistry we found that CXCL12 is expressed in the majority of nonsmall cell lung cancer tissue sections obtained from stage IA to IIB nonsmall cell lung cancer patients undergoing operation. Histopathologic examination of these sections indicated that high CXCL12 expression correlated with increased tumor inflammation. In addition, disease recurrence rates in a subgroup of adenocarcinoma patients showed a tendency to correlate with high CXCL12 expression in the tumor. Isolation of adenocarcinoma-infiltrating immune cells demonstrated an increase in the percentage of CD4+CD69+CXCR4+ T cells as compared with normal lung tissue. About 30% of these cells expressed the regulatory T cell markers CD25high and FoxP3. The percentage of CD8 T cells within the tumor did not change, however; the percentage of NK and NK T cells was significantly reduced. In correlation with CXCR4 expression, CD4 T cells showed increased migration in response to CXCL12 compared with CD8 T cells and NK cells. Overall, these observations suggest that CXCL12 expression may influence tumor progression by shaping the immune cell population infiltrating lung adenocarcinoma tumors.
Genes within the Idd5 and Idd9/11 Diabetes Susceptibility Loci Affect the Pathogenic Activity of B Cells in Nonobese Diabetic Mice
Authors: Silveira Pablo A. , Chapman Harold D. , Stolp Jessica , Johnson Ellis , Cox S. Lewis , Hunter Kara , Wicker Linda S. , Serreze David V. 
Published: April 2014

Abstract
Autoreactive T cells clearly mediate the pancreatic β cell destruction causing type 1 diabetes (T1D). However, studies in NOD mice indicate that B cells also contribute to pathogenesis because their ablation by introduction of an Igμnull mutation elicits T1D resistance. T1D susceptibility is restored in NOD.Igμnull mice that are irradiated and reconstituted with syngeneic bone marrow plus NOD B cells, but not syngeneic bone marrow alone. Thus, we hypothesized some non-MHC T1D susceptibility (Idd) genes contribute to disease by allowing development of pathogenic B cells. Supporting this hypothesis was the finding that unlike those from NOD donors, engraftment with B cells from H2g7 MHC-matched, but T1D-resistant, nonobese-resistant (NOR) mice failed to restore full disease susceptibility in NOD.Igμnull recipients. T1D resistance in NOR mice is mainly encoded within the Idd13, Idd5.2, and Idd9/11 loci. B cells from NOD congenic stocks containing Idd9/11 or Idd5.1/5.2-resistance loci, respectively, derived from the NOR or C57BL/10 strains were characterized by suppressed diabetogenic activity. Immature autoreactive B cells in NOD mice have an impaired ability to be rendered anergic upon Ag engagement. Interestingly, both Idd5.1/5.2 and Idd9/11-resistance loci were found to normalize this B cell tolerogenic process, which may represent a mechanism contributing to the inhibition of T1D.
IL-10 Deficiency Promotes Increased Borrelia burgdorferi Clearance Predominantly through Enhanced Innate Immune Responses
Authors: Lazarus John J. , Meadows Michelle J. , Lintner Robert E. , Wooten R. Mark 
Published: April 2014

Abstract
Borrelia burgdorferi is capable of persistently infecting a variety of hosts despite eliciting potent innate and adaptive immune responses. Preliminary studies indicated that IL-10-deficient (IL-10−/−) mice exhibit up to 10-fold greater clearance of B. burgdorferi from target tissues compared with wild-type mice, establishing IL-10 as the only cytokine currently known to have such a significant effect on spirochetal clearance. To further delineate these IL-10-mediated immune effects, kinetic studies indicated that spirochete dissemination to target tissues is similar in both wild-type and IL-10−/− mouse strains, and that enhanced clearance of B. burgdorferi in IL-10−/− mice is correlated with increased B. burgdorferi-specific Ab as early as 2 wk postinfection. Immunoblot analysis indicated that Abs produced by infected IL-10−/− and wild-type mice recognize similar ranges of spirochetal Ags. Immune sera from IL-10−/− and wild-type mice also exhibited similar bactericidal activity in vitro, and passive transfer of these immune sera into B. burgdorferi-infected SCID mice caused similar reductions of bacterial numbers in target tissues. Infectious dose studies indicated that 8-fold more B. burgdorferi were needed to efficiently infect naive IL-10−/− mice, suggesting these animals possess higher innate barriers to infection. Moreover, macrophages derived from IL-10−/− mice exhibit enhanced proinflammatory responses to B. burgdorferi stimulation compared with wild-type controls, and these responses are not significantly affected by the presence of immune serum. These findings confirm that B. burgdorferi clearance by innate immune responses is more efficient in the absence of IL-10, and these activities are not directly related to increased levels of B. burgdorferi-specific Ab.
Bruton’s Tyrosine Kinase Is Required for TLR-Induced IL-10 Production
Authors: Schmidt Nathan W. , Thieu Vivian T. , Mann Brandon A. , Ahyi Ayele-Nati N. , Kaplan Mark H. 
Published: April 2014

AbstractBruton’s tyrosine kinase (Btk) is a critical signaling mediator downstream of the B cell Ag receptor. X-linked agammaglobulinemia is caused by mutations in Btk resulting in multiple defects in B cell development and function, and recurrent bacterial infections. Recent evidence has also supported a role for Btk in TLR signaling. We demonstrate that Btk is activated by TLR4 in primary macrophages and is required for normal TLR-induced IL-10 production in multiple macrophage populations. Btk-deficient bone marrow-derived macrophages secrete decreased levels of IL-10 in response to multiple TLR ligands, compared with wild-type (WT) cells. Similarly, Btk-deficient peritoneal and splenic macrophages secrete decreased IL-10 levels compared with WT cultures. This phenotype correlates with Btk-dependent induction of NF-κB and AP-1 DNA binding activity, and altered commensal bacteria populations. Decreased IL-10 production may be responsible for increased IL-6 because blocking IL-10 in WT cultures increased IL-6 production, and supplementation of IL-10 to Btk-deficient cultures decreased IL-6 production. Similarly, injection of IL-10 in vivo with LPS decreases the elevated IL-6 serum levels during endotoxemia in Btk-deficient mice. These data further support a role for Btk in regulating TLR-induced cytokine production from APCs and provide downstream targets for analysis of Btk function.
Evidence of a Functional Role for Mast Cells in the Development of Type 1 Diabetes Mellitus in the BioBreeding Rat
Authors: Geoffrey Rhonda , Jia Shuang , Kwitek Anne E. , Woodliff Jeffrey , Ghosh Soumitra , Lernmark Åke , Wang Xujing , Hessner Martin J. 
Published: April 2014

Abstract
Human type 1 diabetes mellitus (T1DM) arises through autoimmune destruction of pancreatic β cells and is modeled in many respects by the lymphopenic and spontaneously diabetic BioBreeding (BB) DRlyp/lyp rat. Previously, preonset expression profiling of whole DRlyp/lyp pancreatic lymph nodes (PLN) revealed innate immune activity, specifically that of mast cells and eosinophils. Furthermore, we observed that pancreatic islets of DRlyp/lyp rats as well as those of diabetes-inducible BB DR+/+ rats potentially recruit innate cells through eotaxin expression. Here we determine that lifelong eotaxin expression begins before 40 days of life and is localized specifically to β cells. In this report, we find that PLN mast cells are more abundant in DRlyp/lyp compared with related BB DR+/+ rats (2.1 ± 0.9% vs 0.9 ± 0.4% of total cells, p &lt; 0.0001). DRlyp/lyp PLN mast cell gene expression profiling revealed an activated population and included significant overrepresentation of transcripts for mast cell protease 1, cationic trypsinogen, carboxypeptidase A, IL-5, and phospholipase Cγ. In the DR+/+ rat, which develops T1DM upon depletion of T regulator cells, mast cells displayed gene expression consistent with the negative regulation of degranulation, including significant overrepresentation of transcripts encoding tyrosine phosphatase SHP-1, lipid phosphatase SHIP, and E3 ubiquitin ligase c-Cbl. To recapitulate the negative mast cell regulation observed in the DR+/+ rats, we treated DRlyp/lyp rats with the mast cell “stabilizer” cromolyn, which significantly (p &lt; 0.05) delayed T1DM onset. These findings are consistent with a growing body of evidence in human and animal models, where a role for mast cells in the initiation and progression of autoimmune disease is emerging.
Expression and Functions of the Vascular Endothelial Growth Factors and Their Receptors in Human Basophils
Authors: de Paulis Amato , Prevete Nella , Fiorentino Isabella , Rossi Francesca Wanda , Staibano Stefania , Montuori Nunzia , Ragno Pia , Longobardi Amelia , Liccardo Bianca , Genovese Arturo , Ribatti Domenico , Walls Andrew F. , Marone Gianni 
Published: April 2014

Abstract
Angiogenesis is a multistep complex phenomenon critical for several inflammatory and neoplastic disorders. Basophils, normally confined to peripheral blood, can infiltrate the sites of chronic inflammation. In an attempt to obtain insights into the mechanism(s) underlying human basophil chemotaxis and its role in inflammation, we have characterized the expression and function of vascular endothelial growth factors (VEGFs) and their receptors in these cells. Basophils express mRNA for three isoforms of VEGF-A (121, 165, and 189) and two isoforms of VEGF-B (167 and 186). Peripheral blood and basophils in nasal polyps contain VEGF-A localized in secretory granules. The concentration of VEGF-A in basophils was 144.4 ± 10.8 pg/106 cells. Immunologic activation of basophils induced the release of VEGF-A. VEGF-A (10–500 ng/ml) induced basophil chemotaxis. Supernatants of activated basophils induced an angiogenic response in the chick embryo chorioallantoic membrane that was inhibited by an anti-VEGF-A Ab. The tyrosine kinase VEGFR-2 (VEGFR-2/KDR) mRNA was expressed in basophils. These cells also expressed mRNA for the soluble form of VEGFR-1 and neuropilin (NRP)1 and NRP2. Flow cytometric analysis indicated that basophils express epitopes recognized by mAbs against the extracellular domains of VEGFR-2, NRP1, and NRP2. Our data suggest that basophils could play a role in angiogenesis and inflammation through the expression of several forms of VEGF and their receptors.