bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Primary Site of CD4−8−B220+ αβ T Cells inlprMice: The Appendix in Normal Mice
Authors: Yamagiwa Satoshi , Sugahara Satoshi , Shimizu Takao , Iwanaga Toshihiko , Yoshida Yuhei , Honda Shigeru , Watanabe Hisami , Suzuki Kenji , Asakura Hitoshi , Abo Toru 
Published: December 2022

AbstractThere have been no reports on an abundance of CD4−8−B220+ αβ T cells, seen in autoimmune mice carrying the lpr gene (abnormal Fas gene), in any immune organs of normal mice. We herein report, however, that such αβ T cells were abundant at intraepithelial sites of the appendix in normal mice. They lacked the expression of NK1.1 Ags (C57BL/6 mice), but had the morphology of granular lymphocytes and contained forbidden T cell clones in the minor lymphocyte-stimulating antigen (Mls) system (C3H/He mice with Mls-1b2a). In other words, many properties of intraepithelial T cells in the appendix resembled those ascribed to abnormal αβ T cells, which expand in the lymph nodes and spleen of lpr mice. In the case of lpr mice, CD4−8−B220+ αβ T cells first expanded in the appendix and then extended to other organs. CD4−8−B220+ αβ T cells seemed to originate in situ from c-kit+ stem cells in the appendix. These results suggest that the appendix is one of the primary sites in which CD4−8−B220+ αβ T cells exist, and that these cells carry many primordial properties as prototype T cells.
Dependence of Antibody Somatic Diversification on Gut-Associated Lymphoid Tissue in Rabbits
Authors: Vajdy Michael , Sethupathi Periannan , Knight Katherine L. 
Published: December 2022

AbstractBy ∼4 to 8 wk of age, the IgH VDJ genes of essentially all rabbit B lymphocytes have undergone somatic diversification. Some of this diversification occurs in the appendix, which is a gut-associated lymphoid tissue (GALT). To determine whether GALT is essential for somatic diversification, we surgically removed the appendix, sacculus rotundus, and Peyer’s patches from neonatal rabbits (designated GALT-less) and examined the extent to which VDJ genes were somatically diversified. We found that the IgM VDJ genes of peripheral B cells from 2- to 5-mo-old GALT-less rabbits had undergone considerably less somatic diversification than those of control rabbits. Further, the percentage of peripheral B cells in the GALT-less rabbits was generally less than that of controls. Our data suggest that, in rabbits, the primary Ab repertoire develops in GALT, and B cell expansion also occurs there. Hence, GALT may function as a mammalian bursal homologue.
Identification of an Immunodominant IgE Epitope of theParietaria judaicaMajor Allergen
Authors: Colombo Paolo , Kennedy2 Derek , Ramsdale Tracie , Costa Maria A. , Duro Giovanni , Izzo Vincenzo , Salvadori Severo , Guerrini Remo , Cocchiara Roberta , Mirisola Mario G. , Wood Stephen , Geraci Domenico 
Published: December 2022

AbstractPar j 1.0101 is one of the two major allergens of the Parietaria judaica (Pj) pollen, and its three-dimensional structure was built by three-dimensional structural homology modeling. The resultant model was used to identify putative IgE binding regions. Western blot analysis of gene fragmentation products showed that the 1 to 30 region was capable of binding specific IgE from a pool of sera (n = 30) of patients allergic to Pj pollen. Using the structural model as a guide, deletion and site-directed mutagenesis of the 1 to 30 region was performed, and the amino acids involved in IgE binding were identified. In addition, a synthetic peptide covering the 1 to 30 region was capable of binding human IgE without triggering histamine release from basophils of Pj allergic patients (n = 6) and thus represents a haptenic molecule with potential use as an immunotolerant agent. This epitope is also present on the Par j 2.0101 major allergen representing a common IgE epitope. It is an immunodominant epitope, since it was capable of inhibiting 30% of all specific IgE against the Pj major allergens, and therefore, it might be a candidate for the future development of immunotherapeutics.
Relationship Among Immunodominance of Single CD8+ T Cell Epitopes, Virus Load, and Kinetics of Primary Antiviral CTL Response
Authors: Weidt Gunnar , Utermöhlen Olaf , Heukeshoven Jochen , Lehmann-Grube Fritz , Deppert Wolfgang 
Published: December 2022

AbstractThe primary CTL response of BALB/c mice infected with the lymphocytic choriomeningitis (LCM) virus strain WE is directed exclusively against one major epitope, n118, whereas a viral variant, ESC, that does not express n118 induces CTL against minor epitopes. We identified one minor epitope, g283, that induces primary lytic activity in ESC-infected mice. Infections of mice with WE and ESC were used to study the hierarchical control of a T cell response. Presentation of minor epitopes is not reduced in WE-infected cells. Generation of CTL against n118 does not suppress the generation of minor epitope-specific CTL systemically, as mice coinfected with WE and ESC developed CTL against n118 and g283. However, elimination of ESC and development of minor epitope-specific CTL in ESC infection were slower than elimination of WE and development of CTL against n118. CD8+ T cells against the minor epitope were activated in ESC and WE infection, but did not expand in the latter to show lytic activity in a primary response. We explain the absence of minor epitope-specific lytic activity in WE infection by the fast reduction of virus load due to the early developing n118-specific CTL. Immunodominance of CTL epitopes in primary virus infections thus can be explained as a kinetic phenomenon composed of 1) expansion of CD8+ T cells specific for individual epitopes, 2) stimulatory effect of virus load, and 3) negative feedback control on virus load by the fastest CTL population.
Functional Differences Among Multiple Isoforms of Guinea Pig Decay-Accelerating Factor
Authors: Wang Guixian , Nonaka Mayumi , He Changqing , Okada Noriko , Nakashima Izumi , Okada Hidechika 
Published: December 2022

AbstractDecay-accelerating factor (DAF, CD55) is a membrane inhibitor that protects host cells from the autologous C-mediated attack. The guinea pig homologue of DAF consists of multiple isoforms generated by alternative splicing from a single copy gene. These isoforms are mainly comprised of a glycosylphosphatidylinositol (GPI)-anchored form and a transmembrane form (TM) that is not present in human DAF. Both forms occur in at least three variations that differ in the length of the Ser/Thr-rich region (termed ST-a, ST-ab, and ST-abc). We have transfected cDNAs of the six major isoforms into Chinese hamster ovary cells, and their functional differences were evaluated in inhibition of C-mediated cytolysis and C3 deposition, using the transfectants expressing DAF at the same level on cell membranes. The degree of inhibition in both the classical and alternative pathways differed according to the length of the ST region in the order of abc &gt; ab &gt; a in both GPI and TM forms. When GPI and TM forms were compared, those with the ab or abc variation exhibited almost the same activity, whereas a-TM was less efficient than a-GPI. Although several isoforms are expressed constitutively in most of tissues, spermatozoa preferentially express the abc-GPI isoform, suggesting that this isoform offers effective protection to spermatozoa in the female genital tract.
Role of the Rho GTPase in Bradykinin-Stimulated Nuclear Factor-κB Activation and IL-1β Gene Expression in Cultured Human Epithelial Cells
Authors: Pan Zhixing K. , Ye Richard D. , Christiansen Sandra C. , Jagels Mark A. , Bokoch Gary M. , Zuraw Bruce L. 
Published: December 2022

AbstractRecent evidence suggests a novel role of bradykinin (BK) in stimulating gene transcription. This study examined the effect of BK on nuclear factor κB (NF-κB) activation and IL-1β synthesis in human epithelial cells. Stimulation of A549 cells and primary bronchial epithelial cells with BK rapidly activated NF-κB. BK also increased the level of secreted immunoreactive IL-1β in A549 culture supernatants, an effect that was blocked by actinomycin D and the B2 BK receptor antagonist HOE-140. The role of NF-κB activation in BK-induced IL-1β synthesis was demonstrated by the ability of BK to stimulate increased chloramphenicol acetyltransferase (CAT) activity in A549 cells transfected with a reporter plasmid containing three κB enhancers from the IL-1β gene, while deletion of the κB enhancer sequences eliminated BK-stimulated CAT activity. C3 transferase exoenzyme, an inhibitor of Rho, abolished BK-induced NF-κB activation at 10 μg/ml and significantly inhibited BK-stimulated IL-1β synthesis at 5 μg/ml. A dominant-negative form of RhoA (T19N) inhibited BK-stimulated reporter gene expression in a dose-dependent and κB-dependent manner. Cotransfection of A549 cells with an expression vector encoding a constitutively active form of RhoA (Q63L) along with the IL-1β promoter-CAT reporter plasmid resulted in a marked increase in NF-κB activity compared with transfection with the IL-1β promoter-CAT reporter plasmid alone. These results demonstrate that BK stimulates NF-κB activation and IL-1β synthesis in A549 cells, and that RhoA is both necessary and sufficient to mediate this effect.
Cutting Edge: Physical Interaction Between Dendritic Cells and Tumor Cells Results in an Immunogen That Induces Protective and Therapeutic Tumor Rejection
Authors: Celluzzi Christina M. , Falo Louis D. 
Published: December 2022

AbstractDendritic cells (DCs) are potent professional APCs capable of presenting Ag in the context of costimulatory signals necessary for T cell activation. Although tumor cells express target Ags, they are generally incapable of stimulating an immune response. We show that the short term physical interaction of DCs and tumor cells, with or without cell fusion, results in rapid, efficient, and stable DC-tumor cell association. Immunization of naive mice with unselected, irradiated DC-tumor cell conjugates induces tumor-specific CD8+ cytotoxic T cells and protection from lethal tumor challenge. Furthermore, the immunogenicity of this cellular vaccine is dependent on the physical interaction of DCs and tumor cells before injection. Immunization with DCs and tumor cells after physical interaction can result in the regression of established tumors and persistent antitumor immunity. These results suggest that immunization with DC-tumor cell vaccines may be a simple, rapid, and potent strategy for tumor immunotherapy.
Cutting Edge: Human Myelomonocytic Cells Express an Inhibitory Receptor for Classical and Nonclassical MHC Class I Molecules
Authors: Colonna Marco , Samaridis Jacqueline , Cella Marina , Angman Lena , L. Allen Rachel , O’Callaghan Chris A. , Dunbar Rod , S. Ogg Graham , Cerundolo Vincenzo , Rolink Antonius 
Published: December 2022

Abstract
Leukocyte activation can be negatively regulated by inhibitory receptors specific for MHC class I molecules. While one inhibitory receptor, Ig-like transcript 2 (ILT2), is expressed by all lymphoid and myelomonocytic cell types, other receptors display a more selective tissue distribution. Here we characterize an inhibitory receptor, termed ILT4, which is selectively expressed in monocytes, macrophages, and dendritic cells (DCs), binds classical class I molecules and the nonclassical class I molecules HLA-G, and transduces negative signals that can inhibit early signaling events triggered by stimulatory receptors. ILT4 may control inflammatory responses and cytotoxicity mediated by myelomonocytic cells and may modulate their Ag-presenting functions, focusing immune responses to microbial challenges and avoiding autoreactivity.
CD1.1 Expression by Mouse Antigen-Presenting Cells and Marginal Zone B Cells
Authors: Roark Jessica H. , Park Se-Ho , Jayawardena Jayanthi , Kavita Uma , Shannon Michele , Bendelac Albert 
Published: December 2022

AbstractMouse CD1.1 is an MHC class I-like, non-MHC-encoded, surface glycoprotein that can be recognized by T cells, in particular NK1.1+ T cells, a subset of αβ T cells with semiinvariant TCRs that promptly releases potent cytokines such as IL-4 and IFN-γ upon stimulation. To gain insight into the function of CD1.1, a panel of nine mAbs was generated and used to biochemically characterize and monitor the surface expression of CD1.1 on different cell types. CD1.1 is a heavily glycosylated, β2-microglobulin-associated surface protein. Its recognition by a panel of 12 Vα14-positive and -negative CD1-specific αβ T cell hybridomas was blocked by two groups of mAbs that bound to adjacent clusters of epitopes, indicating that different αβ TCRs bind to the same region of CD1.1, presumably above the groove. Remarkably, CD1.1 was mainly expressed by dendritic cells, B cells, and macrophages, suggesting a function in Ag presentation to Th cells. Furthermore, the cell type that expressed the highest levels of CD1.1 was the splenic marginal zone B cell, a distinct subset of B cells that also expresses CD21 (the C3d receptor) and may be involved in natural responses to bacterial Ags. Altogether, the results support the idea that CD1.1 may function in recruiting a form of innate help from specialized cytokine producer αβ T cells to APCs, a role that might be important at the preadaptive phase of immune responses to some microbial pathogens.
Characterization of Signal Transduction Through the TCR-ζ Chain Following T Cell Stimulation with Analogue Peptides of Type II Collagen 260–267
Authors: Tang Bo , Myers Linda K. , Rosloniec Edward F. , Whittington Karen B. , Stuart John M. , Kang Andrew H. 
Published: December 2022

Abstract
The immunodominant T cell determinant of type II collagen (CII) recognized by DBA/1 mice (I-Aq) is CII 260–267. The aims of this study were to determine the role of the amino acid residues within CII 245–270 in T cell signal transduction. To that end, we utilized I-Aq-restricted, CII-specific T cell hybridomas and examined tyrosine phosphorylation of TCR-ζ following stimulation with either wild-type CII 245–270 or a panel of analogue peptides. A variety of patterns occurred, ranging from increased phosphorylation of TCR-ζ to either partial or a complete abrogation of phosphorylation. Critical substitutions also completely abrogated the phosphorylation of ZAP70, a downstream molecule in TCR-ζ signaling. Evaluation of the supernatants of the T cell hybridomas for cytokine production in response to the peptides revealed a close correlation between the induction of phosphorylation of TCR-ζ and the amount of cytokine induced. Selected analogue peptides were tested as tolerogens in neonatal mice. Analogues that did not induce the phosphorylation of ζ chain, such as B3 (CII 251–270s263F→N), were completely unable to induce tolerance, while analogues that caused a partial phosphorylation, such as B6 (CII 251–270s267Q→T) and A3 (CII 245–270s269P→A), induced partial tolerance judged by intermediate degrees of suppression of arthritis. We conclude that discrete alterations in specific amino acid residues of antigenic peptides had profound effects on T cell signaling and that the signaling correlated with T cell cytokine secretion and T cell function in the induction of tolerance and suppression of arthritis.
An In Vitro Model of T Cell Activation by Autologous Cytomegalovirus (CMV)-Infected Human Adult Endothelial Cells: Contribution of CMV-Enhanced Endothelial ICAM-1
Authors: Waldman W. James , Knight Deborah A. , Huang Emina H. 
Published: December 2022

AbstractCellular immunity is strongly implicated in control of CMV disease; however, many mechanistic details remain unresolved. We previously demonstrated T cell activation responses to CMV-infected allogeneic endothelial cells (EC), suggesting EC as a mediator of CMV response in the transplant recipient. We now test the hypothesis that CMV-specific T cell responses can be directly stimulated by infected EC in an environment free of potentially confounding allogeneic factors. By isolating splenic T cells and gonadal vein endothelial cells (GVEC) from individual cadaveric organ donors, we have developed an in vitro model of T cell interaction with autologous CMV-infected EC. Proliferation assays demonstrated significantly enhanced responses by CMV-seropositive donor-derived T cells cocultured with CMV-infected GVEC, as compared with those elicited by uninfected cells. Similarly, as determined by limiting dilution analysis of IL-2-producing cells, T cell response frequencies to infected GVEC were significantly greater than to uninfected EC. In contrast, responses of CMV-seronegative donor-derived T cells were minimal, regardless of CMV status of stimulator GVEC. Intriguingly, CD4 responses were observed in spite of the fact that CMV-infected EC express no HLA class II. Finally, attenuation of CMV-stimulated T cell proliferation observed in the presence of blocking Ab specific for ICAM-1 suggests a contributing role for CMV-enhanced endothelial ICAM-1 expression in the activation response. These studies demonstrate that EC can stimulate autologous T cell responses to CMV in the absence of accessory APC and suggest potentially novel mechanisms of immune activation.
Antibodies to Domains II and III of the IL-1 Receptor Accessory Protein Inhibit IL-1β Activity But Not Binding: Regulation of IL-1 Responses Is Via Type I Receptor, Not the Accessory Protein
Authors: Yoon Do-Young , Dinarello Charles A. 
Published: December 2022

AbstractThe IL-1R accessory protein (IL-1RAcP) plays a role in IL-1R signaling by forming a complex with IL-1RI bound to the IL-1 ligand. We identified four hydrophilic peptide regions of the extracellular IL-1RAcP that may be available for complex formation (peptide 1, 71–83 domain I; peptide 2, 204–211 domain II; peptide 3, 282–292 domain III; and peptide 4, 304–314 domain III). These peptides were synthesized, coupled to keyhole limpet hemocyanin, and used to produce rabbit antisera. Each affinity-purified antiserum showed specificity for the respective peptide without cross-reactivity. Anti-peptide 2, 3, and 4 recognized surface expression of IL-1RAcP on the Th2 D10S cells by FACS and inhibited IL-1-driven proliferation. Anti-peptide 4 recognized intact IL-1RAcP and soluble IL-1RAcP. Anti-IL-1RAcP-peptide 4, which targets the terminal segment of domain III, inhibited 80% of IL-1β-driven proliferation of D10S cells. However, these IL-1RAcP Abs had no effect on the activity of human or mouse IL-1α. Whereas IL-1β down-regulated IL-1RI surface expression (p &lt; 0.05), there was no change in the surface expression of IL-1RAcP. Moreover, murine IL-10 increased surface expression of IL-1RI, but did not affect expression of IL-1RAcP or the proliferation of D10S cells. Steady state levels of mRNA for IL-1RAcP and IL-1RI in D10S cells showed a similar pattern to that of surface expression of the respective receptors. We conclude that 1) blocking IL-1RAcP inhibits IL-1 signaling in D10S cells, 2) domains-II and III may be involved in complex formation with IL-1RI, 3) IL-1RAcP is not regulated as is IL-1RI in the same cells, and 4) IL-1 responsiveness is dependent on the expression of IL-1RI, not IL-1RAcP.
Purified MHC Class I and Peptide Complexes Activate Naive CD8+ T Cells Independently of the CD28/B7 and LFA-1/ICAM-1 Costimulatory Interactions
Authors: Goldstein Julia S. , Chen Trina , Brunswick Mark , Mostowsky Howard , Kozlowski Steven 
Published: December 2022

AbstractT cells play a central role in the initiation, maintenance, and regulation of the immune response. Effector responses of T cells are controlled by complex combinations of lymphokines and adhesion/costimulatory molecule signals. To isolate the effects of specific adhesion/costimulatory molecules and to define the minimal molecular requirements of naive CD8+ T cell activation, we have developed an APC-free system for stimulation of naive CD8+ T cells. In this report, we demonstrate that immobilized MHC class I-peptide complexes can activate naive CD8+ T cells from TCR transgenic mice at low cell densities. The CD8+ T cells were stimulated to proliferate and secrete IL-2 independently of the molecular interactions between CD28/B7.1-B7.2 or LFA-1/ICAM-1 surface receptors. Previous reports have shown that CD28 ligation is necessary for late T cell survival of APC-stimulated naive CD8+ T cells. Our data suggest that under certain specific conditions of high intensity T cell signaling, early activation and late cell proliferation can occur independently of APC-derived costimulatory signals.
Kinetics of Multivalent Antigen DNP-BSA Binding to IgE-FcεRI in Relationship to the Stimulated Tyrosine Phosphorylation of FcεRI
Authors: Xu Keli , Goldstein Byron , Holowka David , Baird Barbara 
Published: December 2022

Abstract
Multivalent DNP-BSA is commonly used to cross-link anti-DNP IgE bound to FcεRI to stimulate cellular responses, although key features of the binding process are unknown. Fluorescence quenching can be used to study the kinetics of DNP-BSA binding to FITC-IgE. We observe that DNP-BSA binds more slowly to IgE than does an equimolar amount of a monovalent DNP ligand, suggesting that the average effective number of DNP groups per BSA is less than one. The binding data are well described by a transient hapten exposure model in which most of the DNP groups are unavailable for binding but have some probability of becoming exposed and available for binding during the time of the binding measurement. Additional experiments indicate that, for suboptimal to optimal concentrations of DNP-BSA, most of the FITC fluorescence quenching on the cell surface is due to cross-linking events. With these concentrations at 15°C, the kinetics of FITC fluorescence quenching by DNP-BSA correlates with the kinetics of DNP-BSA-stimulated tyrosine phosphorylation of FcεRI. At 35°C, the phosphorylation kinetics are biphasic during the time period in which cross-linking continues to increase. Our results establish a quantitative relationship between the timecourse for cross-linking by multivalent Ag and FcεRI-mediated signaling, and they provide the means to predict the kinetics of cross-linking under a wide variety of conditions.
Inhibition of an In Vitro CD4+ T Cell Alloresponse Using Altered Peptide Ligands
Authors: Daniel Claude , Grakoui Arash , Allen Paul M. 
Published: December 2022

AbstractIn this study, we explore the potential of altered peptide ligands (APLs) to modulate the alloresponse of CD4+ T cells using elements of the murine hemoglobin (Hb) Ag model. We first demonstrated that the T cell 2.102, specific for the Hb(64-76)/I-Ek complex, was alloreactive against splenocytes of the H-2p haplotype. Using Ab-blocking and transfection experiments, we further showed that this alloreactivity was restricted to the class II molecule I-Ep. We tested a panel of APLs previously shown to antagonize the Hb response of 2.102 and found that these peptides could also effectively inhibit the alloresponse to I-Ep. Importantly, these peptides were able to antagonize the alloresponse of naive T cells derived from mice transgenic for the 2.102 TCR, as well as Th1 and Th2 cell lines. The antagonism required the presence of both I-Ep and I-Ek on the same APC. Our study demonstrates the effectiveness of APLs to antagonize the primary alloresponse of specific T cells and provides a basis for the development of immunotherapeutics for use in transplantation and immune-mediated diseases.