bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human β2-Glycoprotein I Binds to Endothelial Cells Through a Cluster of Lysine Residues That Are Critical for Anionic Phospholipid Binding and Offers Epitopes for Anti-β2-Glycoprotein I Antibodies
Authors: Del Papa N. , Sheng Y. H. , Raschi E. , Kandiah D. A. , Tincani A. , Khamashta M. A. , Atsumi T. , Hughes G. R. V. , Ichikawa K. , Koike T. , Balestrieri G. , Krilis S. A. , Meroni P. L. 
Published: January 2023

Abstractβ2-Glycoprotein I (β2GPI) is a phospholipid-binding protein recognized by serum autoantibodies from the anti-phospholipid syndrome both in cardiolipin- and β2GPI-coated plates. We found that: 1) recombinant wild-type β2GPI bound to HUVEC and was recognized by both human monoclonal IgM and affinity-purified polyclonal IgG anti-β2GPI anti-phospholipid syndrome Abs; and 2) a single amino acid change from Lys286 to Glu significantly reduced endothelial adhesion. Double and triple mutants (from Lys284,287 to Glu284,287, from Lys286,287 to Glu286,287, and from Lys284,286,287 to Glu284,286,287) completely abolished endothelial binding. A synthetic peptide (P1) spanning the sequence Glu274–Cys288 of the β2GPI fifth domain still displayed endothelial adhesion. Another peptide (P8), identical with P1 except that Cys281 and Cys288 were substituted with serine residues, did not bind to HUVEC. Anti-β2GPI Abs, once bound to P1 adhered to HUVEC, induced E-selectin expression and up-regulated IL-6 secretion. Control experiments conducted with irrelevant Abs as well as with the P8 peptide did not show any endothelial Ab binding nor E-selectin and IL-6 modulation. Our results suggest that: 1) β2GPI binds to endothelial cells through its fifth domain; 2) the major phospholipid-binding site that mediates the binding to anionic phospholipids is also involved in endothelial binding; 3) HUVEC provide a suitable surface for β2GPI binding comparable to that displayed by anionic phospholipids dried on microtiter wells; and 4) the formation of the complex between β2GPI and the specific Abs leads to endothelial activation in vitro.
Differential Regulation of Chemoattractant-Stimulated β2, β3, and β7 Integrin Activity
Authors: Sadhu Chanchal , Masinovsky Boris , Staunton Donald E. 
Published: January 2023

AbstractLeukocyte adhesion to endothelium and extravasation are dynamic processes that require activation of integrins. Chemoattractants such as IL-8 and FMLP are potent activators of leukocyte integrins. To compare the chemoattractant-stimulated activation of three integrins, α4β7, αLβ2, and αVβ3, in the same cellular context, we expressed an IL-8 receptor (IL-8RA) and FMLP receptor (FPR) in the lymphoid cell line JY. Chemoattractants induced a rapid increase in αLβ2- and αVβ3-dependent JY adhesion within 5 min, and it was sustained for 30 min. In contrast, stimulation of α4β7-dependent adhesion was transient, returning to basal levels by 30 min. The activation profiles of the integrins were similar regardless of whether IL-8 or FMLP was used for induction. We also demonstrate that α4β7-dependent adhesion was uniquely responsive to the F actin-disrupting agent cytochalasin D and the protein kinase C (PKC) inhibitor chelerythrin. While αVβ3- and αLβ2-mediated cell adhesion was significantly reduced by cytochalasin D, α4β7-mediated adhesion was enhanced. Chelerythrin inhibited both the IL-8 and PMA activation of αLβ2 and αVβ3. In contrast, inducible α4β7 activity was unaffected, and basal activity was increased. These findings demonstrate that the mechanism of α4β7 regulation by chemoattractants is different from that of αLβ2 and αVβ3 and that it appears to involve distinct cytoskeletal and PKC dependencies. In addition, PKC activity may be a positive or negative regulator of integrin-dependent adhesion.
Antigen Activation Rescues Recent Thymic Emigrants from Programmed Cell Death in the BB Rat
Authors: Ramanathan Sheela , Norwich Ken , Poussier Philippe 
Published: January 2023

Abstract
One of the diabetes susceptibility genes of the BB rat is a mutation at the lyp locus that decreases the thymic output of T cells and the life span of most recent thymic emigrants (RTE). Consequently, there is a 10-fold reduction in the number of CD4+ and CD8+ T cells in secondary lymphoid organs. Results presented in this work demonstrate that the BB rat lyp mutation is associated with an accelerated apoptotic death in vitro of mature CD4+8− and CD4−8+ thymocytes and peripheral T cells. The stability of the pool of recirculating T cells (PRL) of BB rats over time results from a &gt;10-fold increase in the mitotic activity of T cells as assessed in vivo by bromodeoxyuridine incorporation. This increased mitotic activity is not observed when BB T cells develop in the context of a normal sized PRL. MHC haploidentical WF and BB rats differ at minor histocompatibility loci. Intravenous injection of (WF × BB)F1 T cells into euthymic BB rats led to the rejection of donor T cells within 3 wk by unprimed recipients and within 1 wk by primed recipients. This secondary immune response was unaffected by postpriming thymectomy. F1 T cells were not rejected, but rather expanded after their injection into thymectomized BB rats that had been primed as early as 48 h after thymectomy. These results strongly suggest that the BB rat PRL is devoid of long-lived naive T cells and that rescue of recent thymic emigrants from programmed cell death is initiated by Ags, exclusively.
NK Cell Modulation of Murine Cytomegalovirus Retinitis
Authors: Bigger John E. , Thomas Charles A. , Atherton Sally S. 
Published: January 2023

Abstract
CMV retinitis, the most common ophthalmic infection of AIDS patients, causes blindness if left untreated. To study the role of NK cells in the modulation of CMV ocular infection, 9.0 × 102 plaque-forming units of the Smith strain of murine CMV (MCMV) was injected into the supraciliary space of the left eyes of BALB/c mice. Lysis of NK-sensitive target cells (YAC-1) by effectors from the draining lymph nodes peaked at day 5 postinfection, while the splenic cytolytic response was biphasic, with peaks at days 2 and 7 postinfection. Flow cytometry showed that NK cells (DX-5+) increased in spleens and eyes 5 days after supraciliary infection with MCMV compared with uninfected or mock-infected controls. Eight days after supraciliary injection with 9.0 × 102 plaque-forming units of MCMV, 7 of 10 NK-depleted mice developed retinitis compared with only 2 of 10 non-NK-depleted control mice. Poly(I-C) activation of NK cells in T cell-depleted animals protected mice from MCMV retinitis; only 2 of 10 mice in the poly(I-C)-treated group developed retinitis compared with 8 of 10 T cell-depleted, non-poly(I-C)-treated control mice. These results show the importance of NK cells in preventing MCMV retinitis and suggest that NK cells may also be involved in modulation of cytomegalovirus retinitis in human patients.
The Generation of Human γδ T Cell Repertoires During Fetal Development
Authors: McVay Laila D. , Jaswal Sheila S. , Kennedy Christine , Hayday Adrian , Carding Simon R. 
Published: January 2023

Abstract
The nature of how human γδ T cells are normally generated is not clear. We have used an RT-PCR assay and DNA sequencing to identify and compare δ-encoded TCRs (TCRDs) that are generated de novo in the fetal gut, liver, and thymus and to determine when, where, and how the TCRD repertoire is established during normal embryonic development. Rearranged TCRDV genes are first expressed outside of the thymus in the liver and primitive gut between 6 and 9 wk gestation. Although DV1Rs and/or DV2Rs predominated, differences in the pattern of TCRDV gene rearrangement and transcription in each tissue during ontogeny were identified. Specific, DV2-encoded TCRs are highly conserved throughout ontogeny in the tissues from the same and between genetically distinct donors. Although the thymic and intestinal γδ T cell repertoires partially overlap early in development, they diverge and become nonoverlapping during the second trimester, and the generation of the intestinal γδ T cell repertoire is characterized by differences in the processing of DV1Rs and DV2Rs. Whereas the structural diversity of DV1Rs progressively increases during gut development up to birth, DV2Rs have limited structural diversity throughout ontogeny. Together, our findings provide evidence for the ability of different fetal tissues to support the development of γδ T cells.
Structural Requirements for a Specificity Switch and for Maintenance of Affinity Using Mutational Analysis of a Phage-Displayed Anti-Arsonate Antibody of Fab Heavy Chain First Complementarity-Determining Region
Authors: Wong Yee Wah , Gill Davinder S. , Parhami-Seren Behnaz , Short Mary K. , Sompuram Seshi Reddy , Margolies Michael N. 
Published: January 2023

AbstractWe previously showed that a single mutation at heavy (H) position 35 of Abs specific for p-azophenylarsonate (Ars) resulted in acquisition of binding to the structurally related hapten p-azophenylsulfonate (Sulf). To explore the sequence and structural diversity of the H chain first complementarity-determining region (HCDR1) in modulating affinity and specificity, positions 30–36 in Ab 36–65 were randomly mutated and expressed as Fab in a bacteriophage display vector. Ab 36–65 is germline encoded, lacking somatic mutations. Following affinity selection on Sulf resins, 55 mutant Fab were isolated, revealing seven unique HCDR1 sequences containing different amino acids at position H:35. All Fab bound Sulf, but not Ars. Site-directed mutagenesis in a variety of HCDR1 sequence contexts indicates that H:35 is critical for hapten specificity, independent of the sequence of the remainder of HCDR1. At H:35, Asn is required for Ars specificity, consistent with the x-ray crystal structure of the somatically mutated anti-Ars Ab 36–71, while Sulf binding occurs with at least seven different H:35 residues. All Sulf-binding clones selected following phage display contained H:Gly33, observed previously for Ars-binding Abs that use the same germline VH sequence. Site-directed mutagenesis at H:33 indicates that Gly plays an essential structural role in HCDR1 for both Sulf- and Ars-specific Abs.
An Antigen Recognized by Autologous CTLs on a Human Bladder Carcinoma
Authors: Guéguen Maryse , Patard Jean-Jacques , Gaugler Béatrice , Brasseur Francis , Renauld Jean-Christophe , Van Cangh Paul J. , Boon Thierry , Van den Eynde Benoı̂t J. 
Published: January 2023

Abstract
By stimulating blood lymphocytes with autologous bladder carcinoma cells that had been transfected with B7-1, we obtained a panel of CTL clones which lyse specifically the bladder tumor cells in an MHC class I-restricted fashion. Based on inhibition with anti-HLA Abs and the recognition of allogeneic tumor cells, we could distribute our clones in three groups that recognized three distinct Ags. We characterized one of these Ags by screening a cDNA library prepared with the RNA from this bladder tumor line. This new tumor Ag is a peptide presented by HLA-B4403 molecules. It is produced by a point mutation in a gene that is recorded in databases under the name KIAA0205, is ubiquitously expressed, and whose function is unknown. We also found this mutation in the tumor sample that was originally resected from this patient, but the mutation was not found in the 100 or more independent tumors of various histologic types that were tested. This report is the first to describe the isolation of CTL clones directed against human bladder cancer and the molecular characterization of a bladder tumor Ag.
Reduced T Helper 1 Responses in IL-12 p40 Transgenic Mice
Authors: Yoshimoto Takayuki , Wang Chrong-Reen , Yoneto Toshihiko , Waki Seiji , Sunaga Shinji , Komagata Yoshinori , Mitsuyama Masao , Miyazaki Jun-ichi , Nariuchi Hideo 
Published: January 2023

Abstract
To investigate the antagonistic effect of IL-12 p40 on IL-12 activity in vivo, we generated transgenic (Tg) mice in which p40 gene was regulated by a liver-specific promoter. Three Tg mouse lines were generated, and they expressed the p40 transgene predominantly in liver. Serum p40 level was extremely high, and it consisted of mainly monomer and homodimer and also of higher m.w. complexes. These Tg mice did not show any apparent phenotypic difference from control littermates in lymphoid cells. Enhancement of NK cell lytic activity in spleen by administration of rIL-12 to these mice was greatly diminished. Ag-induced cytokine production was impaired: decreased production of IFN-γ and increased production of IL-4 and IL-10. Delayed-type hypersensitivity response was also significantly reduced. Moreover, these Tg mice showed increased susceptibility to the infection with an intracellular pathogen, blood-stage Plasmodium berghei XAT, which is an irradiation-induced attenuated substrain of P. berghei NK65, presumably due to the decreased IFN-γ production. These results suggest that p40 functions as an IL-12 antagonist in vivo, and that Th1 responses in p40 Tg mice are significantly reduced. Thus, these Tg mice could be a useful model to evaluate the inhibitory effect of p40 on IL-12-mediated various immune responses in vivo.
The Level of CD4 Surface Protein Influences T Cell Selection in the Thymus
Authors: Frank Gregory D. , Parnes Jane R. 
Published: January 2023

Abstract
During T cell development thymocytes are subjected to positive and negative selection criteria to ensure that the mature T cell repertoire is MHC restricted, yet self tolerant at the same time. The CD4 and CD8 coreceptors are thought to play a crucial role in this developmental process. To elucidate the role of CD4 in T cell selection, we have produced a mouse strain that expresses CD4 at a reduced level. We used homologous recombination in embryonic stem cells to insert neo into the 3′ untranslated region of CD4. The resulting mice have a reduction in the percentage of CD4+ cells in the thymus and a concomitant increase in CD8+ cells. In addition, breeding two individual class II-restricted TCR transgenic mice onto the CD4low (low level of CD4) mutant background affects the selection of each TCR differentially. In one case (AND TCR transgenic), significantly fewer CD4+ cells with the transgenic TCR develop on the CD4low mutant background, whereas in the other (5C.C7 TCR transgenic), selection to the CD4 lineage is only slightly reduced. These data support the differential avidity model of positive and negative selection. With little or no avidity, the cell succumbs to programmed cell death, low to moderate avidity leads to positive selection, and an avidity above a certain threshold, presumably above one that would lead to autoreactivity in the periphery, results in clonal deletion. These data also support the idea that a minimum avidity threshold for selection exists and that CD4 plays a crucial role in determining this avidity.
MHC Class II-Transfected Tumor Cells Directly Present Antigen to Tumor-Specific CD4+ T Lymphocytes1
Authors: Armstrong Todd D. , Clements Virginia K. , Ostrand-Rosenberg Suzanne 
Published: January 2023

Abstract
We have developed and shown to be efficacious an immunotherapeutic strategy to enhance the generation of tumor-specific CD4+ T helper lymphocytes. The approach uses autologous tumor cells genetically modified to express syngeneic MHC class II genes as cell-based immunogens and is based on the hypothesis that tumor cells directly present tumor Ags to CD4+ T cells. Since the conventional pathway for CD4+ T cell activation is indirect via professional APC, induction of immunity following immunization with class II-transfected tumor cells was examined in bone marrow chimeric mice. Both tumor and host-derived cells are APC for tumor Ags, suggesting that the efficacy of tumor cell vaccines can be significantly improved by genetic modifications that enhance tumor cell Ag presentation.
Molecular and Genetic Requirements for Preferential Recruitment of TCRBV8S2+ T Cells in Lewis Rat Experimental Autoimmune Encephalomyelitis
Authors: Weissert Robert , Svenningsson Anders , Lobell Anna , de Graaf Katrien L. , Andersson Roland , Olsson Tomas 
Published: January 2023

Abstract
The underlying mechanisms behind the preferential expression of select TCRBV products in certain autoimmune illnesses, such as multiple sclerosis and some models of experimental autoimmune encephalomyelitis (EAE), have principally remained enigmatic. In this study, we examined the mutual role of nonself- vs self-origin of antigenic myelin basic protein (MBP) peptides and given MHC haplotypes in relation to the relative frequency of activated TCRBV8S2+ T lymphocytes in the Lewis (LEW) rat EAE model. Inbred MHC (RT1) congenic LEW rats (LEW (RT1l), LEW.1AV1 (RT1av1), and LEW.1W (RT1u)) were immunized with the 63 to 88 peptide of the guinea pig MBP (MBPGP63-88). Additionally, LEW rats were immunized with the corresponding autologous rat sequence (MBPRAT63-88). Although EAE ensued in all MBP peptide/LEW rat strain combinations, only LEW rats immunized with the heterologous MBPGP63-88 peptide elicited T cell responses encompassing a bias toward TCRBV8S2 expression, as determined by flow cytometric analyses. Reduction of TCRBV8S2+ T cells led to mitigation of disease severity in LEW rats immunized with MBPGP63-88, but not with MBPRAT63-88, indicating that critical encephalitogenic characteristics are associated with this T cell subset. We conclude that the preferential recruitment of TCRBV8S2+ T cells in the LEW rat EAE model is due to selective, high-avidity recognition of the nonself-MBPGP63-88 in the context of the RT1.Bl molecule. This inference lends support to the notion that the highly restricted TCR repertoire of the self-MBP-reactive T cells in certain genetically predisposed multiple sclerosis patients may have its source in a multistep molecular mimicry event.
Three Populations of Mouse Lymph Node Dendritic Cells with Different Origins and Dynamics
Authors: Salomon Benoı̂t , Cohen José L. , Masurier Carole , Klatzmann David 
Published: January 2023

Abstract
We have identified three distinct populations of mouse lymph node dendritic cells (DC) that differ in their capacity to uptake Ag delivered by different routes, and in their dynamics. The “l-DCs” are large cells that resemble the interdigitating cells and have a mature phenotype and a slow turnover. They derive from the regional tissues. The “sm-DCs” and “sl-DCs” are smaller (hence s-DC), have a more immature phenotype and a rapid turnover. The sl-DC phenotype, including CD8α expression, suggests a lymphoid-related origin. The sl-DC population is expanded 100-fold after an in vivo flt3 ligand treatment. The sm-DC phenotype suggests a myeloid-related origin. Interestingly, sm-DCs can acquire i.v. injected macromolecules in less than 30 min after injection. They may, therefore, play an important role in the immune response against blood Ags.
CXC Chemokines Suppress Proliferation of Myeloid Progenitor Cells by Activation of the CXC Chemokine Receptor 2
Authors: Sanchez Ximena , Suetomi Katsutoshi , Cousins-Hodges Beth , Horton Julie K. , Navarro Javier 
Published: January 2023

Abstract
IL-8 is one of the major mediators of the transendothelial migration of neutrophils from the circulation to the site of injury and infection. In this work we demonstrate that the CXC or α-chemokines, IL-8 and melanoma growth stimulatory activity (MGSA) induce myeloid suppression via direct action on progenitor cells, mediated by activation of the murine homologue of the CXC chemokine receptor-2 (CXCR2) or IL-8R B. We first show that proliferation of the IL-3-dependent murine myeloid progenitor cell line 32D is suppressed by human IL-8 and the functionally and structurally related peptide, MGSA. Second, we show for the first time the high endogenous expression of the murine CXCR2 in 32D cells, as demonstrated by Northern blot analysis, binding to [125I]macrophage inflammatory protein-2, and macrophage inflammatory protein-2-induced calcium responses in 32D cells. Third, we demonstrate that IL-8 and MGSA induce a rise in intracellular calcium in 32D cells. The IL-8-induced Ca2+ response is desensitizing, since a second dose of IL-8 did not trigger a second calcium response. Other chemokines, including neutrophil-activating protein-2, platelet factor-4, RANTES, and macrophage chemotactic protein-1, neither suppressed the proliferation of 32D cells nor induced a rise in intracellular calcium. Finally, the IC50 of IL-8- and MGSA-dependent suppression of proliferation of 32D cells is in good agreement with the EC50 of IL-8- and MGSA-dependent activation of neutrophil Mac-1 up-regulation and chemotaxis. Our studies are consistent with the idea that IL-8 and MGSA suppress the proliferation of 32D cells by activation of murine CXCR2.
High Affinity Receptor for IgG (FcγRI/CD64) Gene and STAT Protein Binding to the IFN-γ Response Region (GRR) Are Regulated Differentially in Human Neutrophils and Monocytes by IL-10
Authors: Bovolenta Chiara , Gasperini Sara , McDonald Patrick P. , Cassatella Marco A. 
Published: January 2023

Abstract
Since IL-10 has been shown to up-regulate the expression of the high affinity receptor for IgG (FcγRI/CD64) in human monocytes, we examined whether the cytokine exerts a similar action toward polymorphonuclear neutrophils (PMN). Unexpectedly, we found that in neutrophils, IL-10 failed to induce either the mRNA accumulation or the surface expression of FcγRI. Consistent with these findings, stimulation of PMN with IFN-γ, but not with IL-10, resulted in the induction of specific DNA-binding activities to the IFN-γ response region (GRR), a regulatory element located in the FcγRI gene promoter, required for transcriptional activation. In electrophoretic mobility shift assays (EMSAs), we confirmed that in PBMC, IL-10 induces the binding to the GRR of both STAT1 and STAT3, two members of the STAT family. In neutrophils, however, these activators did not bind to the GRR in response to IL-10, despite the fact that both STAT1 and STAT3 are expressed in these cells. On the other hand, IFN-γ was an efficient inducer of STAT1 binding to the GRR in both PMN and PBMC. The lack of inducible GRR-binding activity in IL-10-treated PMN could not be ascribed to a lack of IL-10R, and did not appear to reflect an inhibitory effect of the cytokine. Taken together, our data suggest that IL-10 is unable to induce FcγRI gene expression in neutrophils because the intracellular signaling pathway triggered by the cytokine is impaired at the level of, or upstream of, STAT1 and/or STAT3 activation.
Regulation of Monocyte IL-10 Synthesis by Endogenous IL-1 and TNF-α: Role of the p38 and p42/44 Mitogen-Activated Protein Kinases
Authors: Foey Andrew D. , Parry Sarah L. , Williams Lynn M. , Feldmann Marc , Foxwell Brian M. J. , Brennan Fionula M. 
Published: January 2023

Abstract
IL-10 is an anti-inflammatory cytokine with potent immunomodulatory effects, including inhibition of cytokine production. However, regulation of monocyte IL-10 production is poorly understood. In this report we have investigated the mechanisms of LPS-induced IL-10 production by human peripheral blood monocytes and demonstrate that IL-10 synthesis is uniquely dependent on the endogenous proinflammatory cytokines IL-1 and/or TNF-α. LPS signal transduction in monocytes has been shown to involve activation of the p38 and p42 mitogen-activated protein kinase (MAPK) cascades. The results in this paper indicate that inhibition of p38 MAPK potently inhibited the production of IL-10, IL-1β, and TNF-α, whereas blockade of the p42/44 MAPK pathway, while partially inhibiting TNF-α and IL-1β production, had no effect on monocyte secretion of IL-10. Furthermore, neither the inhibition of monocyte TNF-α induced by IL-10 nor the stimulation of soluble TNF receptor production was affected by inhibition of the p42/44 MAPK pathway, suggesting that this signaling event is not involved in either monocyte production of or anti-inflammatory responses to IL-10. These data raise the interesting possibility that proinflammatory TNF-α-mediated effects may be selectively blocked without modulating the induction or the response to IL-10, whereas the signaling events associated with the anti-inflammatory events induced by IL-10 remain to be elucidated.