bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune modulation through silencing CD80 and CD86 in dendritic cells using siRNA (88.4)
Authors: Suzuki Motohiko , Zhang Xusheng , Zheng Xiufen , Vladau Costin , Li Mu , Chen Dong , Gracia Bertha , Min Wei-Ping 
Published: January 2023

Abstract
Dendritic cells (DC) are central cells of the immune system that can stimulate or suppress immune responses, partially depending on their expression of costimulatory molecules. CD80 and CD86 are critical costimulatory molecules for both T cell responses and Th differentiation. Thus, silencing DC expression of CD80 and CD86, using siRNA, could potentially enable manipulation of immune responses. Since silencing of CD80 or CD86 in DC has not been reported, in this study we investigated the tolerogenesis and Th differentiation capacity of CD80/CD86 in DC after siRNA-mediated gene silencing. Gene silencing was performed by transfecting mouse bone marrow-derived DC with CD80 or CD86 siRNA. The gene silencing efficacy was measured by flow cytometry, RT-PCR, and real time PCR. DC that were transfected with CD80 or CD86 siRNA induced inhibition of T cell responses in MLR and generated T regulatory cells. The CD4+CD25+FoxP+ cell subset was significantly increased in a co-culture system that contained CD80- or CD86-silenced DC and allogeneic T cells. Furthermore, CD80 siRNA significantly decreased IFN-gamma, although a reduction in IL-4 was not observed. Conversely, CD86 siRNA significantly reduced IL-4 but did not reduce IFN-gamma. This study suggested, for the first time, that CD80 siRNA and CD86 siRNA can be useful tools for generating tolerogenic DC with a differential effect on modulating cytokine production.
The Importance of IL-2 for FOXP3 expression (88.8)
Authors: Popmihajlov Zoran , Smith Kendall A 
Published: January 2023

Abstract
To examine the role of TCR-induced Interleukin-2 (IL2) in TCR-regulated FOXP3 expression, PBMC from normals were stimulated in vitro with anti-CD3 monoclonal antibody (OKT3) +/− anti-CD25 or anti-IL2, and/or human rIL-2. 4-color flow cytometry was used for the expression of FOXP3. OKT3 increased FOXP3 expression in both CD4+ and CD8+ T cells. Peak occurred at 24h (CD4+ 13.63% ± 0.45 (SEM)) vs. (CD8+ 5.62% ± 0.27 (SEM) (n=26), & by 96h was back to baseline levels (CD4+ 1.82% ± 0.24 (SEM) vs. CD8+ 0.13% ± 0.05 (SEM))(n=18). Both anti-CD25 and anti-IL2 inhibited FOXP3 expression, to a maximal suppression of ~ 60% in both CD4+ and CD8+ T cells. Human rIL-2 restored and prolonged FOXP3 expression. By comparison, anti CD28/CD3 stimulation +/− rIL2 of murine T cells does not activate FOXP3 expression by CD4+ cells and CD8+ cells do not express FOXP3 +/− stimulation. T cells from IL2 KO mice expressed ~ 50% FOXP3 vs. WT mice. Therefore, TCR-activated FOXP3 expression by mature human T cells is regulated in part by IL-2 signaling, and only occurs transiently in a subset of both CD4+ and CD8+ cells. In contrast, murine T cell FOXP3 expression cannot be activated via the TCR and IL2 deficiency reduces, but does not fully abrogate FOXP3 expression.
Supported by NIAID grant # RO1-AI-51181 and the Belfer Foundation.
Identification of a Non-Receptor Form of OSCAR Gene (89.39)
Authors: Khan Emad A , Cui Cai-Bin , Aukhil Ikramuddin , Flood Patrick M 
Published: January 2023

Abstract
Since its discovery, osteoclast-associated receptor (OSCAR) gene has been studied as a receptor protein. Our research is the first to identify and characterize a non-receptor form of OSCAR. While searching for proteins differentially expressed during bone remodeling, a clone of a non-receptor form of OSCAR gene (3D10) was isolated using representational difference analysis. 3D10 was found to be one of a non-receptor group of OSCAR. This group was found to have a non-spliced intron resulting in larger transcripts and proteins lacking a transmembrane domain. Comparisons were made in tissue distribution between the non-receptor and the membrane receptor forms of OSCAR using specific PCR primers and a rabbit polyclonal antibody that we synthesized. The non-receptor forms were found to be expressed in the lung, pancreas, spleen, kidneys and bone marrow, as well as in multinucleated cells and peripheral blood leukocytes. To determine potential binding partners, yeast two-hybrid screening was performed, which showed several potential binding proteins with multiple hits like URP2, PFAAP5 and BAT3. Interestingly, while 3D10 does not have a nuclear localization signal, two of its binding partners were nuclear proteins one of which is an apoptotic regulator (BAT3). 3D10 and some of its binding partners were studied using transfected cell lines with various constructs. Transfection studies using luciferase reporter plasmid for NF-κB binding sites and HEK 293 cells suggest that 3D10 down-regulates NF-κB-dependant inflammatory responses. In conclusion, 3D10 represents a novel non-receptor form of OSCAR which may be involved in the regulation of NF-κB-mediated inflammatory responses and apoptosis regulation.
Alternative Signaling of TH17 Cell Development by Sphingosine 1-Phosphate (S1P) (90.2)
Authors: Goetzl Edward J , Liao Jia-Jun , Huang Mei-Chuan 
Published: January 2023

Abstract
S1P from diverse blood and lymphoid cells signals T cell migration and other functions through its type 1 G protein-coupled receptor (S1P1). Our recent observation of increased levels of Th17 cells in mice with T cell-selective overexpression of transgenic S1P1 prompted studies of mechanisms of stimulation of Th17 cell development by the S1P- S1P1 axis. Incubation of C57BL\6 mouse splenic CD4 T cells on adherent anti-CD3 + anti-CD28 antibodies with IL-1beta, IL-6, and TGF-beta1 led to development of 26+/−9% Th17 cells (mean+/-SD, n=4), quantified by an ELISpot assay, that increased to 59+/−5% with 10-6 M S1P and 61+/−4% with IL-23 after 5 days. On day 5, secretion of IL-17 quantified by ELISA increased from 52+/−30 to 261+/−117, 470+/−98, and 438+/−61 pg/ml/24 hr/106 T cells with S1P, IL-23, and the S1P1–selective agonist SEW2871, respectively. CD4 T cell secretion of IL-4 and IFN-gamma were decreased significantly as IL-17 increased, and addition of recombinant IL-4 + IFN-gamma blunted IL-17 responses significantly. S1P-S1P1 enhancement of Th17 development was suppressed as well by IL-27 and NF-kappaB inhibition. The importance of stimulation of Th17 development and activity by the S1P- S1P1 axis is supported by the similarity of magnitude of effect and susceptibility to immunoregulation to that of IL-23.
Alpha-2-Macroglogulin (a2M) Mediates T Cell Suppression via a Peptide Sequence in its Cytokine-Binding Site but not by Cytokine Neutralization (90.6)
Authors: Koo Peter H. , Khol Matthew 
Published: January 2023

Abstract
a2M family proteins are protease inhibitors, but can also neutralize certain microbial virulence factors and influenza viruses, carry diverse types of cytokines, and inhibit T cell growth. Monoamine-reacted a2M (MA-a2M) is much more inhibitory to T cells than native a2M (N-a2M), but its mechanism of inhibition is unknown. We demonstrated that a2M family proteins form stable complexes with placental protein-14 (PP14; a potent immunosuppressive cytokine) besides TGF-β1; in addition, they enhance PP14’s ability to inhibit T-cell growth and IL2 production while not affecting IL4. Hence we postulate that a2M family proteins belong to a novel class of regulators for T cells. To investigate the role of a2M in T cell regulation and its mechanism of action, we employed a cloned Th cell line (HT), which requires IL2 or IL4 for growth and responds to TGF or PP14. TGF-β1 dose-dependently inhibits IL4-promoted but stimulates IL2-promoted HT-growth. While MA-a2M is consistently much more inhibitory to IL4-promoted HT growth than N-a2M, it dose-dependently neutralizes the immunosuppressive activity of TGF-β1; whereas N-a2M produces little effect. To study the mechanism of T cell regulation by a2M, we tested two recombinant peptides in and around a2M’s cytokine-binding site: the GST-a2M-peptide fusion proteins respectively encoding N591-N774 (FP3, which binds cytokines) and N775-N1082 (FP4, as negative control). Neither FP3 nor FP4 could block the immunosuppressive activity of MA-a2M or TGF-β1. While FP3 is potently inhibitory and adds to the inhibitory activity of TGF-β1 on HT cell growth, FP4 is not. Our data implicates an 184-a.a. sequence in a2M’s cytokine-binding site as the site for mediating T cell suppression but not for neutralization of cytokines.
Analysis of interactions in a soluble tapasin/HLA-B*0801 complex provides a mechanism for peptide selection (93.10)
Authors: Bouvier Marlene , Chen Mingnan 
Published: January 2023

Abstract
The cell-surface presentation of peptides by class I molecules is the culmination of a complex series of events that take place in the endoplasmic reticulum and involves specialized proteins, including tapasin (TPN). Although it is uncontested that TPN plays a critical role in class I maturation, a mechanistic understanding of TPN is lacking.
We examined interactions in a soluble TPN/class I complex using real-time fluorescence measurements. Results show that TPN increases the association and dissociation rates of some, but not all, peptides. TPN acts as a chaperone by increasing the concentration of peptide-deficient class I molecules in solution. We also show that a TPN-assisted mechanism of peptide selection relies on disruption of conserved hydrogen bonds at the C-terminal end of the groove; peptide sequence-dependent interactions along the entire length of the groove also play an important role.
Overall, our results suggest that the presence of TPN in the class I assembly complex ensures that bound candidate peptides that cannot meet a certain minimum energy threshold, as needed to conformationally disengage TPN, are excluded from the repertoire. We propose that the net outcome of a TPN-assisted mechanism of peptide selection is to maximize at any point in time, and according to the pool of peptides available, the diversity of minimally stable class I/peptide molecules on the cell surface.
Funded by NIH-AI45070
Survival of antigenic epitope requires class II MHC capture prior to lysosomal proteolysis (93.21)
Authors: Kim Ae , Hartman Isamu , Sadegh-Nasseri Scheherazade 
Published: January 2023

Abstract
The paradigmatic model for the generation of peptide determinants for class II major histocompatibility complex molecules (MHC II) is that proteolytic fragmentation of antigen precedes the capture of the resulting peptides by MHC II (cut/trim first, bind later). However, circumstantial evidence exists to support an alternate model in which MHC II binding of antigenic epitope occurs prior to the proteolytic fragmentation of that antigen (bind first, cut/trim later). To distinguish between these two models, we analyzed the interaction of HLA-DR1 with two protein antigens, type II collagen and influenza hemagglutinin. Here, using a novel cell?free antigen processing system composed solely of purified soluble protein components, HLA-DR1, two cathepsins, and HLA-DM, combined with mass spectrometric identification of the bound peptides, we demonstrate for both antigens that;
the protein antigens bind MHC class II prior to digestion by lysosomal proteases,the immunodominant epitope of the antigens are degraded by lysosomal proteases if not bound to MHC class II, andthe epitopes, when bound to MHCII, are protected from proteolytic degradation.
These findings conclusively support the “bind first, cut/trim later” model and have important implications in understanding the sequence of events in antigen processing and the correlation between antigen structure and immunodominance.
IL-4 and IL-13 induce type I collagen gene activity via the JNK signaling pathway in human fibroblasts. (94.28)
Authors: Bhogal Rashpal Kaur , Stoica Cristina , McGaha Tracy L , Bona Constantin 
Published: January 2023

Abstract
Little is understood of the molecular mechanisms by which fibrotic diseases such as in Scleroderma, are manifested by interleukins (IL) 4 and 13. Studies support a role for the JNK signaling pathway via transcription factors c-Jun and ATF2, being involved in activating the collagen promoter and translation of the collagen gene. To examine the role of JNK signaling in IL-4/IL-13-induced collagen gene activation, we transfected human fibroblasts with a luciferase reporter plasmid under control of the α2(I) collagen promoter to assess JNK signaling on type I collagen promoter activity. We reveal a critical role for JNK 1 in IL-4/IL-13-induced collagen promoter activity subsequent to ectopic expression of c-Jun and ATF2. In contrast, introduction of a dominant negative (dn) mutant reduces basal and cytokine-induced promoter activity. We demonstrate that the JNK signaling pathway leading to the activation of the collagen gene in fibroblasts is effective not only for TGF-β signaling but also for IL-4/IL-13 signaling.
Mechanisms of processing and secretion of IL-1β in fish (94.30)
Authors: Lopez-Castejon Gloria , Roca Francisco J. , Sepulcre M Pilar , Meseguer José , Mulero Victoriano 
Published: January 2023

Abstract
IL-1β is a potent pro-inflammatory cytokine which is translated as a leaderless 33 kDa precursor protein (proIL-1β) that is processed into its 17 kDa active form by the IL-1β-converting enzyme (ICE, caspase-1). Several stimuli have been reported to activate caspase-1, including the engagement of P2X7 receptors by extracellular ATP and infection with invasive bacteria. While the recognition site for caspase-1 is well conserved in mammals, most of the non-mammalian IL-1β genes cloned so far lack this conserved site. In addition, we have previously shown that extracellular ATP fails to induce the processing and release of this cytokine in the bony fish gilthead seabream. In this study, we report that the stimulation of seabream leukocytes with flagellin or bacterial DNA leads to the processing of proIL-1β into a 20 kDa form, although it largely remains intracellular. However, the infection of leukocytes with salmonella results in the efficient and specific release of the mature form. Interestingly, the processing of IL-1β in this species is not prevented by a specific inhibitor of caspase-1 or a pan-caspase inhibitor. Whatever the case, our results suggest that the processing and release of IL-1β in early vertebrates is mediated by cell death upon bacterial infection by a caspase-1 independent mechanism, while a more sophisticated mechanism operated by activation of ATP-gated P2X7 receptors appeared later in evolution.
This work was supported by the Spanish Ministry of Education and Science (grant BIO2005-05078 to V.M. and fellowship to G.L.-C.).
Function of the fractalkine receptor during autoimmune inflammation (96.15)
Authors: Cardona Astrid E , Sasse Margaret E , Cardona Sandra M , Mazutani Makiko , Hamann Isabell 
Published: January 2023

Abstract
Fractalkine a neuronal derived chemokine, undergoes proteolytic cleavage and is released as a soluble molecule. In the CNS, fractalkine binds CX3CR1 on microglia, promoting microglial survival and tonically inhibiting microglial neurotoxicity. CX3CR1 is also expressed by circulating monocytes, NK cells and a small population of T cells. Cx3cr1−/ − mice exhibited severe EAE, and CX3CR1 was required for the accumulation of regulatory NK in the brain. In order to distinguish the role of CX3CR1 on microglia and NK cells during EAE, we generated bone marrow radiation chimeras. Both KO→WT and WT→KO exhibited a severe clinical EAE. In KO→WT mice, disease was associated with an unusually severe and non-remitting form of EAE with a high proportion of the mice exhibiting ascending paralysis that was sustained up to 45–50 days post-immunization. These results suggest that the EAE phenotype of Cx3cr1−/ − mice is primarily determined by its function on circulating cells, likely CD3−NK cells rather than microglia.
ADAM17 deficiency by mature neutrophils has differential effects on L-selectin shedding (97.14)
Authors: LI YING , HERRERA AMY , WALCHECK BRUCE 
Published: January 2023

Abstract
L-selectin directs neutrophils to sites of inflammation, and upon their activation, surface expression of the receptor is rapidly downregulated by ectodomain shedding. ADAM17 (also known as Tumor necrosis factor-alpha-converting enzyme or TACE) is a sheddase of L-selectin; however, Adam17 gene-targeting (ADAM17−/−) in mice is perinatal lethal and its role in L-selectin shedding by mature leukocytes has not been determined. This issue was addressed here by generating radiation-chimeric mice reconstituted with ADAM17−/−fetal liver progenitor cells. ADAM17-deficient neutrophils, monocytes and lymphocytes failed to shed L-selectin in response to PMA, as did neutrophils infiltrating the inflamed peritoneum. In addition, the lack of functional ADAM17 resulted in significantly increased levels of L-selectin surface expression by leukocytes in peripheral blood, suggesting the sheddase is also involved in the constitutive cleavage of L-selectin. Interestingly, it seems that ADAM17 is not required in all manners of L-selectin turnover. Plasma levels of soluble L-selectin were similar between ADAM17−/−chimeric and control mice, as was the shedding of L-selectin by neutrophils undergoing apoptosis. The latter process, however, was diminished by a metalloprotease inhibitor (TAPI-0), indicating the involvement of a metalloprotease sheddase other than ADAM17. Our data is the first to demonstrate that L-selectin’s surface density on neutrophils is regulated by ADAM17, but homeostatic cleavage of L-selectin is not.
This work is supported by grant HL61613 (B.W.) from the National Institutes of Health.
PARP-1 and iNOS relationship in allergen-induced lung inflammation: dependence of iNOS expression on PARP-1 and its dispensability for eosinophil recruitment post-IL-5 production (98.1)
Authors: Boulares Hamid , Suzuki Yasuhiro , Naura Amarjit , Oumouna Mustapha , Datta Rahul , Hans Chetan 
Published: January 2023

Abstract
The inducible nitric oxide synthase (iNOS) has been suggested to play an important role in the pathogenesis of asthma by contributing to eosinophilia and the ensuing oxidative damage after allergen exposure. IL-5 was shown to induce iNOS expression and that a reduction in iNOS expression reduces airway recruitment of eosinophils in response to allergen exposure. We recently showed that PARP-1 also plays a critical role in the pathogenesis of the disease by promoting eosinophil recruitment by participating in the cascade leading to IL-5 production. Here, we investigated the interrelationship between PARP-1 and iNOS in inducing eosinophilia. Our results show that iNOS gene deletion reduces eosinophil recruitment but to lesser degree as compared to PARP-1 gene deletion, suggesting a partial role for this protein in airway inflammation. PARP-1 gene deletion severely reduced iNOS expression in the airways of ovalbumin (allergen)-challenged mice and consequent nitration of target proteins and this phenomenon was closely associated with an impairment of p65 NF-κB nuclear translocation and phosphorylation of its inhibitor, I-κBα. IL-5-intranasal administration restored the eosinophilia in ovalbumin-challenged PARP-1−/− mice but did not reverse iNOS expression, suggesting that iNOS may be dispensable for eosinophil recruitment after IL-5 production. Altogether, our results further support the role of PARP-1 in the process of eosinophil recruitment during allergen-induced lung inflammation and provide evidence for a potential specific relationship between PARP-1 and iNOS.
Support: NIH-HL072889 and 1P20RR18766 to HB.
Rgs13 acts as a nuclear repressor of CREB in B lymphocytes (B10)
Authors: Xie Zhihui , Johnson Eric N , Druey Kirk M 
Published: January 2023

Abstract
The autonomic nervous system profoundly impacts immune functions, particularly during stress. Norepinephrine stimulates Gαs-coupled β2-adrenergic receptors on B lymphocytes, leading to cAMP response element binding protein (CREB)-mediated transcription of a variety of genes including the B-cell specific Oct 2 coactivator (OCA-B). Regulator of G protein signaling 13 (Rgs13) is a member of a large protein family that attenuates G-protein-mediated signal transduction by acting as GTPase-accelerating-proteins (GAPs) for Gαi and Gαq but not Gαs. Here, we show that Rgs13, which is enriched in germinal center B lymphocytes, is a direct transcriptional repressor of CREB in B cells. OCA-B expression is increased in B cells from Rgs13−/− mice both in the basal state and after exposure to the β2-agonist terbutaline in vitro. β2-adrenergic receptor stimulation induces nuclear translocation of Rgs13 and binding to activated pCREB in a complex with CREB binding protein (CBP/p300). This interaction impairs CREB binding to DNA and transcription of a CRE reporter gene. Rgs13 −/− B lymphocytes exhibit increased basal and agonist-stimulated pCREB-DNA binding. We propose that Rgs13 acts as a direct nuclear inhibitor of CREB-driven transcription in B lymphocytes independent of its GAP activity. As a result, Rgs13 may mediate important aspects of neural regulation of humoral immune responses.
Fcγ receptor activation triggers monocytes to differentiate into CD1b+ immature dendritic cells (B138)
Authors: TANAKA Motoyuki , Krutzik Stephan R , Sieling Peter A , Rea Thomas H , Modlin Robert L 
Published: January 2023

Abstract
Antibodies are potent inducers of inflammation and Fcγ receptors (FcγRs) are considered as important immune-regulators linked to infection immunity, cancer immunity and auto-immunity. We previously reported that CD1b+ dendritic cells (DC) are differentially distributed in leprosy lesions and contribute to the in pathophysiology of the polarized clinical spectrum of the disease. Here we demonstrate that activation of FcγRs on human blood monocytes triggers monocyte differentiation into CD1b+ cells. The CD1b+ population increased in a dose-dependent manner, and the differentiation was blocked by the addition of an anti-CD64 monoclonal antibody. Furthermore, Fcγ receptor ligation triggered transcription of GM-CSF mRNA as measured by real time PCR and CD1b+ cell differentiation was suppressed by the addition of an anti-GM-CSF antibody. Finally, FcγR-induced CD1b+ cells exhibited an immature dendritic cell (DC)-like phenotype. These findings predict that the stimulation of FcγRs induces GM-CSF production that in turn triggers monocyte differentiation into a CD1b+ immature dendritic cell population. In conclusion, these results provide insight into the cross-talk between the humoral and innate immune response as well as new strategies for therapeutic intervention in infectious diseases and autoimmune diseases.
Low incidence of anti-Gal α 1-3Gal and anti-porcine antigens antibodies in xenotransplanted type-1 diabetic patients after 6 years of follow-up (B160)
Authors: Esquivel-Perez Rita , Valdes Rafael A , Ayala-Sumuano Jorge-Tonatiuh 
Published: January 2023

Abstract
We have reported the clinical follow-up of diabetic patients xenotransplanted with islet cells. Here, we report the antibody response elicited against the xenograft after 6 years. Samples were screened by ELISA for anti-Gal IgM, IgG and IgG subclasses. Anti-pig antigen antibodies were tittered by means hemolytic antibody assay. Anti-Gal IgM and IgG titers of pretransplant sera were 90 and 115 respectively with no statistical differences in comparison with sera titers from healthy subjects. After first transplant the mean for anti-Gal IgG was 918 and increased with second and third transplants. After that the levels diminished to basal line. IgM titers were no different. IgG subclasses titers were not different, except for IgG2. Hemolytic anti-pig pretransplant antibodies mean was 320 however at this time the mean is 190. There is a classical humoral response against Gal antigen after each transplant with high levels of IgG but with very lower levels of IgM. However, these levels go backward 6 weeks after each transplant. During this assay we have observed an upsurge of IgG2 over the other subclasses. Low anti-pig levels elicited suggest an immune accommodation induced by this procedure.