bluuebunny/crossref_metadata_2025_split huggingface dataset:
An RNA binding protein, Y14 regulates TNF-α-induced NF-κB activation and IL-6 expression (P6329)
Authors: Togi Sumihito , Muromoto Ryuta , Kon Shigeyuki , Sekine Yuichi , Matsuda Tadashi 
Published: January 2023

Abstract
Y14 (also known as RNA-binding motif protein 8A, RBM8A) is an RNAbinding protein that binds preferentially to spliced mRNAs immediately upstream of the exon-exon junctions, and remains bound to the mRNA after nuclear export. Thereby, Y14 is thought to act mainly as a translational regulator. Recently, we demonstrated that Y14 specifically interacts to STAT3, and enhances IL-6/STAT3-mediated transcriptional activation. These results suggest that Y14 acts as not only translational regulator but also transcriptional regulator by interacting transcriptional factors. However, the roles of Y14 in cytokine signaling are still largely unknown. Here, we analyzed the effect of Y14 on another cytokine signaling mediated by TNF-α/NF-κB. Using small interfering RNA-mediated Y14 knockdown, we found that endogenous Y14 positively regulated TNF-α-induced IL-6 production in HeLa cells. To elucidate the mechanism of Y14-mediated regulation of NF-κB signaling, we screened the Y14-interacting proteins in NF-κB signaling and identified RIP1 and TRADD as a novel Y14-binding partner, both are known as novel regulators of TNF-α/NF-κB signaling. Furthermore, we found that Y14 facilitates the RIP1/TRADD complex formation and enhances RIP1/TRADD-mediated NF-κB transcriptional activity. These results demonstrate that Y14 is a novel regulator of TNF-α/NF-κB signaling by enhancement of the RIP1/TRADD complex formation.
Identification of signaling molecules responsible for IL-2-mediated cytokine expression in human T cells (P6343)
Authors: Kaminuma Osamu , Kitamura Noriko , Mori Akio , Hiroi Takachika 
Published: January 2023

Abstract
IL-2 is an important cytokine regulating growth, differentiation and function of T cells. IL-2 directly induces production of several Th2 cytokines by T cells, especially of human origin. The mechanisms of IL-2-mediated cytokine synthesis have not been clarified, though the contribution of IL-2 receptor (IL-2R)β has been suggested. Here, by employing a proteomic approach, the intracellular signaling molecules downstream of IL-2Rβ were investigated. IL-2Rα and IL-2Rγ were stably transfected in a T cell hybridoma established by fusing an antigen-specific human T cell clone and BUC cells. The resulting hybridoma was further transfected with full-length and intracellular component-truncated IL-2Rβ. Then, the differential protein tyrosine phosphorylation profiles in those cells following IL-2 stimulation were examined by two-dimensional gel electrophoresis and mass spectrometry. Several proteins specifically phosphorylated in full-length IL-2Rβ-expressing cells were identified. Among them, overexpression of protein phosphatase (PP)1β significantly augmented IL-2-induced IL-5 and IL-13 expression in human peripheral CD4+ T cells, whereas TCR-induced cytokine expression was not affected. In contrast, introduction of PP1 regulatory subunit 2 as well as treatment with tautomycin, a PP1 inhibitor, but not ocadaic acid, a PP2A inhibitor, inhibited the IL-2-mediated responses. Conclusively, PP1 is a key molecule responsible for IL-2-mediated cytokine synthesis in human T cells.
The evolution of TNF-induced apoptosis reveals 550 million years of functional conservation (P6345)
Authors: Quistad Steven , Stotland Aleksandr , Barott Katie , Grasis Juris , Wolkowicz Roland , Rohwer Forest 
Published: January 2023

Abstract
Coral reef health is in rapid decline worldwide yet the molecular mechanisms behind coral death remain poorly understood. The Tumor Necrosis Factor (TNF) receptor-ligand superfamily (TNFRSF/TNFSF) is a central mediator of apoptosis and it is hypothesized that the expansion of the TNFRSF/TNFSF occurred following the divergence of invertebrates and vertebrates. Here we challenge this hypothesis and identify more putative coral TNFRSF members than any organism described thus far, including humans. We then predicted Human TNFα (HuTNFα), a known inducer of apoptosis in humans, would also cause apoptosis in coral. Upon HuTNFα stimulation the coral proteome underwent an acidic shift, suggesting the induction signaling cascades. Stimulation of coral with HuTNFα also induced apoptotic blebbing, caspase activation and coral bleaching. This work identifies the first ligand/receptor system to be directly involved with apoptosis and bleaching in coral, and provides evidence for an ancient origin of the TNFRSF/TNFSF that has been functionally maintained for over 550 million years.
Jak3 is a key regulator of actin cytoskeleton dynamics in CCR7 and CXCR4 dependent signaling. (P6292)
Authors: Ambriz Peña Xochitl , Olguín Alor Roxana , Martínez Cuatepotzo Berenice , Macías-Silva Marina , García-Zepeda Eduardo , Soldevila Gloria 
Published: January 2023

Abstract
Jak3 plays an important role in the signaling pathways of chemokine receptors CCR7 and CXCR4. As cytoskeletal dynamics are essential to allow migration of T cell towards chemokines, and migration of T cells is severely impaired in absence of Jak3, here we analyzed the role of Jak3 in chemokine-dependent cytoskeleton reorganization. Our study demonstrated decreased actin polymerization in Jak3-pharmacologically inhibited murine and human T cells and in Jak3 deficient murine T cells in response to CCL19, CCL21 and CXCL12. This correlates with an alteration of the cofilin phosphorylation kinetic observed in the absence of Jak3, but not after Gαi inhibition by pertussis toxin (PTX). Furthermore, analysis of the activation and localization of small GTPases Rac1 and RhoA showed that Jak3 inhibited cells displayed increased basal levels of active Rac1, whose relocalization after chemokine stimulation was impaired. These effects did not occur in PTX treated cells, which showed only a minor activation of Rac1. In contrast, RhoA activation was severely affected both in Jak3-inhibited and PTX treated cells. In summary, our results provide strong evidence that T cells require Jak3 to achieve appropriate actin dynamics, cofilin kinetics and activation of the small GTPases Rac1 and RhoA in response to chemokines. These data supports the notion that Jak3 and the Gαi protein play complementary and independent roles in the chemokine receptor signaling pathways of CCR7 and CXCR4.
NF-κB controls IL-7 receptor expression in T cells (P6295)
Authors: Molinero Luciana , Miller Michelle , Mashayekhi Mona , Chen Luqiu , Zhou Ping , Tramontini Nicole , Michelotti Monica , Liu Xindong , Zhu Xiaoping , Alegre Maria-Luisa 
Published: January 2023

Abstract
IL-7 and tonic TCR signaling control naïve T cell homeostasis. The transcription factor NF-κB plays a key role during T cell activation, proliferation and survival, but little is known on the role of basal NF-κB in quiescent T cells. Using mice bearing NF-κB impaired T cells (IκBαΔN), we show that basal levels of NF-κB signaling in naïve T cells are required for cell survival both in vivo and in vitro. In vitro, IκBαΔN T cells display reduced survival to IL-7, IL-7-mediated STAT5 phosphorylation and Bcl2 upregulation. Indeed, protein levels of IL-7Rα, but not common γc subunit (CD132), are markedly reduced in IκBαΔN naïve T cells. Assessing mice deficient for NF-κB1 and NF-κB2 subunits, canonical (NF-κB1) but not alternate (NF-κB2) NF-κB pathway is required for IL7Rα expression in T cells. Conversely, constitutive activation of NF-κB in T cells (Lck-Cre x IKKβCA) enhances IL-7Rα expression and IL-7 induced T cell survival. RelA/p65 and NF-κB1/p50 might control transcription through a κB binding region located 3.5 kb upstream of il7r gene, as assessed by EMSA and chromatin immunoprecipitation. Notably, using a NF-κB pharmacological inhibitor we show that NF-κB also controls IL-7Rα expression in human T cells. Taken together, our data suggest that NF-κB regulates il7r transcription both in mice and human, therefore affecting homeostasis of naive T cells.
Regulatory dendritic cells suppress NK cell activation by promoting IL-10 secretion and activating an NKp46-mediated inhibitory circuit. (P1072)
Authors: Zwirner Norberto , Avila Damian , Spallanzani Raul , Rossi Lucas , Domaica Carolina , Ziblat Andrea , Fuertes Mercedes , Rabinovich Gabriel 
Published: January 2023

Abstract
Regulatory dendritic cells (regDC) constrain the immune response in physiological and pathological conditions including tumor settings. Cross-talk between mature dendritic cells (mDC) and NK cells leads to reciprocal activation of both cells, but the impact of regDC on NK cells remains unknown. Our aim was to investigate the functional outcome and mechanisms underlying the interactions between regDC and NK cells. Human regDC generated from monocyte-derived DC treated with LPS and dexamethasone, opposed to mDC, triggered very little amounts of IFN-γ secretion by NK cells. This effect was partially due to insufficient amounts of IL-18. Blocking experiments demonstrated that regDC have the potential ability to stimulate IFN-γ secretion by NK cells through NKp30, but that this effect was overridden by a suppressive circuit that involves IL-10, NK cell inhibitory receptors and, unexpectedly, engagement of the activating receptor NKp46. Surprisingly, the opposing role of NKp30 and NKp46 on IFN-γ secretion was also observed during the cross-talk between mDC and NK cells. Accordingly, similar amounts of NKp46 ligands were found to be expressed on mDC and regDC. Our findings unveil a previously unrecognized regulatory mechanism through which regDC regulate NK cell activation and identify a novel inhibitory role for NKp46 which counterbalances the stimulatory activity of NKp30. These results might be relevant in shutting-down NK cell-mediated anti-tumor immune responses.
B cell intrinsic and extrinsic roles of ADP-ribosyltransferase, PARP14 in regulation of IgA and IgE responses (P1078)
Authors: Cho Sung Hoon , Raybuck Ariel , Wei Mei , Erickson John , Williams John , Boothby Mark 
Published: January 2023

Abstract
Immunological memory, including both persistent and recall antibody (Ab) responses, enables more efficient and effective protection against infection, but key molecular mechanisms regulating emergence and persistence of memory B cells and plasma cells remain unclear. Poly-ADP-Ribose Polymerase14 (PARP14) is highly expressed in B cells and identified as a Stat6-interacting protein with intrinsic mono-ADP-ribosyltransferase (mART) activity. Although there are 17 PARP family members, the physiological function of most PARPs are not known well. Here we show that recall IgA and IgE production are impaired in PARP14-deficient mice. Further analysis revealed that, although PARP14 regulation of IgE involves B cell intrinsic function, IgA regulation by PARP14 was predominantly B cell extrinsic. Of note, PARP14 regulates the levels of CD103+ dendritic cells and T helper 17 (Th17) cells which might influence IgA generation in B cells. Moreover, PARP14 regulates the expression of RORα, Runx1 and Smad3 during Th17 differentiation, and mART activity of PARP plays a critical role in Th17 differentiation. Collectively, these results shed new light on differential mechanisms of Ig regulation, provide evidence that an endogenous mono ADP-ribosyltransferase regulates recall Ab production, and may have important implications for a new therapeutic target.
Targets of somatic hypermutation within IgH genes in zebrafish (P1080)
Authors: Caldwell Tomika , Zimmerman Anastasia 
Published: January 2023

Abstract
In mammals, somatic hypermutation (SHM) of IgH genes is critical for the generation of high affinity antibodies and effective immune responses. Knowledge of sequence specific biases in the targeting of mutations can be useful to understand antibody repertoires produced in response to infections, B cell neoplasms, or autoimmune disease. To evaluate potential nucleotide targets of SHM in zebrafish, we constructed a cDNA library of V(D)J_C segments from randomly selected clones which were sequenced and analyzed. Mutations were most prevalent in V regions with a bias towards single base transitions and increased mutation in complementarity determining regions. Mutations were overrepresented at WRCH/DGYW motifs suggestive of activation-induced cytidine deaminase (AID) targeting common in mice and humans. In contrast to mammals, AID hotspots were largely restricted to palindromic WRCH/DGYW motifs. Taken together, the data reveal specific nucleotide targets of SHM in zebrafish and suggest both AID and affinity maturation contributes to antibody diversification in this emerging immunological model.
Myeloid-derived suppressive cells enhance differentiation of Th17 cells in an IL-1β dependent manner (P1096)
Authors: Wang Xiang-Yang , Yi Huanfa , Guo Chunqing , Yu Xiaofei 
Published: January 2023

Abstract
Myeloid-derived suppressive cells (MDSCs) have been implicated in the pathogenesis of several diseases, including cancer and autoimmune disorders. We found that CD11b+Gr-1+ MDSCs from tumor- or experimental autoimmune encephalomyelitis (EAE)-bearing mice promote the differentiation of naïve CD4+ T cell precursors into Th17 cells in a highly efficient manner. The presence of MDSCs also results in elevation of IL-17A production and upregulation of the orphan nuclear receptor RORA and RORC in T cells. IL-1β-derived from MDSCs is identified as a major mediator of the enhanced Th17 differentiation, which involves the IL-1 receptor on CD4+ T cells. Depletion of MDSCs leads to significantly reduced Th17 response and decreased clinical scores of EAE as well as myelin injury. Our data reveal a new feature of MDSC action in the shaping of inflammatory Th17 cell responses and provide additional insights into the pleiotropic functions of this myeloid cell population. These new findings support the concept of targeting MDSCs for potentially effective intervention of Th17 cell/IL-17-mediated immunopathology in cancer and autoimmune diseases (e.g., multiple sclerosis).
Mesenchymal stem cells alleviate Propionibacterium acnes-primed mice liver injury by inducing differentiation of regulatory DCs (P1098)
Authors: Zhang Yi , Jin Min , Zhang Yanyun 
Published: January 2023

Abstract
Fulminant hepatic failure is a clinical syndrome characterized by sudden and severe impairment of liver function. Mesenchymal stem cells have been proposed as a promising therapeutic approach for fulminant hepatic failure. In this study, we have used Propionibacterium acnes-primed, LPS-induced liver injury in mice as an animal model of human fulminant hepatic failure. We demonstrated that administration of mesenchymal stem cells significantly ameliorated liver injury and improved the survival rates of mice subjected to fulminant hepatic failure. Therapeutic efficacy of mesenchymal stem cells could be attributed to decreased infiltration of CD4+ T cells in the liver, inhibition of Th1 cells, and induction of regulatory T cells. Intriguingly, a distinct liver population of CD11c+MHCIIhiCD80loCD86lo regulatory DCs was induced. Further mechanistic studies demonstrated that mesenchymal stem cell-derived prostaglandin E2 and one of its receptors, EP4, played essential roles in the differentiation of CD11c+B220- DC precursors into regulatory DCs in a PI3K-dependent manner. Our findings demonstrated, for the first time, critical regulatory properties of mesenchymal stem cells for induction of regulatory DCs from CD11c+B220- DC precursors. This study further lays a solid foundation for application of mesenchymal stem cells in fulminant hepatic failure therapy.
Human B cells are targets for Brucella abortus infection. (P3130)
Authors: Ramírez Saldaña Maricela , Aguilar Santelises Miguel , Moreno Lafont Martha , Santos Argumedo Leopoldo , Paredes Cervantes Vladimir , López Santiago Rubén 
Published: January 2023

Abstract
It has been demonstrated that Brucella abortus is capable to multiply into professional antigen presenting cells such as macrophages and dendritic cells. However, there are a few reports about Brucella infection into B cells. In this work, we evaluated the ability of B. abortus 2308 for infect the human B cell line, NALM6 R. B cells cultured in RPMI medium supplied with L-glutamine and 10% of fetal calf serum were infected with several MOIs of Brucella abortus 2308 transformed by electroporation with the pBBR1MCS-2-gfp-mut3 plasmid to evaluate the entry of green fluorescent Brucella. The percentage of cells containing bacteria was evaluated by flow cytometry at three time points. To evaluate whether Brucella was on the surface or into the B cells, kinetics of infection was performed and analyzed by transmission electron microscopy. Association of Brucella abortus 2308-gfp-mut3 with NALM6 R cells increased in a dose-time dependent manner to reach a maximum of 50% of NALM6 R infected cells. Electronic microscopy revealed that NALM 6R B cells produce filopodia over B. abortus. Once inside, the bacteria resided into small vesicles. Apparently bacteria underwent some bactericidal mechanism, because the electron microscopy showed bacteria degraded into vesicles. It was not observed evidence of replication of bacteria inside B cells. Brucella abortus 2308 is capable to interact with NALM6 R membrane, to induce filopodia formation and to entry into B cells inside vesicles.
Adhesins and host serum factors drive Yop translocation by Yersinia pseudotuberculosis into professional phagocytes during animal infection (P3142)
Authors: Maldonado-Arocho Francisco , Green Carlos , Fisher Michael , Paczosa Michelle , Mecsas Joan 
Published: January 2023

Abstract
Yersinia delivers Yops into numerous types of cultured cells, but predominantly to professional phagocytes during animal infection. The basis for this cellular tropism during animal infection is not understood. This work demonstrates that Yop translocation into specific cell types by Yersinia pseudotuberculosis (Yptb) is a multi-factorial process where several adhesins and host factors are employed for efficient Yop delivery into phagocytes. Strikingly, when WT or a multiple adhesin mutant strain, ΔailΔinvΔyadA, colonized tissues to comparable levels, ΔailΔinvΔyadA translocated Yops into significantly fewer cells, indicating that adhesins influence the number of cells successfully translocated into during infection. However phagocytes were still selectively targeted for translocation, indicating that other bacterial and/or host factors contribute to this function. Complement depletion showed that complement both limits infection by ΔailΔinvΔyadA but not WT and that adhesins enlist complement to directs Yop translocation into professional phagocytes during animal infection.
Brucella induces an unfolded protein response via TcpB in macrophages (P3116)
Authors: Khan Mike , Magnani Diogo , Harms Jerome , Radhakrishnan Girish , Durward Marina , Liu Yi-Ping , Splitter Gary , Smith Judith 
Published: January 2023

Abstract
Brucella melitensis is a facultative intracellular bacterium that invades and replicates within macrophages and dendritic cells. With greater than 500,000 new infections per year, brucellosis is the most prevalent zoonosis worldwide. Currently, a safe and effective human vaccine does not exist and Brucella’s intracellular replicative niche renders the organism resistant to antibiotics. A better understanding of host-pathogen interactions supporting Brucella replication is necessary for vaccine and therapeutic development. Brucella fuses with the endoplasmic reticulum (ER) in order to replicate and may provoke a conserved ER stress response called the Unfolded Protein Response (UPR). B. melitensis infection in RAW 264.7 murine macrophages and bone marrow-derived macrophages upregulated the UPR target genes BiP, CHOP, and ERdj4, and induced XBP1 mRNA splicing. Upregulation of CHOP and ERdj4 was MyD88-independent whereas XBP1 splicing was MyD88-dependent. A Brucella TcpB mutant showed significantly reduced expression of BiP, CHOP, and ERdj4. Purified TcpB, a microtubule-modulating protein, induced UPR target genes. Also, purified TcpB caused ER restructuring similar to infection with B. melitensis. Finally, Brucella replication was significantly impaired by tauroursodeoxycholic acid, a pharmacologic UPR inhibitor. These results suggest that Brucella induces the UPR to enable its intracellular replication and thus provides a novel therapeutic target for brucellosis treatment.
B cells shape T cell responses during Pneumocystis infection (P3053)
Authors: Elsegeiny Waleed , Zheng Mingquan , Ricks David , Chen Kong , Kolls Jay 
Published: January 2023

Abstract
Pneumocystis pneumonia (PCP) remains one of the leading causes of death in immunocompromised patients. Disease is attributed to the loss of CD4 T cells; however recent studies suggest that B cells also play a protective role in clearing PC in an Ig-independent manner through antigen presentation. Several patients treated with anti-CD20 have developed PCP and thus we investigated the effect of anti-CD20 on primary PC infection. We hypothesized that B cells in part function as a critical antigen-presenting cell to helper T cells. To test this, C57BL/6 WT mice were administered anti-CD20, anti-CD4 (as a pos. control) or both, and then infected with a 105 inoculum of Pneumocystis murina. Lung mononuclear cells were harvested two weeks after infection, assessed for cellularity and then stimulated in vitro with PC antigen for cytokine profiling. Even though CD20-depleted animals had unaltered T cells numbers, there were diminished cytokine responses for IL-5, IL-17, and IL-10. These data suggest that B cells are involved in mediating optimal T cell cytokine responses against PC. We are currently testing if B cells are required in the recall responses from memory T cells by performing B cell depletion during the re-challenge of mice that have recovered from primary PC infection. We are also investigating if B cells modify T regulatory cells during Immune Reconstitution Inflammatory Syndrome (IRIS), a disease that affects a subset of patients upon reconstitution of CD4+ cells.
Regulatory T cells mediate immunosupression induced by experimental hypothyroidism. (P1215)
Authors: Valli Eduardo , Sterle Helena A , Méndez Huergo Santiago , Mascafroni Ivan , Klecha Alicia J , Barreiro Arcos María L , Rabinovich Gabriel A , Cremaschi Graciela A 
Published: January 2023

Abstract
Thyroid status modulates immunity, being the circulating levels of thyroid hormones (THs) responsible for the regulation of lymphocyte activity. Formerly we observed that experimental hypothyroidism (Exp-hypo) decreases Th1 cytokine production and T cell-mediated immunity. Here we aimed to elucidate the mechanisms underlying immunosuppression triggered by Exp-hypo. Lymphocyte subsets were assessed in spleens and lymph nodes of hypothyroid (hypo-WT) and control (C) mice. Percentage of Treg (CD4+CD25+FoxP3+) cells (Tregs %) was significantly increased in the hypo-WT group without differences in CD3/CD19 or CD4/CD8 ratios. When naïve T cells were differentiated to inducible Treg cells in vitro, similar results were obtained. Treg cells overexpress galectin-1 (Gal-1), an immunoregulatory β-galactoside-binding protein, and mice lacking this lectin (Lgals1-/-) showed reduced Treg cell activity. To evaluate the role of Gal-1 in the regulation of Tregs in Exp-hypo we also analyzed lymphocyte reactivity and the percentage of Tregs % in eu- and hypothyroid Lgals1-/- mice (hypo-KO). We found an increased T cell proliferation and a reduction in the Tregs % in hypo-KO mice respect to the hypo-WT group. We conclude that modulation of immunity in the Exp-hypo with low circulating levels of THs is associated to a significant rise in the percentage of spontaneous and inducible Tregs. This increase relies on the expression of Gal-1 and may be related to a functional deficit of T cells.