bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonally expanded α-chain TCR transcripts are present in skin biopsies of patients with Systemic Sclerosis (135.33)
Authors: Zacharakis Nikolaos , Oleszak Emilia , Klaiber Nicholas , Myers Allen , Platsoucas Chris 
Published: January 2023

Abstract
Systemic Sclerosis (SSc) is a chronic autoimmune disease characterized by excessive deposition of collagen in the skin and many internal organs, production of autoantibodies and microvascular alterations. Previous studies in our laboratory have demonstrated the presence of high proportions of identical β-chains TCR transcripts in skin biopsies from patients with SSc of recent onset, suggestive of clonal expansions of T cells. To identify the antigen(s) recognized by clonally expanded T cells in SSc biopsies, we examine the clonality of the α-chain TCR transcripts in patients with SSc. Sequence analysis of α-chain TCR transcripts following non-palindromic PCR/Vα specific PCR and cloning revealed the presence of clonally expanded α-chain TCR transcripts in skin biopsies from four patients with SSc. Substantial proportion of identical α-chain TCR transcripts were found in these skin biopsies accounting from 16% to 32% of the transcripts sequenced. These clonal expansions were confirmed with Vα-specific PCR followed by cloning and sequencing. Identical α-chain TCR transcripts, ranging from 68% to 100%, were identified in individual Vα families. In one of these patients an identical T cell clone was clonally expanded in both peripheral blood and skin. These T cells have undergone clonal expansion in response to, as yet unidentified, specific antigen(s).
IP-10-dependent terminal differentiation of human plasma cells: an implication for autoimmunity (135.5)
Authors: Xu Wei , Dullaers Melissa , Pascual Virginia , Oh Sangkon , Banchereau Jacques 
Published: January 2023

Abstract
AAntibodies secreted by terminally differentiated plasma cells are important in immune defense, but also contribute to the pathogenesis of autoimmune diseases. How do naïve and memory B cells efficiently and promptly undergo terminal differentiation after encountering an antigen remains to be fully understood. We found that in the human tonsil most CD138+ plasma cells are surrounded by CD163+ resident macrophages. This prompted us to explore the role of macrophages in B cell activation. Sorted tonsilar macrophages were co-cultured with autologous IgD+CD27- naïve B or IgD-CD27+ memory B cells that were activated by anti-Ig, CpG and IL-2. Both naïve and memory B cells co-cultured with macrophages underwent significant proliferation and differentiation towards CD138+CD38+ plasma cells, whereas B cells alone failed to do so. A similar finding was obtained by using in vitro-generated macrophages. Such a process was tightly regulated by the dominant production of IP-10 by macrophages and the receptor CXCR3 on B cells. We found that patients with systemic lupus erythematosus (SLE) with active disease display an expansion of CXCR3+ B cells (range 20-90%) compared to those with inactive disease (range 5-15%). Accordingly, serum levels of IP-10 were elevated in active SLE patients. Thus, our data support a previously unrecognized mechanism by which macrophages induce terminal differentiation of plasma cells through secretion of IP-10, which may have potential implications autoimmunity.
CpG-B oligodeoxynucleotides inhibit Toll-like receptor-dependent and -independent induction of type I IFN in dendritic cells (136.10)
Authors: Liu Yi , Gray Reginald , Hardy Gareth , Kuchtey John , Abbott Derek , Emancipator Steven , Harding Clifford 
Published: January 2023

Abstract
CpG oligodeoxynucleotides (ODNs) signal through TLR9 to induce type-I IFN (IFNαβ) in dendritic cells. CpG-A ODNs are more efficacious than CpG-B ODNs for induction of IFNαβ. Because IFNαβ may contribute to autoimmunity, it is important to identify mechanisms to inhibit induction of IFNαβ. In our studies, CpG-B ODN inhibited induction of IFNαβ by CpG-A ODN, while induction of TNFα and IL-12p40 by CpG-A ODN was not affected. CpG-B inhibition of IFNαβ was observed in Flt3L-induced murine DCs, purified murine mDCs and pDCs, and human PBMCs. CpG-B ODN inhibited induction of IFNαβ by agonists of multiple receptors, including MyD88-dependent TLRs and MyD88-independent receptors. CpG-B ODN did not inhibit the IFNαβ positive feedback loop “second wave” IFNαβ, since IFNαβ-induced expression of IFNαβ mRNA was unaffected, and CpG-B inhibition of IFNαβ was manifested in IFNαβR-/- DCs, which lack the positive feedback mechanism. Rather, CpG-B ODN inhibited early “first-wave” IFNα4 and IFNβ. Chromatin immunoprecipitation revealed that association of IRF1 with the IFNα4 and IFNβ promoters was induced by CpG-A ODN but not CpG-B ODN. Moreover, CpG-A-induced association of IRF1 with these promoters was inhibited by CpG-B ODN. Our studies demonstrate a novel mechanism of transcriptional regulation of first-wave IFNαβ that selectively inhibits induction of IFNαβ downstream of multiple receptors and may provide targets for future therapeutic inhibition of IFNαβ expression in vivo.
Inflammasome Activation of Dermal Fibroblasts by an Endogenous Peptide Activate Tissue Resident Immune Cells (136.18)
Authors: Artlett Carol , Sassi-Gaha Sihem , Thacker James 
Published: January 2023

Abstract
Activation of innate immunity is an important strategy for host defense as it is an early response to a pathogen derived danger signal. Recently, we discovered a lipopeptide 1-peptidyl-2,3-diacylglyceride that acts like a danger signaling molecule to induce an innate immune response. The peptide moiety alone (acALY-18) activates the inflammasome inducing the secretion of IL-1β, and subsequently IL6, IL8, MIP1α, and MCP1 in fibroblasts and keratinocytes. Subcutaneous administration of acALY-18 protected mice from a lethal dose of S. typhimurium (survival: 80% treated vs 0% untreated, P&lt; 0.0001). We extended our initial observations with acALY-18 to further determine its effect in fibroblasts and subsequent effects on immune cells. Arrays confirmed the upregulation of IL1β, MIP1α, MCP1, and IL6; C8A, IL1α, IL1F8, IL1R2, IL1RN were also increased. THP1 cells responded to acALY-18 fibroblast conditioned media with the upregulation of CASP1 (2-fold), IL18 (2.6 fold), IL33 (7.5 fold), (IL1β 3600 fold), and IL6 (2.6 fold). The upregulation of IL1β and IL33 was greater than that observed in acALY-18 treated THP1 cells (2.5 fold and 1.6 fold respectively), suggesting that the fibroblast response to acALY-18 can mediate immune cell activation. Additional studies are further investigating the activation of the immune response by acALY-18. acALY-18 could directly translate to a novel therapeutic to enhance non-specific innate immune signaling against pathogens resistant to antibiotics.
Filaggrin knockdown induced the production of IL-6 and IL-8 from HaCaT cells via TLR3 and TLR1 (136.27)
Authors: Lee Kyung Ho , Cho Kyung-Ah , Kim Ji-Yoon , Woo So-Youn , Kim Jin-Woo 
Published: January 2023

Abstract
The skin acts as an indispensible barrier to protect various invaders from the outside. The disturbed skin barrier allows entering innocuous antigens into the skin followed by triggering immune responses and initiate inflammation. Filaggrin (filament-aggregating protein) aggregates the keratin filaments into tight bundles leading to collapse of the coneocytes. Filaggrin deficiency or aberrant expression result the phenotype of ichthyosis vulagaris and atopic dermatitis, characterized by a disturbed skin barrier and dry skin. Filaggrin-deficient mice showed the predisposition of skin inflammation and sensitization of irritants and haptens through epidermis. As keratinocytes are first barrier against exogenous antigens and they possess TLRs as pattern recognition molecules to activate antimicrobial innate immune response. To determine whether the level of filaggrin expression affected the TLR-mediated responses of keratinocytes, we transfected filaggrin siRNA into human keratinocyte cell line, HaCaT, and measured the IL-1β, IL-6 and IL-8 secretion. We found that TLR stimulation did not enhance the IL-1β but IL-6 secretion was increased by poly(I:C). In addition, IL-8 secretion was increased under Pam3CSK4 stimulus in filaggrin knockdown cells. Therefore, these results suggest that the decreased level of filaggrin may trigger innate immune response via TLR stimuli and contribute to pathogenesis of inflammatory skin disease.
Rapid differentiation of MSC into adipocytes and osteocytes is facilitated by Toll-Like receptor engagement (136.43)
Authors: Tas Ibrahim , Tokcaer-Keskin Zeynep , Ayhan Fatma , Gursel Mayda , Akcali Kamil , Gursel Ihsan 
Published: January 2023

Abstract
Mesenchymal stem cells are multipotent progenitor cells capable of differentiating into several lineages including adipocytes, and osteocytes. While they are regarded as non-immunogenic, accumulating evidence suggests that MSC expresses several TLRs. We checked the contribution of TLR ligands to MSC differentiation. Rat bone marrow derived MSC surface marker and TLR transcript levels were checked by FACS and RT-PCR respectively. MSCs were CD29hi, CD71dim, CD90hi, and negative for CD45 & CD34. They expressed TLR1,2,3,4,6, and low levels of 7 and 9 (no TLR5 was detected) at passage zero. Cells were incubated in adipogenic and osteogenic differentiation media either alone or supplemented with, TLR2L:PGN, TLR3L:pI:C, TLR7L:R848, and TLR9L:CpGODN as well as control ODN and followed for three weeks. Oil Red O staining (to assess adipogenesis) suggested that, induction in adipogenic media (by one week) gave no adipose positive cells whereas treatment with R848 or PGN induced significantly high adipose positive cells (1-2% vs 30-35%, respectively). The degree of adipogenic differentiation at wk1, was; TLR7≥TLR2&gt;TLR3&gt;TLR9&gt;Control group≥medium. During osteogenesis (checked by alizarin red staining) by one week the highest differentiation was seen with CpG ODN treatment (TLR9≥TLR7&gt;TLR2&gt;TLR3&gt;Control≥medium). These results strongly support the view that TLR ligands differentially contribute to transition of MSCs into either adipogenic or osteogenic differentiation.
Role of shingosine-1-phosphate receptor 1 in effector CD8 T cell migration (137.15)
Authors: Khanna Kamal , Xu Daqi , Rudenga Benjamin 
Published: January 2023

Abstract
Our previous studies have helped illuminate the landscape in which the endogenous CD8 T cell immune response occurs. However, the factors that regulate the anatomical program followed by antigen-specific CD8 T after infection are still unknown. Recent studies have revealed an important role of sphingosine 1-phosphate receptor 1 (S1P1) in mediating the migration of naive T cells. However, these studies have primarily focused on understanding the role of S1P-S1P1 signaling in T cell trafficking in steady state. The role of the S1P receptors in regulating endogenous CD8 T cell migration in the spleen or lymph nodes (LN) during infection has not been investigated. Here we investigated the role of S1P receptors in the migration and localization of CD8 T cells in lymphoid tissues after infection. We used genetic mouse models, as well as temporal blocking of S1P receptors to reveal a central role of S1P1 in controlling effector CD8 T cell migration from draining LN following viral infections. In the absence of S1P1 receptor signaling, antigen-specific CD8 T cells failed to utilize the lymphatic cortical sinuses to egress from the draining LN. Moreover, our data show that S1P receptors mediate the sequestration of effector CD8 T cells early after bacterial infection in specific compartments of the spleen. Therefore, our studies demonstrate that S1P1 receptor signaling is the dominant factor that regulates endogenous effector CD8 T cell migration in secondary lymphoid organs.
Respiratory syncytial virus hijacks the tumor-suppressor p53 to enhance its replication in lung epithelial cells (137.3)
Authors: Gibbs John , Bian Tao , Menendez Daniel , Resnick Michael , Imani Farhad 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) infection is the major cause of childhood lower respiratory illness and has been associated with the induction and exacerbation of asthma. Previously, we reported that RSV infection induced TGF-β expression that caused cell cycle arrest and subsequently enhanced RSV replication. In the current study, we demonstrate that a downstream target of TGF-β signaling; P53, is a pivotal transcription factor for RSV replication. Over-expression of p53 protein by an inducible system (Tet-off) enhanced RSV replication by 9 folds, whereas, knockdown of p53 using siRNA significantly reduced RSV replication in H1299 and A549 lung epithelial cell lines. Stabilization of p53 with nutlin-3 epithelial (PHBE) cells. We hypothesized that a plausible mechanism of enhanced RSV replication by p53 was through direct binding of p53 to RSV RNA. A search of RSV genome revealed several putative p53-responsive elements. To confirm interaction of p53, EMSA analysis was performed which showed a specific shift with one of the p53 response elements. Taken together, we have identified a novel role for p53 in positive regulation of RSV replication. These findings suggest that enhanced p53 expression through lung injury, smoking or air pollution could facilitate a significant increase in RSV replication leading to more severe respiratory pathologies.
Histone methylation by NUE1, a novel nuclear effector of the intracellular pathogen Chlamydia trachomatis (137.9)
Authors: Pennini Meghan , Perrinet Stephanie , Dautry-Varsat Alice , Subtil Agathe 
Published: January 2023

Abstract
Sequence analysis of the genome of the strict intracellular pathogen Chlamydia trachomatis revealed the presence of a SET domain containing protein, proteins that primarily function as histone methyltransferases. In these studies, we demonstrated secretion of this protein via a type III secretion mechanism and detected its translocation to the host cell nucleus during infection. We therefore named the protein nuclear effector 1 (NUE1). Expression of NUE1 in mammalian cells by transfection reconstituted nuclear targeting, and the protein associated with chromatin. In vitro methylation assays confirmed NUE1 is a histone methyltransferase that targets histones H2B, H3 and H4 and itself (automethylation). Mutants deficient in automethylation demonstrated diminished activity towards histones suggesting automethylation functions to enhance enzymatic activity. Treatment of infected cells with the methyltransferase inhibitor 5’-deoxy-5’-(methylthio)adenosine significantly impaired chlamydial development. Thus, NUE1 is secreted by Chlamydia, translocates to the host cell nucleus and has enzymatic activity towards eukaryotic substrates. This work is the first description of a bacterial effector that directly targets mammalian histones.
The role of TRAF1 in stabilizing TRAF2 from proteasome mediated degradation downstream of 4-1BB signaling (138.1)
Authors: McPherson Ann , Watts Tania 
Published: January 2023

Abstract
TNF receptor family members play important roles in the innate and adaptive immune response, inducing signals for cell survival or apoptosis. This signaling in most cases relies on TNF receptor associated factors (TRAFs) to relay the signal from the TNFR family member to activation of NF-κB or MAPK pathways. Results from our lab have shown that TRAF1 is critical in the downregulation of the proapoptotic molecule Bim and the survival of activated and memory CD8 T cells, acting downstream of the prosurvival TNF receptor family member 4-1BB. We show here that in the absence of TRAF1, signaling downstream of 4-1BB results in the rapid proteasome dependent degradation of TRAF2. To identify interacting binding partners of TRAF1 that may mediate its stabilizing role on TRAF2 we performed a yeast two hybrid screen using a cDNA library from activated mouse lymph nodes. Among the interacting proteins identified were PSMC3, a subunit of the 19S regulatory particle of the 26S proteasome. We have confirmed the interaction between TRAF1 and PSMC3 in T cells and are currently investigating its functional role in the signaling downstream of 4-1BB. The results suggest that TRAF1 may have an important role in controlling the duration of the signal.
Eos mediates Foxp3-dependent gene silencing in CD4+ regulatory T cells. (138.20)
Authors: Barbi Joseph , Pan Fan , Yu Hong , Dang Eric , Yang Huang , Pan Xiaoyu , Jinasena Dilini , Pardoll Drew 
Published: January 2023

Abstract
CD4+ regulatory T cells (Tregs) maintain immunological self-tolerance and immune homeostasis by suppressing aberrant or excessive immune responses. The core genetic program of Tregs and their ability to suppress pathologic immune responses depends on the transcription factor Foxp3. Despite progress in understanding mechanisms of Foxp3-dependent gene activation, the molecular mechanism of Foxp3-dependent gene repression remains largely unknown. Here we identify Eos, a zinc-finger transcription factor of the Ikaros family, as a critical mediator of Foxp3-dependent gene silencing in Tregs. By qRT-PCR analysis we found that Eos is highly expressed in the CD4+CD25+ and CD4+Foxp3+ population of T cells. Additionally, Eos interacts directly with Foxp3 and induces chromatin modifications that result in gene silencing in Tregs. Silencing of Eos in Tregs abrogates their ability to suppress naïve T cell proliferation in vitro. Furthermore, Tregs with Eos knockdown fail to protect recipient Rag2-/- mice from severe colitis when co-transferred with naïve (CD4+CD25- CD62Lhigh ) T cells. Eos silencing in Tregs also endows these cells with partial effector function. These results demonstrate the critical role that Eos plays in Treg programming. They also raise the possibility that the interaction between Foxp3 and Eos may be a therapeutic target for controlling pathological immune responses in which excessive Treg activity plays an important role such as cancer and chronic infections.
Dendritic cell paracrine IL-2 regulates phenotype and function of CD4+CD25+ Treg cells in vitro. (138.5)
Authors: Field Elizabeth , Nasr Mohamed , Kulhankova Katarina , Rouse Todd 
Published: January 2023

Abstract
The development, expansion and function of mouse CD4+CD25+ regulatory T cells (Treg) requires intact IL-2 receptor and paracrine IL-2, but the identity of the paracrine supplier remains obscure. Herein we show in mice that Treg suppressive function in vitro depends on IL-2 from dendritic cells (DC). Anti-CD25 blocked not only Treg inhibition of DO11.10 CD4+CD25- effector cells, but also Treg inhibition of DC stimulatory function, suggesting a DC source of IL-2. We showed by IL-2 ELISPOT, intracytoplasmic flow cytometry and RT-PCR, and we confirmed by transfection studies using IL-2-promoter-driven reporters, that splenic and bone marrow-derived DCs constitutively produced IL-2, and that CpG-B increased IL-2 production. Though secreted IL-2 protein was readily detected in DC cultures by ELISPOT, little or no IL-2 protein was detected in DC cultures that contained Treg cells. The addition of anti-CD25 preserved the level of IL-2 protein detected in co-cultures of DC and Treg cells. Tregs failed to maintain levels of CD25 and foxp3 or to suppress CD4+CD25- effector cells proliferation and IL-2 production in cultures where DCs from IL-2 knockout mice were substituted for wild-type DCs. These results show that dendritic cells supply IL-2 to Tregs and that Treg phenotype and inhibitory function critically depends on paracrine IL-2 from dendritic cells.
Oltipraz inhibits TGF-{beta}-mediated Foxp3+ regulatory T cell differentiation (139.15)
Authors: Kim Il-Kyu , Park Young-Jun , Kim Byung-Seok , Kang Chang-Yuil 
Published: January 2023

Abstract
Oltipraz [5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione] is a synthetic dithiolethione that has been widely studied for the prevention of cancer formation as well as treatment of liver cirrhosis. Although the precise mechanism by which oltipraz inhibits cancer and liver diseases remains unknown, it may be attributed to its ability to induce the expression of numerous Phase 2 detoxification enzymes and to reduce hepatic triglyceride accumulation by S6K1-dependent pathway, respectively. However, whether oltipraz also has an effect on immune cells, especially on T helper cell differentiation has to be elucidated. Here, we found that addition of oltipraz significantly inhibited Th2 differentiation under neutral and Th2-polarizing conditions while there was little, if any, effect on Th1 differentiation. In addition, TGF-{beta}-mediated Foxp3 induction in naïve CD4+ T cells was considerably reduced in the presence of oltipraz. Furthermore, Foxp3 induction was inhibited by oltipraz even in IFN-{gamma}-deficient naïve CD4+ T cells, indicating that oltipraz can inhibit TGF-{beta}-mediated Foxp3+ regulatory T cell differentiation through an IFN-{gamma}-independent manner. Therefore, these results suggest that oltipraz can act as an immune-modulating agent.
IL-1β/p38 signaling controls IL-17 production by T regulatory cells (139.3)
Authors: Li Lequn , Kim Jin Sub , Boussiotis Vassiliki 
Published: January 2023

Abstract
T regulatory (Treg) cells expressing Foxp3 represent a distinct lineage of T lymphocytes committed to suppressive functions. Recent studies have shown that Treg cells can become IL-17 producers in the context of inflammatory cytokine milieu similarly to conventional CD4+ T cells (Tconv). In the present study, we studied the differentiation of IL-17 producing cells in the absence of exogenous cytokines and insults. We showed that under neutral culture conditions, simultaneous activation of naïve Tconv cells and Treg cells in the presence of antigen presenting cells (APC) promoted conversion of Treg but not Tconv into IL-17 producing cells. Using both an in vitro culture system and an in vivo model, we determined that endogenous IL-1β but not IL-6 played an essential role in the conversion process. Mechanistic analysis revealed that IL-1β induced strong activation of p38 MAPK in Treg but not in Tconv cells. Addition of the p38 inhibitor SB203580 in the co-culture abrogated the production of IL-17A by Treg cells, indicating that p38 downstream pathways might be responsible for regulating production of IL-17 by Treg. Our findings indicate that Treg cells are subjected to regulation that is mediated through APC and activated Tconv and reveal a central role of IL-1β and p38 MAPK in this process. These observations provide a new dimension to our understanding of Treg functions and may have important implications in therapeutic strategies using Treg cells.