bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeted knockdown of the B lineage transcriptional activator E2A in B cell chronic lymphocytic leukemia (CLL) enhances lenalidomide sensitivity and regulates cellular proliferation (88.7)
Authors: Borghesi Lisa , Kardava Lela , Yang Qi , Foon Kenneth , Lentzsch Suzanne , Vallejo Abbe , Milcarek Christine 
Published: January 2023

Abstract
Chronic lymphocytic leukemia (CLL) is a common malignancy characterized by the accumulation of B lymphocytes with an antigen-experienced, activated CD19+CD5+ clonal phenotype. Clinically, approximately 50% of cases will behave more aggressively. Here we used siRNA knockdown to investigate the contribution of E2A, a key transcriptional regulator of B cell activation, to CLL survival and proliferation. E2A silencing in primary CLL cells leads to a modest increase in spontaneous apoptosis in both CD38+ (aggressive) and CD38- (indolent) cases. E2A is known to restrain lymphocyte proliferation, and E2A disruption promotes cell cycle progression of aggressive but not indolent CLL. Lenalidomide, an immunomodulatory (IMiD) anticancer drug with pro-apoptotic activity in some B lineage cancers, shows synergistic effects with E2A knockdown. While lenalidomide alone fails to induce detectable apoptosis in CLL, the combined treatment of lenalidomide plus E2A silencing dramatically increases apoptosis beyond either treatment alone. Thus, disruption of a transcription factor associated with the B cell activation profile enhances the anti-tumor potential of lenalidomide, providing the opportunity for improved drug efficacy.
Supressor T cell–derived miRNA that acts in part via attached antigen specific Immunoglobulin and Prostaglandin-E2 (PGE2) (89.10)
Authors: Askenase Philip , Szczepanik Marian , Majewska Monika , Hafner Markus , Tuschl Tom , Kleinstein Steven , Redegeld Frank , Ptak Wlodzimierz , Bryniarski Krzysztof 
Published: January 2023

Abstract
Soluble antigen (Ag)-specific T cell-derived suppressive factor (TsF) of contact sensitivity (CS) is a small RNA, not a protein, induced in suppressor cells of spleen and nodes by high dose Ag iv tolerance; and is not IL-10 nor TGF-beta. The RNA TsF inhibits effector Th1 cells that elicit classical cutaneous CS and in vitro inhibits responsiveness of T cell lines to rIL-2; both in a paracrine manner; like exosomes containing specific mRNA and miRNA (Nature Cell Biol 9:654, '07). The TsF obtained by phenol chloroform extraction of cell supernatants, is degraded by RNase A, and RNase III (specific for ds RNA like pre-miRNA), but not DNase. It is in the RNA fraction from a Quiagen DNA/RNA separation column and about 75bp size (like pre-miRNA) on denaturing electrophoresis.

The suppressive RNA TsF likely is associated with Ig (likely kappa light chain, Nat Med 8:694, '02) and PGE2 (Jo Im 150:2102, '93), that may account for Ag specificity and some suppression. The miRNA part of TsF, after uptake by target cells, may block translation via degrading mRNA encoding a protein in the IL-2 pathway, that is needed by CS Th1 effector cells.
Thus, an Ag-specific TsF is dsRNA, associated with Ig light chain and inhibitory PGE2. This complex, released by a suppressor cell mix, perhaps via exosomes acts in a paracrine manner to target the effector T cells of CS, to intracellularly degrade mRNA translating protein of the IL-2 pathway, needed for effector T cells to elicit CS. Supported by grants from NAID, NIH, the Yale Molecular Hematology program, and the Polish Ministry of Science and Higher Education.
Differential effects of galectin-9 ligation with TIM-3 expressed on Th1 and Tregs (89.12)
Authors: Sehrawat Sharvan , Hirashima Mitsuomi , Rouse Barry T 
Published: January 2023

Abstract
TIM-3 (T cells immunoglobulin and mucin -3) is a surface protein expressed differentially on terminally differentiated Th1 but not Th2 cells. Ligation of galectin-9 with TIM-3 on Th1 cells induces a lethal signal leading to apoptosis of these cells. We report here that same molecule i.e. TIM-3, when expressed on Foxp3+ Tregs, instead of delivering a lethal signal, promotes their proliferation and functional activity. We show that TIM-3 expression was upregulated on a significant numbers of CD4+ T cells including Foxp3+CD4+ T cells, after ocular HSV infection. Furthermore, 50% or more of T cells in ocular lesions (stromal keratitis) caused by HSV in mice express TIM-3 and blocking signals from its natural ligand with a monoclonal antibody results in more severe lesions. More importantly the provision of additional galectin-9 diminished the severity of SK lesions that was achieved by multiple mechanisms including apoptosis of the orchestrating effector T cells, an increase in the representation of two separate subtypes of regulatory cells. The molecular events induced in Tregs and Teffectors after galectin-9 ligation to TIM-3 would be discussed. Our results indicate that galectin-9 therapy may represent a useful approach to control HSV induced lesions, the commonest cause of infectious blindness in the Western World.
Work supported by AI 063365 and EY 05093
Induction of “regulatory” dendritic cells via AhR activation (89.15)
Authors: Bankoti Jaishree , Rase Ben , Shepherd David M. 
Published: January 2023

Abstract
Aryl hydrocarbon receptor (AhR) activation by its prototypical ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is shown to induce Tregs. Dendritic cells (DCs) are key antigen presenting cells governing T cell activation and differentiation. How AhR activation in DCs may induce Tregs is undefined. We hypothesize that AhR activation induces a novel population of inflammatory DCs (GM-CSF derived) that can generate T regs. To test this hypothesis, inflammatory BMDCs were generated in the presence of vehicle or TCDD. TCDD decreased CD11c expression but increased MHC class II, CD86 and CD25 expression on BMDCs. The effects were strictly AhR- dependent as no differences in the phenotypic markers were observed using TCDD-treated BMDCs from AhR KO mice. Induction of indoleamine 2,3-dioxygenase (IDO) and TGF-β3 has been implicated in the generation of Tregs following AhR activation. AhR activation by TCDD increased IDO1, IDO2 and TGF-β3 mRNA levels in BMDCs as compared to vehicle. TCDD upregulated LPS-and CpG-induced TNF-α and IL-6 production in these BMDCs. AhR activation is demonstrated to alter NF-kB signaling. TCDD downregulated LPS- and CpG-induced p65 levels and induced a trend towards upregulation of RelB levels in BMDCs. The results suggest that AhR activation can induce a regulatory phenotype in DCs, an effect that may govern generation of Tregs. The research was supported by grants ES013784 and RR17670.
Novel population of CD39-expressing T cells enriched in the inflamed site (89.21)
Authors: Moncrieffe Halima , Nistala Kiran , Wedderburn Lucy R 
Published: January 2023

Abstract
CD39-mediated hydrolysis of proinflammatory ATP is a newly described mechanism of Treg suppression. We describe the presence and function of a novel population of CD39+ Foxp3- CD4+ T cells enriched in the human inflammatory site. 36 patients with juvenile idiopathic arthritis (JIA) and 25 healthy controls were included in this study with full ethical approval (LREC). Mononuclear cells purified from peripheral blood (PBMC) and synovial fluid (SFMC) were analysed by FACS, functional suppression and ATP assays.
CD39+ Foxp3- CD4 T cells were significantly enriched (p&lt;0.001) in the inflamed joint, compared to PBMC from patients or healthy controls (18.6%, 2.9%, 4.2%, respectively). Unlike CD39+Foxp3+ Treg, this novel population produced the proinflammatory cytokines IFNg and IL-17 and also IL-2. CD39+Foxp3- cells expressed lower CCR4 and higher levels of CD127 than classical Treg. Upon cell sorting, CD39+Foxp3- cells had comparable ATP hydrolysis activity to Treg, but crucially, failed to suppress cell proliferation in vitro.
Thus, the expression of Foxp3 with CD39 may be dissociated in the inflamed site and CD39 expression on CD4 T cells may not result in regulatory status. This will be important in understanding the complex effects of extracellular ATP in human inflammation.
This study was supported by SPARKS UK and the Big Lottery Fund. KN is supported by an ARC Fellowship (Ref. 17998).
Defective Tregs expression of the NTPDase CD39 in lupus (89.24)
Authors: Khan Islam U , Anderson A. Shane , O'Rourke Kenneth S. , Loza Matthew J. 
Published: January 2023

Abstract
The role of aberrations in the regulatory T cells (Tregs) pool for the development of systemic lupus erythamatosus (lupus) remains uncertain. Treg-mediated generation of adenosine, dependent on the ectonucleotidase CD39, is an important mechanism for suppression of T-cell responses. We studied 15 SLE patients along with 6 rheumatoid arthritis and 24 healthy controls. Levels of Treg phenotypic markers, including CD39 expression, were studied by flow cytometric analysis. Varying numbers of sorted Tregs cells were co-cultured with responder T (Tresp) cells, with proliferation assessed by 3H-thymidine incorporation. The proportion of Foxp3+ CD25+high CD127-/low Tregs was similar between lupus and control populations. CD39-expressing Tregs comprised 37 ± 13% of the Treg population in healthy controls and 36 ± 21% in lupus subjects using nonsteroidal immunosuppressants to control active disease, but was nearly absent in 5 of 6 lupus subjects with minimally active disease. In lupus subjects with the CD39 defect, Treg-mediated suppression was significantly reduced and, unlike in healthy control subjects, adenosine receptor antagonism could not reverse the observed suppression. These results suggest that functional defects in Tregs, rather than reduced Treg numbers, may be important for the loss of peripheral tolerance in lupus.
Supported by NIH RO1-AR39501,WFUSM Venture Funds.
TNF/TNFR2 signaling in T regulatory (Treg) cells induces a distinctive NF-kB-dependent cellular program that modulate their suppressive capacity (89.27)
Authors: Nagar Meital , Jacob-Hirsch Jasmine , Vernitsky Helly , Amariglio Ninette , Rechavi Gideon , Goldstein Itamar 
Published: January 2023

Abstract
Anti-TNF therapy has a proven high-degree of clinical efficacy in the treatment of selected T cell-dependent autoimmune disorders. In treated patients, TNF-blockade augments the number and suppressor function of Foxp3+ T regulatory cells (Treg), whereas TNF treatment, in vitro, has opposite effects. Thus, it was of interest to define in vitro the cellular programs induced by TNF in human Treg using various methods: gene expression arrays, RTqPCR, and protein expression analysis. Here we show that TNF/TNFR2 signaling induces within 2 hrs the transcription of distinct NF-κB dependent gene networks rather unique to Treg. Members of the following biological pathways were particularly induced by TNF in Treg: (a) TNF super family (TNFSF) signaling; (b) NF-κB cascade; (c) negative regulation of apoptosis; and (d) immune-response related receptors. No significant effect on the transcription of FOXP3 and other "Treg signature" genes was detected during the first 2 to 24 hrs after TNF treatment. The suppressive function of Treg was partially inhibited by TNF, and this effect was enhanced by co-treatment with 4-1BB ligand (TNFSF9). In summary, TNF induces a pro-inflammatory NF-κB dependent cellular program in Treg that modulates their suppressive function and renders them more susceptible to inhibition by other TNFSF members.
T-regulatory cells and IL-10 are important in maintaining control of germinal center reactions (89.29)
Authors: Alexander Carla-Maria , Waldschmidt Thomas 
Published: January 2023

Abstract
Previous work from our laboratory demonstrated the primary splenic germinal center (GC) reaction to display traits of a steady state, especially in regards to the ratio of IgM+ to switched GC B cells. The GC is a site of intense proliferation, class switching, apoptosis and selection, and as such must have strict regulation. Studies in our laboratory have shown that T regulatory cells (T-regs) play a pivotal role in regulation of the GC, as steady state dynamics were disrupted when T-regs were depleted or dysregulated by anti-CD25 and anti-GITR, respectively. Current studies are exploring the mechanism by which T-regs exert their control within the GC. Based on previous reports studying the means by which T-regs suppress their targets, we have tested whether granzyme B, perforin, Fas and IL-10 contribute to the homeostasis of GC responses. GC reactions in granzyme B-/-, perforin-/-, and B6.lpr mice were found to be normal after immunization, demonstrating that the granzyme B/perforin and Fas/Fas ligand pathways are unlikely to play a central role in controlling GCs. Treatment with a blocking anti-IL-10R mAb did result in loss of GC control however, suggesting that T-regs may be utilizing this cytokine to maintain the balance of IgM+ to switched B cells within the GC. Studies are continuing to determine if T-regs and IL-10 also affects other elements of B cell differentiation including affinity maturation and memory.
NEGATIVE FEEDBACK REGULATION OF T CELLS: INTERLEUKIN 2 AND FOXP3 RECIPROCITY (89.8)
Authors: Popmihajlov Zoran , Smith Kendall A 
Published: January 2023

Abstract
TCR activation induces T cell FOXP3 expression, thereby calling into question FOXP3 as a distinct marker for Regulatory T cells. We investigated the role of IL2 in the TCR/CD3-induction of FOXP3 expression by normal human and murine T cells in vitro. Freshly isolated human PBMCs were stimulated with soluble anti-CD3, and four-color flow cytometry was used to determine the expression of FOXP3. Anti-CD3-activation increased the % of cells expressing FOXP3 in both T cells subsets with a peak at 24h. Both anti-CD25 and anti-IL2 inhibited anti-CD3-stimulated FOXP3 expression. The addition of rIL2 restored and prolonged FOXP3 expression. When anti-CD3-activated PBMCs were monitored daily for 4 days, FOXP3 and IL2 expression remained mutually exclusive, indicating that FOXP3 restricts but does not suppress IL2 expression, even upon TCR/CD3-restimulation. By comparison, soluble anti-CD3/CD28 stimulation +/- rIL2 of murine splenocytes did not up-regulate FOXP3 expression. However, upon solid-phase anti-CD3 activation, the presence of both exogenous TGFβ and rIL2 induced FOXP3 expression by both CD4+ and CD8+ T cells.
Therefore, TCR-activated T cell FOXP3 expression is primarily regulated by IL2/IL2R signaling and occurs only transiently in a subset of both CD4+ and CD8+ T cells. Since FOXP3 functions to restrict TCR-induced IL2 gene expression, these results are consistent with an IL2-dependent FOXP3-mediated negative feedback loop that regulates IL2 production via FOXP3 at the level of transcription. Therefore, FOXP3 cannot be considered solely a phenotypic marker for T-Reg cells. Instead, FOXP3 plays a key role in the feedback regulation of IL2 availability, thereby affecting the proliferation and survival of T cells via a passive suppressive mechanism.
Ndfip1 Regulates Adaptive and Innate Immune Responses in a Model of Inflammatory Bowel Disease (90.17)
Authors: Ramon Hilda E , Riling Christopher R , Hakonarson Hakon , Oliver Paula M 
Published: January 2023

Abstract
Ndfip1 is an adaptor protein that regulates the E3 ubiquitin ligase Itch. Ndfip1 promotes Itch ubiquitination of JunB, a transcription factor involved in TH2 differentiation. Ndfip1-/- mice develop a TH2-mediated inflammatory disease in the skin and lungs. We now show that Ndfip1-/- mice also develop gastrointestinal (GI) inflammation, characterized by the infiltration of eosinophils. The GI inflammation is accompanied by weight loss and premature death. We have found that Ndfip1-/- T cells are both necessary and sufficient to recruit eosinophils into the GI tract. Furthermore, we have found that IL-5 plays a major role in disease induction. Ndfip1-/- mice show increased IL-5 levels in the blood and Ndfip1-/- T cells secrete IL-5 when activated ex vivo. Taken together, our results indicate that the eosinophilic inflammation of the GI track in Ndfip1-/- mice is caused by T cell activation and consequent secretion of IL-5. A similar mechanism could lead to Inflammatory Bowel Disease (IBD) in humans, in particular, TH2-mediated forms of the disease. Single Nucleotide Polymorphisms (SNPs) were analyzed within the Ndfip1 gene. Comparing patient populations with or without IBD, significant differences were found (p-value &lt;0.001) in several SNPs. Thus, Ndfip1-/- mice are a novel genetic model of TH2-driven gastrointestinal inflammatory disease that could provide novel insights into IBD.
NIH training grant: T Lymphocyte Development and Activation.
Construction and characterization of three chimeric proteins of CD38 (90.29)
Authors: Vences-Catalán Felipe , Cedillo-Barrón Leticia , Santos-Argumedo Leopoldo 
Published: January 2023

Abstract
CD38 is a surface receptor as well as an enzyme present in various cell types, including B and T lymphocytes. It has been implicated in several biological functions such as chemotaxis, cell activation and proliferation, rescue or induction of apoptosis. It is not known how this molecule has different functions in different cells. CD31 was identified and characterized as a possible ligand; however, these data are still controversial. In the mouse there is less information, since only two molecules have been identified (without a definitive characterization) as potential ligands. In order to identify CD38 ligand(s) in mice, we designed three soluble chimeric proteins of CD38. One fused with CD8α, a second one fused with the Fc from the IgG1 immunoglobulin, both from human, and a third one containing only a V5 paramyxovirus epitope and a histidine tag. The proteins were characterized by Western blot and enzymatic activity assays. The results showed that all the proteins formed soluble dimers and exhibited enzymatic activity. With these tools, we obtained data suggesting the existence of a possible ligand present on the surface of CD11c+ cells from mice′s spleen. In conclusion the chimeric proteins can be useful tools to continue the characterization of potential ligands of CD38. Supported by CONACyT 56836.
Identification and Characterization of Vstm3 as an inhibitory member of the CD28 family (90.31)
Authors: Levin Steven D , Brandt Cameron S , Howard Edward D , Johnston Janet , Chadwick Eric , Hammond Angela , Taft David W , Hebb Luanne , Wolf Anitra , Bukowski Thomas R , Rixon Mark , Ostrander Craig D , West James W , Fox Brian , Gao Zeren , Lewis Katherine , Xu Wenfeng , Ramsdell Fred 
Published: January 2023

Abstract
Members of the B7-CD28 family play critical roles in the response of T cells. We have identified the transmembrane protein Vstm3 as a member of the CD28 family based on gene structure. It has two immunoreceptor tyrosine inhibitory motifs in its cytoplasmic domain and is expressed on NK cells and a subset of T cells. Antibodies against VSTM3 antagonize multiple aspects of T cell activation including proliferation and cytokine production indicating it plays an inhibitory role in T cell activation. We have also identified two counter-structures for this protein, the previously identified proteins CD155 and CD112, which are expressed on activated antigen presenting cells. CD155 and CD112 also bind to the activating receptor CD226 and hence this extended family of interacting proteins forms a network of molecules similar to the well characterized CD28-CTLA4-CD80-CD86 network. A soluble form of Vstm3 binds to CD155 and CD112 and disrupts their ability to trigger an activating response through CD226, and hence antagonizes immune responses in vitro and in vivo. On the other hand, an antibody that specifically blocks Vstm3 interaction with CD155 and CD112 tends to enhance T cell responses in vitro and in vivo. Finally, mice that lack Vstm3 are more sensitive to the development of autoimmune diseases. Our data indicate that this novel member of the CD28 family negatively regulates T cell responses.
Reciprocal control of IL-4 and IFN-Lambda (IL-29); mechanisms for the control of Th2 polarization (90.32)
Authors: Megjugorac Nicholas J , Gallagher Grant E , Gallagher Grant 
Published: January 2023

Abstract
The newly-described Type III IFN family is comprised of three members: IL-29 (IFN-α), IL-28A (IFN-β) and IL-28B (IFN-γ). All three signal through the same receptor complex, which consists of IL-28Rα (a unique binding and signaling subunit) and IL-10Rβ. While much of the early work describing the activity of IFN-λ1 has focused on its antiviral function, IFN-λ has also been shown to exert powerful immunomodulatory effects, by antagonizing the effect of IL-4 on T cells and inhibiting production of Th2-associated cytokines. To determine whether Th2 cytokines exert reciprocal control over IFN-λ production, PBMC were treated with IL-4 and IL-13 during stimulation. Interestingly, these cytokines significantly enhanced IFN-λ1 production in response to stimuli such as herpes simplex virus (HSV). Intracellular flow cytometry and magnetic bead depletion were used to identify the IL-4-sensitive, IFN-λ -producing cells in peripheral blood. While plasmacytoid DC are a major HSV-responsive cell, they are not responsible for enhanced IFN-λ production. Instead, myeloid cells mediate this response. This identifies a novel mechanism for the regulation of T cell responses.
Talin is required for LFA-1-induced natural killer cell polarization and cytotoxicity (91.1)
Authors: Mace Emily M , Takei Fumio 
Published: January 2023

Abstract
The purpose of this study is to elucidate the role that the cytoskeletal adaptor protein talin1 plays in the function of the integrin leukocyte function associated antigen-1 (LFA-1) in NK cells. It has been proposed that LFA-1 not only mediates adhesion of NK cells to target cells but is also an important activating receptor for NK cell cytotoxicity. Talin is known to act as a link between integrins and the actin cytoskeleton and to regulate ligand-binding function of LFA-1. We generated NK cells in vitro from talin1 knockout (KO) embryonic stem cells, tested the effects of talin deficiency on these NK cells, and found that talin plays a dual role in NK cell cytotoxicity. First, it is required for LFA-1 mediated adhesion to the target cell. Second, it is required for the accumulation of actin and actin polymerization machinery, including vinculin and WASP, following binding of LFA-1 to its ligand ICAM-1.This LFA-1- and talin-dependent actin accumulation is a critical for further steps leading to NK cell cytotoxicity. Although talin-KO NK cells adhere to target cells in the presence of Mn++, they are unable to kill the prototypic NK target YAC-1. Wild-type, but not talin-KO, NK cells polarize cytotoxic granules following engagement of both LFA-1 and the activating receptor NKG2D. These data show that LFA-1 mediated actin accumulation precedes and is required for subsequent signalling that leads to cytotoxicity.
This work is supported by a grant from the Canadian Institutes of Health Research (CIHR).