bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palmitoylation is required for Fas receptor clustering and cell death in CD4+ T cells (LYM7P.722)
Authors: Cruz Anthony , Ramaswamy Madhu , Sengupta Prabhudda , Lippincott-Schwartz Jennifer , Siegel Richard 
Published: January 2023

Abstract
Fas-Fas ligand (FasL) interactions are critical for apoptosis and T cell homeostasis, with deficiencies in either Fas or FasL leading to autoimmunity in both mice and humans. Fas can trigger apoptotic cell death directly through recruitment of a death-inducing signaling complex (DISC) consisting of FADD and Caspase-8. We have previously shown a correlation between lipid raft-associated Fas and sensitivity to apoptosis in CD4+ T cells, with the Fas-sensitive memory population having increased lipid raft receptor localization. Palmitoylation of human Fas at cysteine 199 (Cys-194 in mouse) is required for localization to lipid rafts. To investigate the role of palmitoylation in Fas signaling, we developed a transgenic mouse defective in palmitoylation of Fas receptor (Fas C194→V) backcrossed to the Fas-defective lpr/lpr mouse (FasC194Vlpr/lpr). These mice developed autoimmunity characteristic of lpr mice, but CD4-CD8- “Double-Negative” (DN) T cells did not accumulate. T cells expressing C194V mutant Fas were resistant to Fas- and TCR-induced cell death, indicating lipid raft localization is required for the apoptotic function of Fas, but not accumulation of DN T cells. High-resolution PALM imaging of cells expressing wild-type or C194V mutant Fas revealed receptor clustering into higher-order oligomers at the plasma membrane required palmitoylation. These findings identify palmitoylation as a key post-translational modification of Fas that controls the apoptotic signal.
High-throughput T cell receptor (TCR) sequence tracking reveals clonal intrinsic selection for skin resident T cells in human genital HSV-2 infection (MUC7P.771)
Authors: Zhu Jia , Kask Angela , Diem Kurt , Robins Harlan , Wald Anna 
Published: January 2023

Abstract
T cells resident in the barrier surface have been implicated to play an important role in rapid control of invading pathogen. Human genital herpes infection is characterized by frequent bursts of reactivating HSV-2 virus and rapid containments of host immune responses in genital skin and mucosa surface, thus a valuable human disease model for deciphering tissue resident immunity in vivo. Previously, we showed that both CD4 and CD8 T cells persisted locally for prolonged time period after complete resolution of HSV-2 infection. To understand the mechanism of T-cell resident immunity in the barrier tissue, we used high-throughput TCR sequencing to investigate the persistence, breadth and clonality of TCR vβ repertoire in sequential biopsy tissues obtained during HSV-2 lesion evolution from active lesion, healed, to 2, 4, and 8 weeks post healing. Each tissue TCR vβ repertoire is consisted of thousands unique productive sequences, a diverse yet oligoclonal T-cell profile. Interestingly, high frequency TCRVβ sequences dominated in post-healed tissues were poorly represented in circulating T cells from the blood, vice versa was also true. Although hundreds of TCRVB sequences were found commonly shared among sequential biopsies in the same subjects, only a few clones showed increased persistence, emerging from low frequency in lesion to dominance in post healed tissue. These data suggest a T-cell intrinsic mechanism in dictating T cell survival and/or self-renewal in human tissue.
KIR2DS1+ decidual natural killer cells show ex-vivo activation and cytotoxicity but not cytokine secretion (MUC7P.756)
Authors: Crespo Angela , Tilburgs Tamara , Strominger Jack 
Published: January 2023

Abstract
Decidual natural killer cells (dNK) are the most abundant lymphocytes at the fetal-maternal interface. dNK have been shown to have limited cytotoxic capacity but secrete high levels of cytokines to facilitate extravillous trophoblast (EVT) invasion. Previous studies have shown that mothers expressing the activating Killer Immunoglobulin-like Receptor-S1 (KIR2DS1) are protected from pregnancy complications when carrying a fetus expressing HLA-C2 (KIR2DS1 ligand) (Hiby et al, 2010). In this study, a significantly higher percentage of dNK expressed KIR2DS1 and KIR2DL1 than pNK. dNK and pNK expressed similar levels of perforin and granzyme B, but dNK contained markedly increased granulysin levels. Although pNK were more cytotoxic than dNK against HLA- targets, this cytotoxicity was inhibited by HLA-C1+ and HLA-C2+ targets. In contrast, the cytotoxicity of dNK from KIR2DS1+ mothers was not efficiently inhibited by HLA-C2+ targets. Moreover, higher phosphorylation of ZAP70/SYK in dNK from KIR2DS1+ mothers than KIR2DS1- mothers was showed. Thus, a higher activation state of KIR2DS1+ dNK cells interacting with HLA-C2+ targets may dominate over inhibition by HLA-C2 through KIR2DL1+ dNK. Contrary to stimulation of NK cell receptors with antibodies or cell lines, stimulation of dNK and pNK with EVT revealed no specific production of NK cytokines such as IFNγ or IL-8. These results suggest a dominant role for KIR2DS1+ dNK cells in cytotoxicity, but not cytokine secretion.
Expression and regulation of the TGF-β activating integrin αvβ8 on human mononuclear phagocytes (MUC8P.809)
Authors: Travis Mark , Fenton Thomas , Schulthess Julie , Arancibia Carolina , Lehtinen Markus , Powrie Fiona 
Published: January 2023

Abstract
Induction of Foxp3+ Tregs is important in suppressing immune responses to commensal bacteria and innocuous antigen in the gut. Previous work from our lab has shown that, in mice, expression of the integrin αvβ8 on intestinal dendritic cells (DC) is important for activation of the cytokine TGF-β and subsequent Treg induction, with lack of this pathway resulting in severe inflammatory bowel disease (IBD). Additionally, integrin αvβ8 is highly expressed on murine intestinal CD103+ DC compared to other intestinal mononuclear phagocytes, and is required for enhanced Treg induction by CD103+ intestinal DC and maintenance of immune homeostasis. However, pathways that control integrin αvβ8 expression are poorly understood and the role of integrin αvβ8 in human immunology is currently unknown. Here, we show that integrin αvβ8 is expressed preferentially on CD64+ macrophages and to a lesser extent on DC populations, in contrast to what is found in mouse models. Analysis of monocyte-derived macrophage populations indicated that M2-like macrophage populations preferentially expressed integrin αvβ8. Interestingly, treatment of monocyte-derived DCs with the LPS causes up-regulation of integrin αvβ8 expression, indicating that bacterial ligands may be an important cue in triggering integrin αvβ8 expression on DC. Thus, enhanced expression of integrin αvβ8 on certain human mononuclear phagocyte subsets may implicate these populations in the control of TGF-β dependent immune responses.
PD-1 and CTLA-4 signals are not important for the maintenance of tolerant self-reactive CD8 T cells in the small intestine (MUC8P.808)
Authors: Nelson Christine , Conemac Clare , McCurtain Jennifer , Fife Brian , Vezys Vaiva 
Published: January 2023

Abstract
Tolerance is an important mechanism by which the immune system distinguishes between self and non-self. Peripheral T cell tolerance is critical for the control of self-reactive cells that escape negative selection. Anergy is one mechanism that controls self-reactive cells in the periphery and prevents autoimmunity. Using a system that allows for the study self-specific CD8 T cell responses to a known intestinal auto-antigen, we determined that mucosal antigen signaling can lead to a long-term, stable population of cells in the intestine that have a classic anergic phenotype. These cells do not produce effector cytokines or induce intestinal damage. Inhibitory molecules, like PD-1 and CTLA-4, are believed to be important for both the induction and maintenance of T cell tolerance. We show that the induction phase of CD8 T cell tolerance to self was highly sensitive to control through both PD-1 and CTLA-4. However, once tolerance was established, the maintenance of tolerant CD8 T cells was independent of PD-1 or CTLA-4 signaling. Overall, this indicates that distinct mechanisms are responsible for the induction and maintenance of tolerant T cells. In addition, there may be many tolerant T cells resistant to immunotherapeutics targeting these pathways. Determining which subsets of self-reactive cells are susceptible to modulation through these pathways is important for understanding basic mechanisms tolerance and autoimmunity and for improving cancer therapeutics.
The structural basis for the anti-inflammatory activity of sialylated antibodies (THER5P.822)
Authors: Pincetic Andrew , Ahmed Alysia , Lomino Joseph , Wang Lai-Xi , Bjorkman Pamela , Ravetch Jeffrey 
Published: January 2023

Abstract
Antibodies (Ab) mediate pro-inflammatory effector functions through the engagement of Fc receptors (FcγRs) expressed on leukocytes. A complex, N-linked glycan attached to the Fc domain of IgG regulates the interaction to FcγRs by maintaining the Fc in a biologically active conformation. However, attaching sialic acid sugar residues to this Fc-associated glycan reduces affinity for FcγRs and confers binding to an alternate class of receptors, the C-type lectins (DC-SIGN). This switch in receptor specificity coincides with a switch in effector function in vivo as sialylated IgG (sFc) suppresses inflammation in mouse models of autoimmunity. The structural mechanism that regulates the sialic acid-dependent change in Ab effector function remains poorly understood. Biophysical analysis reveals that sialylation destabilizes the Fc fragment by increasing the hydrophobic surface area exposed to solvent. Upon solving a crystal structure of sFc, we observe that this loss of stability correlates with inter-domain flexibility such that the sFc in the crystal is found in both “open” and “closed” states. Mutagenic analysis of sFc further identifies key contact sites between the Fc-glycan and the Fc-backbone necessary to induce this conformational change and attain anti-inflammatory activity in vivo. These studies demonstrate that the conformational diversity of the Fc fragment serves as a general strategy to shift receptor specificity in order to effect different immunological outcomes.
Fullerene C60 derivatives suppress the acquired immune responses (THER5P.832)
Authors: Yoshioka Yasuo , Udaka Asako , Hirai Toshiro , Aoshima Hisae , Kokubo Ken , Oshima Takumi , Ohe Tomoyuki , Mashino Tadahiko , Tsunoda Shin-ichi , Higashisaka Kazuma , Tsutsumi Yasuo 
Published: January 2023

Abstract
Fullerene C60 derivatives are the most promising nanomaterials because of its unique ability to scavenge large numbers of free radicals. Therefore fullerene C60 derivatives with antioxidant effects have been expected to apply to the medicine for inflammatory disease such as inflammatory bowel disease. We have previously shown that fullerene C60 derivatives have the anti-inflammatory effects independent of an antioxidant effects in vitro. However, little is known about the effect of fullerene C60 derivatives on acquired immune system. Here, we examined the effects of fullerene C60 derivatives on the acquired immune responses. At first, we examined the effects of fullerene C60 derivatives on ovalbumin (OVA)-induced immune responses in vivo. Treatment of OVA plus fullerene C60 derivatives induced a lower level of OVA-specific IgE and IgG than did treatment of OVA alone, suggesting that fullerene C60 derivatives suppressed acquired immunity. Next, we investigated the influence of C60 fullerene derivatives on T cell proliferation in a mouse mixed lymphocyte reaction. The fullerene C60 derivatives suppressed the production of IL-2 from responder splenocytes. Furthermore, fullerene C60 derivatives also suppressed the IL-2 production from CD4+ T cell stimulated by anti-CD3 and anti-CD28 antibodies, although NAC (anti-oxidant medicines) didn’t show such effect. These results show that the fullerene C60 derivatives have the effect to suppress the acquired immune system.
Human gingiva-derived mesenchymal stromal cells inhibit graft-versus-host disease through CD39 and IDO (THER5P.844)
Authors: Zheng Song Guo , Chen Maogen , Wang Julie , Olsen Nancy 
Published: January 2023

Abstract
Mesenchymal stem cells have the capacity to maintain immune homeostasis and prevent autoimmunity. We recently reported that human-derived gingival mesenchymal stem cells (GMSCs) have strong capacity to suppress immune responses and T cell-mediated collagen-induced arthritis in animals. However, it is unclear whether these cells can suppress human T cell-mediated diseases. Here, we used a xeno-GVHD model to investigate the interventional role of human GMSCs in NOD/SCID mouse, which is a best animal model to study human cell therapy prior to a clinical trial. We found that GMSCs potently suppressed the proliferation of PBMC and T cells in vitro. Co-transfer of GMSC and human PBMC significantly prolonged the mouse survival. Moreover, we demonstrated that GMSCs inhibited human PBMCs-initiated xenogenic responses via CD39 and IDO signals. Thus, GMSCs can suppress human immune responses and immune system-mediated diseases, offering a potential clinical option to be used for modulating GVHD and other autoimmune diseases.
Development of human B-lymphocyte targeted bi-specific DART® molecules for the treatment of autoimmune disorders (THER5P.830)
Authors: Chen Wei , Nordstrom Jeffery , Burke Steve , Shah Kaplana , Ciccarone Valentina , Li Haiquan , Hotaling Tim , Li Jonathan , Gorlatov Sergey , Li Hua , Alderson Ralph , Koenig Scott , Bonvini Ezio , Johnson Syd , Moore Paul 
Published: January 2023

Abstract
B-cell targeted immunotherapy for autoimmune disorders is often limited by general immune suppression caused by significantly altered B-cell homeostasis. To overcome this, we developed MGD010, a bi-specific Dual-Affinity Re-Targeting (DART) molecule that coligates the inhibitory Fcγ receptor IIb (CD32B) and the B-cell receptor component, CD79B, on B cells. Previous work has shown that CD32BxCD79B DARTs engage CD32B in a BCR-dependent manner and inhibit B-cell activation without B-cell depletion. MGD010, a CD32BxCD79B DART bearing an Fc domain to enhance pharmacokinetic (PK) properties, was generated to support potential clinical development. Favorable PK properties and lack of safety signals, including no cytokine release nor B-cell depletion, were observed in non-human primate dose-escalated with MGD010 to up to 10 mg/kg. Pharmacodynamic analysis demonstrated dose-correlated target binding to B cells and reduced B-cell calcium flux induced by ex vivo BCR-crosslinking. In addition, MGD010 blocked B-cell function ex vivo in samples from autoimmune patients. Repeat administration of MGD010 also inhibited both humoral immune responses and the development of chronic graft-versus-host disease in a humanized mouse model. Thus, MGD010, an Fc-bearing CD32BxCD79B DART with extended PK, may represent a promising B-cell intervention strategy for the treatment of autoimmune diseases, with limited impact on B-cell homeostasis.
Targeting natural killer cell reactivity by employing antibody to NKp46: implications for type 1 diabetes (THER6P.857)
Authors: Yossef Rami , Hadad Uzi , Jonjić Stipan , Mandelboim Ofer , Porgador Angel 
Published: January 2023

Abstract
Natural killer (NK) cells belong to the innate lymphoid cells. NK cells are able to eliminate transformed cells and virus-infected cells without the need of prior antigen stimulation. Their cytotoxic activity is regulated through the delicate balance between activating and inhibitory signals. NKp46 is a member of the primary activating receptors of NK cells; and it is reported to interact with the hemagglutinin (HA) of the influenza virus, heparan sulfate and vimentin. Moreover, our group and others have reported that NKp46 is involved in the development of type 1 diabetes (T1D) autoimmune disease. Subsequently, we hypothesized that blocking of the NKp46 could prevent T1D development or prolong its honeymoon period. To address this goal we characterized monoclonal antibodies for the murine NKp46. One mAb, F15, was able to down-regulate the surface expression of NKp46 on primary murine NK cell following antibody injection. Additionally, F15 treatments were able to down-regulate cytotoxic activity mediated by NKp46, but not by other NK receptors. To test our primary assumption, we examined T1D development in two models, NOD mice and low-dose streptozotocin. The results showed significantly lower incidence of diabetic mice in the F15-treated group comparing to control groups. This study directly demonstrates the involvement of NKp46 in T1D development and suggests possible treatment for early insulitis
Identification of swine leukocyte antigen-derived peptides inducing epitope-specific CTL responses in HLA-A2 transgenic mice (TRAN3P.882)
Authors: Lee Chong-Kil , Im Sun-A , Park Chan-Su , Kim Kyungjae 
Published: January 2023

Abstract
Xenotransplantation of porcine organ is considered a potential solution to the problem of allograft shortage. A xenograft is rejected by cross-primed CD8 cytotoxic T cells as these cells show cytotoxicity against xenografts by recognition of swine leukocyte antigen (SLA). However, the precise swine leukocyte antigen (SLA)-derived immunogenic peptides that are presented in the context of human HLA molecules remain to be elucidated. In the present study, the SLA-derived peptides that bind to HLA-A*0201, a representative of the A2 supertype, were predicted using a computer-assisted algorithm. The candidate peptides were synthesized, and then the stability of peptide/HLA-A*0201 complexes was compared by MHC stabilization assays using HLA-A*0201-expressing Tap knock out T2 cells. Of 15 candidate peptides, two peptides, peptide-35 and peptide-43, were selected to have high affinity and stability with HLA-A*0201. Immunization of HLA- A*0201-transgenic mice with peptide-35 elicited potent CD8 CTL cell responses, while immunization with peptide-43 did not induce noticeable CTL responses. Induction of peptide-35-specific CD8 T cells was also confirmed by intracellular IFN-g staining of CD8 T cells from peptide-35 primed mice. This study has important implications not only for the identification of an immunogenic HLA-A*0201-restricted indirect epitope derived from SLA, but also for the development of epitope-specific immunoregulation strategies.
Different competency of CMV-pp65 or Flu-M1 specific CD8+ T cells in naïve and central memory population in healthy human adults (TRAN3P.885)
Authors: Chen Guobing , Solokina Arina , Li Huifen , Truong Thai , Oelke Mathias , Wersto Robert , Schneck Jonathan , Leng Sean , Weng Nan-ping 
Published: January 2023

Abstract
The competency of antigen specific (Ag+) lymphocytes plays a critical role in the outcome of an adaptive immune response during an infection. Although the precursor frequency of Ag+ T cells often serves as an indicator, the evaluation of the proliferative capacity of Ag+ T cells of healthy humans to known viral antigens is limited. Here, we compared CD8 T cell responses to the antigen from cytomegalovirus (CMV-pp65) or influenza virus (Flu-M1) using an artificial antigen presenting system in vitro. We found that CD8 T cell responses (proliferation and Granzyme B production) to these two antigens varied in 23 healthy adults analyzed. The antigen specific CD8 T cell expansion did not correlate with the precursor frequency of total Ag+ CD8 T cells. Further comparing the response of isolated naïve (Tn) and central memory (Tcm) CD8 T cells showed that Tcm expanded more than Tn did to both antigens. Finally, we found that longer telomere lengths in CD8 T cells were positively correlated with the better expansion of these Ag+ CD8 T cells. Together, our study shows that antigen specific CD8 T cell response to CMV-pp65 and Flu-M1 is varied in healthy adults and the capacity of proliferation of these Ag+ CD8 T cells depends partly on the telomere length in these cells.
Trafficking of intra-graft T cells to recipients’ lymphoid organs after skin transplantation (TRAN3P.916)
Authors: Marino Jose , Tocco Georges , Mordecai Scott , Benichou Gilles 
Published: January 2023

Abstract
The skin contains T lymphocytes including significant numbers of FoxP3+ regulatory T cells (Tregs). However, their role in skin transplantation is still unknown. In this study, we investigated the trafficking of intra-graft donor T cells to the recipient’s lymphoid organs after skin transplantation in mice. To test this C57BL/6 (B6) mice received a skin transplant from a double transgenic B6 donor whose T cells expressed DSred while FoxP3 expression was associated with GFP (Tregs being double positive). At different time points after transplantation, cell suspensions of recipients’ lymph nodes, spleen and thymus were prepared. The presence and characterization of fluorescent donor cells was investigated using imaging flow cytometry analysis. First, the presence of T cells (DSred+ FoxP3-) was detected only at d4-d7 post-transplantation i.e. after skin graft revascularization and essentially in the host’s thymus. On the other hand, double positive (DSred+ FoxP3+) Tregs were found in all recipient’s lymphoid organs. Surprisingly, high frequencies of single positive GFP+ cells were found in both ipsilateral lymph nodes and thymus. The nature of these cells is being investigated. In summary, our results show that most T cells leaving the graft are Tregs spreading through all recipient’s lymphoid organs while other intra-graft T cells migrate preferentially to the host’s thymus.
Control of B lymphoma through regulation of TRAF protein degradation during nutrient stress (TUM7P.932)
Authors: Abdul Sater Ali , McPherson Ann , Laister Rob , Minden Mark , Watts Tania 
Published: January 2023

Abstract
The TNFR family of receptors includes members, such as CD40, that mediate important immune functions. TNFRs play critical roles in regulating cellular survival, where they utilize TNFR associated factors (TRAFs), including TRAF1 and TRAF2, as adaptors to signal through NF-κB and MAPK pathways. TRAF1 is linked with increased lymphoma cell survival and is overexpressed in over 50% of human lymphomas, with highest expression in most refractory B-CLL. Thus there is interest in blocking TRAF1 induced survival signaling in lymphoma. Here we show that during nutrient deprivation, induced by low glutamine in the media or by treatment with the licensed drug Erwinaze, TRAF1 is essential for maintaining protein levels of another pro-survival signaling adaptor, TRAF2, in RAJI cells (Burkitt's lymphoma). The PKC, PKN1, has been shown to phosphorylate TRAF1. Utilizing shRNA knockdown, we show that loss of PKN1 reduces TRAF1 expression, suggesting that PKN1 phosphorylation stabilizes TRAF1. Importantly, we demonstrated that Erwinaze treatment causes cell death in TRAF1 deficient RAJI cells but not in wild type cells. Moreover, PKN1 deficient RAJI cells, which exhibit lower TRAF1 expression, were also susceptible to treatment with Erwinaze. Together, these findings suggest that a combination therapy that targets TRAF1 for degradation (i.e. PKN1 inhibitor) along with Erwinaze to cause nutrient stress mediated loss of TRAF2 constitutes an effective and aggressive therapy for B cell lymphoma