bluuebunny/crossref_metadata_2025_split huggingface dataset:
TGFβ down-regulates PGE2 receptor subtype 2 in differentiating naïve human CD4+ T cells, resulting in a lack of expression and function in Th17 cells (P6281)
Authors: Poloso Neil , Vu Chau , Woodward David 
Published: January 2023

Abstract
Prostaglandin E2 (PGE2) is an important component in inflammatory diseases. Recently, PGE2 has been recognized as playing a critical role in determining CD4+ T helper cell differentiation and expansion (Th1 and Th17, respectively). In order to better understand the role prostaglandins play in differentiated human T-helper cells we determined the expression of various PG receptors in in vitro differentiated human Th1, Th2, and Th17 cells. Surprisingly, we found that while Th1 and Th2 cells express all four PGE2 receptor subtypes, Th17 cells did not express EP2 subtype as determined by qPCR. Stimulation with specific EP receptor agonists confirmed that Th17 cells did not express a functional EP2 receptor. This is in contrast with mouse Th17 which do not show this phenotype. We further found that this down-regulation of EP2 in human Th17 cells was dependent on exposure to TGFβ, and was dose dependent. This is in contrast to TGFβ reported effects on other cell types and also in mouse CD4+ T cells. This finding could explain why differentiated Th17 cells expand in the presence of PGE2, as they down-regulate an important regulatory feedback loop through EP2. Additionally, our data suggests that PGE2 receptor expression and biology in T cells may not translate from rodents to humans.
B7x modulates the adaptive immune response and diminishes renal injury in murine antibody mediated nephritis (P5168)
Authors: Pawar Rahul , Goilav Beatrice , Xia Yumin , Herlitz Leal , Ghosh Kaya , Zang Xingxing , Putterman Chaim 
Published: January 2023

Abstract
B7x (B7-H4, B7S1), a member of the B7/CD28 co-stimulatory superfamily, is an inhibitor of T cell activation and proliferation. B7x is highly expressed in peripheral, non-lymphoid tissues. However, the in vivo function of B7x is largely unknown. We hypothesized that B7x may modulate the pathogenesis of antibody mediated nephritis through its effects on T cells. We induced nephritis in B7x-deficient (B7x-/-) (n=10) and B7x-wild type (WT) B6 mice (n=10) pre-immunized with rabbit IgG by intravenous injection of nephrotoxic sera (rabbit anti-mouse glomerular antibodies). Following nephritis induction we observed a significant increase in the levels of serum IgG, particularly of the IgG2b and IgG1 isotype, in B7x-/- mice as compared to B7x WT mice. At the mRNA level, IL-23, CCL2 and CCR5 were significantly upregulated in B7x-/- kidney tissue. Immunohistochemistry revealed significantly increased glomerular infiltration of CD3+ T cells and CD68+ macrophages in B7x-/- kidneys. Furthermore, kidney histopathology was more severe in B7x-/- mice, in terms of infiltrating polymorphonuclear cells in both glomerular and interstitial compartments, crescent formation, and tubular atrophy/dilatation, as compared to B7x WT mice. In conclusion, B7x plays a protective role in immune mediated nephritis, likely through exerting an inhibitory effect on T cell activation and restricting the migration of immune cells. Our results indicate a potential role for modulation of the B7x pathway for the treatment of nephritis mediated by pathogenic antibodies, including anti-glomerular basement membrane disease (Goodpasture’s syndrome), lupus nephritis, and related conditions.
Role of human IgM memory B cells in influenza vaccine response (P4401)
Authors: Kim Jin Hyang , Reber Adrian , Biber Renata , Cao Weiping , Chirkova Tatiana , Katz Jacqueline , Sambhara Suryaprakash 
Published: January 2023

Abstract
Influenza virus-specific memory B cells are critical to mount an accelerated antibody response against subsequent influenza infections. While multiple layers of humoral memory are involved in the protection against influenza, the unique role of IgM memory B cells is largely unknown. In this study, we demonstrated that human IgM memory B cells are similar to class-switched memory B cells in their basic effector functions: the ability to proliferate and to present antigens to T cells. However, ELISPOT analysis of peripheral blood mononuclear cells revealed that the frequency of influenza-specific IgM memory B cells is 10-fold higher than that of IgG memory B cells and doesn’t readily change by seasonal vaccination. Interestingly, IgM memory B cells exhibited broad cross-reactivity against contemporary seasonal as well as pandemic strains. Serum antibody analysis showed that although the level of influenza-specific IgM was approximately 20-fold less than that of IgG, the breadth of cross-reactivity of IgM-secreting cells is broader than that of IgG counterparts. Given that a recent study in mice showed that the majority of IgM memory B cells are preferentially recruited to the ensuing secondary response, we propose a model that upon vaccination, some IgM memory B cells are directly differentiated into highly cross-reactive IgM-secreting plasmablasts to confer the host early line of cross-protection, while the rest of IgM memory B cells are recruited to the secondary response.
Arming oncolytic vaccinia virus with T cell engager to improve virus therapy (P4413)
Authors: Song Xiaotong , Yu Feng , Gottschalk Stephen , Bartlett David 
Published: January 2023

Abstract
Oncolytic vaccinia virus (VV) therapy has shown promise in preclinical models and in clinical studies. Complete responses, however, have rarely been observed. The limitations presented by VV therapy typically have been suboptimal virus spread through the tumor and the limited induction of antigen-specific T-cell responses. Here we describe a novel strategy to overcome these limitations. We have constructed T-cell Engager Armed Vaccinia Viruses (TEA-VVs) encoding secretory bi-specific T-cell engager (single chain variable fragment, scFv) that binds both to CD3 and a tumor cell surface antigen EphA2 (EphA2-TEA-VV). The expression of EphA2-TE was demonstrated in cell culture. Also, the replication and oncolysis efficiency of EphA2-TEA-VV in cell culture were similar to that of the parental virus. However, the EphA2-TEA-VV killed EphA2-positive tumor cells A549 more effectively in the presence of human PBMC as determined by target cell lysis, compared to unmodified VV. In addition, EphA2-TEA-VV induced bystander killing of tumor cells that are not infected with virus as determined by in vitro assay. Importantly, EphA2-TEA-VV resulted in a significant decrease in tumor growth in an established A549 lung cancer model. Thus, TEA-VV represents a unique and effective strategy to improve oncolytic virus therapy by engaging T cells for cancer therapy.
TLR2 ligands modulate Fcγ receptor expression and function in monocytes (P4397)
Authors: Fatehchand Kavin , Shah Prexy , Patel Hemal , Fang Huiqing , Justiniano Steven , Mo Xiaokui , Jarjoura David , Tridandapani Susheela , Butchar Jonathan 
Published: January 2023

Abstract
Fcγ receptor (FcγR) clustering on monocytes/macrophages leads to phagocytosis, cytokine release and other responses designed to clear the antibody-opsonized targets. Toll-like Receptor 2 activation elicits strong proinflammatory responses, so we explored the possibility that ligands for TLR2 could indirectly strengthen FcγR activity. We treated human peripheral blood monocytes (PBM) with the TLR2 agonist Pam2CSK4 and found significantly enhanced FcγR-mediated cytokine production and phagocytosis. Further examination showed that the agonist increased the mRNA and protein levels of FcγRIIa and the common γ-subunit. Interestingly however, the inhibitory receptor FcγRIIb was also upregulated. We also found a concurrent decrease in SHIP and an increase in miR-155, which may help explain the enhanced FcγR function despite upregulated inhibitory FcγRIIb. Next, using a murine Her2/neu solid-tumor model of antibody therapy we found that Pam2CSK4 significantly enhanced antibody-mediated reduction of tumor growth, although the effects were not superadditive. Finally, we tested whether the effect was acylation-specific by treating PBM with the tri-acylated Pam3CSK4 and measuring FcγR expression and function. Results showed that Pam3CSK4 was equally effective at all dosages tested. Collectively, these findings show that TLR2 ligands can positively modulate FcγR expression and function, and hence may warrant further investigation as putative adjuvants for antitumor antibody therapy.
The two-faced T cell epitope: examining the host-microbe interface with JanusMatrix (P4399)
Authors: Gutierrez Andres , Bailey-Kellogg Chris , Moise Leonard , Terry Frances , Abdel Hady Karim , Leng Qibin , Losikoff Phyllis , Verberkmoes Nathan , Martin William , Rothman Alan , De Groot Anne 
Published: January 2023

Abstract
To explore the intersection of commensals, pathogens, and the human genome at the T cell epitope level, we leveraged the vast genomic sequence information available in databases of microorganisms to which humans are exposed. We developed the JanusMatrix immunoinformatic tool that identifies potentially cross-reactive T cell epitopes from both HLA binding and TCR-facing sides to allow comparison across large genome sequence databases including common human pathogens (HP), the human gut microbiome (HGM), the human genome (HG), and the human plasma proteome (HPP). Initial studies reveal different levels of HPP/HG, HGM, and HP cross-reactivity (XR) for known Treg and Teff epitopes. In Hand Foot Mouth Disease (HFMD), extensive XR with HGM seems to predict immunodominance; more limited XR with enteroviruses (e.g., polio) may protect against severe HFMD. For common Teff epitopes, HPP/HG XR is more limited than HGM XR. For Treg epitopes defined in HCV disease and for Tregitopes (De Groot et al, Blood, 2008), HPP/HG XR is more extensive. Overall, greater XR with HPP/HG compared to HGM seems to distinguish known Treg and Teff epitopes. While predicting all influences on immune responses may be impossible, the vast availability of human pathogen and commensal organism sequences now allows T cell epitope comparisons in these large datasets. Startling discoveries relevant to vaccine development and T cell response phenotype understanding are emerging as we apply this powerful technology.
Presence of lipoxin A4 during early phase of tularemia delays apoptosis of macrophages and favors exponential bacterial growth (P1354)
Authors: Singh Anju , Rahman Tabassum , Sellati Timothy 
Published: January 2023

Abstract
The high infectivity and virulence of Francisella tularensis (Ft) subspecies tularensis coupled with its ease of aerosolization make it an ideal bioweapon. During respiratory tularemia, caused by inhalation of Ft, we postulate that bacteria establish a principally anti-inflammatory environment and subvert host cell death programs to facilitate their unfettered replication within various cell types. Here we have explored the role of lipid mediators such as leukotrienes [i.e., lipoxin A4 (LXA4)] and prostanoids [i.e., prostaglandin E2 (PGE2)] in host inflammatory responses manifested early during infection with Ft. LXA4 has potent anti-inflammatory properties and also is involved in down-regulation of PGE2. Addition of exogenous LXA4 during in vitro infections with Ft inhibits apoptosis and also ablates the PGE2 release by macrophages, which is restored in the presence of MK 886. Our studies show that Ft facilitates its survival and exponential replication by triggering the release of LXA4, which inhibits apoptosis of macrophages and other cells within the first ~3 days of infection. We are also elucidating the course of Ft infection in 5-lipoxygenase knockout mice to observe the effects of LXA4 deficiency on the bacterial burden, histopathology and mouse survival. Targeting such lipid mediators may have therapeutic benefit by limiting bacterial growth in tularemic individuals and perhaps those infected with other highly virulent respiratory pathogens.
The histone methyltransferase Ezh2 regulates differentiation and plasticity of CD4 T helper cells. (P1334)
Authors: Tumes Damon , Onodera Atsushi , Suzuki Akane , Shinoda Kenta , Endo Yusuke , Iwamura Chiaki , Hosokawa Hiroyuki , Koseki Haruhiko , Tokoyoda Koji , Suzuki Yutaka , Nakayama Toshinori 
Published: January 2023

Abstract
Upon encountering antigen, naïve CD4 T cells rapidly differentiate into discrete subsets of effector T helper (Th) cells that direct immune responses to different types of infection. Polarizing cytokines induce the expression of lineage-specifying genes (Tbx21 for Th1 cells and Gata3 for Th2 cells) that control differentiation. We found that the histone H3K27 methyltransferase Ezh2 controls differentiation of Th1 and Th2 cells, and that inactivation of Ezh2 enhances plasticity of both of these subsets. Tbx21 and Gata3 experienced large changes in Ezh2 occupancy during Th differentiation, and inactivation of Ezh2 depleted H3K27-trimethylation (H3K27-Me3) at these loci. Additionally, loss of Ezh2 caused increased pathology in a mouse model of allergic asthma and progressive accumulation of memory phenotype Th2 cells in vivo. This study establishes a functional link between Ezh2 and transcriptional regulation of lineage-specifying genes in terminally differentiated peripheral T cells via H3K27-Me3. These data may therefore contribute to the development of therapies that target this pathway to enhance or repress immune responses in human diseases.
Dendritic cells in Th2 immune responses (P1313)
Authors: Ronchese Franca , Connor Lisa , Hyde Evelyn , Ochiai Sotaro , Tang Shiau Choot , Le Gros Graham 
Published: January 2023

Abstract
We have examined the role of dendritic cells using different models of Th2 allergic immune responses in the skin. In the first model we used the nematode parasite Nippostrongylus brasiliensis, which infects rodent hosts by penetrating through the skin. Material from labelled N. brasiliensis is taken up by migratory dendritic cells and transported to the draining lymph node where it initiates a strong Th2 immune response. We have characterized the surface phenotype of these dendritic cells in terms of lineage markers, and for expression of markers associated with Th2 immune responses. We find that these dendritic cells express markers that are compatible with a steady-state population of dermal dendritic cells. In addition, we have carried out dendritic cell transfer experiments to show that these migratory dendritic cells maintain the full capacity to prime Th2 immune responses in vivo. Additional models of Th2 immune responses, such as those initiated by the powerful allergen House Dust Mite and by application of the vitamin D analogue MC903, are currently being investigated. Our data indicate that dendritic cells can carry a sufficient set of signals to instruct the initiation of Th2 immune responses in secondary lymphoid organs.
Intraperitoneal injection of Δ-9-tetrahydrocannabinol induces local MDSCs with potent immunosuppressive properties (P1319)
Authors: Sido Jessica , Nagarkatti Prakash , Nagarkatti Mitzi 
Published: January 2023

Abstract
The mechanism of immune regulation by cannabinoids remains unclear. Δ-9-tetrahydrocannabinol (THC) is the most widely studied cannabinoid isolated from the Cannabis sativa plant. Our laboratory has previously shown that, in mice, THC induces myeloid derived suppressor cells (MDSCs), a heterogeneous population of immunoregulatory cells. In this study, we focused on the role of THC in MDSC expansion and generation. Intraperitoneal injection of THC induced local MDSCs which were able to suppress T-cell proliferation ex vivo, in response to mitogenic activation. THC-induced MDSCs comprised a significantly higher proportion of granulocytic MDSCs compared to MDSCs isolated from naïve bone marrow (BM). These induced MDSCs also expressed higher levels of Arginase1 than did naïve BM MDSCs. We also found that THC-induced MDSCs expressed and secreted significantly higher levels of S100A8 protein, compared to BM MDSCs, and this occurred in a Signal Transducer and Activator of Transcription (Stat) 3-dependent manner. S100A8 has been shown in tumor models to drive MDSC accumulation and activation, and may act as a chemoattractant and stimulator of local MDSCs upon THC treatment. Together these data show that in vivo THC treatment is able to induce a highly immunosuppressive granulocytic MDSC population, which may be expanded locally to restore homeostasis.
Indoleamine 2,3-dioxygenase and T-cell based anti-tumor immunotherapies targeting immune checkpoints (P2010)
Authors: Holmgaard Rikke , Zamarin Dmitriy , Munn David , Wolchok Jedd , Allison James 
Published: January 2023

Abstract
The CTLA-4 blocking antibody ipilimumab results in durable responses in metastatic melanoma, though therapeutic benefit has been limited to a fraction of patients. This calls for identification of resistance mechanisms and development of combinatorial strategies. We examine the inhibitory role of indoleamine 2,3-dioxygenase (IDO) on the anti-tumor efficacy of antibodies targeting immune checkpoints. We show widespread systemic induction of IDO in tumor-bearing mice. This IDO is present even after antibody treatment, demonstrating that the extensive target for IDO inhibitors is indeed present. Further, we study the anti-tumor effects of combining therapies targeting immune checkpoints with pharmacological inhibition of IDO.
Understanding the role of host innate immune responses in viral vector-mediated gene delivery and strategies to achieve sustained transgene expression (P6357)
Authors: Ankathatti Munegowda Manjunatha , Hu Jim 
Published: January 2023

Abstract
Stunning progress in genomic research has changed the way we address diseases. With the identification of disease causing genetic modifications, genomic research has helped us to decipher the patho-physiology of diseases and given us an extra tool to address the basic cause by correcting those genes. Only few drugs target the cause of disase, but for most of them we still need to deliver proper genes. Although many viral vectors are being used to deliver genes to target cells, most have problems related to safety and sustained expression. In our previous studies we have used HD-AD to successfully deliver cystic fibrosis correcting human-CFTR gene to mice achieving sustained expression and disease correction in CFTR KO mice. Where as in larger animals, there is an acute phase of reduction in transgene expression. Our preliminary studies suggest that, this difference may be due to difference in NK cell activity. To address this problem we have designed human cell based in-vitro evaluation assay to find out the role of NK cells and to find out effective small molecule to block NK cells during the window period of their activity. Our results show that NK cells are killing viral vector- transduced cells. We also demonstrate that this gene transduced cell killing can be inhibited by JAK and NF-kB inhibitors. These findings will help in designing better viral vector-based gene therapy to achieve sustained expression in large animals and in human studies.
Antibodies in dengue patients contain both anti-thrombotic and pro-fibrinolytic activities (P6359)
Authors: Yeh Trai-Ming 
Published: January 2023

Abstract
Dengue virus (DENV) infection may result in severe dengue hemorrhagic fever (DHF). However, the mechanisms that cause hemorrhage in DHF are unclear. In this study, we demonstrated that antibodies against human thrombin were increased in the sera of dengue patients but not in other virus-infected patients. To further characterize the properties of these antibodies, affinity-purified anti-thrombin antibodies (ATA) were collected from DENV patients’ sera by thrombin and protein A/L affinity columns. We found human ATA bound not only to DENV, human thrombin, but also cross-reacted to human plasminogen (Plg). In addition, human ATA could inhibit not only thrombin activity but also enhance Plg activation in vitro. Taken together, these results suggest that antibodies induced by DENV, which contain both anti-thrombotic and pro-fibrinolytic activities, may contribute to the development of hemorrhage in DHF.
Cooperative functions of MHC II, HLA-DM, and cathepsins enhance the selection of immunodominant epitopes (P5008)
Authors: Kim Ae , Hartman Isamu , Poore Bradley , Boronina Tatiana , Lanar David , Krzych Urszula , Cole Robert , Sadegh-Nasseri Scheherazade 
Published: January 2023

Abstract
We developed a minimalist cell-free antigen-processing system for MHC class II that can identify physiologically selected T cell epitopes from antigens. The system utilizes purified proteins: HLA-DR1, cathepsin B, H, S, and HLA-DM. It was designed to mimic the specialized compartment for antigen processing with known defined molecular composition so that it can be a useful tool for elucidating steps involved in antigen processing and understanding the mechanisms of epitope selection. We found that prior digestion of antigens even for a few minutes eliminated the possibility of their immunodominant epitope capture by DR1. However, if those antigens were captured by DR1 first in the presence of DM, dominant epitopes were successfully selected. We observed simultaneously binding of DR1 and DR4 to denatured proteins detected by the biacore method. In another case, pre-digestion of antigen did not destroy the dominant epitope even though it showed sensitivity to DM mediated dissociation. We saw that this epitope got selected because it was less susceptible to enzymatic digestions and it was able to rebind to DR1 even in the presence of DM. Therefore, In general, most peptides generated from proteins do not get a chance to bind MHC II for presentation because they are sensitive to both DM and enzymatic digestions. Selection of immunodominant epitope is the results of collaborative reactions of DR1, DM, and cathepsins by increasing abundance of epitope capture by MHC II.
Triggering receptor expressed on myeloid cells 2 induces obesity by promoting adipogenesis (P3107)
Authors: Park Min , Choi Harim , Kang Hyung-Sik 
Published: January 2023

Abstract
The role of TREM2 in adipogenesis and obesity has not yet been defined. Here, we report that TREM2-transgenic (TG) mice were much more obese than wild-type mice after feeding with a high-fat diet (HFD), independent of the quantity of food intake. These HFD-fed TREM2 TG mice manifested adipocyte hypertrophy, glucose and insulin resistance and hepatic steatosis. The expression of adipogenic regulator genes, such as peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, fatty-acid synthase and CD36, was markedly increased in the epididymal white adipose tissue (EWAT) of the HFD-fed TG mice. In addition, the EWAT of the HFD-fed TG mice exhibited decreased Wnt10b expression and increased GSK-3β-mediated β-catenin phosphorylation. In contrast, the blockade of TREM2 signaling using TREM2-Ig resulted in the inhibition of adipocyte differentiation in vitro and a reduction in body weight in vivo by downregulating the expression of adipogenic regulators. Taken together, these results suggested that TREM2 induces obesity by promoting adipogenesis via the upregulation of adipogenic regulators in conjunction with the Wnt10b/β-catenin signaling pathway.