bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antigen –specific immunotherapy inhibited Th2 via GATA-3 and Th17 cells in the absence of T-bet in an allergic asthma model (140.6)
Authors: Zhivkova Nataliya , Karwot Roman , Maxeiner Joachim , Soó-Becker Kinga , Lehr Hans-Anton , Susetta Finotto 
Published: January 2023

Abstract
Asthma is caused by T-helper 2 (Th2)-driven immune-responses in which upregulation of GATA-3 has been shown to play a crucial role in both in humans and in murine models of this disease.
T-cell tolerance, induced by respiratory exposure to allergen prior to allergen sensitization, can inhibit the development of airway hyperractivity (AHR), a cardinal feature of asthma. However, the subset of T cells that mediates this protective function in allergic asthma has not been clearly identified yet. We recently set up a tolerogenic model of allergic asthma. In this model, peripheral T cell tolerance is induced by respiratory exposure to allergen and is characterized by decreased Th2 (IL-4,IL-5 and IL-13)-based responses via downregulation of the main Th2 transcription factor GATA-3 in the lung which results in decreased allergen induced AHR and lung eosinophilia.
In addition, we found that our tolerogenic model is characterized also by decreased differentiation of Th17 cells. Moreover respiratory exposure to allergen prior to sensitization protected also airway hyperreactivity induced in the absence of T-bet. Thus this model suppressed effector Th2 and Th17 mediated immune responses also in the absence of IFN-gamma and could therefore provide a new avenue also for genetically determined allergic diseases.
This work is supported by a SFB 548-B8 project in Mainz, Germany
Dendritic cell (DC)- derived exosomes spread donor allo-antigen between recipient's DC following cardiac transplantation (141.11)
Authors: Montecalvo Angela , Divito Sherrie J , Shufesky William J , Beer-Stolz Donna , Larregina Adriana T , Morelli Adrian E 
Published: January 2023

Abstract
Exosomes are nanovesicles generated in multivesicular endosomes that are released to the extracellular space by different cell types. Since DC-derived exosomes (dexosomes) express MHC-peptide and costimulatory molecules, we investigated the role of dexosomes in elicitation of the anti-donor response in transplantation. Dexosomes were generated from bone marrow-derived DC and labeled with PKH67 for traffic studies. CD4+ TCRtg T cells (Thy1.1+) specific for the IEα52-68 (BALB/c)-IAb (B10) complex were CFSE-labeled and transferred i.v. to host Thy1.2+ B6 mice. Graft infiltrating DC were isolated from BALB/c (CD45.2+) cardiac grafts 3 days after transplantation in B6 (CD45.2+) recipients and genetically-engineered ex vivo to release exosomes expressing the reporter marker eGFP, and then transferred i.v. into host CD45.1+ B6 mice. We demonstrated that although graft-infiltrating leukocytes release exosomes ex vivo, they do not secrete enough exosomes in circulation to stimulate donor-reactive T-cells in lymphoid organs. Instead, migrating DCs (generated in vitro or isolated from allografts), once they home in the spleen, they transfer exosomes expressing eGFP to spleen-resident DCs. Thus, exchange of exosomes between DCs in lymphoid organs constitutes a mechanism by which passenger leukocytes transfer alloAg to recipient's APC and amplify generation of donor-reactive T-cells.
Bioimaging to monitor the in vivo Distribution of administered Mesenchymal stem cells (MSCs) for treating Graft versus Host Disease (GVHD) (141.12)
Authors: Ju Sun-Young , Cho Kyung-Ah , Jung Yun-Jae , Park Seong-Yeol , Choi Yong-Bock , Hong Kyeong-Man , Kim Han-Seong , Seoh Ju-Young , Woo So-Youn , Ryu Kyung-Ha 
Published: January 2023

Abstract
Acute Graft-versus-Host Disease (GVHD) remains a major complication after allogeneic hematopoietic cell transplantation (HCT). Several publications show a potential benefit of human MSCs for the treatment of refractory GVHD; however, their cellular fate and distribution remain unclear. We set out to develop an animal model that can be used to study the effect of MSCs on GVHD. GVHD was induced by transplantating C3H/he or C57BL/6 donor bone marrow cells (5 × 106) and CD3+ spleen cells (1 × 106) into lethally irradiated BALB/c recipient mice. C3H/10T1/2 cell lines were transfected with a pcDNA3.1-luciferase construct (luc-MSCs). Bioluminescence of these cells was measured (IVIS-Xenogen system) after treatment with luciferin, showing a linear increase of photon emission with rising cell numbers. To track these cells in vivo, groups of mice were injected with various dose luc-MSCs per animal and imaged with bioluminescence imaging at various time points. After transplantation, mice were monitored daily for weight and survival. Differences in symptom severity were compared using a clinical GVHD scoring system. We conclude that this mouse model can be used to study the effects of MSCs on acute GVHD and the described bioluminescence technology provides a sensitive and safe tool for the repeated in vivo tracking of infused luc-MSCs in GVHD target organs.
Selective deletion of HY-reactive CD8+ T cells by saporin-coupled MHC class I tetramers (141.15)
Authors: Hess Paul R , Murray Sabrina L , Buntzman Adam S , Young Ellen F , Steele Shaun P , Collins Edward J , Frelinger Jeffrey A 
Published: January 2023

Abstract
CD8+ T cells are the principal effectors mediating rejection of allografts performed across minor histocompatibility (H) antigen (Ag) barriers. Previously we have shown that cytotoxic class I tetramers are capable of selectively deleting cognate T cells in vivo; in this study, we hypothesized that tetramers targeting minor H Ag-reactive T cells would permit long-term tolerance of mismatched grafts. To investigate this prediction, we used the male HY Ag in C57BL/6 mice as a model of a minor H barrier. A single immunization of female mice with male bone marrow cells reliably primed T cells against the two major H2-Db-restricted HY epitopes, Uty and Smcy, with peak expansion at 14 days. We prepared Db-Uty and Db-Smcy tetramers coupled to the ribosome-inactivating toxin, saporin. When administered prior to immunization, cognate CD8+ T cell responses were no longer evident in the blood at day 14, and cytotoxic T lymphocyte (CTL) responses measured against peptide-pulsed and native targets in vivo were significantly diminished. Treatment with saporin-coupled HY tetramers allowed prolonged survival of male bone marrow allografts in female mice. This work demonstrates that cytotoxic tetramers can exert meaningful biologic effects in vivo, and illustrates a potentially useful means of obtaining Ag-specific transplantation tolerance. This project is supported by grants from the NIH (1K08DK082264-01A1) and NCSU-CVM.
CD40L-specific mAb mediates its tolerogenic effects through engagement of FcgRIIB, not via depletion of activated T cells (141.17)
Authors: Lucas Carrie L. , Fehr Thomas , Haspot Fabienne , Sykes Megan 
Published: January 2023

Abstract
Objective: To determine the mechanism by which a widely used anti-mouse CD40L mAb (clone MR1) given with allogeneic bone marrow cells (BMCs) tolerizes peripheral CD8 T cells.
Methods: B6 mice received 3Gy total body irradiation one day prior to ip injection of 2mg a-CD40L & iv infusion of 25x106 MHC-mismatched B10.A BMCs. This regimen induces long-term mixed chimerism, as measured by durable presence of donor leukocytes, without depletion of recipient CD4 or CD8 T cells.
Results: Although genetic deficiency of CD40L alone allowed graft acceptance in recipients depleted of CD8 cells, it did not prevent rejection in mice replete with CD8 T cells. Thus, Fc-dependent functions of a-CD40L were studied. A role for complement was excluded, as 4/5 C3 KO recipients became chimeric. CD8 T cell-intrinsic CD40L was dispensable (3/5 chimeras each in mice with WT or KO CD8 cells), indicating that a-CD40L need not act directly on CD8 cells. However, FcgRIIB KO recipients promptly rejected donor BM unless CD8 T cells were depleted (5/7, 0/5, 7/8, & 5/7 chimeras for WT, KO, WT + a-CD8, & KO + a-CD8 groups, respectively). Recipient B cells are the likely source of FcgRIIB, as DC-derived FcgRIIB was not essential (4/6 chimeras each in mice with WT or KO DC).
Conclusions: A-CD40L with allogeneic BMCs generates immune complexes that ligate FcgRIIB, inducing as yet undefined downstream effects essential for CD8 T cell tolerance.
Supported by NIH Grant RO1 49915 & NDSEG Fellowship.
Analysis of CD4 Gene Expression in Hematopoietic Cell Transplant (HCT) Tolerant Patients (141.20)
Authors: Tabellini Laura , Fan Wenhong , Bumgarner Tara E , Flowers Mary E , Grogan Bryan M , Martin Paul J , Zhao Lue Ping , Hansen John A 
Published: January 2023

Abstract
Although graft-vs-host disease (GVHD) remains a significant problem following allo HCT, tolerance eventually occurs in many patients. To better understand the mechanism(s), RNA from purified CD4 T cells from 22 tolerant patients (T) and 20 normal controls (NC) was hybridized on Illumina Ref-8 expression arrays. Transcriptional profiles of tolerant patients were very different from NC. A cluster analysis of genes showing differential expression revealed 2 distinct subgroups based on the time of study post-HCT: "early" (mean 1.0, 1.0-2.6) years (TE, n=10), and "late" (mean 4.0, 2.5-7.4) years (TL, n=12).
1073 genes were differentially expressed between TE and NC, 810 genes were differentially expressed between TL and NC, and there were 203 genes overlapping TE and TL. Analysis of TE revealed increased gene expression of the IFNG, TCR and IL2 signaling pathways, with increased expression of CTLA4. Analysis of TL revealed down regulation of genes involved in glycolysis, nucleotides biosynthesis and cell cycle, and down regulation of the IL2 and TCR signaling pathways compared to NC and TE.
These data suggest that 1) tolerance is an active and dynamic process, and 2) that this adaptive response evolves over time. The changes observed suggest elements of both immune regulation and immune exhaustion. Functional studies will be necessary to further interpret these transcriptional changes and define mechanisms.
Quiescent recipient splenic dendritic cells (DC) re-process therapeutic DC into alloantigen for presentation to and down-regulation of anti-donor T cells to prolong allograft survival (141.31)
Authors: Divito Sherrie J. , Montecalvo Angela , Wang Zhiliang , Shufesky William J. , Erdos Geza , Larregina Adriana T. , Morelli Adrian E. 
Published: January 2023

Abstract
Current dogma in transplantation presumes that therapeutic maturation-resistant dendritic cells (MR-DC) prevent allograft rejection by directly interacting with donor-reactive T-cells in vivo. However, this assumption remains untested. Our study therefore aimed to elucidate the mechanism by which donor MR-DC down-regulate the anti-donor response to prolong allograft survival in mice. We employed as prototypic donor MR-DC, bone marrow-derived DC treated with the active form of vitamin D3, 1α,25(OH)2D3. We demonstrate that donor-derived MR-DC prolonged cardiac allograft survival similarly as donor apoptotic or viable splenocytes, suggesting that different donor-derived cellular therapies share a common mechanism of action. We determined that once injected i.v., MR-DC were short-lived and failed to directly tolerize donor-reactive T-cells. Rather, apoptotic MR-DC were internalized and re-processed by quiescent recipient splenic CD11chiCD8α+ and CD11chiCD8- DC, which in turn induced deletion of effector T-cells and outgrowth of regulatory T-cells via the indirect pathway. Importantly, activated recipient DC induced robust T-cell activation via indirect presentation. Our data suggest that therapeutic DC, like other more practical cellular therapies, serve as a source of alloantigen for recipient quiescent DC that in turn down-regulate the anti-donor response to prolong allograft survival.
Leukaemia Inhibitory Factor (LIF) is a Treg cytokine (141.35)
Authors: Metcalfe Su M , Gao Wenda , Muthukumarana Poorni , Zhou Qiang , Fahmy Tarek , Strom Terry B 
Published: January 2023

Abstract
Priming of the T lymphocyte results in either regulatory (Treg), or effector (Teff), lineage development. During priming the immediate micro-environment contributes to outcome and LIF, a pluripotent cytokine of the IL6 family, appears to be linked to Treg: in contrast IL6 is associated with Teff. Here we ask, is LIF a Treg cytokine? We found in vitro (i) exogenous LIF (10ng/ml) increased transcription of both Foxp3 - the Treg lineage transcription factor - and LIF: and (ii) when naive CD4+ Foxp3- T cells were activated by anti-CD3/anti-CD28, the presence of exogenous LIF enhanced numbers of Foxp3+ cells. We therefore asked, can LIF be used as a tolerogenic therapy? To avoid LIF's rapid degradation by serum proteases we developed a delivery system wherein LIF was encapsulated within nanoparticles and targeted to CD4+ T cells by surface-attached anti-CD4. In vitro LIF-nano proved efficacious, increasing Foxp3+CD4+ T cell numbers. In vivo, donor-specific Foxp3 Treg expansion was promoted by LIF-nano therapy in recipients of an allogeneic spleen cell transfusion. Confirmation of LIF's involvement in Treg differentiation in vivo was sought by removal of LIF: anti-LIF therapy significantly inhibited antigen-specific nTreg expansion. We conclude that LIF is a Treg cytokine, able to support the Treg lineage and Foxp3 expression during antigen-specific T cell responses. Funding Support: BHF, NIHR, NIH, JDRF, NSFCA.
TH17 ANTAGONIZE TREG TO REJECT ALLOGRAFTS (141.38)
Authors: Yang Yu , Xu Jiangnan , Ochando Jordi C , Bromberg Jonathan S , Ding Yaozhong 
Published: January 2023

Abstract
Treg are central in controlling immune responses and transplant tolerance, and TGFβ plays an important role in inducing and maintaining Treg. However, when TGFβ is combined with IL-6, CD4 T cells develop along the Th17 pathway, and Treg have been suggested to be one of the main sources for TGFβ in Th17 differentiation. We determined how Treg affected Th17 induction, function, and allograft rejection. Vascularized cardiac allografts were performed in SCID mice, and Treg and/or Th17 were adoptively transferred 4 days later and graft survival monitored. We found that in the presence of Treg, proliferation of CD4 T cells was inhibited, and IL-6 partially abolished proliferative suppression by Treg. However, Treg did not inhibit but actually increased IL-6 driven IL-17 expression, suggesting that Treg did not suppress Th17 differentiation. Allograft survival was significantly prolonged when effector T cells were co-transferred with Treg, with mean survival increasing from about 14 to &gt; 50 days. Treg were not as effective when co-transferred with Th17, allograft survival increasing from 10 to only 15 days. These findings have important implications for understanding the signals necessary for preventing Th17 development and function in order to prolong graft survival and induce tolerance.
Preformed Alloantibodies Prevent the Induction of Allograft Tolerance by Enhancing Alloreactive T cell Priming (141.4)
Authors: Troutman Audrea M , Chong Anita 
Published: January 2023

Abstract
The presence of alloantibodies (alloAbs) in transplant recipients is often associated with increased Ab-mediated as well as cellular rejection. We hypothesize that alloAbs can facilitate cellular rejection by enhancing T cell activation and have tested this hypothesis by investigating the effect of alloAbs in a BALB/c to C57BL/6 skin transplant model. Long-term acceptance was induced with anti-CD154 (MR1) plus DST. The impact of alloAbs was investigated using anti-Kd (HB159; mouse IgG2a) mAbs, administered at the time of transplantation. Anti-Kd mAbs prevented anti-CD154-mediated graft acceptance (MST=12d). We hypothesize that alloAbs form immune complexes that facilitate allo-antigen uptake and presentation by APCs. We used CFSE-labeled T cells from three different TCR-Tg mice (TCR75-CD4+, OT-II -CD4+, and OT-I -CD8+ TCR Tg T cells to measure T cell responses in BL/6 recipients of OVA-BALB/c skin ± anti-CD154/DST ± anti-Kd mAbs. Anti-Kd mAbs enhanced proliferation of all three TCR-Tg T cells in anti-CD154/DST-treated recipients compared to anti-CD154/DST-treated recipients. In conclusion, alloAbs promote the CD40-CD154-independent activation of allo-T cells, thus preventing allograft tolerance.
Insights into the Mechanism Responsible for Spontaneous Acceptance of Liver Allografts (141.41)
Authors: Zhuo Ming , Ito Takashi , Wang Mouer , Esquivel Carlos O , Martinez Olivia M. , Krams Sheri M. 
Published: January 2023

Abstract
Transplantation of fully histoincompatable livers between strains of rodents often results in spontaneous acceptance of the graft. Lewis rats reject DA livers in 14 days while DA recipients of Lewis livers have long-term graft survival. We sought to determine the mechanism of this spontaneous graft survival.
NK cells and subsets of T cells express NKG2D. On NK cells, NKG2D functions as a stimulatory receptor that induces effector functions. We examined NKG2D receptor and ligand expression post-transplant. Groups of Lewis rats received livers from DA (rejection combination) or Lewis donors (syngeneic) and DA rats received livers from Lewis (non-rejection combination) or DA donors (syngeneic). NKG2D expression was low in syngeneic grafts but increased 7-fold in Lewis→DA grafts and 17-fold in DA→Lewis grafts by day 7 post-transplant.
Ligands of NKG2D were not expressed in normal liver but were up regulated in all liver grafts by day 1 post-transplant, suggesting that ischemia/reperfusion injury and trauma induce expression of these ligands. RAE1L and RRLT were significantly up regulated specifically in DA→Lewis liver grafts by day 7 post-transplant. In marked contrast, the expression of RAE1L and RRLT in Lewis→ DA liver grafts was similar to the levels detected in syngeneic liver grafts suggesting that signals that lead to an increase in NKG2D ligand expression are absent in this strain combination. In conclusion, the absence of NKG2D ligand expression in the liver graft may play a role in preventing rejection, and decreasing the expression of these proteins may be a useful strategy to promote graft non-responsiveness. Supported by AI044095
Combined mTOR inhibition and post-transplant infusion of alloantigen-specific Treg promotes long-term graft survival in otherwise unmanipulated hosts (141.42)
Authors: Raimondi Giorgio , Sumpter Tina L , Matta Benjamin , Corbitt Natasha , Tokita Daisuke , Wang Zhiliang , Thomson Angus W 
Published: January 2023

Abstract
Protocols that achieve donor-specific tolerance of MHC-mismatched organ grafts remain an unmet clinical goal. We report a strategy that combines post-transplant administration of alloAg-specific Treg (AAsTreg) with inhibition of the mammalian target of rapamycin (Rapa) (mTOR) to promote long-term, donor-specific heart graft survival.
AAsTreg selection was achieved by co-culture of CD4+CD25+ Treg with immature dendritic cells (DC) in the presence of conditioned media. This rendered cells that potently inhibited T cell proliferation in an Ag-specific manner. However, AAsTreg remained unable to control T cell activation when stimulated by mature DC, - a phenomenon dependent on IL-6 release. Exploiting the in vivo inhibitory effects of Rapa on inflammatory cytokine (IL-6) production, T cell proliferation and graft infiltration, AAsTreg were administered post-transplant (d7) in combination with short-term Rapa. AAsTreg exerted a pro-tolerogenic effect: &gt;80% long-term graft survivors [LTS] (MST&gt;150d). Polyclonal Treg exerted an inferior protective effect: 40% LTS (MST=45d). Moreover, the pro-tolerogenic effect was Ag-specific as AAsTreg selected against third party DC failed to prolong graft survival. Significantly, LTS exhibited alloreactive T cell anergy. Thus, combination of mTOR inhibition with AAsTreg is an effective, clinically-applicable approach to promote long-term graft survival.
Inverse relationship between liver γδT cells and Foxp3+CD25+CD4+ Tregs contributes to liver allograft tolerance and rejection (141.44)
Authors: Malone Frances R , Wang Weigang , Meng Zihui , Reyes Jorge D , Li Wei 
Published: January 2023

Abstract
Our previous studies have demonstrated that Foxp3+CD25+CD4+ regulatory T (Treg) cells play an important role in inducing liver transplant tolerance. It is unknown whether γdT cells are involved in liver tolerance and how they interact with other types of cells. In this study, we examined the involvement of γdT cells in liver transplant tolerance by using an orthotopic liver transplantation model in which liver allografts are accepted spontaneously across the MHC barrier. Controls received either anti-CTLA4 mAb or anti-CD25 mAb pre- or peri-operatively, which induced acute liver allograft rejection. The majority of γdT cells were located in the liver and were CD4 and CD8 negative, did not express TCRαβ and NK receptors. In contrast to Foxp3+CD4+CD25+ Treg, γdT cells were decreased in the spontaneously tolerant liver allografts throughout the time courses from day 1 to day 100 posttransplantation and increased in the rejected liver grafts at day 5 posttransplantation. The CD4 and CD8 marker expression on γdT cells were increased in the tolerated livers post transplantation (10-20%). We speculate that the decreased number of γdT cells in the tolerated liver allografts may be due to the suppressive effect of Foxp3+CD4+CD25+ Treg. Therefore, γδ T cells, expressed in opposite frequency to Foxp3+CD4+CD25+ Treg, are involved in the processes of liver transplant tolerance.
NKG2D-mediated activation of NK cells by allogeneic CD34+ blood cells. (141.9)
Authors: Arpinati Mario , Nicolini Benedetta , Steinle Alexander , Rondelli Damiano 
Published: January 2023

Abstract
Background: We have previously demonstrated that human CD34+ cells and allogeneic T lymphocytes cross-interact in-vitro. In this study, we addressed the interaction bewteen CD34+ cells and allogeneic NK cells.
Methods: Purified CD3-CD56+ NK cells were cultured with allogeneic CD34+ or CD14+ blood cells or with 1000 U/ml IL-2. NK cells were then used to lyse NK-sensitive K562 (NK activity) or NK-resistant Daudi cells (LAK activity) in a 51Cr release assay.
Results: CD34+ cells induced greater NK activity than monocytes (p=0.02). While LAK activity was negligible before culture, it increased upon culture with CD34+ cells, but not monocytes (p=0.01). Activation of NK cells by CD34+ cells was comparable to high dose IL-2. NK cell activation was also documented by CD69 and CD25 in NK cells and by production of IFN? and TNF?. CD34+-induced NK activation was inhibited by anti-NKG2D antibody. However, anti-NKG2D antibody did not prevent NK activation by IL-2. Moreover, surface expression of NKG2D on NK cells was downregulated by CD34+ cells but not IL-2. Expression of NKG2D ligands (MICA-B and ULBP1-3) is currently being tested in CD34+ cells. Finally, NK cells affected the phenotype of CD34+ cells, that upregulated their expression of CD40 and CD86.
Conclusions: Our study suggest a cross talk between NK cells and allogeneic CD34+ cells through a NKG2D-related mechanism.