bluuebunny/crossref_metadata_2025_split huggingface dataset:
HLA targeting efficiency correlates with human T cell response magnitude and with mortality from influenza A infection (P6082)
Authors: Hertz Tomer , Oshansky Christine , Roddam Phillipa , DeVincenzo John , Caniza Miguela , Jojic Nebojsa , Mallal Simon , Phillips Elizabeth , James Ian , Thomas Paul , Halloran M. , Corey Larry 
Published: January 2023

Abstract
Experimental and computational evidence suggests that human leukocyte antigens (HLAs) preferentially bind conserved regions of viral proteins, a concept we term “targeting efficiency,” and that this preference can provide improved clearance of infection in several viral systems. One potential advantage of targeting conserved regions of a virus is the higher likelihood of cross-reactive protection from other viral strains, including those newly introduced, such as pH1N1. We hypothesized that individuals that targeted less conserved regions of influenza- A viruses would have weaker T-cell responses following infection with pH1N1. To test this hypothesis, T cell responses to A/H1N1 (2009) were measured from PBMCs obtained from a household cohort study performed during the 2009-2010 influenza season. We found that HLA targeting efficiency scores significantly correlated with IFNγ ELISpot responses (p=0.042, multiple regression). A further population-based analysis found that the carriage frequencies of the alleles with the lowest targeting efficiencies, A*24, were associated with pH1N1 mortality (r=0.37, p=0.031). Interestingly, these are common in certain indigenous populations in which increased pH1N1 morbidity has been reported. The computational tools utilized in this study may be useful predictors of potential morbidity and identify immunologic differences of new variant influenza strains more accurately than evolutionary sequence comparisons.
Blockade of chronic type I interferon signaling to control persistent virus infection (P6048)
Authors: Wilson Elizabeth , Brooks David 
Published: January 2023

Abstract
While both immunostimulatory and inhibitory signals are triggered by acute viral infections, persistent infections are characterized by sustained expression of an immunosuppressive program that inhibits antiviral immunity, interferes with viral clearance, and poses a barrier to effective antiviral therapeutics. However, the signals that govern the immunosuppressive program are not understood. Viral infections elicit type I interferons (IFN-I) and these proteins have potent direct antiviral effects. However, IFN-I expression has also been associated with hyper immune activation and increased disease severity in persistent viral infections. We demonstrate that antibody blockade of IFN-I signaling diminished chronic immune activation, and the immunosuppressive program, while increasing multiple immune parameters associated with control of virus replication, ultimately allowing for clearance of the persistent infection. These data highlight the duality of the IFN-I response during viral infection-serving both as a direct extinguisher of viral replication and as a central rheostat and regulator of the immunosuppressive program, dampening T cell responses and preventing viral clearance. Thus, we identify IFN-I as a key factor in immuno-surveillance during viral infection and demonstrate that therapeutic ablation of chronic IFN-I signaling can enable control of persistent viral infection.
Th17 cells demonstrate stable cytokine production in allergic inflammation (P1143)
Authors: Glosson Nicole , Sehra Sarita , Yu Qing , Stritesky Gretta , Nguyen Evelyn , Kaplan Mark 
Published: January 2023

Abstract
Th17 cells are critical for the clearance of extracellular bacteria and fungi, but also contribute to the pathology of autoimmune diseases and asthma. Th17 cells can acquire a Th1-like phenotype in vitro and in vivo, but less is known about their ability to adopt Th2 and Th9 effector programs. To explore this in more detail, we generated an IL-17F lineage tracer mouse strain that allows tracking of cells that formerly expressed IL-17F and can be used to test stability of the Th17 phenotype. Th17 cells cultured under polarizing conditions that promote Th1, Th2 or Th9 differentiation adopt the respective effector programs, expressing lineage associated transcription factors, and secreting IFN-γ, IL-4 or IL-9, while diminishing IL-17 production and expression of RORγt. To explore the stability of Th17 cells in an in vivo environment that is associated with the development of Th2 and Th9 cells, we used the adjuvant-dependent, OVA/Alum and the adjuvant-free, house dust mite models of allergic airway disease (AAD). In both models of AAD, Th17 cells from the lungs of diseased mice did not secrete alternative cytokines nor adopt Th1, Th2 or Th9 effector programs, but remained stable IL-17-secretors. Thus, although Th1-biased pro-inflammatory environments have been shown to induce alternative cytokine expression from Th17 cells in vivo, our data suggest that during allergic inflammatory disease, Th17 cells are remarkably stable, and retain the potential to produce IL-17.
Specialized microenvironment within the lymph node controls antigen-presentation properties of dendritic cells and Th2 differentiation. (P1119)
Authors: León Ruiz Beatriz , Ballesteros Tato André , Randall Troy , Lund Frances 
Published: January 2023

Abstract
T cells need to encounter antigen-bearing dendritic cells (DCs) to undergo clonal expansion and effector development. These interactions, within lymphoid tissues, are orchestrated by the expression of chemokines and chemokine receptors. Indeed, CCR7 expression by both T cells and DCs is thought to facilitate DC/T cell encounters within the T cell area of the lymph node. However, it is unknown whether co-localization of the DCs and T cells within the T cell area is obligate for effector generation. Here, we show that, following infection with an intestinal nematode, antigen-bearing DCs and the responding CD4+ T cells upregulate expression of CXCR5 and migrate in a CXCR5/CXCL-13 dependent fashion to the B cell area of the mesenteric lymph node. We further demonstrate that CXCR5-dependent localization of DCs and T cells near the CXCL13-expressing B cell follicles are required for optimal Th2 responses. Furthermore, we found that disrupting DCs from accumulating in the perifollicular region prevents the DCs from initiating Th2 differentiation. Finally, we demonstrated that DCs receive conditioning signals within the perifollicular microenvironment that change Class II Transactivator (CIITA) expression, maturation and antigen-presenting properties of DCs that allow the DCs to initiate Th2 priming. These results show that specialized microenvironments within the lymph node directly influence dendritic cell antigen presentation and function for effective priming of Th2 responses.
SIRT1 enhances Th17 cell generation by deacetylating RORγt (P1163)
Authors: Lim Hyung , Kang Seung Goo , Ryu Jae Kyu , Fei Mingjian , Lee Intelly , Kehasse Amanuel , Kasler Herbert , Kwon Hye-Sook , Shirakawa Kotaro , Schnölzer Martina , Gibson Bradford , Ott Melanie , Akassoglou Katrina , Xiao Changchun , Littman Dan , Verdin Eric 
Published: January 2023

Abstract
Although Sirtuin 1 (SIRT1), an NAD-dependent protein deacetylase, has emerged as a critical regulator of the cell cycle, replicative senescence, inflammation, and metabolism, its contribution to immune function remains to be fully investigated. Here we report that SIRT1 regulates the function of IL-17 producing CD4 T helper cells (Th17 cells) by modulating the activity of the Th17 master transcription factor RORγt. We found that Sirt1 interacts with RORγt and increases its transcriptional activity by deacetylating lysine residues K16 and K81. In mixed hematopoietic chimeras, cells from donors in which Sirt1 is deleted in ROR γ+ cells (SIRT1-cKO) exhibited compromised Th17 differentiation. Moreover, SIRT1-cKO mice were resistant to developing experimental autoimmune encephalomyelitis (EAE) upon MOG peptide immunization. Importantly, the SIRT1 specific inhibitor Ex-527 substantially inhibited trans-differentiation to Th17 cells in vitro, and injection of Ex-527 into mice strongly blocked EAE disease progression in vivo. These findings reveal a previously unappreciated proinflammatory role of SIRT1 in CD4 T cells, and provide significant evidence that pharmacological SIRT1 inhibitors might constitute a novel approach in the treatment of Th17-mediated autoimmune diseases such as multiple sclerosis.
Th2 differentiation during atopic asthma (P1167)
Authors: Pepper Marion , Hondowicz Brian , Garza Esteban , Moon James 
Published: January 2023

Abstract
Asthma is an inflammatory disease of the airways that affects more than 300 million people worldwide. Clinically, asthma is characterized by acute, intermittent and recurrent episodes of inflammation that can be induced by a specific allergen. CD4+ T cells contribute to this process by producing the Type 2 cytokines IL-4, IL-5, and IL-13 and inducing B cell production of IgE in response to T cell receptor (TCR) recognition of allergen peptides bound to MHCII molecules on host cells. In both murine models of disease and asthmatic patients, quiescent allergen peptide:MHCII (pMHCII)-specific CD4+ memory T cells can persist in lungs and lymphoid organs long after resolution of inflammation. Upon subsequent exposure to allergen, CD4+ memory T cells rapidly drive asthma-induced immunopathology making these cells attractive targets for allergen-specific immune modulation. Little is known, however, about how these cells orchestrate the asthmatic response due to the challenge of tracking small populations of CD4+ T cells that express allergen pMHCII-specific TCRs. To address this lack of knowledge, we have utilized a MHCII tetramer containing a peptide from the Der p1 protein of the house dust mite (HDM), Dermatophagoides pteronyssinus, the most common cause of atopic asthma. Using this tetramer and a novel magnetic bead-based cell enrichment method, we can assess the differentiation and function of Der p1 pMHCII-specific Th2 effector and memory cells in mice responding to HDM.
Serine antiprotease trappin-2 induces IL-9 in human peripheral blood mononuclear cells (P1171)
Authors: Alija Ana , Ambrosi Nella , Hernández Del Pino Rodrigo , Guerrieri Diego , Alvarez Belén , Tateosian Nancy , Garcia Verónica , Chuluyan Eduardo 
Published: January 2023

Abstract
Trappin-2 is a 9.9 kDa serine protease inhibitor produced by epithelial cells and immune cells such as macrophages and γδT cells. It has anti-inflammatory and microbicide activities. The aim of the present work was to evaluate the effect of Trappin-2 on peripheral blood mononuclear cells (PBMC) by analyzing proliferation response, apoptosis, cytokine production and transcription factors expression. After 5 days of culture, Trappin-2 decreased lymphocyte proliferation induced by IL-2 and diminished the early apoptosis of cells. Moreover, culture supernatants derived from PBMCs treated with Trappin-2 (48 h) showed a slight increase in IL-4 production, what was confirmed by intracellular staining of IL-4 on CD3 T cells. Besides, Trappin-2 significantly increased GATA-3 expression on PBMCs as determined by Western Blot. However, the most significant result was a clear increase in IL-9 expression on CD4 T cells, after 48 h of culture of cells with Trappin-2. Moreover, the expression of PU.1 was also increased on Trappin-treated cells. Finally, TGF-β was measured in the culture supernatants of PBMC treated with Trappin-2, given that naive CD4+ T cells differentiate in vitro into IL-9-secreting cells by effect of IL-4 and TGF-β. The results obtained showed that Trappin-2 in fact increased TGF-β at 48 h of culture. Overall, our findings suggest that Trappin-2 induces a cytokine microenvironment compatible with a potential Th9 pattern.
The role of TOX in peripheral T cell subsets (P1121)
Authors: Aliahmad Parinaz , Kadavallore Asha , Seehus Corey , de la Torre Brian , Kaye Jonathan 
Published: January 2023

Abstract
TOX (Thymocyte-selection associated HMG-box) is a DNA-binding protein identified in our laboratory that is required for development of the CD4 T cell lineage, including canonical CD4 T cells, NKT cells and T regulatory (Treg) cells. In addition, NK cell and lymphoid tissue inducer cell development requires TOX, the latter resulting in failure of lymph node development in TOX-deficient mice. Here we turn our attention to investigation of TOX in mature CD4 T cell subsets, facilitated by a knock-in Tox reporter (tdTomato) strain of mouse. The reporter faithfully mirrors TOX expression in the thymus and NK cells. We find that TOX (Tomato) is also upregulated in natural Treg and at highest levels in T follicular helper (Tfh) cells. Interestingly, both T cell subsets show heterogeneity in reporter expression, with cell populations of high, intermediate and low expression evident. In Treg, varied expression of TOX is independent of FOXP3 expression, as demonstrated by analysis of FOXP3 and TOX dual reporter mice. Among Tfh cells (CXCR5hiPD1hi), Toxhi cells are Bcl6hiCCR7-CD62Llo and likely represent mature follicular effector cells. To study the functional role of TOX, we expressed Cre in CD4 T cells from OTII Tox conditional knockout mice, and analyzed the development of phenotypically-defined Tfh in response to antigen upon adoptive transfer. Loss of TOX prevented Tfh cell development in this system, indicating a critical role for TOX in this peripheral T cell subset.
Foxp3+ regulatory T cells consist of rapidly dividing and quiescent subpopulations (P1179)
Authors: Punkosdy George , Shevach Ethan 
Published: January 2023

Abstract
While Treg exhibit an anergic phenotype in vitro, Treg proliferate in vivo at a rate similar to memory phenotype (MP; defined as CD44hi, CD62Llo) CD4+ T cells. In short-term BrdU labeling experiments, both populations uptake the label at a rate of 6% to 10% of cells in a 24-hour period. However, MP T cells are made up of multiple cell populations that proliferate at different rates and short-term labeling experiments only label the rapidly dividing population. To address whether Treg may also consist of multiple populations of cells dividing at different rates, we conducted long-term labeling experiments by providing BrdU in the drinking water. Adult thymectomized mice were used to control for new T cell development. In mice labeled for 20 days, only ~60% of the Treg were BrdU positive suggesting that a significant population of Treg is non-proliferative. BrdU incorporation was positively correlated with the level of CD44 expression on Treg and nondividing Treg uniquely expressed the cell surface marker Ly-6C. Ly-6C positivity represented a stable phenotype of Treg, as sorted Ly-6C negative and positive Treg retained their respective Ly-6C expression following adoptive transfer into a naïve host. These findings suggest that Treg are made up of rapidly dividing and quiescent subpopulations. The functional significance of these distinct populations is being investigated.
Mapping CD4+ T cell differentiation decision space: Flexibility and heterogeneity under mixed input conditions (P1181)
Authors: Eizenberg Inbal , Rimer Jacob , Friedman Nir 
Published: January 2023

Abstract
T helper cell differentiation is influenced by the spectrum of cytokines in the cells' milieu. In-vivo, cells are expected to sense a complex cytokine environment. Therefore, we aimed to study differentiation under mixed input conditions. By exposing cells to varied combinations of cytokines, we mapped the "decision space" of the differentiation process. Naïve CD4+ T cells were exposed to all 64 binary combinations of 6 cytokines, which induce the differentiation of the main T helper subsets: Th1, Th2, Th17 and iTreg. We examined the differentiation outcome in terms of cytokine-production pattern and expression of lineage-specifying transcription factors, by multi-color flow cytometry. Our data indicate that mixed conditions result in mixed phenotypes with cells expressing markers of opposing subsets simultaneously. Clustering and principal component analysis revealed up to eight different Th subsets, some of which are in accordance with known states. We also identified a hierarchical organization of input signals in their influence on driving differentiation into those subsets. Our results demonstrate flexibility and heterogeneity in Th cell differentiation. Under uncertain conditions, rather than following a hard, binary decision, cells reflect uncertainty through a biased stochastic decision process. This strategy allows flexibility and plasticity of the response at the single-cell level, while maintaining an average, possibly optimized response at the population level.
Autoimmune Regulator (Aire) is critical for the thymic development of naturally occurring Treg specificities (P1185)
Authors: Leventhal Daniel , Malchow Sven , Nishi Saki , Fischer Benjamin , Paner Gladell , Savage Peter 
Published: January 2023

Abstract
While the transcription factor Autoimmune Regulator (AIRE) has been shown to play a critical role in establishing immune tolerance through the negative selection of T cells reactive to peripheral antigens, the role of AIRE in the thymic development of Foxp3+ regulatory T cells (Tregs) remains controversial. Previously in our lab, the naturally occurring Treg T-cell receptor (TCR) “MJ23”, isolated from the prostates of tumor-bearing TRAMP mice, was used to create a monospecific TCR transgenic (tg) mouse model. By generating MJ23 tg low frequency bone marrow chimeras (BMCs), we determined that the MJ23 TCR facilitates thymic Treg development in both male and female hosts, even though MJ23 T cells are reactive to a prostate-specific antigen. By generating MJ23 BMCs into Aire+/+ and Aire-/- hosts, we determined that the thymic development of MJ23 Tregs was Aire-dependent, regardless of host gender. These results were also observed for a second naturally occurring Treg specificity. In BMCs, we found no evidence of Aire-dependent MJ23 negative selection, suggesting that for this specificity, Aire plays an exclusive role in the thymic selection of Tregs. Finally, while autoimmune prostatitis was observed in male Aire-/- mice, we found no indications of Foxp3neg MJ23 T cell expansion in Aire-/- BMC hosts. In sum, our data provide mechanistic evidence that a subset of peripheral organ-specific Tregs are dependent on Aire for their selection into the Foxp3+ Treg lineage in the thymus.
Detection of AHR in in vitro-generated Th17 cells using novel monoclonal antibodies (P1191)
Authors: Funatake Castle , Araji Soha , Alvarez Miguel , Atteberry Brandi , Li Shourong , Huang Qiulong , Schrantz Nicolas , Kerkvliet Nancy , Just Peggy 
Published: January 2023

Abstract
Several studies have shown an increase in the mRNA levels of AHR in both mouse and human Th17 cells, however, protein levels in Th17 cells have been difficult to assess due to lack of reagents for flow cytometry. We developed novel monoclonal antibodies to enable detection of AHR by flow cytometry. The antibodies were characterized by western blot, flow cytometry, and immunocytochemistry. By western blot, both antibodies produced bands of approximately 95-100 kDa in lysates prepared from transiently transfected HEK-293T cells and HepG2 or Hepa1c1c7 cells (for human and mouse AHR, respectively). The anti-mouse AHR antibody also recognized a band of 95 kDa in liver lysates prepared from C57Bl/6 mice but not from AHR knockout mice. High levels of AHR protein were detected in cells polarized under Th17 conditions for 3 days, and these levels decreased on days 6 and 10, while AHR was not detected if Th17 were polarized from splenocytes from AHR knockout mice. Analysis of AHR expression by immunocytochemistry showed that these antibodies recognized AHR in the cytoplasm of untreated cells. Upon treatment of cells with FICZ, a high affinity ligand for AHR, AHR translocated to the nucleus. These antibodies will enable the examination of expression levels of AHR by flow cytometry and immunocytochemistry to provide insight into the role of AHR in many biological systems.
Epigenetic licensing of Th17 and Treg cell differentiation (P1197)
Authors: Antignano Frann , Burrows Kyle , Hughes Michael , Oudhoff Menno , Han Jonathan , Gold Matthew , McNagny Kelly , Levings Megan , Zaph Colby 
Published: January 2023

Abstract
Naïve CD4+ T helper (Th) cells acquire a range of fates depending on the cytokine milieu and anatomical location. For example, IL-17 producing Th17 and Foxp3+ regulatory (Treg) cells are dependent upon TGFβ1 and are critical for intestinal homeostasis. G9a is a histone lysine methyltransferase with di-methyl activity towards histone H3 lysine 9. H3K9me2 is a highly conserved histone modification and is commonly linked to transcriptional repression. In this study we examine the role of G9a in the control of Th17 and Treg cell differentiation. Using chromatin immunoprecipitation (ChIP) we found that there is a concomitant loss H3K9me2 and increase in H3K9Ac (an activating histone modification) at lineage specific genes of WT Th17 and Treg cells compared to naive. Meanwhile, naïve G9a-/- T cells have low levels H3K9me2 that results in enhanced sensitivity to TGFβ1 and an increase in the differentiation of both Th17 and Treg cells in vitro. Using the T cell transfer colitis model, we found that transfer of G9a-deficient T cells fails to cause the weight loss and colonic inflammation typical of the model. Furthermore, T effector-cell production of IFNγ was significantly reduced and IL-17 was enhanced when G9a-/- T cells were transferred. In addition, compared to WT controls, a higher proportion of G9a-deficient T cells express Foxp3. We conclude that G9a-dependent H3K9me2 is a homeostatic epigenetic checkpoint that controls the magnitude of Th17 and Treg cell responses.
MiR-17~92 family microRNAs are critical regulators of T follicular helper cell differentiation (P1133)
Authors: Kang Seung Goo , Liu Wen-Hsien , Teijaro John , Lim Hyung Wook , Shepherd Jovan , Verdin Eric , Qi Hai , Oldstone Michael , Xiao Changchun 
Published: January 2023

Abstract
Germinal center (GC) reaction is a key event in B cell-mediated immune responses and CD4+ T cell help plays an essential role in these process. A distinct CD4+ effector T cell subset, T follicular helper cells (TFH), provides this help to B cells. However, molecular mechanisms underlying TFH differentiation are still largely unknown. A recent study revealed that Bcl-6 is a signature transcription factor regulating TFH differentiation and it represses the expression of miR-17~92 in CD4+ T cells. MiR-17~92 in turn suppresses the expression of CXCR5, a critical chemokine receptor controlling CD4+ T cell migration into B cell follicles. The authors therefore concluded that miR-17~92 functions as a negative regulator of TFH differentiation. Here we report the surprising finding that mice with miR-17~92 family microRNAs (miRNAs) deleted specifically in T cells exhibited severely compromised TFH differentiation, germinal center formation, and reduced antibody responses upon protein antigen immunization. Those mutant mice were also defective in TFH differentiation and germinal center B (GCB) cell formation during lymphocytic choriomeningitis virus (LCMV) clone-13 infection and failed to control the virus. Conversely, T cell-specific miR-17~92 transgenic mice spontaneously accumulated TFH cells. Novel cellular and molecular mechanisms underlying miR-17~92 family miRNA-mediated regulation of TFH differentiation will be presented at this meeting.