bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of asthma on susceptibility to influenza A virus infection (VIR2P.1029)
Authors: Furuya Yoichi , Sanfilippo Alan , Metzger Dennis 
Published: January 2023

Abstract
Asthma exacerbations by respiratory infections are a serious health issue and, thus significant effort has been put into understanding the impact of respiratory infections on asthma. However little remains known about how the asthmatic phenotype could influence immune responses against respiratory viral pathogens. Using a mouse model of allergic lung inflammtion, we investigated the susceptibility of asthmatics to influenza A virus challenge. Unexpectedly, asthmatic mice were highly resistant to primary infection with the H1N1 2009 pandemic strain. However, the increased survival rate did not correlate with viral lung titers. Strikingly, asthmatic mice exhibited a significant reduction in cytokine storm, total protein levels and cytotoxicity in the airway; observations that indicate minimal tissue injury. Further, we found that asthmatic mice had significantly increased levels of TGF-β1 and that the heightened resistance of asthmatic mice was abrogated in the absence of TGF-β receptor II. Thus, we conclude that a transient increase in TGF-β expression following an asthma attack is responsible for temporary protection against influenza virus challenge via suppression of lung immunopathology.
The human respiratory syncytial virus nucleoprotein is expressed on the surface of dendritic cells and inhibits immunological synapse assembly by T cells (VIR2P.1018)
Authors: Céspedes Pablo , Bueno Susan , Ramírez Bruno , Depoil David , Sacristan Catarina , Cammer Michael , Dustin Michael , Kalergis Alexis 
Published: January 2023

Abstract
The human Respiratory Syncytial Virus (hRSV) is the major cause of children severe respiratory tract infections worldwide. Both, the poor activation of T cells and the limited generation of memory T cells following disease resolution are considered key processes favoring hRSV epidemics, which are based on re-infections. It is known that hRSV infects Dendritic cells (DCs) dampening their capacity to prime antigen-specific naïve T cells, a process needed to mount a proper antiviral immune response and eliminate hRSV from the airways. Here we show that the hRSV Nucleoprotein (N) is expressed at the surface of a variety of infected cells, including DCs. After estimating the approximate density of N in the surface of DCs and other cells, we evaluated whether these physiological densities could affect the assembly of the immunological synapse (IS) by naïve CD4+ T cells. We observed that N, but not control proteins inhibited the assembly of IS by interfering with TCR-pMHC interactions, which was accompanied with reduced accumulation of TCR and reduced central clustering of pMHC at the T cell-bilayer interface, as well as with reduced phosphorylation of tyrosine residues in the interacting pole of stimulated T cells. Altogether, our findings propose N-hRSV as a key virulence factor responsible for the suboptimal T cell activation observed in hRSV-infected individuals.
Optineurin is dispensable for LPS- and Salmonella typhimurium-induced autophagy (INM3P.412)
Authors: Munitic Ivana , Giardino-Torchia Maria Letizia , Ashwell Jonathan 
Published: January 2023

Abstract
In vitro studies demonstrated that optineurin, a ubiquitin (Ub)-binding protein, becomes an autophagy cargo receptor upon being phosphorylated on Ser177 by TANK binding kinase 1 (TBK1) in response to cytosolic Salmonella typhimurium. Phosphorylated optineurin then regulates autophagy by delivering ubiquinated bacteria to autophagosomal membranes via light chain 3 (LC3), hence restricting their growth. To test the in vivo relevance of these findings, we used a mouse model with C-terminal optineurin truncation, which lacks the Ub-binding region (Optn470T). No difference was found between WT and Optn470T macrophages in LC3 lipidation during LPS-induced autophagy. Similarly, p62+LC3+ aggresome-like structures generated upon LPS or Salmonella typhimurium stimulation in Optn470T macrophages colocalized with lysosomal marker LAMP1 to the same extent as in WT cells, demonstrating no perturbation in autophagosome fusion to lysosomes. Importantly, upon in vivo infection with Salmonella typhimurium, no difference was found in bacterial replication in WT and Optn470T mice. These results argue against the role of optineurin in Salmonella typhimurium infection in vivo.
The involvement of Mycobacterium leprae Hlp-DNA complex in bacterial recognition and airways epithelial activation (INM3P.404)
Authors: Dias Andre , Silva Camila , Silva Carlos Adriano , Santos João Pedro , Pereira Geraldo , Pessolani Maria Cristina 
Published: January 2023

Abstract
Airways are considered the main site of entry of Mycobacterium leprae (ML), the causative agent of leprosy. ML expresses a histone-like protein (Hlp), present in the cell envelope, which has been implicated in the binding of this mycobacterium to respiratory epithelial cells (ECs). So we investigated whether mycobacterial DNA-Hlp complexes are able to increase the human alveolar epithelial cell line A549 responses to ML through recognition by TLR9. ELISA results showed that ML and soluble CpG-Hlp complexes increase IL-8 secretion in ECs. Moreover, immunoblotting and ELISA assays revealed that ML induces the NF-κB nuclear translocation in A549 cells and the IL-8 production was dependent of that translocation. The antagonist of the nucleic acid PRRs also affected the ML-induced IL-8 production by ECs. In culture medium, the M. smegmatis wild-type (wt), but not the mutant strain for the gene hlp, was able to form clumps in the presence of exogenous mycobacterial DNA. Furthermore, the addition of CpG to M. smegmatis wt increased the production of IL-8 by A549 cells. Finally, conditioned medium from ECs pre-treated with ML was able to increase the CD40 and CD86 co-stimulatory molecules expression on plasmacytoid dendritic cells (DCs). Altogether, these observations suggest a potential role for the M. leprae DNA-Hlp complex in the activation of the airways epithelium, and an involvement of DCs in the protection of the host at the initiation of infection.
Interleukin-17 receptor A (IL-17RA) is a key regulator of type 2 inflammatory responses involved in maintaining immune system homeostasis. (IRC7P.431)
Authors: FLOUDAS ACHILLEAS , Saunders Sean , Fallon Padraic 
Published: January 2023

Abstract
IL-17 cytokine family signaling is a key mediator of skin inflammatory disorders including atopic dermatitis and psoriasis. It has previously been shown that deficiency of IL-17 producing cells and especially TCRγδ T cells attenuates the skin inflammatory phenotype observed in murine models of psoriasis. Mice lacking IL-17 receptor A expression, through which IL-17A and other IL-17 family cytokines signal, develop severe and progressive skin inflammation. This spontaneous skin inflammation was characterized by increased epidermal thickness with cellular infiltration, which was accompanied with lymphadenopathy, and type 2 responses, including eosinophilia and increased serum levels of IgE. On a cellular level a significant increase in the numbers of innate lymphoid cell subpopulations was observed. Additionally IL-17RA-/- mice have increased γδ T cells with an activated memory-like phenotype. To further elucidate the role of IL-17 family cytokines in atopic dermatitis (AD) we crossed IL-17RA-/- mice with mice, carrying a mutation previously associated with human AD, that results in a spontaneous atopic dermatitis-like disease. The absence of IL-17RA signaling resulted in a severely accelerated AD like inflammation. This highlights that IL-17RA signaling is required for maintaining homeostasis including the regulation of Th2 responses.
Antigen presentation via MHC class II by lymphatic endothelial cells dampens CD4+ T cell response (IRC7P.436)
Authors: Potin Lambert , Maillat Lea , Dubrot Juan , Duraes Fernanda , Hugues Stéphanie , Swartz Melody 
Published: January 2023

Abstract
Lymphatic endothelial cells (LECs) can directly interact with CD8+ T cells via presentation of peptide-MHCI complexes, resulting in tolerance due to lack of costimulatory molecules and high levels of PD-L1 expression by LECs. Moreover, we and others have recently demonstrated that LECs can present peptide-MHCII complexes (pMHCII) to CD4+ T cells. However, the functional implications of antigen presentation by LECs to CD4+ T cells remain unclear. Here, we explore the tolerogenic potential of pMHCII presentation by LECs to CD4+ T cells using ovalbumin (OVA) as a model antigen. In vitro, LECs isolated from mice lacking MHCII could acquire pMHCII from wildtype dendritic cells (DCs). Subsequent LEC interactions with TCR-transgenic CD4+ T cells resulted in increased levels of CD4+ cell apoptosis, indicating deletion. Moreover, the ability of DCs to induce CD4+ T cell proliferation was decreased when LECs were present in the culture system. To examine the role of endogenous MHCII expression by LECs, we created an inducible mouse model lacking MHCII expression in LECs using a Cre-recombinase approach. In these mice, T cell responses to vaccination effects were enhanced with respect to circulating OVA-specific CD8+ T cells, indicating increased T cell help (CD4). Together, these data suggest that LEC expression of MHCII may serve to dampen or regulate immune responses. Further studies are needed to elucidate the functional role of LEC expression of MHCII in pathological conditions.
GITR sustains IL-2+ CD4 helper T cells to facilitate early control of a chronic viral infection (IRC7P.422)
Authors: Clouthier Derek , Zhou Angela , Wortzman Michael , Luft Olga , Levy Gary , Watts Tania 
Published: January 2023

Abstract
CD4 T cells are critical for control of persistent infections; however, the key signals that regulate CD4 T help during infection remain incompletely defined. Here we show that during lymphocytic choriomeningitis virus (LCMV) clone 13 infection, glucocorticoid-induced TNFR (GITR)-deficient mice exhibit defective CTL responses and viral control. Differences in CTL responses and viral control between GITR+/+ and GITR-/- mice were lost when CD4 T cells were depleted. Furthermore, mixed bone marrow chimeric mice and transfer of LCMV-specific CD4 or CD8 T cells demonstrated that these effects of GITR are CD4 T cell-intrinsic. GITR is dispensable for initial CD4 T cell proliferation and differentiation, but supports the post-priming accumulation of IL-2+ Th1 cells to facilitate CTL expansion and early viral control. In vivo GITR-dependent activation of p65 NF-kB and S6 ribosomal protein was detected at day 3 p.i., a time at which GITR-L is maximally expressed on macrophages. Defects in CD4 T cell accumulation in GITR-deficient T cells were apparent starting at day 5 p.i. Consistently, we pinpoint IL-2-dependent CD4 T cell help for CTLs to between days 4-8 p.i. GITR also increases the ratio of T follicular helper to T follicular regulatory cells, thereby enhancing LCMV-specific IgG production. Together, these findings identify a CD4 T cell-intrinsic role for GITR in sustaining early CD8 and late humoral responses to collectively promote control of chronic LCMV clone 13 infection.
The iron sequestering protein Lipocalin 2 is critical to IL-33-exposed dendritic cell stimulation of Th2 responses and allergic airway disease (IRC7P.424)
Authors: Lott Jeremy , Liu Quan , Matta Benjamin , Mathews Lisa , Pociask Derek , Sperling Anne , Kolls Jay , Turnquist Heth 
Published: January 2023

Abstract
IL-33 is an IL-1 cytokine with emerging pleotropic functions, but ascribed a prominent role in Type 2-mediated responses to pathogens due to its capacity to generate and support T helper type 2 (Th2) cells. Likewise, IL-33 and Th2 cell are viewed as dominant drivers of inflammatory lung disorders, including asthma. Previous studies have revealed that IL-33 stimulates the capacity of dendritic cells (DC) to initiate Th2 responses and, thus instigate allergic airway disease (AAD) in mice. However, the precise mechanisms by which IL-33 promotes DC-mediated Th2 polarization was not known. To answer this question, we preformed microarray analysis on DC after exposure to IL-33. This analysis identified multiple genes involved in iron homeostasis and metabolism upregulated by IL-33. The most dramatically increase gene in DC by IL-33 was Lipocalin 2 (Lcn2), an iron sequestering protein that facilitates DC iron uptake. After IL-33-exposure, DC deficient in Lcn2 displayed a significantly reduced capacity to generate Th2 responses, however, LPS-exposed DC lacking Lcn2 were fully capable of Th1 polarization. Identical finding were observed when DC iron uptake was blocked through chelation during their exposure to IL-33. In a DC-induced model of AAD, blocking DC iron uptake resulted in significantly decreased disease severity. These data define a novel role for IL-33-stimulated iron uptake by Lcn2 in the generation of Th2 responses.
Engineered FVIII-specific human CD4 T cells: does TCR avidity modulate T-helper phenotypes? (IRC7P.425)
Authors: Adair Patrick , Kim Yongchan , Pratt Kathleen , Scott David 
Published: January 2023

Abstract
We recently demonstrated that expanded human CD4 T cells can be transduced to express TCRs specific for a given epitope. These cells proliferate and secrete cytokines in response to their cognate peptide/MHC. Herein, we examined whether TCR- transduced cells could be skewed to different T-helper subsets, or alternatively if previously skewed T cells could be modulated after transduction. Two HLA DR1-restricted TCRs were cloned from Th2 and Th17/Th1-type CD4+ T-cell clones specific for a coagulation factor VIII peptide (pC2). Engineered CD4+ T cells expressing these TCRs exhibited different proliferation kinetics during titration with pC2. All pC2-stimulated cells expressed IFN-g, IL-4, and IL-2 intracellularly but did not express cytokine signatures characteristic of their parental Th2 and Th17/Th1 clones. CD45RA+ and CD45RA- T cells were skewed to Th1, Th2 or Th17 and then transduced with each of the 2 TCRs. The higher-avidity TCR cells that were skewed to Th2 and then stimulated with low [pC2] maintained a Th2 cytokine signature, whereas the same cells stimulated with higher [pC2] expressed lower levels of IL-4 and GATA3. In contrast, Th1, Th17 and Th0-skewed cells transduced with the same TCR expressed their respective cytokines at all pC2 doses. Differences between the low-avidity TCR-engineered cells were less pronounced. These studies will inform our strategies for designing novel T-helper cellular therapies.
Synergistic T cell modulation by innate and adaptive immune signals (IRC8P.446)
Authors: Jun Janice 
Published: January 2023

Abstract
One of the most effective anti-inflammatory agents that has successfully prevented disease in multiple inflammatory disease models is the capsular carbohydrate polysaccharide A (PSA) of the commensal bacteria Bacteroides fragilis. PSA triggers a potent anti-inflammatory response characterized by T cell-dependent IL-10 production, yet little is known about the antigenic mechanism underlying this extraordinarily effective suppressive response. While this effect of PSA is known to require TCR engagement on CD4+ T cells by MHCII presentation of processed PSA by APCs, little else is known about why this engagement, which is common to all conventional T cell antigens, selectively leads to IL-10 production and the inhibition of inflammatory disease. We have taken a reductionist approach to identify the types of antigenic stimuli selectively leading to IL-10 production in T cells and have discovered that innate signals directly on the T cell, independent of the APCs, can modulate IL-10 secretion if the T cell receptor signaling cascade is actively engaged. Moreover, these innate signals leading to IL-10 production are specific for the effector/memory T cell subsets and are not effective within the classically-defined naïve or regulatory T cell populations. This suggests a novel role for T cell-intrinsic innate signals working in conjunction with traditional adaptive signals in inducing a potent IL-10 response with therapeutic ramifications.
Cellular and molecular basis of Ag-specific and Ag-nonspecific T-dependent antibody responses in vivo (IRC8P.447)
Authors: Watanabe Masashi , Hodes Richard 
Published: January 2023

Abstract
Although B7 is essential for T-dependent Ag-specific Ab production, little is known about cell type specific role of B7 for these responses. Utilizing B7cKO mice, the cell type specific roles of B7 costimulation for T-dependent GC and Ab responses were analyzed. Upon NP-OVA/Alum immunization, NP-specific IgG1 production was profoundly defective in mice lacking B7 expression on DC (DC-B7KO) but was intact in mice lacking B7 on B cells (BC-B7KO). Consistent with this, NP-binding GC B cells and Ag-specific CD4+ T cell expansion were not observed in DC-B7KO. Surprisingly, however, GC formation and total numbers of GC B and TFH were undiminished in DC-B7KO; whereas BC-B7KO showed reduction of total number of GC B and TFH despite normal numbers of NP-binding GC B. These results demonstrate that B7 on DC but not B cells is critical for Ag-specific CD4+ T cell expansion and IgG1 production. In contrast, a distinct pathway dependent upon B7 on B cells but not DC supported apparently Ag-nonspecific GC response. Of interest, MHCII on B cells but not on DC was required for Ag-nonspecific GC response, indicating that cognate T-B but not T-DC interaction was responsible for eliciting Ag-nonspecific GC response. Our study revealed a previously unappreciated B7-dependent Ag-nonspecific Ab production pathway and demonstrated distinct cellular and molecular pathways for Ag-specific and Ag-nonspecific components of T-dependent Ab responses.
RGC-32 regulates T lymphocyte cell cycle activation in a phosphatidylinositol 3- kinase and IL-2 -dependent manner (IRC8P.442)
Authors: Rus Horea , Tegla Cosmin , Cudrici Cornelia , Nguyen Vinh , Kruszewski Adam , Mekala Amurgam , Rus Violeta , Badea Tudor 
Published: January 2023

Abstract
We have previously shown that RGC-32 is involved in cell cycle regulation in vitro. To define the in vivo role of RGC-32, we generated RGC-32 knockout mice. To assess the effect of RGC-32 deficiency on cell cycle activation in T cells, we determined the proliferative rates of CD4+ and CD8+ T cells from the spleens of RGC-32-/- mice, as compared to wild-type (WT) mice. After stimulation with anti-CD3/anti-CD28, CD4+ T cells from RGC-32-/- mice displayed a significant increase in [3H]-thymidine incorporation when compared to WT mice. In addition, both CD4+ and CD8+ T cells from RGC-32-/- mice displayed a significant increase in the proportion of proliferating Ki67+ cells, indicating that in T cells, RGC-32 has an inhibitory effect on cell cycle activation induced by T-cell receptor/CD28 engagement. Furthermore, Akt and FOXO1 phosphorylation induced in stimulated CD4+ T-cells from RGC-32-/- mice were significantly higher, indicating that RGC-32 inhibits cell cycle activation by suppressing FOXO1 activation. We also found that IL-2 mRNA and protein expression were significantly increased in RGC-32-/- CD4+ T cells when compared to WT CD4+ T cells. In addition, the effect of RGC-32 on the cell cycle and IL-2 expression was inhibited by pretreatment of the samples with LY294002, indicating a role for phosphatidylinositol 3- kinase (PI3K). Thus, RGC-32 is involved in controlling the cell cycle of T cells in vivo, and this effect is mediated by IL-2 in a PI3K-dependent fashion.
Mechanism of lipid droplet accumulation in mononuclear phagocytes during sepsis (IRM9P.461)
Authors: ROSAS-BALLINA MAURICIO , Guan Xue Li , Schürmann Nura , Schmidt Alexander , Bumann Dirk 
Published: January 2023

Abstract
Lipid droplet formation in phagocytes is associated with various important inflammatory conditions, and their accumulation modulates disease progression. We used proteomics, lipidomics, and cell bioenergetics experiments to unravel the metabolic basis of lipid droplet accumulation in a murine model of Salmonella infection. Lipid droplets accumulated in inflammatory monocytes and neutrophils within spleen inflammatory lesions, and this is recapitulated in vitro by treating monocytes with the pro-inflammatory cytokine IFNγ. Bioenergetic experiments suggested that iNOS-derived nitric oxide blocks the mitochondrial electron transport chain thus inhibiting respiration and oxidation of fatty acids, which instead accumulate within lipid droplets. Surprisingly, metabolite tracing with 13C-labeled substrates revealed that de novo synthesis of fatty acid from glutamine or glucose plays no major role in lipid accumulation, in stark contrast to the otherwise similar metabolism of cancer cells. Instead, the glycerol head group in triacylglycerol and phospholipid entirely derives from glucose, while the fatty acid carbons originate from uptake of external lipids. Our results identify neutrophils and inflammatory monocytes as a depot of neutral lipid during infection, and establish remodeling of imported lipids with exchange of head groups for newly synthesized glycerol as the underlying metabolic mechanism of lipid droplet accumulation upon activation with IFNγ.
Selective modulation of B cell mRNA and microRNA expression by histone deacetylase inhibitor (IRM10P.615)
Authors: shen Tian , Nasrollahi Helia , Taylor Julia , Tat Connie , Zan Hong , Casali Paolo 
Published: January 2023

Abstract
As we suggested, epigenetic factors such as miRNAs, can interact with genetic programs to regulate B cell functions and inform antibody response. We have shown that histone deacetylase inhibitors (HDIs) valproic acid and butyrate, inhibited class-switch DNA recombination (CSR), somatic hypermutation (SHM) and plasma cell differentiation by modulating B cell intrinsic mechanisms. They repressed AID and Blimp-1 expression, which are critical for CSR/SHM and plasma cell differentiation, in mouse and human B cells by upregulating selected miRNAs that silenced AICDA/Aicda and PRDM1/Prdm-1 mRNAs, as demonstrated by qRT-PCRs. To further define the selectivity of HDI-mediated modulation of miRNA and gene expression, we performed miRNA-Seq and mRNA-Seq analysis in B cells stimulated with LPS plus IL-4 followed by VPA treatment. Consistent with our recent findings (J. Immunol. 193:5933-5950, 2014), these B cells showed reduced Aicda and Prdm1 expression, and increased expression of miR-155, miR-181b and miR-361, which target Aicda, and miR-23b, miR-30a and miR-125b, which target Prdm1,. The HDI-mediated modulation of mRNA was very selective. Among over 22,000 mRNAs analyzed, less than 20 mRNAs, including Aicda and Prdm1, significantly expressed in activated B cells were reduced by over two fold. Our findings indicate that, in B cells, HDI selectively modulate mRNAs, possibly through miRNA upregulation and as a result of HDACs existing in unique contexts of HDAC/co-factor complexes,.