bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibrocytes secrete periostin to promote myofibroblast differentiation in lung fibrosis (IRC10P.407)
Authors: Ashley Shanna , Wilke Carol , Moore Bethany 
Published: January 2023

Abstract
Fibrocytes are bone-marrow-derived circulating mesenchymal precursors (CD45+, col 1+) that are recruited to fibrotic areas. Fibrocytes secrete a number of profibrotic mediators including periostin; a matricellular protein that regulates cellular interactions with extracellular matrix components (ECM). In bleomycin-induced fibrosis,loss of periostin by either structural or hematopoietic cells can limit the development of pulmonary fibrosis.To test the hypothesis that hematopoietic-derived fibrocytes might secrete soluble factors to signal structural myofibroblast differentiation, wild-type (WT) fibroblasts were treated with conditioned medium from fibrocytes isolated from bleomycin-treated WT or periostin-/- mice. After 48hrs we observed an increase in α-smooth muscle actin expression in cells treated with the conditioned medium from WT fibrocytes. Adoptive transfer of WT fibrocytes augmented lung fibrosis to a greater extent than transfer of fibrocytes from periostin-/- mice. We performed in vitro analyses of lung mesenchymal cells isolated from WT and periostin-/- mice by sorting fibroblasts and fibrocytes then treating with TGFβ1 or periostin. We demonstrate that these treatments increase the expression of X-linked inhibitor of apoptosis protein and collagen 1 mRNA. Taken together these data suggest that fibrocytes may augment bleomycin-induced fibrosis via secretion of periostin and TGFβ and which then promote the accumulation of apoptotic resistant myofibroblasts.
Synergistic effects of lipopolysaccharide on Treg cell generation is through an IDO-dependent pathway (IRC11P.431)
Authors: Goldberg Michael , Appel Moshe , Elizur Arnon , Katz Yitzhak 
Published: January 2023

Abstract
Over the past several years there has been increased awareness of the importance of early-life exposures, to long term immune disposition. Using lipopolysaccharide (LPS) activation as a surrogate marker for environmental stimulation, we previously noted that a high proliferative response to LPS in cord blood mononuclear cells (CBMC) was impaired in infants born to atopic parents (Ped. Res. 2013 Aug;74(2):211-6). Furthermore, LPS treatment can result in hypomethylation of the FOXP3 promoter in CBMC. To explore the role of LPS in promoting an immunoregulatory phenotype in CBMC, its effects on the generation of Treg cells was explored. LPS minimally induced Foxp3 expression on FACS analysis. However, in a subset of CBMC (7/14), it synergistically increased the generation of Foxp3+ Tregs induced by T cell stimulation by anti-CD3 antibody and IL-2. Priming by LPS was a necessary first step for this synergy. LPS treatment of CBMC increased indoleamine pyrrole 2,3-dioxygenase (IDO)-1 and IDO-2 expression, characteristically expressed in tolerogenic dendritic cells. Importantly, the addition of 1-Methyltryptophan, an IDO inhibitor, completely blocked FoxP3 expression. These results suggest that LPS priming, working through an IDO-dependent pathway may have early effects on the cellular milieu, resulting in the generation of Treg cells. Future experimentation will address whether early life environmental induction of Tregs is indicative of one's longer term immune disposition.
Repository corticotropin injection (H.P. Acthar® Gel) exerts direct effects on human B cells to suppress IL4/CD40L-stimulated proliferation and immunoglobulin G production in vitro (IRC11P.437)
Authors: Olsen Nancy , McAloose Carl , Benko Ann , Kovacs William , Decker Dima , Becker Patrice 
Published: January 2023

Abstract
Effects of melanocortin peptides on human B cells were described more than two decades ago, but therapeutic applications have not been fully explored. This study examined B cell responses to a clinically available melanocortin peptide preparation, repository corticotropin gel. Peripheral blood B cells isolated from healthy donors using CD19 magnetic beads were cultured with and without Interleukin 4 (IL-4) and CD40 ligand (CD40L). Repository corticotropin or Placebo Gels were added in serial dilutions. Cultures were harvested after 7 days for measurement of secreted IgG by ELISA, B cell proliferation using CFSE and viability with trypan blue. Mean IgG in IL-4/CD40L-stimulated cultures was 241.4 ng/ml and was reduced in a dose-dependent fashion with corticotropin gel; maximal suppression was to 65.55 ng/ml (p= 0.008; n=8). Addition of Placebo Gel or dexamethasone (1μM) to IL-4/CD40L cultures resulted in no change in IgG (240.3 and 248.1 ng/ml). The effect on IgG was paralleled by inhibition of B cell proliferation. In IL4/CD40L-stimulated cultures, 61% of cells were dividing, vs 8% with corticotropin gel (p&lt;0.0001) and 58% with Placebo Gel (ns). Inhibition of proliferation was not accompanied by increased cell death. Repository corticotropin gel exerted dose-dependent inhibition of IgG production and B cell proliferation without effects on cell viability. These data support potential efficacy of repository corticotropin gel in diseases characterized by B cell activation.
Treg suppressor function in inflamed peripheral tissue and lymphoid tissue occurs through distinct mechanisms (IRC11P.426)
Authors: Camirand Geoffrey , Rothstein David 
Published: January 2023

Abstract
The mechanisms by which Treg (CD4+Foxp3+) affect DC function and modulate immunity in inflamed non-lymphoid tissues remain poorly understood. Here, we used 2-photon intravital microscopy to visualize how Treg suppressor function operates within allografts. To restrain the immune reaction to the transplant site, we adoptively transferred effector T cells (Teff), wt Treg, or both (2-3x106 each) to B6 mice lacking 2° lymphoid organs (SLO; splenectomized LTβR-/-) 3-4 days after transplantation of BALB/c islets. Teff alone induced acute allograft rejection. However, the co-transfer of Teff + wt Treg led to long-term allograft survival in ~50% of recipients. Intravital microscopy of transplanted islets on day 2 showed that wt Treg infiltrated the peri-islet region, where they predominantly made contacts with DCs. Wt Treg restrained the motility parameters of Teff in the peri-islet region, reduced Teff-DC contacts, and decreased Teff intra-islet infiltration (insulitis), compared to Teff alone. Treg constitutively express the ecto-nucleotidase CD73, which generates anti-inflammatory adenosine from AMP. CD73-/- mice do not develop autoimmunity, and CD73-/- Treg are potent suppressors in vitro. In contrast, CD73-/- Tregs were unable to prevent allograft rejection by Teff, despite their presence at the graft site. These results indicate that Treg function does not require priming in SLO and that their mechanisms of action may differ from those used in SLO.
Intrinsic function of B7-H1 is linked with p38 MAPK pathway in activated CD8 T cells for T cell survival. (IRM14P.443)
Authors: Dong Haidong , Liu Xin , wu xiaosheng , Krco Christopher 
Published: January 2023

Abstract
B7-H1 (also named PD-L1) is up-regulated on activated CD8 T cells at the late stage of antigen stimulation, and is required for T cell survival during contraction phase. Since more anti-B7-H1 (PD-L1) antibody has been used in clinical trials of treatment of human cancers, it is necessary to know whether antibody ligation of B7-H1 expressed by T cells would affect T cell function and survival. After screening several anti-B7-H1 antibodies, we found that some antibody triggered the activation of p38 MAPK in activated CD8 T cells. In addition, the levels of activated p38 MAPK increased in T cells isolated from B7-H1 knockout mice compared to wild type mice. Inhibition of DNA-PKcs activation increased the activation of p38 MAPK in wild type T cells but not in B7-H1 KO T cells, suggesting B7-H1 may negatively regulate p38 MAPK through DNA-PKcs pathway. To that end, we identified an association of B7-H1 with DNA-PKcs in activated human T cells but not in resting T cells. Since p38 MAPK inhibition rescued activated CD8 T cells from apoptosis, the pro-survival function of T cell intrinsic B7-H1 may be mediated by suppression of p38 MAPK. However, ligation of B7-H1 by agonist antibody may disrupt B7-H1’s pro-survival function by increasing p38 MAPK activation. Our results identified a link of B7-H1 with p38 MAPK pathway and may help to define agonist function of anti-B7-H1 antibody prior to clinical application.
Smad4 plays an integral role in memory CD8 T cell differentiation (IRM14P.444)
Authors: Hu Yinghong , Cauley Linda 
Published: January 2023

Abstract
Tissue resident memory CD8 T cells (TRM) are a unique subset of virus-specific CTLs which bolster local immune responses after becoming lodged in previously infected tissues. These cells provide enhanced protection by intercepting returning pathogens before a new infection gets established. In contrast, central memory CD8 T cells (TCM) circulate in the bloodstream and proliferate in secondary lymphoid organs before replenishing effector and memory CD8 T cell populations in remote parts of the body. Both populations of virus-specific memory CD8 T cells participate in immunity to influenza virus infection however the signaling pathways that instruct developing memory CD8 T cells to distribute to specific tissues are poorly defined. We show that TGFβ promotes the development of pulmonary TRM cells via a signaling pathway that does not require the downstream intermediate Smad4. In contrast, circulating memory CD8 T cells have no requirement for TGFβ but show signs of arrested development in the absence of Smad4 including aberrant CD103 expression. These signaling pathways alter the distribution of virus-specific CTLs in the lungs, but do not prevent robust cytokine responses. Our data show that Smad4 is required for normal differentiation of multiple subsets of virus-specific CTLs. In normal circumstances, Smad4 may be activated via a pathway that bypasses the TGFβ receptor. Improved understanding of these signaling pathways could be used to augment vaccine-induced immunity.
Endocytosis of cytotoxic granules in CD8 T lymphocytes is required for multiple killing of target cells (IRM14P.448)
Authors: Chang Hsin-Fang , Halimani Mahantappa , Krause Elmar , Rettig Jens , Pattu Varsha 
Published: January 2023

Abstract
Cytotoxic (CD8+) T lymphocytes (CTLs) eliminate tumorigenic and virus-infected target cells by releasing the contents of cytotoxic granules (CGs) at the immunological synapse. Even though CTLs have only a limited number of pre-existing fusogenic CGs, they can efficiently kill multiple target cells upon activation. We therefore hypothesized that, following CG fusion, the remaining components are recycled and subsequently refilled with cytotoxic substances to become available for the next round of fusion, thus enabling efficient multiple killing. We visualized endogenous CGs and their recycling in real-time in CTLs from synaptobrevin2-mRFP knock-in mice by fluorescently-labeled anti-RFP antibodies. We found that endocytosis (recycling) of CGs was blocked by Dynasore, an inhibitor of dynamin. Additionally, clathrin was colocalized with endocytosing CGs at the plasma membrane following dynasore pretreatment. Thus, endocytosis of CGs is clathrin- and dynamin-dependent. Importantly, although CTLs pre-treated with Dynasore showed no immediate effect on CG exocytosis, they exhibited a 50% deficiency in killing target cells after 2 hours of incubation. Our data strongly suggest that recycling of CGs plays an important role in CTLs for executing multiple killing of target cells.
Role of atypical protein kinase on Th17 differentiation and function (IRM15P.606)
Authors: Yang Jun-Qi , Guo Fukun , Zheng Yi 
Published: January 2023

Abstract
We have reported that PKCλ/ι, a member of atypical protein kinase family, is critical for the control of cell polarity during T cell activation, Th2 cytokine production and allergic airway inflammation. However, the effect of PKCλ/ι on Th17 cells remains unknown. By the use of mice with conditional PKCλ/ι knockout in activated T cells, we investigated the potential roles of this protein kinase on Th17 differentiation, effector cytokine secretion and allergic airway inflammation. We found that loss of PKCλ/ι in activated CD4+ T cells impaired Th17-differentiation in vitro. The secretion of Th17 effector cytokines was down-regulated from PKCλ/ι-deficient T cells either under non-polarized or Th17-polarizd conditions. Furthermore, PKCλ/ι-deficiency inhibited OVA-induced allergic airway inflammation in vivo, where Th17 effector cytokines were also reduced along with Th2 cytokines. Further studies are ongoing for underlying mechanisms whereby PKCλ/ι controls Th17 cells. Our preliminary findings indicate that PKCλ/ι might be a novel regulator for Th17 cells.
OX40 ligation recruits the E3 ubiquitin ligases TRAF6 and cIAP2 that cooperatively activate the non-canonical NF-κB pathway (IRM15P.608)
Authors: Fan Yihui , Xiao Xiang , Shi Xiaomin , Ghobrial Rafik , Minze Laurie , Li Xian 
Published: January 2023

Abstract
The signaling cascades triggered by OX40 in the control of diverse responses from initial T cell activation to the generation of memory and regulatory T cells remain incompletely defined. OX40 preferentially activates and sustains the non-canonical NF-κB pathway, but the underlying mechanisms remain unknown. Here, we found that in primary CD4+ T cells activated under OX40 costimulation, TRAF6 and cIAP2 are two essential molecules and both cooperatively activate the non-canonical NF-κB pathway. Mechanistically, OX40 directly recruited TRAF6 and TRAF2/TRAF3/cIAP2/NIK complexes in which TRAF6 acted as the E3 ligase to mediate Lys63-linked polyubiquitination of cIAP2. Consequently, cIAP2 used its E3 ligase activity to promote TRAF3 Lys48-linked polyubiquitination and degradation. The UBA domain of cIAP2 inhibited the E3 ligase activity of cIAP2 targeting to TRAF3 and this autoinhibition could be released by the C-terminal RING domain polyubiquitination mediated by TRAF6. The lysines 585 and 594 at cIAP2 C-terminus were two main ubiquitin acceptor sites for TRAF6-mediated polyubiquitination, as combined mutation of such sites abolished Lys48-linked TRAF3 polyubiquitination. Thus, in TRAF6 knockout T cells, OX40 failed to induce sufficient non-canonical NF-κB activation and the downstream IL-9 production due to insufficient TRAF3 degradation. Our study identifies a previously unknown mechanism of OX40 controlled non-canonical NF-κB activation in T cells.
Cyclin-dependent kinase 5 represses Foxp3 gene expression and Treg development through specific phosphorylation of Stat3 at Serine 727 (LYM8P.641)
Authors: Lam Eric , Choi SungHee , Pareek Tej , Kim B , Letterio John 
Published: January 2023

Abstract
Cyclin-dependent kinase 5 (Cdk5) is a unique member of the family of cyclin-dependent serine/threonine kinases whose contextual and lineage-restricted activity is regulated by association with highly specific co-activators, p35 and p39. We previously demonstrated induction of both p35 expression and Cdk5 activity follows T cell receptor stimulation and is linked to post-translational modification of proteins that influence T cell activation and function. Here, we show IL-6-induced repression of Foxp3 gene expression in CD4+ T cells (Treg) requires Cdk5-mediated phosphorylation of the signal transducer and activator of transcription 3 (Stat3) specifically at Serine 727 (p-S727). Either lineage-restricted disruption of Cdk5 gene expression in T cells or pharmacological inhibition of Cdk5 activity abrogates the suppression of TGF-β-induced Foxp3 expression by IL-6. Cdk5-dependent phosphorylation of Stat3 does not alter either the abundance or nuclear localization of Stat3, nor phosphorylation of Stat3 at tyrosine 705, but it is required for proper Stat3 DNA binding to the Foxp3 gene on the enhancer II region and for the consequent disruption of Smad-dependent TGF-β-induced activation of Foxp3. These data define Cdk5 as molecular mediator of the repression of Foxp3 gene expression by inflammatory cytokines and suggest the potential to exploit specific inhibitors of Cdk5 to enhance the expansion of endogenous regulatory T cells.
Immunological characterization of human hosts to Ascaris lumbricoides and Trichuris trichiura infection in a population living in the rural municipality of Colomoncagua, Honduras (MPF6P.654)
Authors: Briggs Neima , Bottazzi Maria Elena , Beaumier Coreen , Sastry Jagannadha , Hotez Peter 
Published: January 2023

Abstract
Soil-transmitted helminth (STH) infections, specifically Ascaris, Trichuris, and Hookworm, compose three of the most prevalent Neglected Tropical Diseases, infecting over a billion people worldwide. Recurrent childhood STH infections have been shown to cause stunted physical growth, reduced physical fitness, and decreased school performance. Ascaris and Trichuris are of notable interest, given their abrupt decline from a peak prevalence and intensity in pre-adolescence to adulthood, with no known published works evaluating the possible underlying immunological mechanism. We used modern molecular techniques to (a) determine the burden of disease and (b) evaluate the immune profile of 30 adolescents and 51 adults between the ages 13-45, in rural Honduras, endemic for Ascaris and Trichuris. Using quantitative PCR of DNA extracted from stool we quantified the burden of disease of both Ascaris and Trichuris. Positive samples were stratified into groups based on the degree of infection, and controlled for with samples positive for 6 other common gastrointestinal parasites. Each group was immunologically characterized for serum Th1, Th2, and Th17 cytokines and associated antibodies. Results from this pilot study identify the basic serum immune profile associated with protection against Ascaris and Trichuris and serve as the foundation for a second, more comprehensive study that will guide vaccine antigen selection against each parasite by mimicking endemic host protective responses.
Timing effects on the inhibition of apoptosis by Toxoplasma gondii infection (MPF6P.655)
Authors: Peberdy Anna , Nash Paul 
Published: January 2023

Abstract
Toxoplasma gondii inhibits apoptosis in infected cells. This inhibition requires ongoing protein synthesis. Toxoplasma gondii is a protozoan that exists as an obligate intracellular parasite. Inhibiting apoptosis in infected cells may help preserve the parasite from damage by cytotoxic T lymphocytes during the immune response. Many inducers of apoptosis, such as cytokine withdrawal, have a long lag time and others, such as CTL killing, are cumbersome, so for this study, we focused on apoptosis induced by beauvericin and measured by nuclear morphology of cells observation in a UV microscope. Beauvericin is a toxin produced by certain fungi that is capable of inducing programmed cell death when cells are exposed. To determine the longevity of the inhibitory effect by Toxoplasma, we used cycloheximide to inhibit protein production after infection of the cells and monitored the loss of inhibition over time. We also evaluated how quickly after infection inhibition of apoptosis can be observed. We also share our observation of an in vitro artifact we inadvertently discovered: that mycoplasma infection interferes with infection of some cells by Toxoplasmam, resulting in a reduction in the inhibition of apoptosis.
The human protein resistin drives detrimental inflammatory monocyte responses in helminth infection (MPF7P.710)
Authors: Nair Meera , Jang Jessica , Barnes Mark , Le Gros Graham , Cooper Philip , Steel Cathy , Nutman Thomas , Lazar Mitchell 
Published: January 2023

Abstract
Resistin-like molecules (RELM) belong to a family of secreted proteins that are expressed in multiple helminth infections with important effects on the host immune response. However the importance of human RELM proteins in helminth infections is less well understood. To investigate this, we utilized transgenic mice that expressed the human resistin gene (Tg+). Following infection with Nippostrongylus brasiliensis, a hookworm that colonizes the lung and intestine, Tg+ mice exhibited significant lung inflammation, characterized by increased inflammatory monocytes and elevated parasite burdens compared to control Tg- mice. Genome-wide transcriptional profiling of the infected lung tissue from Tg+ and Tg- mice revealed that genes associated with cytokine and TLR signaling were significantly elevated in Tg+ mice. To delineate the downstream cellular mediators of resistin, we performed a resistin binding and chemotaxis assay and identified monocytes as the main cell-types that were responsive to resistin. Moreover, monocytes sorted from the infected lung tissue of Tg+ mice expressed significantly higher TNFα compared to Tg- mice. In human studies, increased serum resistin was associated with higher helminth burdens and was positively correlated with inflammatory cytokines. Together, these studies identify a detrimental role for human resistin in instigating a non-protective inflammatory response that may be mediated by monocytes.
Characterizing regulatory T cell differentiation to bacterial antigens in the gut (MUC8P.727)
Authors: Nutsch Katherine , Russler-Germain Emilie , Hsieh Chyi-Song 
Published: January 2023

Abstract
Regulatory T cells are an essential component of immune tolerance towards gut bacteria. Conversely, the microbiota shape the colonic Treg population. However, it is unclear if and how commensal bacteria direct naïve T cells to become peripheral Treg (pTreg) cells. Here, we define the process of pTreg development using transgenic T cells expressing commensal antigen reactive TCRs isolated from colonic Treg cells. We show that naïve TCR transgenic cells transferred into lymphoreplete mice are initially activated in a specific distal mesenteric lymph node. Treg cell differentiation is rapid, starting within 3 days, and efficient, with over 50% Foxp3+ cells arising 1 week after transfer. Contrary to prior observations, Foxp3+ cells are the most divided cells, suggesting that Treg cell differentiation is the primary cell fate upon commensal antigen encounter for these T cells. The most efficient period of Treg cell differentiation in TCR transgenic cells is around the age of weaning. Although T cells deficient in CNS1 showed a marked block in early Treg cell selection, dnTGFβRII cells were only partially deficient in Treg cell generation 1 week after transfer. By contrast, CNS1-deficient cells can upregulate Foxp3 at later time points. Thus, these data illustrate the kinetics, geography, and robustness of peripheral Treg cell selection to commensal bacteria, and suggests that CNS1 is an important region involved in early Foxp3 induction in a relatively TGFβ-independent fashion.