bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deletion of Gab adaptor proteins leads to impaired macrophage development and chronic colitis (P4175)
Authors: Vaughan Tamisha , Imhoff Barry , Wang Zhengqi , Denning Tim , Bunting Kevin 
Published: January 2023

Abstract
Inflammatory Bowel Disease (IBD), commonly Crohn’s and Ulcerative Colitis, is characterized by chronic inflammation of the gastrointestinal tract. Although the cause of this disorder is not known, alterations in immune responses and uncontrolled intestinal microflora are thought to be involved. Our lab has uncovered an important role for the Grb2 associated binding (Gab) adaptor protein family in the development and pathogenesis of IBD. In mice, Gabs include three family members that play critical regulatory roles in modulating cytokine receptor signaling in T-cells and macrophage. Our studies demonstrate that knock-out (KO) of only two of these, Gab2/3, leads to intestinal inflammation associated with spontaneous rectal prolapse as early as 8 weeks of age that is not observed in single KO mice. Bone marrow derived macrophage (BMDM) cultured from mice lacking Gab2/3 expanded poorly compared to wild-type mice or mice lacking only Gab2 or Gab3 but expressed mature markers. RT-PCR analysis showed dysregulated expression of both pro- and anti-inflammatory cytokines. Importantly, pro-inflammatory cytokines IL-6, TNF-α, IL-12p40 were significantly induced in Gab2/3 KO BMDM compared to control. Upon TLR4 activation, Gab2/3 KO cells had prolonged activation of signaling molecules IκBα and NFκB. Together these data support our conclusion that Gabs play a critical role in the pathogenesis of IBD and provide insight toward new therapeutic approaches to control and treat IBD.
Elucidating the molecular mechanism of Syntaxin11 function in cytotoxic T lymphocytes (P3032)
Authors: Halimani Mahantappa , Pattu Varsha , Krause Elmar , Hoth Markus , Schwarz Eva , Rettig Jens 
Published: January 2023

Abstract
Cytotoxic T lymphocytes (CTL) play a crucial role in eliminating virus infected and cancer cells through exocytosis of perforin and granzymeB containing lytic granules (LGs). Soluble NSF Attachment Protein Receptors (SNAREs) function as executors of exocytosis. The importance of SNAREs and SNARE associated proteins in CTL function and LG exocytosis is evident in the form of Familial Hemophagocytic Lymphohistiocytosis (FHL). Mutations within Syntaxin11 (Stx11), a Qa-SNARE protein, result in FHL subtype-4, however the mechanism by which Stx11 malfunction leads to this severe phenotype remains unknown. Here, we investigate the molecular mechanism of Stx11 function in primary human CTLs. High resolution live cell imaging with CTLs before and after target cell contact showed sequential polarization of Stx11 followed by LGs to the immunological synapse. Using TIRF (total internal reflection fluorescence) microscopy we further showed an association of LGs with plasma membrane-bound Stx11 at the IS. Further, knockdown studies using Stx11 specific siRNA resulted in a strong reduction of both LG fusion and dwell time at the IS. We therefore propose that Stx11 is required for the final fusion of LG at the IS, explaining the severe FHL4 phenotype.
Cytokine regulation of BAFF expression in human myeloid cells (P3005)
Authors: Ragheb Samia , Li Yanfeng , Dore-Duffy Paula , Lisak Robert 
Published: January 2023

Abstract
B-cell activating factor (BAFF) has an essential role in B cell homeostasis. It is synthesized and released by myeloid cells (monocytes & macrophages). BAFF over-expression promotes the survival and maturation of autoreactive B cells. Increased BAFF levels are found in several human autoimmune diseases, suggesting a role for BAFF in disease pathogenesis and progression. However, the regulatory signals that affect BAFF production are largely unknown. Using the human monocytic cell line THP-1, we examined the capacity of several cytokines to modulate BAFF expression; these included tumor necrosis factor-α (TNF-α), IL-4, IL-10, IL-12, IL-17, and the type I & type II interferons (IFN-α, IFN-β, and IFN-γ). Replicate cultures were used to measure BAFF RNA transcripts and released BAFF protein. Quantitative real-time PCR (QRT-PCR) was used to measure BAFF RNA at 6 hrs; β-actin was used as the reference housekeeping gene. BAFF protein in the culture supernatants was measured by ELISA at 96 hrs. All interferons upregulated BAFF expression (RNA & protein); however, IFN-β was the most potent (IFN-β &gt; IFN-α &gt; IFN-γ). We also tested various combinations of cytokines to assess synergistic or antagonistic effects on BAFF expression. TNF-α inhibited BAFF expression by IFN-β−stimulated cells. Similar results were obtained with primary cultures of human peripheral blood monocytes.
Polysaccharides isolated from Alchornea cordifolia modulate monocyte/macrophage function (P3006)
Authors: Quinn Mark , Kouakou Koffi , Yapi Ahoua , Kirpotina Liliya , Jutila Mark , Schepetkin Igor 
Published: January 2023

Abstract
Extracts of leaves from different species of the genus Alchornea have been used for centuries to treat medical problems in tropical Africa; however, little is known about the active components conferring therapeutic properties to these extracts. We investigated the phagocyte immunomodulatory properties of water-soluble polysaccharides extracted from the leaves of Achornea cordifolia. Extracted polysaccharides were fractionated by DEAE-cellulose, Diaion HP-20 resin, and preparative Sepharose 6B size-exclusion chromatography and characterized. Fractions containing type II arabinogalactan had potent immunomodulatory activity. Specifically, the parent fraction AP-AU and its high-molecular weight sub-fraction AP-AU1 induced nitric oxide and cytokine (IL-1β, IL-6, IL-10, TNF-α, and GM-CSF) production by human peripheral blood mononuclear cells and human and murine monocyte/macrophages cell lines in vitro. We also evaluated the ability of selected fractions to activate mitogen activated phagocyte protein kinase (MAPK) pathways using a phospho-MAPK array and found that treatment of phagocytes with AP-AU1 induced phosphorylation of Akt2, p38δ/p38γ, p70S6K1, RSK2, and mTOR, as well as stimulation of NF-κB transcriptional activity. Thus, these results provide a molecular basis to explain a portion of the beneficial therapeutic properties of water extracts from A. cordifolia leaves in traditional folk medicine of Africa.
Induction of autophagy by Type I interferon in human cancer cells (P6217)
Authors: Zoon Kathryn , Fey Samuel , Horowitz Julie , Fischer Elizabeth , Balinsky Corey , Miyake Kotaro , Bekisz Joseph , Snow Andrew , Schmeisser Hana 
Published: January 2023

Abstract
Type I IFNs (interferons) are cytokines that induce an antiviral state in cells and have antiproliferative, pro-apoptotic, and immunomodulatory activities. Autophagy is a basic cellular mechanism that involves degradation of cellular components via lysosomes. While induction of autophagy is well documented for Type II IFN, induction of autophagy by Type I IFN has not been previously reported. We determined that Type I IFN can induce autophagy in multiple human cancer cell lines. IFN-α2c and IFN-β induces autophagy in Daudi B cells, as indicated by an increase in autophagy markers LC3-II, Atg5-Atg12 complexes, and a decrease in p62. An increase in LC3-II was also detected post IFN-α2c treatment in HeLa S3, MDA-MB-231, T98G and A549 cell lines. The presence of autophagosomes in selected cell lines was confirmed by electron microscopy analysis. An increase in autophagy markers correlated with inhibition of mTORC1 activity and cell proliferation as well as changes in the cell cycle progression in Daudi cells. Treatment of Daudi and T98G cells with IFN-α2c and rapamycin (mTOR inhibitor), or LY294002 (PI3K inhibitor) increased the level of LC3-II, indicating that the PI3K/Akt/mTORC1 signaling pathway may affect IFN-induced autophagy in Daudi and T98G cells. The role of mTOR in Type I IFN-induced autophagy was confirmed by siRNA silencing experiments. Taken together, our findings demonstrate a novel function for Type I IFN as inducer of autophagy in multiple cancer cell lines.
Differential requirement of C3a receptor in APC-driven emphysema in response to cigarette smoke (P6225)
Authors: Yuan Xiaoyi , Shan Ming , You Ran , Wetsel Rick , Drouin Scott , Seryshev Alexander , Song Li-zhen , Corry David , Kheradmand Farrah 
Published: January 2023

Abstract
Pathogenic lung antigen presenting cells (APCs) are abundant in the lungs of smokers with emphysema and are capable of inducing T helper type 1 (Th1) and Th17 cell differentiation. Mice exposed to chronic cigarette smoke develop emphysema and harbor CD11b+CD11c+ APCs that can transfer the disease to naïve mice. Proteolytic products from activated innate immune cells cleave complement proteins but the contribution of their downstream signaling in APC-driven lung parenchyma destruction is less clear. We show here that relative to control smokers, complement 3 (C3) is increased in the plasma and its cleaved products are deposited on the lung tissue of smokers with advanced lung disease. Matrix metalloproteinase 12 and neutrophils elastase directly cleave human C3, and generate multiple activated signaling products. Compared to wild type, C3 deficient mice exposed to chronic smoke showed reduced CD11b+CD11c+ cells in the lungs and were protected against emphysema development. C3a and C5a, two of the major anaphylatoxin and chemoattractant mediators downstream of C3 activation, are present in the lungs of mice exposed to smoke, but only C3a signaling was critical in emphysema development because deficiency in C3a receptor (C3aR) but not C5aR phenocopied C3-/- mice in this model. These findings suggest a critical role for C3aR in the pathogenesis of smoke induced lung disease, and could be explored to develop specific new therapeutic targets for emphysema treatment.
Cholinergic neuronal signals attenuate inflammasome activation through inhibiting mitochondrial stress (P1264)
Authors: Lu Ben , Levine Yaakov , Yang Huan , Kwan Kevin , Olofsson Peder , Andersson Ulf , Chavan Sangeeta , Tracey Kevin 
Published: January 2023

Abstract
The mammalian immune system and the nervous system coevolved under the influence of cellular and environmental stress. Immunity is highly linked with mitochondrial stress, which importantly regulates the activation inflammasome, a key component of innate immunity. Here we show that cholinergic neuronal signals attenuate inflammasome activation by inhibiting mitochondrial stress. Cholinergic receptor agonists or vagus nerve stimulation significantly inhibited the inflammasome activation and mitochondrial stress; whereas genetic deletion of alpha 7 nicotinic acetylcholine receptor (a7 nAchR) significantly enhanced the inflammasome activation and mitochondrial stress. Immunohistochemical analysis revealed that a7 is localized in the mitochondria. We also found that extracellular acetylcholine rapidly influxes into macrophage cytoplasm upon ATP stimulation in a P2X7 receptor-dependent manner. Importantly, acetylcholine significantly attenuated calcium or hydrogen oxide-induced mitochondrial damage and the subsequent mitochondrial DNA release. Together, these findings unravel a novel neurotransmitter-mediated signaling pathway, in which acetylcholine translocates into cytoplasm of immune cells during inflammation, and inhibits inflammasome activation by preserving mitochondrial membrane integrity.
Specification of CD8+ T lymphocyte fates during adaptive immunity revealed by single cell gene expression analyses (P1448)
Authors: Arsenio Janilyn , Kakaradov Boyko , Yeo Gene , Chang John 
Published: January 2023

Abstract
Although it is well established that heterogeneity of lymphocyte fate is an essential feature of adaptive immune responses, how and when these divergent cellular fates are specified remains unknown. It has been previously shown that a T lymphocyte responding to a microbial infection can undergo asymmetric division to yield two daughter cells that are differentially fated from inception. Such a model suggests that the progeny arising from each of the two differentially fated daughter cells might exhibit distinct patterns of gene expression. Because strategies analyzing bulk cell populations cannot distinguish differences among individual cells, we applied high-throughput single cell gene expression profiling to interrogate single CD8+ T lymphocytes throughout the course of an immune response to a bacterial infection. We demonstrate that terminally differentiated effector cells and self-renewing memory cells exhibit unique gene expression profiles. Moreover, we are able to identify cells early during the immune response, beginning with the first cell division, that exhibit distinct gene expression patterns characteristic of effector or memory cells. Finally, we derive a network model that allows us to predict the sequential activation of genes that orchestrate each cellular fate, providing a comprehensive view of CD8+ T lymphocyte differentiation. Together, these results provide novel insights into the specification of lymphocyte fates during an immune response.
The role of immunological tolerance in humoral responses to the 2F5 epitope of HIV-1 (P6183)
Authors: Yang Guang , Holl T. , Nojima Takuya , Verkoczy Laurent , Moody M. , Haynes Barton , Kitamura Daisuke , Kelsoe Garnett 
Published: January 2023

Abstract
Many human antibodies (Ab), e.g., 2F5, that neutralize multiple clades of HIV-1 are self-reactive. We previously identified kynureninase (KYNU) as the primary self-antigen recognized by 2F5, suggesting that generation of Ab to the 2F5 epitope of HIV-1 may be proscribed by immune tolerance, a notion supported by impaired B-cell development in mice expressing the 2F5 VH and VL regions (2F5 KI). Here, we use Nojima-Kitamura single B-cell cultures to determine the pre- and post-tolerance Ab repertoire to HIV-1. All cultured B cells differentiate into IgG-secreting cells, including autoreactive cells normally subject to tolerization in vivo. The pre-tolerance compartment (small pre-B) from 2F5 KI mice represents cells that express the 2F5 V(D)J rearrangements, and maintain reactivity to HIV-1 gp41, KYNU, and cardiolipin. Mature, post-tolerance B cells from 2F5 KI mice, however, are purged of gp41- and KYNU-reactivity, but retain cardiolipin-binding, and sequence analysis reveals extensive light-chain editing. This loss of HIV-reactivity is followed in unmodified C57BL/6 mice, where B cells expressing 2F5-like BCR are lost during maturation in the bone marrow, as determined by binding to 2F5 epitope. Our results demonstrate that tolerance of the 2F5 epitope is driven by specific reactivity to KYNU, but not general cross-reactivity to cardiolipin and offer a mechanism for determining how immunological tolerance impairs humoral responses to HIV-1.
The death receptor Fas mediates a non-apoptotic signaling cascade in apoptosis resistant CD4+ T cells via the MAPK pathway. (P1304)
Authors: Ramaswamy Madhu , Cruz Anthony , Barden Mary , Siegel Richard 
Published: January 2023

Abstract
The Fas death receptor mediates peripheral tolerance by apoptotic deletion of autoreactive T cells through Restimulation Induced Cell Death (RICD). Previously, we have shown that within a pool of T cells, effector memory were more sensitive to Fas-induced apoptosis than activated naïve CD4 T cells due to efficient DISC formation. Recently, we found that FasL induces an early MAPK response in the form of pJNK activation, preferentially in activated naïve, but not memory T cells. In apoptosis resistant FADD or Caspase-8 deficient Jurkat T cells, the pJNK response is exaggerated indicating that in the absence of a functional Fas apoptotic response, an alternate non-apoptotic pathway is elicited. Further, in HH cells, a CTCL resistant to Fas apoptosis, pJNK activation was upregulated when compared to HUT78, a highly apoptosis sensitive cell line. In an attempt to identify the upstream activators of Fas-induced pJNK, we studied the role of the kinase RIP1, a known component of the Fas DISC. Inhibition of RIPK1 decreased pJNK activation in Jurkat cells and RIP deficient Jurkat cells were unable to activate pJNK upon FasL stimulation. Immunoprecipitation studies also indicated a preferential recruitment of RIPK1 to the Fas DISC in apoptosis resistant T cells. These preliminary results indicate a role for Fas mediated non-apoptotic MAPK signaling in early activated naïve T cells that precedes its traditional apoptotic role in the elimination of effector memory cells.
Innate imprinting of resident alveolar macrophages in RSV-induced allergic asthma exacerbations (P6003)
Authors: Naessens Thomas , Schepens Bert , Pollard Charlotte , Bogaert Pieter , De Koker Stefaan , Saelens Xavier , Grooten Johan 
Published: January 2023

Abstract
Acute RSV-infections are seen as instigators of exacerbations in allergic asthma patients. The question which cells and/or molecules that orchestrate viral-induced asthma exacerbations remains unanswered. We now show that the innate (antiviral) functionality of post-asthma resident alveolar macrophages (rAM), present after the clearance of the allergic bronchial inflammation, is imprinted by this preceding allergic inflammation. In contrast to naïve rAM, post-asthma rAM exhibited strong proinflammatory reactivity during RSV-infection which significantly contributed to the increased global pulmonary inflammation observed in RSV-infected post-asthma mice. The strong proinflammatory reactivity of post-asthma rAM was mainly due to increased NF-κB p65 activation in these cells upon RSV-infection. Furthermore, compared to naïve rAM, post-asthma rAM displayed no direct contribution to virus clearance. In fact, post-asthma rAM did not show efficient uptake of the virus. Finally, compared to naïve rAM, the basal activation state of post-asthma rAM was found to be strongly skewed towards an M2-phenotype. Consequently, the polarized M2-activation status of post-asthma rAM can serve as a possible explanation for the aberrant antiviral innate responses of these cells. Together, innate imprinting of rAM by a preceding allergic inflammation strongly impairs RSV-antiviral responses of the post-asthma lungs and can therefore contribute to the onset of asthma exacerbations.
Sex differences in macrophages in allergic inflammation (P6043)
Authors: Heller Nicola , Robinson Dionne , Klein Sabra , Fang Jessie 
Published: January 2023

Abstract
Patients hospitalized for asthma are up to 3 times more likely to be female than male and women comprised 64% of asthma-associated deaths in 2009. Hallmark features of allergic lung inflammation are worse in female mice compared to male mice. Both allergen-sensitized and challenged female mice and humans with asthma have greater numbers of alternatively activated macrophages (AAM) in the lung, compared to males. IL-4 or IL-13 triggers AAM differentiation, characterized by expression of the arginase I, Fizz1 and Ym1 genes in mice. To test the role of estrogen (E2) in AAM differentiation in allergic lung inflammation, we subjected female mice to ovariectomy (OVX) and implantation with E2 or placebo, followed by a typical ovalbumin-induced allergic lung inflammation protocol. There were more Ym1+ macrophages, giant cells and epithelial cells and more mucus-producing cells (PAS+) the OVX + E2 allergic group, compared to placebo. Female bone marrow-derived macrophages stimulated with IL-4 expressed double the amount of mRNA for Ym1 compared to male cells and E2 augmented expression of IL-4-induced Fizz1 mRNA and protein in both male and female macrophages. Finally, we measured distinct differences in characteristic AAM surface markers on human male and female monocytes stimulated with IL-4. Taken together, these data indicate there are intrinsic sex differences in AAM differentiation and that E2 enhances AAM differentiation and allergic lung inflammation.
STAT6 controls Tregs in vivo to enhance allergic lung inflammation (P6049)
Authors: Dorsey Nicolas , Chapoval Svetlana , Smith Elizabeth , Keegan Achsah 
Published: January 2023

Abstract
STAT6 plays a pivotal role in IL-4-mediated allergic responses. Several studies indicate that regulatory T cells (Treg) can be modulated by IL-4 in vitro. We previously showed that STAT6-/- mice are highly resistant to allergic lung inflammation even when wild type (WT) Th2 effectors were provided and have increased numbers of Tregs. However, the role of STAT6 in modulating Tregs in vivo during allergic lung inflammation has not been thoroughly investigated. To investigate Treg and STAT6 interaction during allergic inflammation, STAT6-/-, STAT6xRAG2-/- and RAG2-/- mice were subjected to Ova sensitization and challenge following adoptive transfer of ova-specific, WT Th2 effectors. Treg depletion was performed in a duplicate STAT6-/- mouse group using anti-CD25 (PC61). As expected, STAT6-/- mice were highly resistant to airway inflammation and remodeling. In contrast, allergic lung inflammation was partially restored in STAT6-/- mice treated with PC61 to levels observed in STAT6xRAG2-/- mice. When the susceptible STAT6xRAG2-/- mice were also given Tregs along with Th2 effectors, allergic inflammation and airway remodeling was suppressed to levels comparable to STAT6-/- mice. These results demonstrate that STAT6 acts to suppress the development of Tregs in vivo in order to promote allergic airway inflammation.
Regulation of CD4+ T cell responses: The impact of limiting CD28 costimulation (P1083)
Authors: Briggs Zoe , Sansom David 
Published: January 2023

Abstract
Controlling T cell activation is important to prevent autoimmunity. Costimulatory molecules CD28 and CTLA-4 bind the same ligands (CD80 and CD86) but cause opposite outcomes: CD28 signalling enhances TCR signals whereas CTLA-4 inhibits T cell activation. The mechanism of CTLA-4 action has been unclear however we have identified a novel mechanism whereby CTLA-4 removes its ligands from antigen presenting cells by trans-endocytosis. This reduces the availability of costimulatory ligands for CD28 engagement and thereby regulates T cell activation. This model predicts that there is a threshold number of costimulatory ligands required for T cell stimulation. We are using a dose-dependent inducible expression system to determine this threshold and compare the two ligands. We have also begun to examine the functional consequences of stimulating CD4+ T cells while restricting costimulation and observed that CD28 costimulation is not always required for T cell activation and proliferation, but without CD28 engagement T cells do not fully differentiate or upregulate a number of functional proteins. Interestingly in our studies, human T cells activated in the absence of CD28 signalling are not classically anergic. Establishing the characteristics of T cells activated without adequate costimulation may be a useful surrogate for CTLA-4 function and improve our understanding of immune responses in the context of autoimmunity, tumour biology or transplant rejection.
Galectin-1 as a novel effector molecule of cytotoxic cells (P1061)
Authors: Amarante-Mendes Gustavo , Machado Tiago , Vieira Narciso , Zorn Telma , Dias-Baruffi Marcelo , Rodrigues Maurício , Martin Seamus 
Published: January 2023

Abstract
The mechanism of cytotoxicity mediated by Natural Killer (NK) cells and Cytotoxic T Lymphocytes (CTL) is involved in the control of cancer progression, virus mediated diseases and many other intracellular related pathologies. These cells are particularly adapted to promote contact mediated cell death due to their ability to produce a special type of organelles, namely secretory lysosomes, aka cytotoxic granules. By proteomic analysis, we identified dozens of putative novel cytotoxic granule proteins in NK and CTL, as well as most of the already known granule constituents. Here we show that galectin-1, a protein previously described to have immunomodulatory activity, including regulation of apoptosis, is indeed present inside the cytotoxic granules. Moreover, galectin-1 deficient mice display an impaired in vivo cytotoxic activity against antigen-specific targets, suggesting that galectin-1 is a novel effector component of the cytotoxic cell machinery.