bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aging-related changes in lymphatic collectors predispose to pathogen dissemination in tissues (INC4P.342)
Authors: Nizamutdinova Irina , Zolla Valerio , Scharf Brian , Clement Cristina , Maejima Daisuke , Akl Tony , Nagai Takashi , Luciani Paola , Leroux Jean-Christophe , Halin Cornelia , Stukes Sabriya , Tiwari Sangeeta , Casadevall Arturo , Jacobs William , Entemberg David , Condeelis John , Fooksman David , Zawieja David , Gashev Anatoliy , Santambrogio Laura 
Published: January 2023

Abstract
Herein we analyze how the aging process affects the structure and functionality of the lymphatic collectors (LCs) with reference to their ability to maintain pathogen clearance. Ultrastructural, biochemical and proteomic analysis indicated a loss of extracellular matrix proteins, an increase in protein oxidative modifications as well as activation of nuclear factor-κB signaling as sign of “low grade” inflammation in aged LCs. This resulted in a decrease in contractile and pumping activity of LCs, as measured in vivo. Functionally, this impairment also translated into a reduced ability for in vivo bacterial transport as determined by time-lapse microscopy. Ultrastructural and proteomic analysis also indicated a decrease in the thickness of the endothelial cell glycocalyx and loss of gap-junction proteins in aged LCs. Redox proteomic analysis mapped an aging-related increase in the glycation and carboxylation of endothelial cell glycocalyx structural proteins. Functionally, these modifications translated into higher ability of the pathogen to escape from aged LCs into the surrounding tissue. Altogether, our analysis mapped the complexity of the aging-related anatomical, biochemical and functional changes in LCs. The decreased ability to transport bacteria to the draining nodes, associated with increased bacterial escape in the surrounding tissue can contribute to the decreased ability of the immune system to clear pathogens in the elderly, as observed in immunosenescence.
A surprising role for COX-2 signaling in promoting IL-22 in the absence of IL-33 or TLR9 during invasive aspergillosis (INC4P.326)
Authors: Garth Jaleesa , Reeder Kristen , Gessner Melissa , Godwin Matthew , Dunaway Chad 
Published: January 2023

Abstract
IL-33 is a proallergic cytokine thought to play a role in severity of fungal asthma whereas TLR9 signaling has been previously reported to constrain lung immune responses to invasive aspergillosis (IA). We have previously reported a critical role for IL-22 in host defense during IA and therefore questioned whether IL-33 or TLR9 signaling affected IL-22-mediated immune responses. Results show that mice deficient in the receptor for IL-33 (Il1rl1-/- mice) demonstrated enhanced clearance of A. fumigatus from the lungs, which correlated with elevated IL-22 production independent of elevated IL-23 levels. Similar results were observed with mice deficient in TLR9 (Tlr9-/- mice). To this end, we show that PGE2 was induced at higher levels in both Il1rl1-/- and Tlr9-/- mice. In contrast, PGD2 was not detected in either Il1rl1-/- and Tlr9-/- mice whereas PGF2α was observed to be higher in Il1rl1-/-, but not Tlr9-/-, mice. Moreover, treatment of normal mice with IL-33 resulted in attenuated IL-22 induction after A. fumigatus exposure, which correlated with lower PGE2 production. Finally, treating either Il1rl1-/- or Tlr9-/- mice with Celecoxib, a nonsteroidal anti-inflammatory drug which inhibits COX-2 (PGE2/PGF2α induction), attenuated IL-22 production and eliminated the enhanced fungal clearance. These data suggest that signaling via IL1RL-1 and TLR9 regulates COX-2 mediated IL-22 during lung infection with A. fumigatus.
The flagellin D2/D3 domain induces TLR5- and inflammasome- independent antibody responses (INM2P.357)
Authors: LU CHUNCHI , Lopez-Yglesias Americo , CHEN HSINHUI , Zhao Xiaodan , Chao Tiffany , VandenBos Tim , Strong Roland , Smith Kelly 
Published: January 2023

Abstract
The detailed understanding of the molecular mechanisms underlying the biological activity adjuvants is critical for rational design of more effective vaccines. Bacterial flagellin, a potent immunogen, is being developed as a new adjuvant and platform for human vaccines. We have demonstrated that the conserved D0 and D1 domains of flagellin promote antibody responses through activation of their respective innate immune receptors, but are not required for Salmonella flagellin (FliC) induced antibody responses. We hypothesized that additional flagellin domains also influence specific aspects of flagellin-induced B cell responses. Mice were immunized with a mixture of FliC mutants proteins and ovalbumin, and sera were collected for quantification of anti-flagellin and anti-ovalbumin specific antibody responses. The results from our studies demonstrate that the D2/D3 domain of the FliC is also required for flagellin-induced primary antibody responses and robust secondary responses. D2/D3 domain is capable of inducing antibody responses independent of TLR5 and the inflammasome. Our data indicate the flagellin D2/D3 domain synergizes with the TLR5 (D1) and inflammasome (D0) activating domains to induce potent antibody responses, and that the D2/D3 domain also functions as an adjuvant to promote antibody responses against co-administered antigens. Future studies will elucidate the contribution of the FliC D2/D3 domain to B cell responses and its utility in vaccines.
Identification of a novel protein protein interaction pathway with NLRC3 (INM2P.359)
Authors: Davis Beckley , Tocker Aaron , Talento Suzanna , Jacob Kimberly 
Published: January 2023

Abstract
Nucleotide binding domain, leucine rich repeat CARD containing protein 3 (NLRC3) is a member of the NLR gene family. Members of this family have been associated with human inflammatory diseases such as Crohn’s disease and cryopyrin-associated periodic syndrome. Although NLRC3 (and others) are not associated with human diseases, it is expressed preferentially in the immune system and functions in pathogen recognition. NLRC3 is an intracellular protein involved in the sensing of lipopolysaccharide and cytosolic nucleic acids. NLRC3 is hypothesized to act as a negative regulator in response to bacterial and viral infection, suggesting that the vertebrate immune system has evolved specific inhibitors to limit the inflammatory response. We performed an unbiased yeast two-hybrid screen using an amino terminal fragment of NLRC3 to identify putative interacting proteins that might help elucidate the mechanism by which NLRC3 might inhibit inflammatory responses. To this end, we identified several interacting proteins. One protein in particular acts as a scaffold important in regulating the cytoskeleton, cell adhesion and proliferation. Structure function analysis has localized the domains necessary and sufficient for interacting with NLRC3. Additionally, confocal microscopy demonstrates that these two proteins colocalize in transformed human epithelial cells. This data suggests that NLRC3 interacts specifically with a novel scaffold.
Chronic pulmonary exposure of iron oxide nanoparticls induced Th1-type immune response accompanying suppression of antigen-presenting function (IRM12P.647)
Authors: Park Eun-Jung , Lee Sang , Lee Kyuhong , Kim Younghun , Lee Byeong-Seok 
Published: January 2023

Abstract
Accumulated evidence shows that pulmonary nanoparticles induce adverse health effects by modulating immune system in the body. In this study, we investigated local and systemic immune response following a single intratracheal instillation of iron oxide nanoparticles (FeNPs, the oxidized form of magnetite). FeNPs had a needle-like shape, and hydrodynamic area in suspension is 101.3 ± 4.2 nm. At day 90 after a single instillation (0.5, 1, and 2 mg/kg), FeNPs remained in the lung, and particle-laden macrophage increased a dose-dependent manner in BAL fluid. The number of total cells and the portions of neutrophils and lymphocytes significantly increased at 2 mg/kg dose. We also observed that the percentage of apoptotic cells and LDH release increase in a dose-dependent manner. Moreover, Th1-type cytokines were dominantly secreted accompanying the elevated secretion of chemotaxis-related cytokines, including GM-CSF, MCP-1, and MIP-1, in BAL fluid. Distribution of T cells and helper T cells relatively increased along with the enhanced production of IgG and IgM, but not IgE. Additionally, we found that expressions of antigen-presenting-related proteins are suppressed on splenocytes by FeNPs exposure. Taken together, we suggest that chronic pulmonary of FeNPs may locally induce Th1-type immune response, and systemically suppress function of antigen-presenting cells. We also consider the possibility of delayed-type hyperresponsiveness following FeNPs exposure.
Tetanus toxin C fragment immunization generates a robust localized tetanus-binding B cell population (LYM5P.712)
Authors: Kenderes Kevin 
Published: January 2023

Abstract
A long-term objective of our studies is to identify, isolate, and characterize rare antigen-specific B cells. Our approach for identifying B cells has been to use flourophore-conjugated multivalent B cell antigens that can bind to cognate B cells in vivo. We generated a recombinant monobiotinylated tetanus toxin C fragment (TTCF; described in Blood:118:348) and tetramerized it using fluorescently-labeled streptavidin. To generate a population of antigen-specific B cells, we immunized mice subcutaneously with TTCF, in alum; the cells were collected from the draining axial and brachial lymph nodes for flow cytometric analysis. Immunization generated a striking number of TTCF-binding B cells which were detected at frequencies of over 90 percent of the lymph node B cells on day 9 post-immunization; B cell frequency decreased to a few percent of total B cells by day 30. TTCF binding was neither detected in transgenic mice that expressed a hen egg lysozyme-specific BCR, nor in mice immunized with an irrelevant antigen. We propose three hypotheses to explain the extraordinary high frequency of TTCF-binding B cells detected after immunization: 1) the TTCF binds TTCF-specific B cells that have undergone major clonal expansion; 2) TTCF binds via a non-clonal co-receptor expressed on B cells (e.g., antibody bound to FcγRIIb); and 3) B cells in immunized mice express a TTCF receptor. We are currently addressing these hypotheses experimentally.
The timing of stimulation and IL-2 signaling regulate secondary CD8 T cell responses (LYM5P.701)
Authors: Khan Shaniya , Martin Matthew , Starbeck-Miller Gabriel , Xue Hai-Hui Howard , Harty John , Badovinac Vladimir 
Published: January 2023

Abstract
Memory CD8 T cells provide protection to immune hosts by eliminating pathogen-infected cells during re-infection. While parameters influencing the generation of primary (1o) CD8 T cells are well established, the factors controlling the development of secondary (2o) CD8 T cell responses remain largely unknown. Here, we explored the mechanisms involved in the generation and development of 2o memory (M) CD8 T cells. We observed that the time at which 1o M CD8 T cells recognize Ag and become activated impacts their fate and differentiation into 2o M CD8 T cells. Late-entry of 1o M CD8 T cells into an immune response not only facilitated the expression of transcription factors associated with memory formation in 2o effector CD8 T cells, but also influenced the ability of 2o M CD8 T cells to localize within the LN, produce IL-2, and undergo Ag-driven proliferation. The timing of stimulation of 1o M CD8 T cells also impacted the duration of expression of the high-affinity IL-2 receptor (CD25) on 2o effector CD8 T cells and their sensitivity to IL-2 signaling. Importantly, by blocking or enhancing IL-2 signaling in developing 2o CD8 T cells, we confirmed the role of IL-2 in controlling the differentiation of 2o CD8 T cell responses. Thus, our data suggest that the process of 1o M to 2o M CD8 T cell differentiation is not fixed and can be manipulated, a notion with relevance for the design of future prime-boost vaccination approaches.
KMT2D histone methyltransferase modulates chromatin accessibility during regulatory T cell development (LYM6P.714)
Authors: Placek Katarzyna , Cui Kairong , Hu Gangqing , Lee Ji-Eun , Wang Chaochen , Konkel Joanne , Zhang Dunfang , Chen WanJun , Ge Kai , Zhao Keji 
Published: January 2023

Abstract
Gene regulatory elements are associated with histone H3 lysine 4 (H3K4) methylation and H3 acetylation and DNase I hypersensitivity. Whilst much is known about changes in histone modification patterns and chromatin accessibility during T cell differentiation, little is known about the role of histone modifying enzymes in this process. KMT2D is a histone methyltransferase that shapes enhancer landscape by regulating H3K4me and H3K27ac. To determine whether KMT2D plays a role in T cell development, we deleted KMT2D in T cells. Our data show that KMT2D deficiency results in reduced number of T cells in periphery. Moreover in the absence of KMT2D, differentiation of regulatory T (Treg) cells is compromised. KMT2D co-localizes with active chromatin marks. We showed that DNaseI hypersensitive sites (HS) bound by KMT2D tend to decrease in accessibility upon KMT2D deletion in CD4+ T cells that leads to reduced expression of nearby genes. The decreased HS are linked to genes involved in Treg differentiation and are enriched in transcription factor (TF) binding motif important for CD4+ T cell development. We found that KMT2D co-localizes and interacts with TF in CD4+ T cells. KMT2D binds to Treg master regulator: Foxp3 upstream enhancer and imposes H3K4me1 and H3K4me2 at Foxp3 regulatory elements. Our data suggest that KMT2D modulates CD4+ T cell development by maintaining chromatin accessibility and thus enabling TFs binding at genes involved in Treg cell differentiation.
Survival advantage of E. coli in the inflamed gut is mechanistically linked to enterobactin-mediated inhibition of myeloperoxidase and regulation by lipocalin 2 (MPF4P.736)
Authors: Singh Vishal , Yeoh Beng San , Bachman Michael , Borregaard Niels , Joe Bina , Vijay-Kumar Matam 
Published: January 2023

Abstract
During an inflammatory response in the gut, several commensal bacteria such as E.coli not only survive but also thrive and consequently contribute to the disease pathogenesis. The mechanisms by which such opportunistic pathogens bloom despite the hostile pro-inflammatory milieu of the inflamed gut remain largely unknown. We demonstrated that enterobactin (Ent), a siderophore released by E. coli, is a potent inhibitor of a key bactericidal enzyme of the host innate immune system, myeloperoxidase (MPO). The inhibitory activity is specific as glycosylated Ent (salmochelin) and non-catecholate siderophores such as yersiniabactin and ferrichrome failed to inhibit MPO activity. An E. coli ferrienterobactin permease mutant (ΔfepA) overexpressing Ent, but not 3-dehydroquinate synthase (ΔaroB)/ΔfepA double mutant inhibited MPO activity and exhibited enhanced survival in inflamed guts. This survival advantage was counter-regulated by the host siderophore binding protein, lipocalin 2, which rescued MPO from Ent-mediated inhibition. Spectral analysis revealed that Ent interferes with compound I [oxoiron, Fe(IV)=O] and reverts the enzyme back to its native ferric [Fe(III)] state. These findings define a fundamental mechanism by which E. coli surpasses the host innate immune responses during inflammatory gut diseases and gains a distinct survival advantage.
The yype I IFN pathway in C. difficile infection: impact on morbidity and mortality in mice (MPF4P.737)
Authors: Snyder Deann , Hedges Jodi , Robison Amanda , Broadaway Susan , Walk Seth , Jutila Mark 
Published: January 2023

Abstract
Infections with C. difficile are increasingly prevalent in individuals in health care settings and are becoming a concern in food animals. C. difficile is a gram positive, anaerobic bacteria known for its ability to form spores that are exceedingly difficult to kill. Disruption of the normal gut microbiota allows C. difficile spores to germinate, divide and produce toxins that compromise the intestinal barrier resulting in extreme inflammation. Currently, little is known about the innate immune response in Clostridium difficile infection (CDI). We hypothesized that type I IFNs may play a crucial role in innate protection from CDI. We found that IFNAR-deficient mice succumbed to CDI more rapidly compared to wild type mice. In addition, wild type mice treated with type I IFN-inducing dsRNA mimetic, polyIC, had delayed onset of symptoms compared to mice treated with saline. Since type I IFNs can block damaging inflammasome activity, this potential mechanism was explored. Wild type and IFNAR-deficient mice were treated with DMSO or the inflammasome-blocking agent, Glibenclamide. Glibenclamide-treated IFNAR-deficient mice faired better than all groups. This finding suggests that type I IFN signaling may protect from CDI in part by blocking the inflammasome. Considering that recombinant type I IFN is already used clinically, investigation of this pathway may present new treatment options for this emerging infection.
Inflammasomes recruit natural killer cells to prevent infection by a ubiquitous environmental bacterium (MPF4P.726)
Authors: Maltez Vivien , Tubbs Alan , Aachoui Youssef , Cook Kevin , Whitmire Jason , Miao Edward 
Published: January 2023

Abstract
Our lab has shown that inflammasome-triggered pyroptosis ejects microbes from replication niches in macrophages, exposing them to neutrophil killing. Because bona fide intracellular pathogens must evade pyroptosis in vivo, the role of pyroptosis in defense has primarily been observed in pathogens deprived of evasion strategies. To identify naturally occurring bacteria that are cleared via pyroptosis, we considered pathogens that are specific to chronic granulomatous disease (CGD), a neutrophil killing deficiency. We hypothesize that a subset of these microbes may be detected by inflammasomes and cleared via pyroptosis. In a survey of CGD pathogens, we discovered a ubiquitous environmental microbe, Chromobacterium violaceum, that is avirulent in WT mice (which resist a 1,000,000 CFU challenge), but is extremely virulent in inflammasome deficient mice (succumb to 100 CFU). This is the most penetrant inflammasome phenotype against any infection: bacterial, viral, fungal, or parasitic. Further, our studies with C. violaceum reveal a unique link between inflammasome driven IL-18 and NK cell cytotoxicity that functions in parallel to pyroptosis to eliminate intracellular replication niches. We posit that a subset of environmental microbes can be developed as powerful in vivo tools to study innate immune responses in the context of an appropriate and fully functional inflammasome response.
Simulated microgravity disrupts intestinal homeostasis and increases colitis susceptibility (MUC5P.763)
Authors: Ge Qing , Li Pingping , Shi Junxiu 
Published: January 2023

Abstract
The innate and adaptive immune systems can be altered by spaceflight in many aspects. But microgravity-related mucosal immune changes and its clinical significance has not been well studied. To investigate whether simulated microgravity influences the intestinal homeostasis and increases the susceptibility to colon inflammation, a hindlimb unloading (HU) microgravity mouse model was combined with dextran sulfate sodium (DSS)-induced colitis model. Compared to ground control mice, the HU ones revealed an impaired intestinal homeostasis and increased susceptibility to DSS-induced colitis. This includes an early change in intestinal microbiota, a decrease in regulatory T cell (Treg) numbers and IL-10 production, an increase in colonic IL-1β expression, an increase in circulating neutrophils and colonic neutrophil infiltration. The application of antibiotics ameliorated Treg and IL-10 reductions but did not significantly dampen neutrophilia and elevated expression of colonic IL-1β. These results indicate that the intestinal microflora and innate immune system both respond to simulated microgravity and together contribute to the proinflammatory shift in the gut microenvironment. The data provide useful insights in the changes of interactions between the hosts and microbiota under microgravity. It also emphasizes the necessity for evaluating the susceptibility of inflammatory bowel diseases in distant space travels.
Defining the immune regulatory function of LIGHT specific LTβR interactions in mucosal tissue. (MUC5P.747)
Authors: Zahner Sonja , Krause Petra , Kim Gisen , Morris Venetia , Tumanov Alexei , Fu Yang , Kronenberg Mitchell 
Published: January 2023

Abstract
Inflammatory bowel disease is characterized by an exacerbated inflammation of the intestine. While blocking tumor necrosis factor α (TNFα) helps many patients, it also causes significant side effects including a hampered host defense. TNFSF14/LIGHT, another member of the TNF superfamily, can bind to two receptors, HVEM and lymphotoxin β receptor (LTβR). Though LIGHT expression by T cells has been described to be inflammatory, we have recently shown that LIGHT interaction with LTβR is protective in murine colitis, indicating therapeutic promise for LIGHT. In absence of LIGHT-LTβR interactions, the innate immune system prolongs and exacerbates intestinal inflammation, with increased IL-1β and oncostatin M expression leading to increased IL-6. To define the cell-cell interactions leading to the excessive inflammation, we have analyzed mice with a conditional deletion of the LTβR. A dendritic cell-specific lack of the LTβR caused aggravated colitis compared to wild type but less severe colitis than in LIGHT-deficient mice. Thus, other LTβR-expressing cell types may be involved. To identify the cell types involved in the protective LIGHT-LTβR interaction in mouse colitis, we generated conditional mutants of LIGHT and are currently analyzing these mice. Intriguingly, mice lacking lymphotoxin β (LTβ), a subunit of the other ligand for the LTβR, were protected from severe disease. These data suggest that there are antagonistic effects of LIGHT and LTβ engagement of the LTβR.
Parenteral immunization with double-mutant heat labile toxin engages CD103+ dermal dendritic cells and redirects T cell immunity to the gut mucosa. (MUC5P.751)
Authors: Frederick Daniel , Cunningham David , Freytag Lucy , McLachlan James 
Published: January 2023

Abstract
The majority of infectious agents enter via mucosal compartments. Despite this, most current vaccines are administered by parenteral injection, which induce limited mucosal T cell responses. It is known that certain adjuvants can induce mucosal antibody responses regardless of route; however, there is minimal evidence that these injections direct antigen-specific effector T cells to the mucosa, where they are likely needed for relevant protection. In the current study we examine the potential of dmLT (double-mutant heat-labile toxin), a detoxified adjuvant derived from the mucosal human pathogen enterotoxigenic Escherichia coli, to drive antigen-specific T cells to the intestinal mucosa after parenteral immunization. By using a combination of antibodies and tetramers specific for a known peptide:MHCII, we can track intradermal delivery of dmLT plus antigen, with regards to antigen-presentation and the antigen-specific CD4 T cell response. We show this immunization results in T cell upregulation of the gut mucosal homing marker, α4β7 in local draining lymph nodes, mucosal lymph nodes, colon, and small intestine when compared to immunization with CpG plus the same antigen. We also observed an increased frequency of CD103+ dendritic cells in response to dmLT administration that were presenting the injected antigen. Lastly, we determined that dmLT imparts a balanced Th1/Th17 cytokine response and is capable of providing protection against oral Salmonella typhimurium challenge.