bluuebunny/crossref_metadata_2025_split huggingface dataset:
The age-related loss of FoxN1 and associated thymic involution leads to increased susceptibility to autoimmunity by impairing negative selection rather than influencing the generation of Tregs. (HEM4P.235)
Authors: Coder Brandon , Wang Hongjun , Su Dong-Ming 
Published: January 2023

Abstract
The thymus maintains immunotolerance to self-antigen by deleting self-reactive T cells and generating nTregs. The thymus involutes with age, which is driven by the loss of FoxN1. Thymic involution is thought to be linked with increased susceptibility to autoimmune disease. However, how the age-related loss of FoxN1 induced thymic involution impacts autoimmunity remains unclear. We used a FoxN1 cKO mouse model that mimics natural thymic involution. We found impaired negative selection in the FoxN1 cKO thymus, evidenced by an increase in the frequency of CD4 and CD8 SP thymocytes and a decrease in Aire+ mTECs. Recent thymic emigrants from the FoxN1 cKO thymus have increased proliferation and are more often CD44+, indicating that they may be self-reactive T cells. Additionally, we found that nTreg frequency was increased in the thymus, but not in the spleen. We adoptively transferred aged wild-type splenocytes, in which there are a higher proportion of Treg cells into young Rag2-/- mice. We found that the young periphery was able to reverse Treg accumulation. Additionally, the adoptive transfer led to an increase in salivary infiltration independent of peripheral age. We conclude that loss of FoxN1 impairs negative selection, which may lead to an escape of self-reactive T cells. However, the age-related accumulation of Tregs depends on the age of the microenvironment in which they stay.
NKT cell-dependent differential effects of OPN on functional modulation of macrophages and T lymphocytes in RSV infection (HYP6P.273)
Authors: Durre Kainath , Qureshi Nagib , Beal Brooks , Qureshi Mahboob 
Published: January 2023

Abstract
RSV bronchiolitis is an important cause of pediatric hospitalization, which often leads to developing asthma in later life. Studies have indicated a Th2 skewed polarization of the lung environment in these children, which can be modulated by exogenous administration of osteopontin (OPN). In this study, using an NKT cell KO (CD1d-/-) mouse model, we have examined the effects of OPN on macrophages (MQ) and T lymphocytes (Tc) during RSV infection and identified the role of NKT cells in this process. Flowcytometry analysis determined that OPN treatment in RSV infection had reduced MQ and Tc recruitment in the lung parenchyma and alveolar spaces. However, OPN induced activation of the CD4 and CD8 Tcs in an NKT- dependent fashion, as the magnitude of activation was reduced to only 20% in the CD1d-/- mice as compared to the wild type (WT) mice. Also, expression of MHCII on MQs was significantly increased in the CD1d-/- mice, indicating a downregulatory effect of NKT cells. Altogether, these data suggest that OPN differentially affects MQ and Tc response and their functional modulations in an NKT cell-dependent fashion. A better understanding of these inverse effects of OPN on different immune effector cells during RSV infection may help establish OPN as a potential therapeutic for prevention of RSV-associated asthma in children.
Silver nanoparticles induce silver nanoparticle-specific allergic responses (HYP6P.274)
Authors: Hirai Toshiro , Yoshioka Yasuo , Ichihashi Ko-ichi , Mori Takahide , Nishijima Nobuo , Handa Takayuki , Takahashi Hideki , Tsunoda Shin-ichi , Higashisaka Kazuma , Tsutsumi Yasuo 
Published: January 2023

Abstract
Metals, such as Au, Ag, and Ni cause various types of allergic reactions. Several models have been proposed to explain the activation of metal-allergy, for example, analogous to typical haptens such as TNP, T cell recognize a complex of metal ions with MHC-embedded self-peptides. In general, metal-allergy means metal-ion allergy. On the other hand, with recent development of nanotechnology, nanomaterials (≤ 100 nm) including metal nanoparticles have been used in variety of fields, such as cosmetics and food. Due to their ultrafine size, nanoparticles have distinct property including their in vivo dynamics compared with both molecules and bulk particles. Here, we evaluated the sensitization potential of silver nanoparticles (nAg). The BALB/c mice were immunized with various size of nAg (10-100 nm) with LPS as adjuvant. One week after weekly immunization for 4 weeks, we challenged their immunized nAg on their ears and evaluated the ear swelling for 4 days. nAg with diameter of 10 nm, but not more than 10 nm, enhanced nAg-mediated ear swelling. Thus nAg less than 10 nm might have sensitization potential. Because nAg-immunization did not enhance Ag ion (Ag+)-mediated ear swelling, nAg-elicited immune responses did not have cross-reactivity to Ag+. Therefore, nAg-elicited immune responses were nAg-specific immune responses. We are now analyzing which cells and how the cells enable the specific recognition of nAg to reveal new perspective of acquired immune systems.
Mechanism of food allergy (FA) induction by medium chain triglycerides (MCT). (HYP7P.314)
Authors: Khodoun Marat , Gudimetla Vishnu , Krishnamurthy Durga , Strait Richard , Finkelman Fred 
Published: January 2023

Abstract
Food ingestion generally induces antigen (Ag)-specific tolerance rather than immunity. Consistent with this, induction of IgE-mediated intestinal FA in mice has required either Ag priming through a parenteral route or ingestion of Ag with a potent toxin. In contrast, we recently reported (JACI, 131:442-50, 2013) that Ag-specific, IgE-mediated FA is induced when a protein Ag is ingested with the widely used nutrient, MCT. We also showed that MCT ingestion induces increased epithelial cell expression of the pro-Th2 cytokines TSLP, IL-25 and IL-33. We now report that MCT ingestion, by itself, can induce shock by damaging intestinal epithelium, with a consequent increase in intestinal permeability. In contrast, ingestion of the anionic detergent, sodium dodecyl sulfate, damages intestinal epithelium but does not promote a Th2 response. Both direct MCT induction of intestinal epithelial damage and MCT promotion of a Th2 response and FA to co-ingested egg white are suppressed in mice treated with the lipase inhibitor orlistat, which blocks intestinal triglyceride absorption. Consistent with MCT induction of TSLP, IL-25 and IL-33, treatment with a cocktail of mAbs to these cytokines or their receptors blocks FA induction by ingested MCT plus egg white. Taken together, these observations suggest that MCT must be absorbed to damage epithelial cells and induce the pro-Th2 cytokines that promote FA development; they also provide a potential paradigm for natural FA development.
Regulation of respiratory mucosal immunity by epithelial cell secreted antimicrobial molecules (INC5P.330)
Authors: Di Peter , Liu Yanyan , Di Marissa 
Published: January 2023

Abstract
The ability of the host to avoid infection depends largely on mechanisms of innate immunity. Several secreted epithelial cell-secreted proteins including MUC5AC, SPLUNC1, SP-A, and LL37 form an antimicrobial milieu to clear inhaled pathogens and to participate in immune response. In this study, we try to determine the underlying mechanisms of pulmonary antimicrobial activity following Pseudomonas aeruginosa infection. Splunc1 KO mice showed accelerated mortality and increased susceptibility to microbial infection with significantly decreased survival rates, increased bacterial burdens, exaggerated tissue injuries, and elevated proinflammatory cytokine levels, compared with those of their wild-type littermates. Increased neutrophil infiltration in Splunc1 KO mice was accompanied by elevated levels of chemokines including Cxcl1, Cxcl2, and Ccl20. Moreover, the expression of several epithelial secretory proteins such as Muc5ac, Muc5b, and CCSP, as well as antimicrobial molecules including LL37, lysozyme, and lactoferrin, was considerably suppressed in the lungs of Splunc1 KO mice. The deficiency of Splunc1 in mouse airway epithelium also resulted in increased biofilm formation. Using in vitro and in vivo approaches, we demonstrated the role of secreted antimicrobial molecules in protecting the host from Pseudomonas-induced respiratory infections and supported the notion that host antimicrobial milieu plays a critical role in determining infectious susceptibility.
Neural control of innate immunity by beta2-adrenergic receptor (INC5P.323)
Authors: Agac Didem , Estrada Leonardo , Murray Sean , Farrar David 
Published: January 2023

Abstract
The nervous system controls a variety of physiological responses through the release of several chemical messengers. Although the immune system has been thought to be a self-regulated system, there is growing evidence that the immune system and the nervous system are capable of reciprocally regulating their function. We recently identified a unique role for adrenergic signaling in modulating the innate response to pathogen-associated molecular patterns. First, we found that norepinephrine (NE) can suppress pro-inflammatory cytokine secretion from bone marrow-derived macrophages and dendritic cells in response to TLR signaling in vitro. This suppressive effect depends on the early induction of the anti-inflammatory cytokine IL-10, where neutralizing the autocrine IL-10 signaling restores the cytokine secretion. NE exerts its effects by signaling through the beta2-adrenergic receptor (ADRB2). Second, upon challenging mice with a sub-lethal dose of Listeria monocytogenes, ADRB2 knockout mice present with splenomegaly and enhanced bacterial clearance. Additionally, treatment of whole human blood with TLR ligands in the presence of the ADRB2 agonist albuterol suppresses TNFα secretion, demonstrating the presence of this pathway in humans. This supports the hypothesis that ADRB2 signaling is a negative regulator of TLR signaling and suggests that this pathway plays an important role in immune activation and homeostasis.
GM-CSF and IL-4 produced by NKT cells inversely regulate IL-1β production by macrophages (INC6P.402)
Authors: Jeong Dongjin , Ahn Sehee , Oh Sae Jin , Ahn Ji Ye , Lee Seung Hyo , Chung Doo Hyun 
Published: January 2023

Abstract
NKT cell is a distinct T cell subset that links innate and adaptive immune responses. IL-1β, produced by various immune cells, plays critical role in the regulation of innate immunity in vivo. However, it is unclear whether NKT cells regulate IL-1β production in vivo. Here, we demonstrate that NKT cells regulate production of IL-1β by macrophages via producing GM-CSF and IL-4. Among cytokines secreted from NKT cells, GM-CSF enhanced IL-1β production by macrophages through regulating pro-IL-1β expression and NLRP3-dependent inflammasome activation, whereas IL-4 enhanced M2-differentiation of macrophages, thereby decreasing IL-1β production. Furthermore, NKT cells aggravated IL-1β-mediated peritonitis by producing GM-CSF, but attenuated peritonitis via producing IL-4. Taken together, our findings suggest the NKT cells exert double-sided effects on IL-1β-mediated innate immune responses by producing IL-4 and IL-1β.
Tyrosine phosphorylation of IFITM3 blocks an endocytic motif necessary for its complete influenza virus restriction (INM8P.438)
Authors: Chesarino Nicholas , McMichael Temet , Hach Jocelyn , Yount Jacob 
Published: January 2023

Abstract
Influenza viruses are a major health concern, with seasonal influenza afflicting an average of 5% to 20% of the US population annually. Interferon-induced transmembrane protein 3 (IFITM3) is important for the inhibition of influenza infection by blocking entry of endocytosed viruses into the cytoplasm. However, the exact mechanisms of IFITM3 regulation and antiviral activity are not clearly defined. Tyrosine phosphorylation by Fyn kinase at the N-terminus of IFITM3 has been previously identified, but the effects of this modification are unknown. We observe IFITM3 cell surface retention for phosphorylation-deficient mutants, minimal cell surface localization in Fyn-deficient cells, and cell surface retention as result of Fyn kinase overexpression. These findings are reproduced for both mouse and human IFITM3, and suggest that phosphorylation of tyrosine 20 in both species blocks an endocytosis motif. Accordingly, tyrosine 20 mutants lose anti-influenza virus activity, confirming the role of endosomal localization in the antiviral function of IFITM3. Our findings classify phosphorylation as a negative regulator of IFITM3, and provide important insights towards delineating the mechanisms by which IFITM3 traffics and restricts viral infection.
Cobalt-chrome micro-particles induce a robust MyD88-independent type 2 immune response (IRM7P.495)
Authors: Mishra Pankaj , Palma Mark , Millman Ariel , Hallab Nadim , Beebe Kathleen , Benevenia Joseph , Kanneganti Thirumala-Devi , Gause William 
Published: January 2023

Abstract
Orthopaedic wear debris may contribute to harmful inflammation and implant failure. In this study, we examined whether Cobalt Chrome (CoCr) can trigger inflammatory responses under aseptic conditions. Intra-peritoneal injection of mice with CoCr microparticles induced a type 2 innate immune response with marked increases in M2 macrophages, neutrophils and eosinophils in WT and MYD88/TRIF-/- mice. In contrast, although Th2 cytokine MRNA elevations were intact, a marked decrease in neutrophil and M2 macrophages occurred in Caspase-1-/- mice compared to wild type mice. SYK pathway blockade with the inhibitor BAY 61-3606 caused a marked general decrease in type 2 inflammation. Adjuvant properties of CoCr particles were assessed by immunizing mice with CoCr+OVA peptide after transfer of CFSE-labeled OVA specific DO11.10 CD4+ T cells. After 7 days, marked increases in OVA-specific T cell proliferation and IL-4 production were observed compared to mice immunized with OVA alone. To more closely approximate effects of wear debris in joint replacements, localized immune cell infiltrates were examined after intra-articular knee injections of CoCr particles. Infiltration of specific immune cells and mRNA expression were similar to peritoneal inoculation. These studies indicate that the type 2 immune response is triggered by solid particles, independent of toll like receptor signalling, and differentially modulated by Inflammasome and SYK signaling pathways
Rab7 plays a B cell-intrinsic and critical role in T-dependent and T-independent antibody responses by mediating AID expression and class switch DNA recombination (IRM8P.706)
Authors: Xu Zhenming , Pone Egest , Lam Tonika , Edinger Aimee , Casali Paolo 
Published: January 2023

Abstract
Rab7 is a small GTPase that mediates endosomal functions and regulates T cell homeostasis. Here, we have addressed the B cell-inherent role of Rab7 in antibody responses and underlying mechanisms by constructing Igh+/Cγ1-cre Rab7fl/fl mice. These mice displayed normal B cell and T cell development and survival, and were knocked-out of the Rab7 gene specifically in B cells activated to undergo IgH germline Iγ1-Sγ1-Cγ1 transcription. This transcription process is induced by IL-4 plus a primary CSR-inducing stimulus, and is required for antibody switching from IgM to IgG1, but not to other Ig isotypes. Igh+/Cγ1-cre Rab7fl/fl mice had virtually abrogated levels of IgG1, but normal levels of IgM and other switched Ig isotypes, and failed to mount specific IgG1 responses to T-dependent or T-independent antigens. They showed markedly reduced IgG1+ B cells and antibody-forming cells, with unaltered B cell proliferation, survival and differentiation into germinal center B cells and plasma cells. Purified naïve B cells from these mice were defective in CSR to IgG1, despite normal proliferation and plasma cell differentiation. These together with the unaltered germline transcription but significantly decreased expression of AID (essential for CSR and SHM) demonstrate that B cell Rab7 mediates CSR and, therefore, the antibody response by upregulating AID, likely by regulating intracellular membranes that facilitate signal transduction for activation of specific transcription factors.
Biochemical and structural studies reveal a canonical mode of molecular recognition between TIGIT and nectin-2 (IRM10P.735)
Authors: Samanta Dibyendu , Udupi Ramagopal , Almo Steven 
Published: January 2023

Abstract
Besides antigen-specific signal from the interaction between T-cell receptor and peptide-MHC complex expressed on antigen presenting cells (APCs), the process of optimal T-cell activation and differentiation requires antigen-independent costimulatory signals. Costimulatory signals are provided by interaction between a number of activating as well as inhibitory receptors expressed on T cells with specific ligands expressed on APCs. The balance between activating and inhibitory signals critically controls the mammalian immune responses. Therefore, understanding the mechanisms and designing corrective therapeutics involving T-cell costimulation are imperative in both infectious as well as autoimmune diseases. TIGIT (T cell immunoglobulin and ITIM domain), a recently identified immune receptor expressed on T and NK cells, upon interaction with either of its two ligands, nectin-2 or PVR, that are over-expressed on certain tumors, inhibits activation of T and NK cells. Several biophysical studies, including X-ray crystallography suggest that TIGIT may exist in its monomeric as well as dimeric forms. Based on the structural and biochemical studies, we mapped the nectin-binding interface on TIGIT. Interestingly, structure-guided mutations that disrupt the interaction between nectin-2 and TIGIT also limit the homodimerization of TIGIT in solution. Our data provide structural insights into how TIGIT recognizes a cell-adhesion molecule nectin-2 to execute immunoregulatory function.
Modification of proteins by O-linked N-acetylglucosamine in activated T cells (IRM10P.756)
Authors: Lund Peder , Elias Joshua , Davis Mark 
Published: January 2023

Abstract
The process of T cell activation is mediated by signal transduction cascades involving changes in protein post-translational modifications. While the importance of some modifications, such as phosphorylation, is well appreciated, relatively little is known about the modification of intracellular proteins by O-linked N-acetylglucosamine (O-GlcNAc). Given that O-GlcNAc appears to regulate signaling pathways akin to phosphorylation, we are investigating how O-GlcNAc may be involved in T cell activation. We have observed that T cell receptor engagement leads to changes in protein O-GlcNAc levels. Furthermore, we have found that the enzyme catalyzing the addition of O-GlcNAc to proteins accumulates at the immunological synapse and differs in the relative expression of its splice isoforms in activated versus resting T cells. To identify proteins that may be regulated by O-GlcNAc, we have employed a chemical labeling strategy on resting and activated human T cells to identify potential O-GlcNAc sites on a number of proteins, such as the transcriptional regulator host cell factor 1. Future experiments will focus on how O-GlcNAc sites responsive to T cell receptor stimulation influence molecular and cellular activity during T cell activation. Beyond its significance to basic cell biology, our work may have clinical implications since abnormal O-GlcNAc levels have been associated with human diseases such as cancer and diabetes.
Potentially neutralizing B cell clonotypes are eliminated at peripheral selection checkpoints (LYM6P.768)
Authors: Scholz Jean , Soldemo Martina , Dosenovic Pia , Naradikian Martin , Zhou Lin , Wilson Richard , Wyatt Richard , Lackner Andrew , Karlsson Hedestam Gunilla , Cancro Michael 
Published: January 2023

Abstract
B lymphocyte stimulator (BLyS) signals via BR3 mediate selection and survival in the transitional, mature, and germinal center B cell pools. We have previously shown that treatment of mice with exogenous BLyS prior to immunization with HIV-1 envelope (Env) trimers improves neutralizing antibody breadth and potency. We are therefore investigating the hypothesis that broadly neutralizing B cell clonotypes are rare because of counter-selection at the transitional or germinal center checkpoints. Here we show that Env-specific murine B cells in pre-immune, germinal center, and memory B cell subsets can be visualized and tracked by flow cytometry using a biotinylated Env probe. Initial results indicate loss of Env+ B cells at both the transitional developmental stage and in the germinal center following immunization. As a first step in testing the feasibility of a BLyS pre-immunization treatment approach in nonhuman primates, we show that BLyS enhances survival of quiescent and dividing rhesus macaque B cells in vitro.
Eosinophils enhance immune pathology and are increased with cell-wall chitin exposure in Aspergillus fumigatus infection. (MPF3P.802)
Authors: Templeton Steven , O'Dea Evan , Li Hongtao , Amarsaikhan Nansalmaa 
Published: January 2023

Abstract
In humans and experimental animals infected with the opportunistic fungal pathogen Aspergillus fumigatus, Th1 responses are considered protective, while Th2 responses are associated with increased morbidity and mortality. How host-pathogen interactions influence the development of these protective or detrimental immune responses is not well understood. We compared lung immune responses to conidia from two fungal isolates that expressed different levels of the fungal cell wall component chitin. We observed that repeated aspirations of the high-chitin expressing isolate, Af5517, induced increased airway eosinophil and Th2 cell recruitment in the lungs of recipient mice when compared to the isolate Af293. In addition, lung transcription of Th2 cytokines/chemokines was increased while IFN-γ was decreased in response to Af5517. Eosinophil recruitment in response to conidia aspiration was correlated with the level of chitin exposure during germination, and was decreased by constitutive lung chitinase expression. Furthermore, eosinophil-deficient mice subjected to multiple aspirations of Af5517 prior to neutrophil depletion and infection exhibited decreased morbidity, mortality, and lung fungal burden when compared to wild-type mice. These results suggest that chitin exposure in germinating conidia promotes Th2-skewed airway immune responses and that recruited eosinophils may be considered as a therapeutic target in patients that respond poorly to A. fumigatus infection .
Pulmonary Th17 immunity is regulated by regenerating islet-derived III-gamma and the gut microbiome (MUC4P.826)
Authors: McAleer Jeremy , Nguyen Nikki , Chen Kong , Armentrout Rachel , Pociask Derek , Ricks David , Binnie Matthew , Hein Aaron , Yu Amy , Vikram Amit , Bibby Kyle , Sheppard Dean , Ouyang Wenjun , Hooper Lora , Kolls Jay 
Published: January 2023

Abstract
Antimicrobial proteins provide an innate immune barrier against pathogen invasion. Here we identify a function for the bactericidal lectin regenerating islet-derived III-gamma (RegIIIγ) in shaping CD4 T cell polarization. Gram-positive bacteria in the intestine induce RegIIIγ expression, which modulates the immune tone of the gut, resulting in decreased Th17-type immunity during pulmonary fungal infection. This was associated with RegIIIγ inhibiting intestinal colonization with segmented filamentous bacteria (SFB), a pro-inflammatory commensal that augments Th17 differentiation. Vancomycin drinking water inhibited IL-17 production in lungs of RegIIIγ-/- and Il22-/- mice, demonstrating that intestinal Gram-positive commensals contribute to systemic inflammation. Reconstituting Il22-/- mice with IL-22 decreased the SFB/Clostridium ratio, while gastrointestinal delivery of recombinant RegIIIγ decreased inflammatory gene expression in lung tissue and protected Il22-/- mice from weight-loss during Aspergillus fumigatus infection. Therefore, intestinal antimicrobial proteins influence the development of adaptive immunity by altering the balance of pro- and anti-inflammatory intestinal commensal species.