bluuebunny/crossref_metadata_2025_split huggingface dataset:
The absence of thymus involution in K5.Cyclin D1 transgenic mice sustains the output of recent thymic emigrants during aging. (LYM7P.717)
Authors: Bolner Michelle , Fink Pamela , Richie Ellen 
Published: January 2023

Abstract
Naïve T cells are continually exported from the thymus and maintain peripheral TCR repertoire diversity. As the thymus involutes with age, thymopoiesis and T cell output wane, reducing the number of recent thymic emigrants (RTEs). Although homeostatic proliferation of memory T cells sustains peripheral T cell numbers, the decrease in naïve T cells restricts immune responsiveness to new antigens. It has been proposed that RTE output would be sustained if thymus involution were prevented. To test this hypothesis, we analyzed RTEs in mice that do not undergo thymus involution due to a keratin 5 promoter-driven Cyclin D1 transgene (K5.D1) expressed in thymic epithelial cells. This transgene maintains functional thymic microenvironmental niches that support thymocyte progenitor maturation. We introduced a RAG2p-GFP transgene to discriminate RTEs from mature naïve (MN) T cells in K5.D1 mice. As previously reported, RTEs decline with age in RAG2p-GFP controls. In contrast, the number of RTEs increases with age in K5.D1;RAG2p-GFP mice. Despite a lower frequency of MN T cells in K5.D1 mice, the number of MN T cells is increased by ~4 fold in 5-6 month old K5.D1;RAG2p-GFP mice compared to RAG2p-GFP littermates. The increase in naïve T cells does not displace existing memory T cells, supporting the notion that naïve and memory T cells occupy distinct homeostatic niches. These data demonstrate that preventing thymus involution sustains the naïve T cell compartment during aging.
Type II NKT cells play a role in the regulation of CD4 T cell subsets (LYM8P.730)
Authors: Robertson Faith , Lu Xiuju , Terabe Masaki , Berzofsky Jay 
Published: January 2023

Abstract
The immunological response to cancer and other diseases depends on the interplay between the innate and adaptive immune systems. CD4 T helper cells are key modulators of immune responses. As an intermediate between the innate and adaptive systems, CD1d-restricted NKT cells may impact the activity of these CD4 T cells. It has been shown that type II NKT cells are immunosuppressive in many disease settings. However, their interaction with CD4 T cells is not well understood. In this study, we investigated the role of type II NKT cells on the activation of various CD4 T cell subsets by stimulating them with sulfatide, an endogenous glycolipid antigen and known type II NKT cell activator. Naïve ovalbumin-specific CD4 T cells isolated from DO11.10 mice were either tested immediately, or polarized in vitro with cytokines and neutralizing antibodies. CFSE dilution was used to assess CD4 proliferative responses upon antigenic stimulation in the presence or absence of sulfatide-activated type II NKT cells. We found that activated type II NKT cells substantially inhibited proliferation of naïve CD4 T cells, and preliminary data show that the polarized populations have different sensitivities to type II NKT cell mediated suppression. Ongoing elucidation of these interactions may not only enhance our understanding of CD4 T cell regulation, but also improve our capability to utilize type II NKT cells for clinical applications.
Comparison of the protective roles of Trypanosoma cruzi-specific Th1 and Th17 cells. (MPF6P.746)
Authors: Blase Jennifer , Eickhoff Christopher , Hoft Daniel 
Published: January 2023

Abstract
Trypanosoma cruzi is the protozoan etiology of Chagas disease. T. cruzi-specific Th1 cells are known to be important for protective immunity, while the role of T. cruzi-specific Th17 cells has yet to be explored in detail. TCR-transgenic, T. cruzi-specific CD4+ T cells were differentiated in vitro into Th1 or Th17 cells and co-cultured with T. cruzi-infected peritoneal exudate macrophages. Protection was measured as inhibition of intracellular amastigote replication. In vivo, T. cruzi-specific Th1 or Th17 cells were adoptively transferred into Rag-/- mice along with naïve polyclonal CD8+ T cells. Mice were challenged with T. cruzi, persistent immune responses were measured, and protection was assessed by parasitemia and survival. In vitro, both Th1 and Th17 cells led to protection against intracellular T. cruzi growth in macrophages. Th1-mediated protection involved IFN-γ signaling and nitric oxide production by macrophages. In contrast, Th17-mediated protection was dependent on IL-17A but independent of iNOS induction. The role of reactive oxygen species, autophagy, apoptosis, and mechanisms of lysosomal killing are being studied. More importantly, Th17 cells were significantly more protective than Th1 cells in vivo, involving enhanced expansion of pathogen-specific CD8+ T cells. Thus, Th17 cells have both direct and indirect effects for T. cruzi protective immunity. Furthermore, we report the novel finding that Th17 cells provide important helper effects for CD8+ T cells.
A new model to study mucosal immunity at the ocular surface (MUC7P.758)
Authors: St. Leger Anthony , Karauzum Hatice , Datta Sandip , Caspi Rachel 
Published: January 2023

Abstract
The ocular surface represents a mucosal interface between the environment and the host. Similarly to the lymphoid tissue of the gut, cells of the conjunctiva-associated lymphoid tissue (CALT) are organized into follicles. Humans exhibit CALT in healthy eyes, and the number and size of follicles increase with inflammation caused by infections, allergies, dry eye, and conjunctivitis, suggesting a functional role for CALT in immunity at the ocular surface. Due to the limited amount of data from animal models, functional studies of CALT are lacking. We aimed to develop a mouse model to study the dynamics and functional parameters of CALT in normal and immunologically perturbed hosts. Towards that end, we used mice deficient in IL-10 and/or IL-22. Upon ocular infection with Staphylococcus aureus (Strain USA300 LAC), we observed an expansion of immune cells in the CALT. This included elements of the adaptive and innate immune systems, with prominent expansion of group 3 innate-like lymphocytes (ILC3), which have hitherto only been shown to localize to the gut and lungs. The increase in cellular infiltrate correlated with an increase in the numbers of TNFα and IL-17 producing cells. Our studies lay the basis for a working mouse model to analyze the functional characteristics of CALT, an understudied component of the mucosal immune system. Also, this model may permit identification of factors that induce ocular inflammation leading to various ocular pathologies.
IL-33/ST2 regulate innate IL-17 production and viral replication in the cornea following a herpes infection (MUC7P.760)
Authors: Rowe Alexander , Harvey Stephen , Hendricks Robert 
Published: January 2023

Abstract
Poorly controlled infections and inflammation can both be very deleterious to tissues such as the cornea whose function requires clarity, so understanding the mechanisms controlling the balance between protective immunity and immunopathology is critical. Since the anti-inflammatory cytokine IL-33 and its receptor ST2 are constitutively expressed in the cornea, we investigated their role in regulating early stages of the immune response to herpes simplex virus type 1 (HSV-1) in the cornea. HSV-1 replicates in the corneal epithelium and is simultaneously axonally transported to the cornea innervating neuronal cell bodies in the trigeminal ganglion (TG). Compared to wild type controls, corneas of ST2 KO mice exhibited elevated IL-17 production from 4 hrs to at least 48 hrs after infection, which correlated with enhanced viral clearance from the cornea at 48 hrs (infectious virus in eye swabs, and viral genome copies in the cornea). Other anti-viral mediators such as IL-6 and type I interferons were not elevated in corneas of ST2 KO mice. Infected corneas of ST2 KO mice had increased numbers of neutrophils, but not macrophages or dendritic cells 2 days after infection. Surprisingly, viral titers in TG of infected ST2 KO mice were not significantly changed relative to wild type controls. We conclude that IL-33 selectively regulates an innate immune response to HSV-1 in the cornea at the expense of impaired viral clearance.
Group 2 innate lymphoid cells are present in mouse uterine tissue and may play roles in healthy pregnancy (MUC7P.763)
Authors: Bartemes Kathleen , Kita Hirohito 
Published: January 2023

Abstract
Innate lymphoid cells (ILCs) are emerging as important effector cells in innate immunity and tissue homeostasis. Group 2 ILCs (ILC2s) have been identified in organs and tissues, such as adipose tissue, small intestine, lungs and skin, where they are involved in helminth immunity, type 2 immune responses, and tissue pathology and recovery. Using flow cytometry, we identified ILC2s in mouse uteri and confirmed IL-5, but not IL-13, production in response to IL-33 both in vivo and in vitro. Furthermore, intraperitoneal administration of IL-33 induced recruitment of activated ILC2s to uteri as well as to lungs. To investigate the possibility that uterine ILC2s might play a role in maintaining a healthy pregnancy, we mated ST2-/- females (on a Balb/c background) with ST2-/-, MHC-matched Balb/c and MHC-mismatched C57B6 males (ST2 is the IL-33 receptor). Balb/c, C57B6 and Balb/c x C57B6 pairs were used as controls. Litter sizes were not significantly different among the pairings. We defined viable pups as those still alive 24 hours after parturition. Total numbers of non-viable pups, percent of litters with at least one non-viable pup and percent of non-viable pups per litter were significantly increased in ST2-/- x C57B6 pairs when compared to control pairs. Thus, IL-33-responsive ILC2s are present in murine uterine tissue and may play roles in successful reproduction.
Exosomes in human semen impair antigen-presenting cell function and decrease antigen-specific T cell responses (MUC7P.767)
Authors: Vojtech Lucia , Hughes Sean , Levy Claire , Tewari Muneesh , Hladik Florian 
Published: January 2023

Abstract
Exposure to semen is the primary route of transmission for many sexually transmitted infections. Mounting evidence suggests that components in semen directly influence leukocytes, which could help to explain the difficulty of inducing vaccination-based protection in the genital mucosa. Exosomes, small microvesicles with demonstrated immunomodulatory functions, are present at an average concentration of 2.2 x 1013 particles per ejaculate (n = 18 healthy semen donors). These seminal exosomes (SE) efficiently and rapidly entered peripheral and vaginal dendritic cells (DCs), whereas T cell uptake of SE was poor. SE impaired the immune responses of DCs stimulated by bacterial lipopolysaccharide, where cytokine production was reduced at both the mRNA level in the cells and the protein level in supernatants. Preliminary experiments also indicated that SE down-regulate CD80 and CD83 expression on DCs. In PBMC cultures, SE impaired memory T cell function, reducing the production of TNF-alpha and/or IFN-gamma in response to virus-derived peptides an average of 73% for CD4+ T cells and 55% for CD8+ T cells, in a dose-responsive manner (n = 4 PBMC donors). Thus, SE likely inhibit antigen-specific T cell responses by affecting the co-stimulatory capacity of antigen-presenting cells. Understanding how programmed immune responses are altered by the presence of semen is important to developing the next generation of vaccine and preventative treatments against sexually transmitted disease.
Topical electrophilic nitro-fatty acids potentiate cutaneous immune responses. (MUC7P.775)
Authors: Mathers Alicia , Carey Cara , Killeen Meaghan , Salvatore Sonia , Schopfer Francisco , Freeman Bruce , Falo Louis 
Published: January 2023

Abstract
Endogenous electrophilic fatty acids mediate anti-inflammatory responses by modulating metabolic and inflammatory signal transduction reactions. In this regard, there is considerable interest in employing nitro-fatty acids and other electrophilic fatty acids for the prevention and treatment of inflammatory disorders. We evaluated nitro-oleic acid (OA-NO2) in a preclinical murine model of allergic contact dermatitis (ACD) as a potential topical therapy for the treatment of ACD. In marked contrast to previous findings, topical OA-NO2 potentiated hapten-dependent inflammation inducing a sustained psoriasis-like inflammatory response characterized by psoriasiform histological features, increased angiogenesis, and an inflammatory infiltrate that included neutrophils, inflammatory monocytes, and γδ T cells. Interestingly, analysis by HPLC-MS-MS of skin from psoriasis patients revealed a significant increase in nitro-fatty acids in lesional skin compared to non-lesional skin. Overall, when applied topically to the cutaneous microenvironment nitro-fatty acids can potentiate inflammatory responses. Thus, it is paramount that a better understanding be obtained of how electrophilic fatty acid derivatives regulate cutaneous immunity due to the widespread use of fatty acids in topical creams and the abundant formation of electrophilic nitro-fatty acids during inflammation.
The role of gap junction protein connexin 43 in Chlamydial pathogenesis (MUC7P.752)
Authors: Murthy Ashlesh , La Salle Sophie , Nicholson Bruce , Manam Srikanth , Holtzman Michael , Zhang Yong 
Published: January 2023

Abstract
We have shown that Chlamydia-specific CD8 T cells do not significantly affect bacterial clearance but cause oviduct pathology, suggesting that they do not target infected cells efficaciously but cause pathology presumably by targeting uninfected cells. This suggests the possibility that chlamydial peptides are presented to CD8 T cells by uninfected cells, but begs the question: “How do uninfected cells acquire chlamydial peptides”? We hypothesized that gap junction mediated antigen transport (GMAT) via channels formed by connexin (Cx) proteins, predominantly Cx43 expressed on oviduct epithelium, contributes to this effect. We have found that HeLa cells engineered to express Cx43, but not those without, can efficaciously transfer Ova257-264 to co-cultured mouse APC, which subsequently activate CD8+ T cells from Ova primed OT-1 mice. Additionally, using Cre-Lox technology, we generated mice (Foxj1Cre-Cx43flox mice) with a conditional deficiency of Cx43 only in ciliated columnar epithelia, including oviducts. The Foxj1Cre-Cx43flox mice displayed comparable kinetics of vaginal chlamydial clearance, comparable splenic antigen-specific cytokine and serum antibody response, but significantly reduced oviduct pathology compared to WT mice on day 80 after intravaginal chlamydial infection. We have thus demonstrated the role of GMAT in immunopathogenesis of microbial infections.
Analysis of CNS tissue-specific Tregs and dendritic cells in T cell responses and autoimmunity (MUC7P.757)
Authors: McPherson Scott , Heuss Neal , Pierson Mark , Gregerson Dale 
Published: January 2023

Abstract
We assessed locally generated, locally acting peripheral regulatory T cells (pTregs) in retinal immune homeostasis and ability of retinal dendritic cells (DC) to support T cell activation/expansion within retina. We used transgenic (Tg) mice expressing beta-galactosidase (bgal mice) as retinal neo-self antigen, TCR Tg mice (BG2) specific for bgal, and mice with labeled, depletable Tregs or DC, based on expression of diphtheria toxin (DTx) receptor and/or GFP controlled by FoxP3 or CD11c promoter (FDG or CDG mice). Treg and DC depletion from retina was done by DTx injection into the eye. T cells and DC were assayed by FACS of retina or blood. Retinal autoimmunity was assessed by histological analysis. After bgal (FDG/bgal mice) or IRBP (FDG mice) immunization, Treg depleted retinas showed increased incidence and severity of autoimmunity. We found local depletion of Tregs from retina sufficient to induce spontaneous autoimmunity in FDG/bgal/BG2 mice but not in single or double Tg mice. Dose of DTx used to eliminate retinal Tregs did not induce retinal autoimmunity if given systemically. DC depletion from the retina prevented Treg and Teff generation within retina after bgal injection. Retinal microglia remaining after DC depletion did not make up for the loss of DC-dependent antigen presentation. We conclude local Tregs within the retina protect against spontaneous organ-specific autoimmunity and local DC must be present within the retina for antigen presentation to T cells.
DC-expressing TRAF6 is important mediator of gut homeostasis in the context of dietary antigen responses (MUC8P.812)
Authors: Han Daehee , Surh Charles 
Published: January 2023

Abstract
The intracellular signaling mediator TRAF6 is critical for Toll-like receptor (TLR)-mediated activation of dendritic cells (DCs). Recently we have reported that TRAF6 in DCs is important to maintenance of intestinal immune tolerance through balanced induction of regulatory T cells versus Th2 immunity. In addition, we found a clue that loss of TRAF6ΔDC mucosal tolerance requires the presence of commensal microbiota in a manner that appears independent of the Myd88 pathway. However, which environmental factors induce abnormal Th2 immunity and disease phenotype in TRAF6ΔDC mice remains unclear. Here we suggest that spontaneous gut inflammation occurred in TRAF6ΔDC mice is strongly associated to dietary antigens as well as microbiota.
Optimal CXCL8 secretion by IL-1 stimulated Caco-2 epithelial cells requires an effect of the Rho associated kinase, ROCK, on the JIP-3 scaffold signaling to JNK (MUC9P.815)
Authors: Banerjee Sayantan , McGee Dennis 
Published: January 2023

Abstract
Elevated levels of Interleukin-1 (IL-1) accompany inflammatory bowel disease. IL-1-stimulated intestinal epithelial cells (IECs) secrete potent chemokines like CXCL-8 (IL-8), which can attract neutrophils and exacerbate inflammation. Previously, we found that inhibiting the Rho-Associated Kinase, ROCK, using the compound Y27632 could inhibit IL-1-induced CXCL8 secretion by the Caco-2 colonic epithelial cell line. We also reported that ROCK inhibition during IL-1 signaling did not affect signaling through IκBα, but suppressed the phosphorylation of JNK. Therefore, ROCK inhibition-mediated suppression of CXCL8 secretion may be due to an inhibition of JNK and not the NF-κB pathway. We now confirm that ROCK inhibition had no effect on the formation of the upstream IRAK1-TRAF6 signaling complex in IL-1-stimulated cells. Also, inhibiting ROCK had no effect on p38 MAPK phosphorylation or the stability of CXCL8 mRNA. Yet, inhibiting ROCK suppressed the IL-1-induced phosphorylation of MKK4, a known activator of JNK, but not MKK7. Immunoprecipitation of the JIP3 scaffold protein from IL-1-stimulated cells showed that inhibiting ROCK suppresed both the association of JNK with JIP3 and the phosphorylation of JNK. Hence, a ROCK-JIP3-JNK interaction may be a crucial regulatory sequence during IL-1-induced chemokine responses by IEC. These studies indicate a novel signaling event, which could provide a target for suppressing IEC chemokine responses involved in mucosal inflammation.
GPR15 mediated homing controls immune homeostasis in the large intestine mucosa (MUC9P.817)
Authors: Kim Sangwon , Xiang Wenkai , Kwak Changsoo , Yang Yi , Lin Xiyao , Ota Mitsuhiko , Sarpel Umut , Rifkin Daniel , Xu Ruliang , Littman Dan 
Published: January 2023

Abstract
The large intestine is the site most commonly affected in inflammatory bowel diseases. However, the mechanism of T cell homing to the large intestine, which contributes to inflammation, had remained unclear. We show here that an orphan G-protein coupled receptor GPR15 controls the specific homing of T cells, particularly FOXP3+ regulatory T cells (Tregs), to the large intestine lamina propria (LILP). GPR15 expression is promoted by gut microbiota and TGF-β1, but not by retinoic acid. GPR15-deficient mice had fewer Tregs in LILP and were prone to develop more severe inflammation in the large intestine, which was rescued by the transfer of GPR15-sufficient Tregs. Our findings thus indicate that GPR15 is a T cell homing receptor for LILP and that GPR15 plays a key role in maintaining gut immune homeostasis, largely by regulating the influx of Tregs. Our study also demonstrates that adaptive immune responses in the gut are functionally compartmentalized through the differential requirements for T cell homing to the small and large bowel.
FcγRIIB regulates T cell autoreactivity, ANCA production and neutrophil activation to suppress anti-myeloperoxidase glomerulonephritis (THER5P.834)
Authors: Ooi Joshua , Gan Poh-Yi , Chen Tong , Eggenhuizen Peter , Odobasic Dragana , Holdsworth Stephen , Kitching A Richard 
Published: January 2023

Abstract
Anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis involves innate and adaptive immune cells in the induction of autoimmunity and in autoimmune effector responses. Most Fcγ receptors (FcγRs) activate immune cells, but FcγRIIB, found in humans and mice on B cells and innate cells, is an inhibitory receptor. These studies tested the hypothesis that endogenous FcγRIIB negatively regulates autoreactivity and effector responses in experimental anti-myeloperoxidase (MPO) glomerulonephritis, using wild type and FcγRIIB-/- mice. After MPO immunization, FcγRIIB-/- mice developed higher MPO-ANCA titers and increased anti-MPO T cell responses. Transfer of FcγRIIB deficient dendritic cells loaded with a nephritogenic MPO peptide (MPO409-428) into wild type mice induced stronger autoimmunity than dendritic cells derived from wild type mice. Transferring anti-MPO antibodies into LPS primed mice resulted in increased glomerular neutrophil accumulation and injury in FcγRIIB-/- mice, showing a role for FcγRIIB in suppressing neutrophil activation. Inducing active autoimmunity to MPO followed by triggering T cell mediated glomerular injury by transfer of subnephritogenic doses of LPS and anti-MPO antibodies resulted in more disease in FcγRIIB-/- mice. Therefore endogenous FcγRIIB negatively regulates anti-MPO autoimmunity and glomerulonephritis via dendritic cells, B cells and neutrophils to limit MPO-ANCA production, T cell responses and neutrophil activation.
Marked induction of long-term islet graft survival in gastric submucosa engrafted rats (THER5P.841)
Authors: Wang Zhiliang , Li JIaxin , Chen Xiang , Wang Ximo 
Published: January 2023

Abstract
Since the first report of successful islet transplantation to treat diabetes mellitus in rodents, selecting the optimal site for transplantation has become a key step for successful treatment. To date, the portal vein (PV) has been the primary site for clinical islet transplantation. Despite some limited success, complications, particularly instant blood-mediated inflammatory reaction (IBMIR), due to the graft site location are not conducive to long-term survival of islets and improvement of diabetes. Therefore finding a more suitable site for islet transplantation has become urgent. The gastric submucosa (GS) and kidney capsule (KC) space are fast becoming the two most common sites for islet transplantation in pre-clinical studies. Thus, these sites were compared for induction of long-term islet graft survival in rats. 24 Sprague Dawley recipients had diabetes induced by streptozocine (STZ); the STZ-induced rats were then distributed into 3 groups based on the different sites for transplantation. In our study, rats that received islets in the GS obtained better control of diabetes compared to KC and PV engrafted animals. IBMIR and pro-inflammatory cytokines also indicated an early loss of the islets in PV transplanted animals that was not evident in GS and KC animals.