bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential requirement of CD8α+/CD103+ dendritic cells for bacterial dissemination versus T cell priming following mucosal infection with Listeria monocytogenes (P3060)
Authors: Princiotta Michael , Laird Renee , Wolf Benjamin , Hayes Sandra 
Published: January 2023

Abstract
Dendritic cells (DCs) are essential in priming CD8+ T cells to bacterial pathogens, such as Listeria monocytogenes (Lm). Interestingly, recent studies suggest that DCs also function in systemic dissemination of Lm, following an i.v. route of infection, as evidenced by the 2 log lower bacterial burden in BatF3-/- mice, which lack both CD8α+ and CD103+ DCs, than in wild-type (WT) mice. Lm infection, however, typically occurs via the mucosal route in humans through the binding of Lm internalin A (InlA) to E-cadherin on the surface of epithelial cells. Since murine E-cadherin does not bind InlA, we generated a “murinized” Lm strain that expresses a modified form of InlA that binds murine E-cadherin in order to test whether DCs are required for bacterial dissemination following a mucosal route of infection. In agreement with the previous study, we found that the bacterial burden was significantly reduced in BatF3-/- mice relative to WT mice, when infected i.v. with murinized Lm. By contrast, there were no significant differences in bacterial burden in BatF3-/- and WT mice following mucosal infection (intragastric and intranasal) with murinized Lm. Surprisingly, despite similar bacterial burden, BatF3-/- mice were unable to prime an Lm-specific CD8+ T cell response. Together, these data demonstrate that, following mucosal Lm infection, CD8α+ and CD103+ DCs are dispensable for systemic dissemination, but are indispensable for priming a CD8+ T cell response.
The interaction of classical complement component C1 with parasite and host calreticulin mediates Trypanosoma cruzi infection of human placenta (P3062)
Authors: Ferreira Arturo , Castillo Christian , Duaso Juan , Maldonado Ismael , Valck Carolina , Rosas Carlos , Aguilar Lorena , Ramirez Galia , Galanti Norbel , Kemmerling Ulrike 
Published: January 2023

Abstract
13 million people are infected with Trypanosoma cruzi in Latin America, plus more than 300,000 in the USA, Canada, Europe, Australia, and Japan. An important number develops circulatory or digestive syndromes. While in poor countries transmission is mainly through arthropod vectors, transplacental infection prevails in developed ones. T. cruzi calreticulin (TcCRT) translocates from the endoplasmic reticulum to the area of flagellum emergence, acting as a virulence factor because it binds maternal complement C1. As measured by qPCR in human placenta chorionic villi explants (HPCVE), C1q mediated up to a 4-fold increase in infectivity. Because anti-TcCRT and anti-HuCRT F(ab')2 antibody fragments are devoid of their Fc-dependent capacity to recruit C1q, they completely reverted the C1q-mediated infectivity by respectively preventing its interaction with cell-bound parasite and HPCVE CRTs. This was corroborated by using competing fluid-phase recombinant TcCRT or human CRT and by a high expression of fetal CRT on free villi. Increased C1q-mediated infection is paralleled by fetal syncytiotrophoblast damage, that is reverted by anti-TcCRT F(ab')2 fragments or fluid-phase HuCRT. Most likely, C1q bridges CRT on the parasite with its placenta orthologue, thus facilitating their first encounter. The placental explants assay used in these studies is the closest ex vivo available correlate now revealing a plausible new mechanism of human congenital T. cruzi infection.
Increased innate immune recognition and viral clearance modulates the immune potential of an engineered CD8 T-cell vaccine (P4463)
Authors: Pavelko Kevin , Bell Michael , Pease Larry 
Published: January 2023

Abstract
We have engineered an attenuated picornavirus vaccine using Theiler’s murine encephalomyelitis virus (TMEV) and are exploring its usefulness in immunotherapy. We find that two different insertion sites within the leader protein of the TMEV genome allow for effective production of virus vaccine strains. One site is at the amino terminal end of the protein after the third amino acid position (p3); the other is at the XhoI restriction site further downstream. We find that vaccine antigen insertion at p3 disrupts the ability of the virus to inhibit type I interferon production by infected cells, whereas XhoI insertion does not. Further, the p3 modified virus can be cleared from animals lacking functional T and B-cells but replicates to high titer in IFNα/β receptor knockout mice, suggesting that innate immune mechanisms are sufficient for viral clearance. In spite of rapid clearance, p3 vaccines readily stimulate proliferation of transgenic T-cells and induce de novo responses to T-cell antigens in wild-type mice, although to a lesser extent than the XhoI modified vaccines strains. The use of either vaccine however effectively delays tumor growth and enhances survival in mice bearing melanoma and breast tumors. This vaccine provides a safe and effective vaccine strategy for the induction of CD8+ T-cell immunity directed towards cancer and provides support for the development of picornaviruses as vaccine vectors for treating human disease.
MyD88, a central innate immune adaptor, is dispensable for spontaneous autoimmune demyelination in a mouse model of multiple sclerosis (P4077)
Authors: Waldner Hanspeter , Wexler Aaron , Frielle Christine , Berry Gregory , Budgeon Lynn , Baccon Jennifer , Christensen Neil 
Published: January 2023

Abstract
Multiple sclerosis (MS) is an autoimmune disease that is mediated by myelin-reactive T cells resulting in CNS demyelination. Mice that are transgenic for a myelin proteolipid protein (PLP)-specific T cell receptor (TCR) spontaneously develop experimental autoimmune encephalomyelitis (EAE), the animal model of MS. MyD88 is the key adaptor protein in Toll-like receptor (TLR), IL-1R and IL-18R signaling, resulting in the activation of innate immune cells, including DCs. Although, MyD88-signaling is critical for T cell responses against microbial agents, it is unknown whether it is required for priming of myelin-reactive T cells in spontaneous EAE or MS. Here, we investigated the requirement of MyD88-signaling for the pathogenesis of spontaneous EAE in PLP TCR transgenic mice that genetically lacked MyD88. We demonstrate that MyD88 is dispensable for the development of spontaneous EAE and autoimmune demyelination in these mice. MyD88-independent EAE was associated with activated DCs that showed superior ability to promote PLP-specific Th1 and Th17 responses in vitro compared to DCs from healthy counterparts. In addition, we provide evidence indicating that the MyD88-independent TRIF signaling pathway was induced in EAE-diseased mice. Taken together, our data suggest that MyD88-independent innate immune signaling critically contributes to priming of myelin-reactive T cells and initiation of spontaneous EAE in our MS model.
Self dsDNA induces IL-1β production from human monocytes by activating NLRP3 inflammasome in the presence of anti-dsDNA antibodies (P4083)
Authors: Shin Min Sun , Kang Youna , Lee Naeun , Kim Sanghyun , Kang Ki Soo , Lazova Rossitza , Kang Insoo 
Published: January 2023

Abstract
The pathogenic hallmark of systemic lupus erythematosus (SLE or lupus) is the autoimmune response against self nuclear antigens, including dsDNA. The increased expression of the pro-inflammatory cytokine IL-1β has been found in the cutaneous lesion and peripheral blood mononuclear cells from lupus patients, suggesting a potential involvement of this cytokine in the pathogenesis of lupus. IL-1β is produced primarily by innate immune cells like monocytes and can promote Th17 cell response, which is increased in lupus. IL-1β production requires cleaving pro-IL-β into IL-1β by the caspase-1-associated multiprotein complex called inflammasomes. Here we show that self dsDNA induces IL-1β production from human monocytes dependently of serum or purified IgG containing anti-dsDNA antibodies by activating the NLRP3 inflammasome. Reactive oxygen species (ROS) and K+ efflux were involved in this activation. Knocking down the NLRP3 or inhibiting caspase-1, ROS and K+ efflux decreased IL-1β production. Supernatants from monocytes treated with a combination of self dsDNA and anti-dsDNA antibody-positive serum promoted IL-17 production from CD4+ T cells in an IL-1β dependent manner. These findings provide new insights in lupus pathogenesis by demonstrating that self dsDNA together with its autoantibodies induces IL-1β production from human monocytes by activating the NLRP3 inflammasome through inducing ROS synthesis and K+ efflux, leading to the increased Th17 cell response.
Influence of drinking water pH on gut microbiota and type 1 diabetes (P4069)
Authors: Sofi Mohammed , Gudi Radhika , Karumuthil-Melethil Subha , Perez Nicolas , Johnson Benjamin , Vasu Chenthamarakshan 
Published: January 2023

Abstract
Type 1 diabetes (T1D) is an autoimmune disease which occurs due to the interaction of genetically determined and environmental factors. T1D is characterized by progressive destruction of insulin secreting beta-cells by T cells leading to hyperglycemia. The non-obese diabetic (NOD) mouse spontaneously develops T1D similar to that in humans and thus widely used as a model for understanding the immunological basis and treatment of the disease. Incidence of TID in NOD mice is thought to be influenced by the degree of cleanliness of the mouse colony. Recent studies have shown a role for gut microbiota in promoting as well as preventing the disease. In this study, we show that pH of drinking water can have a profound influence not only on the type of commensal bacteria colonized in the gut, but also on the rate of disease progression. NOD mice that were on acidic pH water developed insulitis and hyperglycemia rapidly compared to those on neutral water. Interestingly, segmented filamentous bacteria (SFB) positive fecal transplant resulted in a profoundly suppressed insulitis and T1D incidence in NOD mice that are on acidic pH water. Microbial community analysis by pyrosequencing shows a significant difference in the type of gut microflora among the mice that were on acidic and neutral pH drinking water and this profile was altered by SFB+ fecal transplant. Our study shows that T1D incidence in NOD mice is influenced by the type of gut flora, but not the degree of cleanness alone.
Deficiency in SHP-1 triggers a cutaneous autoinflammatory disease that is provoked by IL-1α (P4071)
Authors: Lukens John , Kanneganti Thirumala-Devi 
Published: January 2023

Abstract
Mice homozygous for an Y208N amino acid substitution in the tyrosine phosphatase SHP-1 (referred to as Ptpn6spin mice) spontaneously develop a severe autoinflammatory syndrome that resembles neutrophilic dermatosis in humans and is characterized by persistent footpad swelling and suppurative inflammation. Deficiency in SHP-1 provokes dysregulated production of granulopoietic cytokines and neutrophilia. Genetic abrogation of IL-1R protected mice from cutaneous inflammation, suggesting that IL-1-mediated events potentiate disease. Surprisingly, inflammasome activation and IL-1β-mediated events were dispensable for SHP-1-mediated footpad disease. In contrast, we report a central role for IL-1α in chronic autoinflammation in Ptpn6spin mice. Microabrasion injury further exacerbated inflammatory responses and resulted in elevated cytokine production, neutrophilia, and unremitting tissue damage in Ptpn6spin mice. Bone marrow-derived cells were responsible for the autoinflammatory syndrome and the excessive inflammatory phenotype was rescued by genetic ablation of IL-1α. In contrast, genetic deletion of RIP3 failed to provide protection, suggesting that IL-1α drives spontaneous autoinflammation and aberrant wound-induced cytokine production in Ptpn6spin mice independently of RIP1/RIP3-mediated necrosis. This implicates that dysregulated SHP-1 activity triggers chronic autoinflammatory disease through IL-1α, and independently of inflammasomes or RIP1/RIP3-driven necrosis.
Vaccinia virus preferentially binds to protein enriched in lipid rafts on the surface of leukocytes (P6143)
Authors: Byrd Daniel , Amet Tohti , Hu Sishun , Lan Jie , Yu Qigui 
Published: January 2023

Abstract
The vaccinia virus (VV) has been found to rely on monocytic cell-mediated viremia to spread to tissues distant from initial infection sites. We have found that VV only infects monocytes to a significant degree among human leukocytes; however, VV binds to monocytes, B cells, activated T cells, and, to a lesser extent, neutrophils. Here we investigated the role of lipid raft-specific proteins in VV binding of leukocytes. When incubating fluorescent VV with leukocytes under binding conditions, we found that VV co-localizes with rafts on the surface of monocytes, B cells, activated T cells, and neutrophils. Also, VV strongly co-localizes with rafts when leukocytes are induced to polarize using various chemokines that induce rafts to move to cell uropods. This suggests that VV receptor proteins are enriched in rafts. It was previously found that mouse sera derived from human monocytes can block VV binding to human activated T cells. Using this principle, we created mouse sera from raft-enriched detergent-resistant membranes (DRM) or crude membrane (CM) extracts from monocytes, activated T cells, or resting T cells. Pretreating cells with sera derived from DRM blocked virus binding to the highest degree, but CM sera blocked to a lesser extent. Sera derived from resting T cells had no effect on virus binding. Our data indicates that leukocytes have protein virus receptors enriched in rafts on the cell surface, and that these cells share the expression of VV receptor proteins.
Neonates develop heterologous immunity but with altered crossreactivities (P6151)
Authors: Kenney Laurie , Carter Erik , Selin Liisa 
Published: January 2023

Abstract
The neonatal immune system is immature, lacks memory and is undergoing tolerization. This is also the age when children receive multiple vaccines. Previously, we have shown that sequential infection with unrelated pathogens can alter disease outcome. This is defined as heterologous immunity and is mediated by crossreactive T cells. In adult mice previous exposure to LCMV protects mice from lethal vaccinia virus (VV) infection. Crossreactive LCMV-specific memory cells recognize VV epitopes, are reactivated and expand during VV infection. This causes faster viral clearance and a skewing of the LCMV-specific immunodominance hierarchy. However, some LCMV-immune mice also develop acute fatty necrosis (AFN) of the abdominal fat pads during a VV infection. We questioned if mice immunized as neonates would have protective heterologous immunity during VV challenge. Mice immunized as neonates had comparable reduction in VV load and induction of AFN indicating that heterologous immunity is established during viral infections early in life. Interestingly, the LCMV-specific memory populations that expanded in mice immunized as neonates differed from that of mice immunized as adults. In adult mice 50% of the mice have an expansion of LCMV-NP205-specific CD8 T cells while the majority of neonates expanded the LCMV-GP34-specific CD8 T cell pool. This alteration in dominant crossreactivities may be due to the limited T cell receptor repertoire of neonatal mice.
Controlling viral immunoinflammatory lesions by using a mAb that specifically targets soluble and membrane bound lymphotoxin (P6105)
Authors: Veiga Parga Tamara , Gimenez Fernanda , Mulik Sachin , Chiang Eugene , Grogan Jane , Rouse Barry 
Published: January 2023

Abstract
Herpes simplex virus 1 (HSV-1) infection of the eye can result in stromal keratitis (SK), a chronic immunoinflammatory lesion and a significant cause of human blindness. A key to controlling the severity of SK lesions is to identify cell and molecular events responsible for tissue damage and to modulate their function. This report evaluates the role of LT-α, a proinflammatory cytokine that could be involved in mediating tissue damage during SK, and the use of a mAb that targets it. We show that in response to HSV infection, LT-α is upregulated and derived from proinflammatory cells such as neutrophils, γδ-T cells and T cells. We also show that LT-α, when expressed as LT-α3 (soluble) or LT-α1β2 (membrane bound), has a proinflammatory role in vitro in a corneal cell line. Moreover, mAb treatment during the clinical phase of the disease, which specifically targets cells expressing LT-α1β2 and its soluble version LT-α3, significantly attenuated SK lesions. In these mice, corneas expressed reduced levels of proinflammatory molecules, chemokines, and infiltration of proinflammatory cells when compared to control mice. However, treatment in vivo with a mutant version of the mAb, which only binds to LT-α3 did not decrease SK scores, indicating that the inhibitory activity may be dependent on targeting cells expressing LT-α1β2. We discuss our results in terms of the potential therapeutic value of managing SK in a clinical setting with a mAb targeting cells that express LT-α1β2.
Insoluble substances produced from human cytomegalovirus-infected cells induce deaths of nearby cells through non-classical death signal pathway (P6116)
Authors: Hwang Eung Soo , Kim Jung Heon 
Published: January 2023

Abstract
Human cytomegalovirus (HCMV) has many strategies to evade the host immune system, and eventually resides in some cells in latency. Although the involvement of Fas ligand in T cell death was reported in the pathogenesis of retinitis with HCMV infection to retinal pigment epithelial cells, the cell death near other lesions caused by HCMV infection was not studied in detail by now. The insoluble substances derived from HCMV-infected fibroblasts, induce the deaths of variety of cell lines including Jurkat, HL-60, K562, U937 and THP-1 cells, but not of fibroblasts, HEK293 and U373MG. They were resistant to treatment with 56°C for 30 min to lose death induceability to Jurkat cells. Cell death of Jurkat cells by these substances were not inhibited by the simultaneous treatment with neutralizing antibodies to Fas ligand or TRAIL, or caspase inhibitors. Insoluble substances induced cleavages of poly ADP-ribose polymerase-1 into 89 kDa fragment, but not through caspase 3, 7 or 9 pathway in Jurkat cells. AIF was detected in the cytoplasmic fraction, but not in the nuclear fraction of Jurkat cells from 6 hours following exposure to them. This result suggested AIF was not translocated from mitochondria to nucleus in Jurkat cells by the stimulation with insoluble substances. Collectively human cytomegalovirus infection would induce the death of myeloid and lymphoid cells near the infection site through non-classical death signal pathway.
LPA and autotaxin regulate T cell migration and homing (P5095)
Authors: Knowlden Sara , Chapman Timothy , Emo Jason , Rezaee Fariba , Capece Tara , Kim Minsoo , Georas Steve 
Published: January 2023

Abstract
Lysophosphatidic acid (LPA) has been suggested to regulate lymphocyte entry into lymph nodes because autotaxin (ATX), the enzyme that generates LPA, is constitutively expressed by lymph node high endothelial venules. However very little is known about the effects of LPA on T cell migration and homing. We studied the effects of LPA (16:0 and 18:1, 1-10 µM) on naïve mouse CD4+ T cells. Using chemotaxis assays, we found that LPA induces CD4+ T cell chemorepulsion (1.5±0.5 fold migration away from 1 µM LPA, n=26, p &lt;0.0001) but not chemotaxis. In addition, we found that LPA increases the quality of naïve CD4+ T cell migration on ICAM-1/CCL21 coated plates as shown by increased track length, displacement, and velocity of cells in the presence of LPA (p&lt;0.001). We next investigated the expression of LPA receptor mRNA on resting and anti-CD3/CD28 activated CD4+ T cells using qRT-PCR. We found that LPA2, LPA5, and LPA6 are highly expressed on naïve CD4+ T cells, and the expression of these decreases over the course of cell activation. In preliminary adoptive transfer experiments using gene-targeted mouse models, we found that LPA2 deficiency does not inhibit the recovery of transferred CD4+ cells from recipient lymph nodes after 42 hours, whereas fewer wild-type CD4+ cells were recovered from autotaxin-deficient mice (ATX+/-) compared to wild-type controls. Our results have uncovered previously unsuspected roles for LPA and autotaxin in regulating T cell migration and homing.
Targeting junctional adhesion molecule C improves the protective Th1 immunity through enhanced dendritic cell recruitment in response to Leishmania major infection (P5101)
Authors: Ballet Romain , Emre Yalin , Tacchini-Cottier Fabienne , Imhof Beat 
Published: January 2023

Abstract
Dendritic cells (DCs) are recruited to sites of infection where they process antigens and migrate to the draining lymph node in order to trigger specific T cell responses. In the C57BL/6J mouse model of cutaneous Leishmaniasis, monocyte-derived dendritic cells were shown to initiate the protective Th1 response against the parasite. Junctional adhesion molecule C (JAM-C), a tight junction protein expressed on endothelial cells and fibroblasts, was described in the past few years to control leukocyte migration during inflammation. Here we showed that targeting JAM-C with a monoclonal antibody improves the development of cutaneous lesions after Leishmania major infection. Indeed, we observed a two-fold increase in the number of neutrophils and monocyte-derived dendritic cells recruited one-day post infection without affecting the number and function of resident macrophages. In addition, analysis of the draining lymph node populations at several time points after infection showed a higher number of migratory dendritic cells. This enhanced antigen presenting cells recruitment boosted the activation of the Th1 response as shown by the increased number of IFN-γ-producing CD4 T cells. Overall, targeting JAM-C could represent a new way to enhance T cell response in Leishmaniasis as well as other infection diseases.
Drastic increase of DC movement from immunized site and rapid replacement of antigen-carrying DC was induced in the draining LN during initiation of T cell proliferation (P5103)
Authors: Tomura Michio , Sawano Asako , Miyawaki Atushi , Kanagawa Osami 
Published: January 2023

Abstract
Detailes of spatiotemporal regulation of antigen-carring DCs migrated from immunized site and antigen-specific T cell prolifeaion in the dLN is unknown. Kaede-Tg mice can monitor cellular movement by labeling cells by changing color from green to red by violet light and Fucci-Tg mice can visualize cell-cycle progression. Footpads of Kaede-Tg mice were immunized with CFA/OVA and labeled cells in the footpad and followed their migration to the dLN. After immunization, 100 times of MHC class IIHighDC migrated from immunized footpad compared with that in the steady state and lasted more than 14d. Whereas, MHC class IIInt DCs and pDCs increasead in dLN, which was sustained by increase of precursor immigration from blood circulation, migration from immunized site and proliferation. However, almost all migrated DCs from immunized site in the dLN replaced within less than 24h. Thus rapid replacement of DCs enable to control fine-tune of immune responses and spatiotemporal regulation of DCs under immune response is like “Large supply and mass consumption”. Although antigen-specific T cell proliferation already terminated 7d after immunization, skin-derived DCs continued to carry antigen from immunized site and dLN had capability to induce proliferation of re-transferred naive T cells. Thus termination of antigen-specific T cell proliferation is controlled by T cell intrinsic manner, not for the result of the absence of antigen-presenting DCs in dLN.