bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human mesenchymal stem cells constitutively express the serine protease granzyme B. (P1097)
Authors: Schüll Marion , Beyer Thamara , Lindner Stefanie , Kaltenmeier Christof , Rojewski Markus , Schrezenmeier Hubert , Jahrsdörfer Bernd 
Published: January 2023

Abstract
Human mesenchymal stem cells (MSC) are known for their immunoregulatory potential and are allegedly involved in tolerance induction. Several immune cells have been shown to exhibit their regulatory effects via expression of the cytotoxic serine protease granzyme B including regulatory T cells and plasmacytoid dendritic cells. Since MSC were recently found to express the GrB inhibitor PI-9, which is primarily expressed by cytotoxic cells, we hypothesized that MSC may also express GrB. Using various methods including Western immunoblotting, ELISpot, FACS analysis we found that MSC freshly isolated from healthy donor bone marrow biopsies indeed express considerable amounts of GrB protein. ELISpot assays demonstrated that GrB was not only expressed but also secreted by MSC. Moreover, a colorimetric GrB activity assay confirmed that GrB was secreted in its enzymatically active form. Importantly, when testing the effect of various cytokines we found that G-CSF, IFNg and TPO were capable of further enhancing GrB expression in MSC. Future studies have to elucidate which aspects of the suppressive activity of MSC possibly depend on GrB and which culture conditions may support a suppressive phenotype of these cells including GrB expression. Our results may open novel approaches to the use of MSC as immunoregulatory cellular therapeutics in inflammatory conditions such as graft-versus-host disease.
Ubiquitin E3 ligase deltex1 promotes PKCθ degradation for full T cell anergy (P1109)
Authors: Lai Ming-Zong , Hsu Tse-Sheng , Wu Pei-Jung , Hsiao Huey-Wen 
Published: January 2023

Abstract
The generation of T cell anergy is associated with upregulation of ubiquitin E3 ligases including Cbl-b, Itch, and GRAIL. Both Cbl-b and Itch contribute to the downregulation of PKCθ in anergic T cells. Recently, we identified deltex1 (DTX1) as another E3 ligase that is upregulated in T cell anergy. DTX1-deficiency prevents T cell anergy production and leads to autoimmunity. In the present study, we found that DTX1 also targeted to PKCθ for degradation. DTX1 overexpression stimulated the degradation of PKCθ. There was a direct interaction between DTX1 and PKCθ. Because DTX1 also promotes Cbl-b expression, we showed that Cbl-b knockdown did not affect the ability of DTX1 to downregulate PKCθ, excluding an involvement of Cbl-b in DTX1-mediated PKCθ degradation. We also found that DTX1-induced PKCθ degradation was not prevented by proteasome inhibitor. Instead, DTX1 directed PKCθ into lysosomal pathway for degradation. In addition, T cell anergy-induced proteolysis of PKCθ was prevented in Dtx1-/- T cells, supporting the essential role of DTX1 in PKCθ downregulation. Our results suggest that DTX1 acts together with Cbl-b and Itch to assure a complete silencing of PKCθ for T cell anergy and immune tolerance.
Sublingual immunization with M2-based vaccine induces broad protective immunity (P4301)
Authors: Song Manki , Shim Byoung-Shik 
Published: January 2023

Abstract
Background: M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored. Methods and Results: A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs. Conclusions: The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections.
The B cell response to influenza infection is limited by CD4 T cell help (P4305)
Authors: Knowlden Zackery , Alam Shabnam , Sant Andrea 
Published: January 2023

Abstract
Seasonal influenza and the risk of widespread influenza pandemics are an ongoing major world health concern. In the United States alone, influenza infection results in more than 200,000 hospitalizations and up to 41,000 deaths each year. The current vaccine strategies focus on eliciting neutralizing antibodies against hemagglutinin and neuraminidase, the major surface glycoproteins involved with viral entry and exit from a host cell. Because of the highly mutable nature of influenza, the vaccine must be reformulated each year - highlighting the necessity for an alternate approach that provides broad and long-lasting protection. We have approached this problem by asking if CD4 T cell memory, elicited by peptide priming, is sufficient to accelerate T cell and B cell responses to influenza infection. After immunization with immunogenic peptides derived from A/New Caledonia/20/99 followed by infection with the same virus, we observed an increased frequency of virus specific CD4 T cells 7 days post infection. Additionally, there was an enhanced B cell response both kinetically and in magnitude. We have also observed a strong correlation between the frequencies of follicular T helper cells and germinal center B cells in the peptide primed/infected cohorts that are not seen in the control primed/infected group. Our results suggest that T cell help for a primary B cell response to infection is limiting, and that peptide priming is sufficient to generate a functional memory CD4 pool.
Cross-reactive neutralizing antibody responses to enterovirus 71 infections in young children (P4319)
Authors: Lee Min-Shi , Huang Mei-Liang , Chiang Pai-Shan , Chia Min-Yuan , Luo Shu-Ting , Chang Luan-Yin , Lin Tzou-Yien , Ho Mei-Shang 
Published: January 2023

Abstract
Recently, enterovirus 71 (EV71) has caused life-threatening outbreaks involving neurological and cardiopulmonary complications in Asian children with unknown mechanism. EV71 has one single serotype but can be phylogenetically classified into 3 main genogroups (A, B and C) and 11 genotypes (A, B1~B5 and C1~C5). In Taiwan, nationwide EV71 epidemics with different predominant genotypes occurred in 1998 (C2), 2000-2001 (B4), 2004-2005 (C4), and 2008 (B5). In this study, sera were collected to measure cross-reactive neutralizing antibody titers against different genotypes. We collected historical sera from children who developed an EV71 infection in 1998, 2000, 2005, 2008, or 2010 and measured cross-reactive neutralizing antibody titers against all 11 EV71 genotypes. In addition, we aligned and compared the amino acid sequences of P1 proteins of the tested viruses. Serology data showed that children infected with genogroups B and C consistently have lower neutralizing antibody titers against genogroup A (&gt;4-fold difference). The sequence comparisons revealed that five amino acid signatures (N143D in VP2; K18R, H116Y, D167E, and S275A in VP1) are specific for genogroup A and may be related to the observed antigenic variations. In conclusion, this study documented antigenic variations among different EV71 genogroups and identified potential immunodominant amino acid positions. Enterovirus surveillance and vaccine development should monitor these positions.
Endogenous specialized proresolving mediators enhance antigen-specific antibody response against influenza virus: A new class of adjuvant (P4285)
Authors: Ramon Sesquile , Serhan Charles , Topham David , Phipps Richard 
Published: January 2023

Abstract
Inflammation is a highly regulated process triggered by the presence of pathogens, injury or trauma. Specialized proresolving mediators (SPMs) are endogenous lipid-derived molecules, which regulate the resolution of inflammation. Resolving inflammation is critical for maintaining homeostasis while assuring immune protection against pathogens, such as influenza virus. We previously showed that the SPM 17-hydroxydosahexaenoic acid (17-HDHA) increased human B cell antibody production in vitro and promoted differentiation towards an antibody-secreting phenotype. Herein, we used a pre-clinical influenza virus immunization mouse model to study the effects of 17-HDHA in vivo. Mice immunized with influenza-derived hemagglutinin (HA) protein plus 17-HDHA have enhanced HA-specific IgM and IgG production compared to mice immunized with HA alone. Enhanced HA-specific antibody production was due to plasma cell increase in the bone marrow. HA-specific antibodies were protective against live influenza viral infection as they decreased morbidity and mortality following viral challenge. Our study shows that DHA-derived SPMs play an important role in enhancing B cell-mediated immunity. An enhanced antigen-specific immune response promotes faster pathogen clearance, and thus return to homeostasis. In addition, these new findings highlight the potential applications of SPMs as new endogenous and non-toxic adjuvants or vaccine “boosters”.
The anatomy of a protective CTL response in influenza virus infected lungs (P3204)
Authors: Cauley Linda , Wu Tao , Hu Yinghong 
Published: January 2023

Abstract
Cytotoxic T lymphocytes (CTL) can provide immunity between serologically-distinct strains of influenza virus, known as heterosubtypic immunity. Although the kinetics of the CTL response have been examined in detail by flow cytometry, changes in the distribution of different subsets of virus-specific CTL within the infected lungs are largely undocumented. We previously used parabiosis experiments to show that some virus-specific CD8 T cells, which maintain stable CD69 and CD103 expression, colonize the lungs and local lymph nodes during primary viral infection and remain sequestered from the circulation long after most symptoms of inflammation have resolved. Fluorescence microscopy has been used to follow changes in the distribution of these virus-specific Trm cells as they respond to secondary viral infection. We show that robust transforming growth factor-beta production selectively eliminates KLRG1+ effector CD8 T cells from the lung tissues, while CD103+ Trm cells persist in the airways. When the immune animals are reinfected with a new strain of influenza virus the CTL response is focused on the tissues around the infected airways. Circulating central memory CD8 T cells begin to divide in the local lymph nodes a few days later, but are insufficient to accelerate viral clearance in non-immune animals.
Intestinal CX3CR1+ macrophages induce and maintain unique CD103+ regulatory T cells (P3206)
Authors: Jang Min Seong , Yang Bo Gie , Lee Eun-Jung , Kim Jung-Hwan , Hong Chun Pyo , Jeun Eun Ji , Doh Junsang , Jang Myoung Ho 
Published: January 2023

Abstract
In the gut, there are tremendous antigens existed such as food proteins, commensal bacteria and even self-antigens. For this reason, maintenance of intestinal tolerance is important to regulate excessive inflammations. Recently, Foxp3+ Tregs are required to maintain intestinal tolerance. However, their phenotypes and functions in immune regulation are heterogeneous, thus it is required to find which subpopulations of Tregs in the gut suppress inflammatory cells effectively to prevent inflammatory diseases. Here we found that majority of the Tregs in the small intestinal lamina propria highly express CD103 molecule on their surface compared to Tregs in other tissues such as thymus, spleen, mesenteric lymph nodes and colon. We next investigated which antigen presenting cells from small intestinal lamina propria can induce CD103+ Tregs in vitro. We found that intestinal CX3CR1+ macrophages, which produce immunoregulatory cytokine IL-10 highly, induce CD103+ Tregs more efficiently, but not dendritic cells. These CD103+ Tregs had effect on reducing occurrence of diarrhea in food allergy model. Further, intestinal CX3CR1+ macrophages induced helios+ Tregs which have been recently suggested to be stable Tregs, under inflammatory stimulations. These findings suggest that CD103+ Tregs induced by intestinal CX3CR1+ macrophages raise the possibility of improvement in therapeutic potential of Tregs for inflammatory diseases such as graft versus host diseases and autoimmune diseases.
The dissemination of Listeria monocytogenes shuttled by Batf3-dependent DC from intestine to mesenteric lymph node following oral infection (P3226)
Authors: Xu Daqi , Sheridan Brian , Freitag Nancy , Schubert Wolf-Dieter , Lefrançois Leo 
Published: January 2023

Abstract
Listeria monocytogenes (L.m.) is a food borne disease-causing bacterium. The natural infection route in humans is through consumption of contaminated food. However, the rules governing L.m. dissemination and the subsequent innate and adaptive immune responses in the intestinal mucosa following oral infection have not been clarified. Thus, this study focused on immune responses to L.m. after oral infection using a murinized L.m. to mimic L.m. pathogenicity in humans. Initially, infection was limited to the gut mucosa, and antigen presentation predominantly occurred within mesenteric lymph nodes (MLN) and Peyer’s patches (PP). However, PP were dispensable for bacterial dissemination and clearance. L.m., but not Salmonella, was shuttled intracelluarly by Batf3-dependent DC from the intestine to the MLN, entering through the sub-capsular sinus into the interfollicular zones to eventually converge in the T cell zone. An organized architecture rapidly developed in the MLN with Ly6G+ neutrophils surrounding L.m., and with an outer zone of DCs and T cells, indicating a potential antigen presentation site. In addition, Batf3-dependent DC were also required for dissemination of irradiated L.m. to the MLN, suggesting the existence of a receptor-mediated system for L.m. acquisition. In sum, our data demonstrated organized immune responses to a unique L.m. dissemination pattern in the gut mucosa.
The cathelicidin LL-37 exerts its mucosal adjuvant activity via enhancing germinal center formation and dendritic cell maturation (P3234)
Authors: Jang Yong-Suk , Kim Sae-Hae , Lee Ha-Yan , Lee Hojun , Kim Ju , Kim Dae-Hyuk , Lee Kyung-Yeol 
Published: January 2023

Abstract
Oral mucosal vaccine confers feasibility and efficacy in vaccination. However, it imposes restrictions such as difficulty in antigen delivery and poor immunogenic environment. Consequently, many studies have been concentrated to develop effective mucosal adjuvants. We determined mucosal adjuvant activity of cathelicidin LL-37 based on the previous report of its activity in parenteral vaccination, although it has not been studied in mucosal system. In oral mucosal vaccination using EGFP protein, LL-37-conjugated antigen effectively evoked the antigen-specific systemic and mucosal immunities. Notably, when the LL-37 was applied to pathogenic antigen, an EDIII of dengue virus, antibody responses with high neutralization activity was induced. Further studies on chemokine profiling induced by LL-37 in Peyer’s patch lymphocytes were well accordance with the increase in the number of germinal centers in Peyer’s patch and mesenteric lymph node by chemotactic effect of LL-37. In addition, oral priming with LL-37-conjugated antigen induced Th1- and Th17-skewed immune responses through CD11c+ CD70+ cell activation in Peyer’s patch. More interestingly, we found the expression of formyl peptide receptor-2, one of the receptors for LL-37, in subepithelial dome of Peyer’s patch and M cells. Collectively, we conclude that LL-37 can play a role as mucosal adjuvant through enhanced antigen delivery, dendritic cell maturation, and chemotactic effect by FPR-2 on M cells and subepithelial dome.
Pseudomonas aeruginosa biological functions are inhibited by normal airway epithelial secretions: implications for cystic fibrosis (P3074)
Authors: Bankers-Fulbright Jennifer , Sorum Alexander , Hinz Sandra , Weitz Anna , Zank Allison 
Published: January 2023

Abstract
P. aeruginosa does not colonize healthy individuals, but it is the leading cause of death in patients with cystic fibrosis (CF). The ability of P. aeruginosa to readily colonize CF-lungs is at least partially related to alterations in airway secretions caused by the disease. In addition to being dehydrated, these secretions have reduced antimicrobial activity compared to that found in normal airways. Thus, we proposed that normal airway secretions contain one or more molecules that reduce P. aeruginosa virulence whereas CF airway secretions do not. To test this hypothesis in vitro, we collected apical secretions from polarized CFTR+ and CFTR- Calu-3 cell monolayers. We applied these secretions at various concentrations to the P. aeruginosa strain PA14 and examined the effect of the secretions on two key biological activities associated with P. aeruginosa virulence: motility and biofilm formation. Secretions from CFTR+ (“normal”) cells dose-dependently inhibited both PA14 flagellar motility and biofilm formation. However, secretions from CFTR- (“CF-like”) cells failed to inhibit either biological function. Our preliminary identification experiments suggest that the inhibitory agent(s) in the CFTR+ secretions is a heat-labile, large (&gt;50 kDa) molecule, probably a protein. Thus, it is likely that normal epithelial secretions play a direct role in inhibiting P. aerugionsa virulence and that these secretions are dysfunctional in patients with CF.
Eosinophils promote immune responses that preserve parasitic nematode larvae (P3086)
Authors: Huang Lu , Gebreselassie Nebiat , Gagliardo Lucille , Lee Nancy , Lee James , Appleton Judith 
Published: January 2023

Abstract
We have shown that eosinophils protect, rather than attack Trichinella spiralis larvae during primary infection in the skeletal muscle. Accumulation of Th2 cells at sites of infection is also impaired in the absence of eosinophils. Here we further elucidated the mechanism underlying this effect. Intravenous infection with T. spiralis newborn larvae specifically and rapidly induced the recruitment of eosinophils to skeletal muscle. The presence of eosinophils only during the earliest stages of muscle infection was sufficient to support parasite growth and survival, suggesting that eosinophils are required to be present at the time newborn larvae first arrive in the muscle, when the local immune response is first engaged. Transfer of MHCII-/- eosinophils also supported parasite growth and survival, showing that antigen presentation by eosinophils is not required. Furthermore, the numbers of myeloid dendritic cells in cervical lymph nodes and skeletal muscles were reduced in eosinophil-ablated, infected mice and improved when eosinophils were restored. The reduction in myeloid dendritic cells correlated with decreased numbers of proliferating Th2 cells in cervical lymph nodes, indicating that eosinophils promote accumulation of myeloid dendritic cells, which may promote Th2 responses. Taken together, our findings suggest that eosinophils exert their influence at the very early stages of the immune response that preserves T. sprialis larvae.
Sublingual vaccination using alpha-galactosylceramide adjuvant induces mucosal and systemic adaptive immunity for protection against lung tumors (P4446)
Authors: Singh Shailbala , Yang Guojun , Schluns Kimberley , Sastry Jagannadha 
Published: January 2023

Abstract
Sublingual (SL) route enables safer and convenient administration of vaccines in comparison to other systemic and mucosal strategies. Here we present evidence demonstrating the effectiveness of SL immunization employing the synthetic glycolipid alpha-galactosylceramide (aGC) for harnessing the adjuvant potential of invariant natural killer T (NKT) cells for the induction of cellular and humoral immune responses to co-administered Ovalbumin (OVA) antigen. Compared to OVA alone, co-administration of aGC with OVA by SL route resulted in the generation and persistence of strong antigen specific CD8+ T cell responses along with serum IgG and vaginal IgA responses. Only in the presence of aGC adjuvant, could a booster administration of the antigen by SL route recall adaptive immune responses effectively. Multiple doses of aGC delivered by SL route resulted in repeated NKT cell activation s in the draining lymph nodes and lungs of immunized mice concurrent with the progressively improving adaptive immune responses. This is different compared to systemic intravenous delivery of aGC that induced anergy of NKT cells and subsequent doses of aGC led to dampening of adaptive immune responses. SL vaccination with OVA antigen admixed with aGC, but not OVA or aGC alone, was significantly effective against challenge of B16 melanoma tumors expressing OVA in the lungs supporting clinical utility of aGC-mediated NKT cell activation by SL route for stimulating protective adaptive immunity.
Varicella zoster virus decreases transcription and translation of STAT1 and blocks translocation of pSTAT1 to the nucleus in cerebrovascular adventitial fibroblasts. (P6149)
Authors: James Stephanie , Choe Alexander , Wyborny Ann , Tratkinskiy Igor , Gilden Don , Nagel Maria 
Published: January 2023

Abstract
Varicella zoster virus (VZV) is the only human virus known to replicate in cerebral arteries and produce stroke. After reactivation, virus travels transaxonally from ganglia and initially infects the arterial adventitia. To analyze the virus-host relationship, we infected primary human cerebrovascular adventitial fibroblasts with VZV and studied the interferon-α initiated STAT pathway, which is commonly activated after virus infection. Quantitative PCR showed that expression of STAT1, STAT2 and Mx1 mRNA were significantly decreased in VZV-infected, but not uninfected adventitial fibroblasts (p&lt;0.05). Western blotting confirmed decreased STAT1 and Mx1 expression in VZV-infected fibroblasts compared to uninfected cells. Although Western blotting did not reveal phosphorylated STAT1 (pSTAT1) in VZV-infected cells, interferon-α is known to trigger STAT1 phosphorylation; thus, we treated uninfected adventitial fibroblasts with interferon-α, after which pSTAT1 expression was readily seen on Western blots. Furthermore, immunocytochemical staining detected pSTAT1 exclusively in the cytoplasm of VZV-infected cells. In interferon-α -treated uninfected cells, pSTAT1 was found exclusively in the nucleus, suggesting that VZV infection blocks egress of pSTAT1 from the cytoplasm to the nucleus in cerebral adventitial fibroblasts.