bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating Epidermal T Cell Function by C-C Chemokine Receptor 6
Authors: Bshara-Corson Savannah , Gonzalez Isaac , Miranda Nadia , Jameson Julie 
Published: January 2023

Abstract
The skin is the largest organ on the body and is responsible for providing protection from foreign pathogens. When skin tissue damage occurs, immune cells aid in wound repair. Epidermal T cells play a key role in maintaining skin homeostasis by their secretion of cytokines and chemokines to facilitate inflammatory responses following tissue damage. During obesity and type 2 diabetes, epidermal T cells exhibit reduced production of select cytokine and chemokine receptors one of which is C-C Chemokine receptor 6 (CCR6). The principle ligand for CCR6 is C-C Chemokine Ligand 20 (CCL20). Upon CCL20 binding, CCR6 induces lymphocyte migration however, little is known about the regulatory role CCR6 plays in cellular functions such as cytokine production and cell surface receptor expression. For this study, murine epidermal T cells were harvested and stimulated in the presence or absence of CCL20. Epidermal T cell production of cytokines and chemokines in response to CCL20 were characterized via Luminex assay. Consequently to being stimulated with CCL20 epidermal T cells upregulate IL-2R and downregulate their T cell receptor both of which signify cell activation. Additionally, CCL20 costimulates TCR stimulation to activate epidermal T cells. Using immunofluorescence microscopy, we show that CCR6 has a pivotal role in activation causing morphological changes to skin resident T cells. Future studies will investigate CCR6 activation and receptor expression of αβ and γδ in human skin.
Does TNF-α regulate thymic T cell developmental block in mice with dysregulated expression of Ly-6A?
Authors: Bamezai Anil K , Moxham Sarah , Patel Akshay 
Published: January 2023

Abstract
Ly-6A is a 12 kD GPI anchored member of the Ly-6 superfamily. Ly-6A and other gene family members show broad tissue expression, including expression on T lymphocytes. Ly-6A has been characterized as a cell adhesion molecule and shown to regulate cell signaling in T cells; specifically cytokine secretion. Published work indicates that this protein’s role in signaling regulation extends as far as mediated cell death pathways, resulting in growth arrest and ultimately cell death in T cell lines. Expression of Ly-6A on T cells in the thymus is developmentally regulated. Peak expression occurs during early stages of development, diminishes during maturation, and reappears at low levels on mature, CD4+ T cells. T lymphocytes in the thymus of Ly-6A transgenic (overexpressing) mice have been observed to experience increased instances of cell death and arrested early stage development. However, the underlying mechanisms of reduced cellularity in Ly-6A transgenic mice is unknown. I hypothesized that TNFα, a cytokine known to have cell death inducing properties, contributes to inhibited T cell development, lower cellularity and extensive cell death of developing T cells in thymi of Ly-6A transgenic mice. To address my hypothesis, I investigated the levels of TNFα in normal and Ly-6A transgenic mice. I find that there is decrease in cellularity in the developing thymus of Ly-6A transgenic mice compared to Ly-6A wildtype mice, consistent with published reports. On a per cell basis, this finding corresponds with increased TNFα release from Ly-6A transgenic T-lymphocytes. We plan to investigate development of T cells in Ly-6A transgenic mice that lack TNFα and specifically look for reversal of block in thymic T cell development.
TCR signal strength shapes functional imprinting during CD4 T cell development
Authors: Verstichel Greet , Thiault Nicolas , Kakugawa Kiyokazu , Chen Angeline , Iwaya Hitoshi , Takazawa Ikuo , Cheroutre Hilde 
Published: January 2023

Abstract
Naïve CD4 and CD8ab T cells are selected in the thymus in response to low-avidity TCR interactions. Such weak TCR signals install a quiescent program that guides naïve T cells to the lymph nodes where they differentiate upon encounter of cognate antigen. Thymocytes expressing self-specific TCRs can be agonist-selected in response to a strong TCR signal and differentiate in the thymus to functionally committed double negative T cells, NKT cells or regulatory T cells. Although the role for strength of TCR activation is clear in instructing these different outcomes, the impact of self-recognition in the thymus on “naïve” T cells is unclear. Previous work demonstrated that negative selection of self-specific T cells is not all encompassing and that affinity for self could even enhance immune protection against pathogens.
We have used Stim1fl/fl Stim2fl/fl conditional deletion mice that fail to sustain calcium entry into the cytosol upon TCR activation to assess the role of TCR strength during selection. We confirmed that agonist selection is drastically affected in these mice whereas numbers of conventional T cells are not. Interestingly, viSNE representation of multi-parameter flow cytometry revealed single cell heterogeneity among the CD4SP thymocyte subset that is controlled by Stim1/Stim2. This indicates that differential TCR activation levels give rise to phenotypically different CD4 T cells. Purification of a strongly signaled (Stim1/2-dependent) subset of CD4 thymocytes showed functional differences in terms of their ability to proliferate in response to TCR activation. Our work points to a role for self-recognition during T cell selection that shapes the response of individual CD4 T cells to TCR activation in the periphery.
CTL-derived exosomes enhance the activation of CTLs stimulated by low-affinity peptides
Authors: Xiao Zhengguo , Wu Shu-Wei , Li Lei , Wang Yan 
Published: January 2023

Abstract
Cytotoxic T cells (CTLs) of low TCR affinity play an important role in the control of intracellular pathogens and cancers; however, the mechanisms by which lower-affinity CTLs are activated and maintained are not well understood. We recently discovered that fully activated CTLs stimulated by strong-affinity peptides in the presence of IL-12 are able to secrete exosomes (Exo) that can stimulate bystander CTLs without requiring the presence of antigen. We hypothesized that the exosomes secreted by high-affinity CTLs could strengthen the activation of low-affinity CTLs. To test this hypothesis, naive OT-I CD8+ cells were stimulated with altered SIINFEKL peptides of different affinities in the presence or absence of Exo. The presence of Exo preferentially increased cell proliferation and enhanced the production of IFNγ in CTLs stimulated by low-affinity peptides. The expression of granzyme B (GZB) was augmented in all affinities, with higher GZB production in low-affinity stimulated CTLs than in high-affinity stimulated ones. Exosomes promoted the rapid activation of low-affinity CTLs, which remained responsive to exosomes for a prolonged duration. Unexpectedly, exosomes could be induced quickly (24 hours) following CTL activation and at a higher quantity per cell than later (72 hours). While exosome protein profiles vary significantly between early exosomes and their later-derived counterparts, both appear to have similar downstream functions. These results reveal a potential mechanism for fully activated CTLs in activating lower-affinity CTLs that may have important implications in boosting the function of low-affinity CTLs in immunotherapy for cancers and chronic viral infections.
Teaching hemolytic disease of the newborn (Erythroblastalis fetalis) to undergraduate immunology students through the use of an interactive simulation
Authors: Costabile Maurizio 
Published: January 2023

Abstract
Hemolytic disease of the newborn (HDN, Erythroblastalis fetalis) is a potentially fatal condition. It is initiated due to Rhesus (Rh) antigens on fetal red blood cells (RBCs) being seen as foreign by the mothers Rh− immune system. In the first pregnancy, exposure of the maternal immune system to fetal Rh+ RBCs leads to immune activation, IgM production and memory cell formation. A subsequent pregnancy with another Rh+ fetus, activates memory cells, leading to class switching and IgG production, which is placentally transferred to the fetus. Through multiple effector functions, the IgG leads to hemolysis, causing anemia and in severe cases even death of the fetus. The role of the immune response is key to this disease, hence it is taught to undergraduate immunology students at the University of South Australia. Topics include the primary and secondary immune responses, placental transfer of IgG, deletion of self reactive cells and use of mAbs as therapeutic agents are addressed. Experience has shown that students find this topic challenging. In an attempt to enhance understanding, I developed an interactive simulation to teach these principles which was trialed in 2018. The simulation gave students the opportunity to blood group expecting parents and then discuss possible HDN issues and the treatment option. As with other simulations I have generated, (e.g. flow cytometry and mAbs), I suggest this approach is a new approach to teach complex immunological concepts. This approach can enhance student understanding as well as provide a new means of information transferal. The HDN simulation is freely available to all teaching staff who may wish to use it as part of their teaching approach.
HVEM signaling in pulmonary epithelial cells is required for protection against Streptococcus pneumoniae
Authors: Chou Ting-Fang , Hitomi Kaori , Shui Jr-Wen , Kakugawa Kiyokazu , Cheroutre Hilde , Kronenberg Mitchell 
Published: January 2023

Abstract
The most common cause of community-acquired pneumonia in the world is Streptococcus pneumoniae (S. pneumoniae). It is a serious and urgent issue to develop new therapies including non-antibiotic treatments for this pathogen. The herpes virus entry mediator (HVEM), a member of the tumor necrosis receptor super family 14 (TNFRSF14), has been reported to provide host innate immune defense in intestinal mucosal barriers against Citrobacter rodentium infection. Here we show using C10-Cre transgenic mice crossed to mice with a floxed Hvemallele that mice with pulmonary bronchiolar non-ciliated Clara cell-specific deletion of HVEM (HvemdelCC10) display higher bacterial burden and increased mortality after S. pneumoniae infection. Injection of an HVEM neutralizing antibody had a similar effect. This indicates that epithelial HVEM is also critical for pulmonary mucosal protection during the infection. In response to S. pneumonia, HVEM-deficiency led to reduced CXCL1 secretion, accompanied by impaired neutrophil recruitment to the lung. Likewise, deletion of part of the cytoplasmic tail of HVEM (HvemdelCT), causing loss of the ability of HVEM to signal, showed a similar susceptibility to S. pneumonia, indicating the importance of the intracellular signaling of HVEM in epithelial cells for the bacterial clearance. Taken together, these results reveal the protective role of HVEM in epithelial cells against S. pneumonia infection and suggest that activated HVEM signaling in epithelial cells could be used for the treatment of S. pneumoniae infection.
The transcription factor TCF1 is a critical target of ID2 that limits natural killer cell maturation
Authors: Kee Barbara L , Morman Rosemary , Sun Mengxi , Li Zhong-Yin 
Published: January 2023

Abstract
ID2 is an inhibitor of the E protein transcription factors that is expressed in all innate lymphoid cells. In natural killer (NK) cells, ID2 prevents immature cells from acquiring a naïve T cell – like gene program that restricts NK cell maturation and function. Here we show that Tcf7 (encoding the transcription factor TCF1) is the critical E protein target gene in immature NK cells that maintains NK cell progenitors. TCF1 binds to a subset of key “naïve T cell” genes that are normally expressed at low, but detectable, levels in immature NK cells and whose expression is deregulated in the absence of ID2. Importantly, combined deficiency of TCF1 and ID2 restores expression of these naïve T cell genes to near wild-type levels. Moreover, in the absence of TCF1, ID2-deficient NK cells mature and acquire functional capacity but fail to expand to wild-type numbers. Our data indicate that ID2 is essential for NK cell maturation because it controls TCF1, whose heightened expression arrests NK cell maturation and activates a naïve – like gene program.
Spatial distribution of antigen-specific CD8+ T cells in virally infected skin
Authors: Wynne-Jones Erica , Shannon John P , Reynoso Glennys V , Hickman Heather D. 
Published: January 2023

Abstract
CD8+ T cells play a critical role in the elimination of viral infections. After epicutaneous infection with vaccinia virus (VACV), virus replicates in skin keratinocytes and antigen drains to the lymph node, priming antigen-specific CD8+ T cells. Once activated, CD8+ T cell migration into the skin occurs independent of cognate antigen recognition. In laboratory mice, which are immunologically naive prior to viral infection, only antigen-specific CD8+ T cells are activated and can migrate into the skin. However, as humans are exposed to many more pathogens than laboratory mice, activated CD8+ cells present in the circulation can be recruited to the site of infection, regardless of their antigen specificity. To model this phenomenon in mice, we adoptively transferred OT-I CD8+ T cells, infected in the footpad with non-replicating virus to activate these T cells, and then infected epicutaneously with recombinant VACV expressing or lacking SIINFEKL (the cognate antigen for OT-I cells). This system allows the robust recruitment of both antigen-specific and non-specific antiviral CD8+ T cells into the skin. Using a combination of flow cytometry and confocal and intravital microscopy, we are currently investigating the spatial distribution of antigen-specific and non-specific CD8+ T cells in the skin. Additionally, we are quantifying cytokine production by these CD8+ T cells under various conditions, including after infection with viruses expressing distinct antigens, in close proximity. These studies should provide additional clarity on the role of antigen in CD8+ T cell spatial distribution in infected peripheral tissues.
Swift protection from Flu infections in a systemic lupus mouse model
Authors: Abboud Georges , Choi Seung-Chul , Li Wei , Titov Anton , McKinstry Karl Kai , Strutt Tara M , Salek-Ardakani Shahram , Morel Laurence 
Published: January 2023

Abstract
Patients with systemic lupus erythematosus (SLE) are more susceptible to infections but it is unclear whether this is due to disease or treatment. Using mice expressing three SLE susceptibility loci (triple congenics hereafter called TC mice including genes that affect both innate and adaptive immunity) we surprisingly found that these mice are resistant to respiratory Flu PR8 (H1N1) infection. TC mice lost 5–10% of their initial body weight (IBW) and promptly inhibited viral replication in the lungs compared to B6 mice that lost up to 30% of their IBW, pointing to a protective role of the innate immune system. Indeed, naïve TC lungs showed hyperactivated neutrophils, monocytes and natural killer cells (NK) compared to B6 lungs. Additionally, NK cells were found to constitutively produce IL-22 capable of enhancing the mucosal barrier. Nevertheless, RAG mice on a TC background could not recover from flu infection just like RAG.B6 mice, suggesting a role for adaptive immunity. Interestingly, depleting CD8 T cells, major players in primary flu infections, did not hinder the recovery of WT TC mice from primary infection. Lastly, depletion of both NK and neutrophils led to a reduced weight loss indicating that these cells do not contribute to early or late protection of TC mice from PR8 infection. In conclusion, systemic lupus in mice creates a favorable environment that impairs Flu virus replication and neither classical innate nor cytotoxic cells are singly responsible for this protection.
High-dimensional immune atlas of second trimester human intestinal immunity
Authors: Konnikova Liza , Stras Stephanie , Werner Lael , Toothaker Jessica , Oldham Austin , Shouval Dror 
Published: January 2023

Abstract
It has long been postulated that newborn’s immune system is immature. To this end, a third of neonatal deaths are due to infections. Similarly, newborns tend to have reduced immune responses to vaccines. Nevertheless, most newborns are healthy. There is limited direct human studies focusing on utero fetal mucosal immune development. Therefore, there is a critical need to investigate fetal mucosal immunity. Using cytometry time of flight (CyTOF) and next-generation sequencing of B and T-cell receptor (B/TCR) repertoires of small (S) and large intestines (LI), we show that intestinal immunity is diverse and functional as early as 16 weeks gestation (GA). Similarly, BCR and TCR repertoires are as diverse in early fetal as in full term samples, though an increase in CDR3β length and distance-from-germline correlates with advanced GA. Innate immunity is dominated by antigen presenting cells, including CD103+DCs, innate lymphoid cells and natural killer cells. B-cells are also present in all tissue examined, with follicular and transitional B-cells enriched in the fetal and CD69+IgM+B-cell in neonatal tissue. Finally, there is high complexity in T-cells, representing &gt;50% of immune cells with similar frequencies at all developmental stages and locations studied. Contrary to our assumption, the majority of T-cells are of central and effector memory subsets. Even more surprisingly, functional tissue resident memory T-cells are abundant and functional in fetal and neonatal samples. Our data provide the foundation for a mucosal immune atlas of second trimester human development and challenge the paradigm that the neonatal immune system is immature, suggesting that development occurs significantly earlier than previously reported.
Alpha-synuclein (αS) acts as an alarmin to promote dendritic cell activation and proinflammatory immune response
Authors: Alam Md Masud , Yang De , Trivett Anna L. , Li Xiao-qing , Oppenheim Joost J 
Published: January 2023

Abstract
Alpha-synuclein (αS) protein is involved in the development of neurodegenerative disorders including Parkinson’s disease. Recently, it has been shown that αS expression by enteric neurites in the inflamed tissues of the gut correlates with the degree of inflammation and αS is chemotactic for phagocytes. However, it is not clear whether αS plays any roles in immune responses. Here, we report that αS has potent immunopromoting activity. Treatment of human monocyte derived dendritic cells (Mo-DCs) by αS resulted in upregulation of costimulatory (CD80, CD83, & CD86) and MHC (HLA-ABC & HLA-DR) molecules and production of proinflammatory cytokines such as IL-12 and TNFα. αS activated NF-κB signaling pathways in DCs and conditioned DCs to potentiate Th1 and Th17 polarization of CD4+ T cells in an allogeneic MLR. αS also induced mouse bone marrow derived (BM)-DCs and macrophages in a Th1-polarizing and M1 direction, respectively. αS activation of APCs is mediated by the TLR4-MYD88 signaling pathways. In an in vivo setting, administration of αS induced the recruitment of APCs at the site of injection. Furthermore, αS enhanced the induction of OVA-specific antibody and T cell responses when mice were immunized with a mixture of OVA and αS. Based on the ability of αS to recruit APCs to the site of administration and to promote antigen-specific immune responses, αS can be considered an alarmin capable of promoting the development of innate and adaptive immune responses. Thus, αS, in addition to acting as an inducer of neurodegenerative diseases, exerts a potent previously unappreciated proinflammatory and immunostimulating effect.
Immune responses to the microbiome tune MHC class II antigen presentation by the intestinal epithelium to control gut pathology
Authors: Koyama Motoko , Mukhopadhyay Pamela , Schuster Iona S , Henden Andrea S , Hülsdünker Jan , Varelias Antiopi , Vetizou Marie , Kuns Rachel D , Robb Renee J , Zhang Ping , Blazar Bruce R. , Thomas Ranjeny , Begun Jakob , Waddell Nicola , Trinchieri Giorgio , Zeiser Robert , Clouston Andrew D , Degli-Esposti Mariapia A , Hill Geoffrey R. 
Published: January 2023

Abstract
The factors initiating pathology in the gastrointestinal (GI) tract are largely unknown. Graft-versus-host disease (GVHD) of the gastrointestinal (GI) tract is the principal determinant of lethality following allogeneic bone marrow transplantation (BMT). MHC class II-dependent GVHD is initiated by recipient alloantigens being presented to donor T cells that in turn undergo Th1 and Th17 differentiation to mediate pathology in the GI tract. Critically, the mechanisms that initiate disease, especially the relevant antigen presenting cells, remain unclear. Here, we identify the response of IL-12-secreting macrophages to the microbiome as the key driver of IFNγ secretion by mucosal type-1 innate lymphoid cells (ILC1). The latter controls MHC class II expression and antigen presentation by intestinal epithelial cells (IEC) specifically within the ileum. When these tightly regulated responses between microbiome and lamina propria lymphocytes are perturbed by inflammatory signals driven by pre-transplant conditioning, dramatic increases in antigen presentation by IEC occur in the ileum and lethal GVHD ensues. Conditional and Villin-specific deletion of MHC class II in IEC, or inhibition of IL-12 pre-transplant, completely prevent the initiation of lethal GVHD, identifying a readily translatable therapeutic strategy.
Kinase domain deleted engineered HER2 could elicit efficient tumor immune response
Authors: Jeon Insu , Koh Choong-Hyun , Kang Tae-Seung , Lee Jeong-Mi , Kang Yejin , Im Jiyoung , Shin Kwang-Soo , Song Boyeong , Kang Chang-Yuil 
Published: January 2023

Abstract
In tumor immunotherapeutic vaccines, it is important to select tumor-associated antigen because of immunogenicity and oncogenic properties of tumor antigens. Many vaccination platforms were developed to enhance immunogenicity of antigens. In addition, many strategies are using tumor antigens in artificially mutated or truncated forms to eliminate oncogenic function of antigens. On the other hand, as the T cell immune responses depend on the recognition of epitopes that are loaded on the MHC class I molecules, it is important to maintain the original size as much as possible. In this study, we engineered HER2 antigens with four different forms, K684, K965, K1001, and K1117 and tested immunogenicity in B cell and monocyte based vaccine models. In murine models, we observed antigen specific T cell response in the antigen size dependent manner and antigen specific antibody response in the antigen expression dependent manner. We also tested tumor therapeutic models with full-length HER2 expressing CT26. All of four antigens showed tumor suppression in full-length HER2 expressing CT26 tumor models and K1117 showed highest therapeutic effect. In addition, the K1117 showed significant therapeutic effect in HER2 intracellular domain expressing CT26 tumor models compared to the K684. Moreover, in human PBMC studies, the K1117 showed better CD4 and CD8 T cell responses than the others did. These data suggested that antigens containing wide epitope repertoire could show better therapeutic effect.