bluuebunny/crossref_metadata_2025_split huggingface dataset:
Migratory properties of skin-resident γδ T cell populations (49.20)
Authors: Jiang Xiaodong , Yoo Min Jae , Kupper Thomas 
Published: January 2023

Abstract
γδ T cells preferentially reside in epithelial tissues like skin. Dendritic epidermal T cells (DETC) in epidermis have been studied extensively. Recently, a novel IL-17-producing γδ T cell population in dermis was identified and demonstrated to have pivotal role in skin inflammation. Nevertheless, their migration patterns are largely undefined. In this study, we found that almost 30% γδ T cells in dermis, lymph nodes (LNs) and spleen are Vγ2+. This proportional distribution led us to hypothesize that γδ T cells may re-circulate between dermis and secondary lymphoid tissues. To test this hypothesis, we created GFP+:GFP- parabiotic mice, and demonstrated that dermal γδ T cells are constantly circulating, whereas DETC are stationary and non-recirculating. We next focused on skin homing of dermal γδ T cells and found that these γδ T cells were not diminished in lymphotoxin α-/- mice (lacking LNs), suggesting that dermal γδ T cells can be stably maintained after seeding from perinatal thymus. Further study revealed that dermal γδ T cells express high levels of CD69, CD103, and E- and P-selectin ligands, all of which are required for mature T cell migration to skin. However, in E- and P-selectin ligand-deficient (Fuc T IV/VII-/-) mice, dermal γδ T cells are paradoxically increased, while DETC are remarkably diminished. Taken together, these findings may help better define the role of γδ T cells in peripheral epithelial tissues.
The recognition and internalization of apoptotic cells and Gram negative bacteria share the BAI1-ELMO1 pathway in the gastrointestinal tract (49.4)
Authors: Ernst Peter , Sarkar Arup , Owen Katherine , Ravichandran Kodi , Casanova James , Das Soumita 
Published: January 2023

Abstract
Clearance of apoptotic cells, debris and pathogens by phagocytes is essential role for the homeostasis of host responses. It has been shown previously that the BAI1-ELMO1-Dock180 pathway stimulates Rac1 activity which has a pivotal role in enabling phagocytosis. ELMO1 was first identified as a protein required for the phagocytosis of apoptotic cells bound by BAI1. Recently we found that BAI1 recognizes LPS on Gram-negative bacteria and helps in bacterial attachment. The objective of these studies was to determine if the BAI1-ELMO1 pathway contributes to the internalization of targets relevant to the digestive tract. Both BAI1 and ELMO1 were expressed by macrophages in the murine small intestine. Inhibition of BAI1 function by siRNA decreased the binding of cellular and microbial targets to macrophages from culture or freshly isolated from the gut. Inhibition of ELMO1 reduced internalization of both apoptotic epithelial cells and Salmonella in association with decreased Rac1 activity. This loss of ELMO1 function had no effect on binding suggesting these events are downstream of the surface interaction mediated by BAI1. Interestingly, inhibition of ELMO1/Rac function impaired the pro-inflammatory response to infection. These results suggest a novel role for the BAI1-ELMO1 pathway in Rac1 activation and the scavenging of apoptotic cells and bacteria by macrophages in the digestive tract.
Colitis-associated glycome for local memory CD4+ T cell expansion (49.5)
Authors: Nishida Atsushi , Lau Cindy , Kobayashi Taku , Hisamatsu Tadakazu , Hibi Toshifumi , Mizoguchi Emiko , Fukuda Minoru , Andoh Akira , Blumberg Richard , Mizoguchi Atsushi 
Published: January 2023

Abstract
Immune responses are modified by a diverse and abundant repertoire of carbohydrate structures on cell surface, which is known as the “glycome”. We herein report a colitis-associated glycome&lt;CAG&gt;that is created on the colonic, but not systemic, memory CD4+T cells under intestinal inflammatory conditions. Through gene screening approaches, we found that CAG represents an immature core-1 O-glycan that is created through the decreased expression of an enzyme, core-2 β1,6-N-acetylglucosaminyltransferase&lt;C2GnT&gt;1 that is responsible for the production of core-2 O-glycan branch through an addition of GlcNAc to a core-1 O-glycan. Indeed, restoration of C2GnT1 expressions using T-cell-specific C2GnT transgenic mice abolished the inflammation-induced development of CAG on colonic CD4+T cells. Functionally, the CAG promoted the proliferation of memory CD4+T cells, resulting in the exacerbation of colitis. Mechanistically, CAG induced the “super rafts” formation on memory CD4+T cells, which provide a place for initiating the signaling machinery for T cell activation. Indeed, the CAG contributed for sustaining the activation of protein kinase C θ, a key signaling molecule for T cell activation. These findings suggest that a specific glycome, which is created on memory CD4+T cells under intestinal inflammatory conditions, leads to further exacerbation of diseases by promoting memory T cell expansion.
Re-utilization of germinal centers in multiple PP results in highly synchronized, oligoclonal and affinity matured gut IgA responses (49.6)
Authors: Lycke Nils , Bergqvist Peter , Stensson Anneli , Mehr Ramit , Bemark Mats 
Published: January 2023

Abstract
Whereas recent studies have pointed to multi-centered and diverse gut IgA responses to the microbiota, little information is available on IgA responses following oral immunization with T cell-dependent antigens. Here we have addressed how gut IgA responses develop using a novel approach where NP-hapten was conjugated to cholera toxin (CT), which allowed us to follow, at the molecular level, the site of initiation, expansion, differentiation and distribution of a specific IgA B cell response. Clonal relationships and affinity maturation of specific IgA cells at gut inductive and effector sites were investigated. Unexpectedly, we found gut IgA B cell responses to be oligoclonal and dominated by high affinity maturation. Extensive lineage trees of gut NP-specific IgA cells were generated, revealing strong clonal relationships throughout the entire gut mucosal immune system. Thus, clonally related IgA cells were found in Peyer’s patches, mesenteric lymph nodes and the small and large intestine, suggesting an effective expansion and selection process. This was achieved through synchronization of multiple PP hosting the same high affinity B cell clones. Adoptive transfer experiments showed that this was possible through re-utilization of already existing germinal centers (GC) in multiple PP by previously activated GC GL7+ B cells. The re-utilization required that oral antigen was given prior to cell transfer.
Reversal of normal ovarian function in experimental autoimmune ovarian failure mouse model post-dexamethasone treatment (51.10)
Authors: Mande Purvi , Khole Vrinda 
Published: January 2023

Abstract
Glucocorticoids (GCs) are in widespread clinical use for treatment of autoimmune diseases including Premature Ovarian Failure and In Vitro fertilization-Embryo Transfer failures. Immunosuppression by GCs in these patients inhibits potential adverse effects of Anti-Ovarian Antibodies (AOAs) on oocyte quality, gamete interaction, implantation and embryo development. The present study highlights the restoration of normal follicular development and fertility in experimental autoimmune ovarian failure mouse model after dexamethasone treatment, thus establishing the significance of corticosteroids in human autoimmune ovarian failures. However, their mode of action in these cases remains unknown. Female mice were immunized with immunodominant epitopes of three dominant human ovarian autoantigens and monitored for various ovarian parameters. Immunized female mice showed high AOA titers and specific reactivity to different ovarian cell types. Adverse effects on cyclicity, pregnancy, pre-implantation embryos and fertility were noticed. Ovaries from these mice exhibited fewer healthy corpora lutea (CL) and growing follicles and increased atretic follicles. However, the number of healthy follicles, CL, pre-implantation embryos and fertility was restored to normal in dexamethasone treated mice in a dose dependent manner, thereby establishing that the three putative autoimmune ovarian antigens can be used for developing targeted therapies in human autoimmune ovarian pathologies.
Vitamin D mediated inhibition of Helicobacter species protects mice from colitis (51.7)
Authors: Ooi Jot Hui , Cantorna Margherita 
Published: January 2023

Abstract
Vitamin D regulates experimental inflammatory bowel disease (IBD). Mice that are deficient in the ability to convert vitamin D to the active form (Cyp27B1KO) were highly susceptible to dextran sodium sulphate (DSS)-induced colitis. Depletion of gut bacterial flora using broad-spectrum antibiotics protected Cyp27B1KO mice from DSS-induced colitis, suggesting that the susceptibility of Cyp27B1KO mice to DSS-induced colitis was due to the alterations in gut bacterial flora. 454 pyrosequencing showed that Cyp27B1KO mice had increased numbers of Proteobacteria and Actinobacteria and decreased numbers of Lachnospiraceae. In particular, the Helicobacteraceae family members from the Proteobacteria phylum were significantly elevated in Cyp27B1KO mice. Treating Cyp27B1KO mice with the active form of vitamin D (1,25(OH)2D3) reversed the phenotype of the Cyp27B1KO mice, reduced Helicobacteraceae expression and protected mice from DSS-induced colitis. Full vitamin D-deficiency in WT mice also resulted in increased Helicobacteraceae expression and more severe DSS-induced colitis compared to vitamin D-sufficient WT mice. The presence of elevated Helicobacteraceae results in the increased susceptibility to DSS colitis in vitamin D- or 1,25(OH)2D3-deficient mice. The data show that vitamin D through 1,25(OH)2D3 plays a role in regulating the composition of the intestinal microflora to suppress Helicobacter species and symptoms of experimental IBD.
Fyn kinase is required for B cell IL-4Ralpha-mediated activation of Stat3, Stat5 and Stat6, germinal center formation and antibody production (52.10)
Authors: Falanga Yves , Natalia Chaimowitch , Conrad Daniel , Ryan John 
Published: January 2023

Abstract
The generation of antigen-specific antibodies and the development of immunological memory require collaboration between B and T cells. T cell-secreted IL-4 is important for B cell survival, isotype switching, affinity maturation and the development of germinal centers (GC). Fyn-deficient (KO) T cells have reduced IL-4 production after α-CD3/α-CD28 stimulation. Here we demonstrate that Fyn-deficient mice fail to develop robust humoral immunity following a T-dependent antigen immunization. In fact, Fyn KO mice display low Ag-specific IgG1, IgG2a but not IgM, correlating with low numbers of Follicular Helper T cells (TFH) and spleen plasma cells. More importantly, we demonstrate that Fyn kinase is required for IL-4-induced Stat3, Stat5 and Stat6 phosphorylation, describing a previously unreported role for Fyn in B cell IL-4R signaling. Taken together, our data demonstrate that Fyn kinase plays a critical role in the development of humoral immunity, affecting both B cells and T cells.
Innate memory of human Vγ2Vδ2 T cells: Distinct proliferative, migratory and tumorcidal capabilities of γδ memory subsets (52.17)
Authors: Morita Craig , Ness-Schwickerath Kristin , Nam Ki-Hoan , Siddiqui Akbar , Leon Annette , Brandes Marlene , Moser Bernhard , Oldfield Eric , Wang Hong , Puan Kia-Joo , Jin Chenggang 
Published: January 2023

Abstract
Human Vγ2Vδ2 T cells are unconventional T cells that monitor isoprenoid metabolism by using their antigen receptors to recognize foreign and self prenyl pyrophosphates. Although important for immunity to infections and for tumor immunotherapy, little is known about the development of γδ memory. Elucidation of γδ differentiation pathways will help to develop ways to boost their immunity. Here we report that there are many unique features compared with αβ T cells. Unlike αβ T cells, at birth half of Vγ2Vδ2 cells have memory phenotypes and ~25-40% express inflammatory chemokine receptors. In adults, 98.4% of Vγ2Vδ2 T cells are memory cells that can be separated into CD28+CD27+ TEarly (central); CD28+CD27- TEarly 27-; CD28-CD27+ TIntermediate (effector); and CD28-CD27- CD45RA+ TLate RA (effector) subsets. The memory subsets display distinct functional properties with differential expression of effector molecules, NK receptors, and chemokine receptors. Intermediate and late effector memory cells express higher levels of cytotoxic effector molecules, innate CXCR1, CXCR2, and CX3CR1 chemokine receptors, KIR, CD16, CD56, and CD57 NK receptors, and lower levels of the β7 integrin, and proliferate poorly compared with early memory cells that express CXCR6, CCR1, and CCR2. Thus, different inflammatory chemokines attract each Vγ2Vδ2 memory subset. The rapid conversion of Vγ2Vδ2 cells from naive to memory allows them to mount memory responses to primary bacterial and protozoan infections.
TLR activated-dendritic cells (*) enhance the response of aged naïve CD4 T cells in vivo (52.5)
Authors: Brahmakshatriya Vinayak , Jones Stephen , Rymeski Barbara , Brauner Matthew , Swain Susan 
Published: January 2023

Abstract
Declines in T cell immune function occur as we age and poor responses of naïve T cells contribute to making the elderly population resistant to immunization with new vaccines and vulnerable to rapidly evolving infectious viral diseases such as influenza. In the young, triggering “danger pathways” such as Toll like receptors (TLR) is an effective adjuvant strategy. We found that cognate antigen presentation by bone marrow-derived and splenic DC, directly activated by TLR ligands (DC*), enhanced expansion and IL-2 production of aged naïve CD4 T cells in vitro, due to small increases in proliferation and better survival of responding cells during effector generation. IL-6, produced by the DC*, was key for these effects. Since only the Ag-specific T cells are targeted, this has therapeutic potential as an adjuvant approach that avoids undesirable bystander effects. Here we are investigating if this approach can work in vivo. We find that DC*, used as APC, can enhance the expansion of both aged and young naïve CD4 T cells in vivo, causing increased proliferation and survival and that IL-6 production by DC* plays an important role in TLR-mediated enhanced responses including enhancing the ability of the CD4 T cells to make IL-2, IFNγ and IL-17. This suggests it should be possible to selectively enhance an Ag-specific response of naïve CD4 T cells in vivo in the elderly, while avoiding systemic exposure to an adjuvant.
Substrate rigidity regulates human T cell activation and proliferation (52.9)
Authors: O'Connor Roddy , Hao Xueli , Shen Keyue , Bashour Keenan , Kam Lance , Milone Michael 
Published: January 2023

Abstract
Adoptive immunotherapy using cultured T cells holds promise for the treatment of cancer and infectious disease. Culture platforms based upon hard materials, such as polystyrene plastic, form the basis of many culture systems. The mechanical properties of a culture substrate can influence cellular adhesion, proliferation, and differentiation. We explored the impact of substrate stiffness on ex vivo T cell activation and polyclonal expansion using substrates with variable rigidity manufactured from poly(dimethylsiloxane) (PDMS), a biocompatible silicone elastomer. We show that the IL-2 production and ex vivo proliferation of human CD4+ and CD8+ T cells are increased an average of 4-fold following stimulation on softer (Young’s Modulus [E] &lt; 100 kPa) compared with stiffer (E &gt;2 MPa) substrates. Mixed peripheral blood T cells cultured on the stiffer substrates also demonstrate a trend towards a greater proportion of CD62Lneg, effector-differentiated CD4+ and CD8+ T cells. Culture of naïve CD4+ T cells on softer substrates yields an average 3-fold greater proportion of IFN-γ producing TH1-like cells. These findings reveal that the rigidity of the substrate used to immobilize T cell stimulatory ligands is an important and previously unrecognized parameter for T cell culture systems used for adoptive immunotherapy. These results also have implications for studies of T cell activation and signal transduction that use immobilized TCR/CD3 and CD28 ligands.
RTA-specific monoclonal antibodies neutralize ricin toxin intracellularly (53.13)
Authors: O'Hara Joanne , Klokk Tove Irene , Sandvig Kirsten , Mantis Nicholas 
Published: January 2023

Abstract
According to the current paradigm, antibodies neutralize protein toxins by either preventing toxin binding to cell surfaces or promoting toxin clearance via Fc-receptor mediated uptake. In the case of the biothreat agent ricin, although this toxin uses its B-subunit (RTB) to gain cell entry the majority of antibodies are produced against its enzymatic A-subunit (RTA). We have previously demonstrated using a collection of monoclonal antibodies (mAbs) against RTA that neutralizing activity and protection in a mouse model is associated with epitope specificity, and not mAb affinity or Ig subclass. We now put forth evidence to indicate that at least two RTA-specific mAbs, R70 and IB2, neutralize ricin intracellulary. Neither R70 nor IB2 prevented ricin binding to cell surfaces, as measured by flow cytometry. Moreover, R70 (and likely IB2) retained toxin neutralizing activity in a Vero cell assay when added after ricin had attached to cell surfaces. Using in vitro assays, we also found that R70 and IB2 affected the ability of protein disulfide isomerase to reduce the single disulphide bond linking RTA to RTB and interfered with RTA’s capacity to arrest protein synthesis. We are currently using a combination of techniques to define more precisely the mechanism by which these and other RTA-specific mAbs neutralize ricin.
A lipidomics analysis of influenza infection and PPARγ activation (53.17)
Authors: Monroe Jacob , Bassaganya-Riera Josep , Ray Keith , Helm Richard , Lu Pinyi , Kronsteiner-Dobramysl Barbara , Hontecillas Raquel 
Published: January 2023

Abstract
While vaccines are a reliable preventative of influenza infection, useful therapeutics for treatment of the disease would be key to minimizing the impact of a major pandemic. In this study we have focused on the use of the anti-inflammatory compounds Abscisic Acid (ABA) and 61610 in the presence of PPARγ to reduce lung inflammation and damage. The mechanisms by which these therapeutics activate PPARγ have not yet been identified, but a promising avenue is through the modification of known lipid mediators produced during Arachidonic Acid metabolism. In this study, we present a lipidomics analysis of influenza infected C57BL6 Wild Type mice treated with ABA and 61610. Our data demonstrate a rise in lipid mediator levels due to infection as well as in the presence of ABA, and to a lesser extent, 61610. Quantitative Real-Time PCR was performed in order to link the expression of lipid metabolic regulators to observed changes in lipid levels. In addition to this, molecular docking studies of PPARγ were performed to compare predicted binding affinities of previously identified ligands to other eicosanoids. The results of the simulations rank many previously identified PPARγ ligands below other metabolites, indicating that studies analyzing for the presence of previously unexplored eicosanoids may be fruitful in identifying new lipid mediators involved in anti-inflammatory pathways.
Bi-specific TCR anti-CD3 fusions for cancer immunotherapy (53.19)
Authors: Jakobsen Bent , Ashfield Rebecca , Bossi Giovanna , Adams Katherine , Harper Jane , Williams Daniel , McGrath Yvonne , Hassan Namir 
Published: January 2023

Abstract
Although cancer patients frequently mount antigen specific T cell responses, the low affinity of T cell Receptors (TCRs) to self-antigens coupled with low levels of HLA-peptide on cancer cells contribute to the failure of the immune system to clear tumours. Peptide epitopes presented by Class I HLA represent the largest class of tumor associated antigens and are ideal targets for cancer immunotherapy, providing that the issues of low TCR affinity and immune-suppression in the tumor microenvironment can be overcome. The most attractive targets for minimising toxicity are expressed on a restricted number of normal tissue cells, for example cancer testis antigens. We have engineered ImmTAC reagents comprising soluble, high affinity TCRs fused to an anti-CD3 scFv domain that redirects a potent, polyclonal T cell response to kill tumour cells expressing as few as 10-20 epitopes. IMCgp100 targets the HLA-A2 presented epitope gp100 280-288 and kills malignant melanoma cells with pico-Molar potency, leaving other HLA-A2 positive cells untouched. This agent is undergoing clinical testing in a Phase I dose-escalation trial and is well tolerated. A second ImmTAC, IMCmage1, targets MAGE-A3 168-176 in the context of HLA-A1. It specifically kills the myeloma population within CD138+ cells extracted from the marrow of a stage III multiple myeloma patient and can re-direct T cells extracted from the tumor microenvironment. IMCmage1 will enter the clinic in 2012.
Monoclonal antibodies against the ricin toxin B subunit: Evidence for extracellular and intracellular mechanisms of toxin neutralization. (53.2)
Authors: Yermakova Anastasiya , Mantis Nicholas 
Published: January 2023

Abstract
Antibodies are remarkable in their capacity to inactivate even the most potent protein toxins, including anthrax, botulinum, diphtheria, and ricin. However, the underlying mechanisms by which this occurs are poorly understood. In this study, we have produced and characterized a collection of monoclonal antibodies (mAbs) directed against the B subunit (RTB) of ricin toxin. RTB plays two roles in ricin cytotoxicity; it promotes toxin attachment to host cell surfaces, and it mediates the intracellular trafficking of the toxin from the plasma membrane to the endoplasmic reticulum (ER). We screened ~2,000 RTB-specific murine B cell hybridomas, and identified 4 mAbs with toxin neutralizing activity. Two of these mAbs, SylH3 and 24B11, passively protected mice against a 5xLD50 dose of ricin, but only partially prevented ricin binding to cell surfaces, indicating that they must neutralize ricin by a mechanism other than simply interfering with receptor attachment. Using a modified Vero cell cytotoxicity assay we found that both SylH3 and 24B11 were able to completely neutralize ricin in vitro even after the toxin had bound to cell surfaces. These data reveal that SylH3 and 24B11 neutralize ricin downstream of attachment, perhaps by interfering with the ability of the toxin to traffic to the ER. We are currently using biochemical and microscopic techniques to localize where in the cell these mAbs interfere with ricin toxicity.