bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the role of plasma membrane order and disorder in antigen-specific responses by CD4+ T lymphocytes
Authors: Bamezai Anil K , Karsalia Ritesh , Sengupta Soumini 
Published: January 2023

Abstract
Model membranes composed of unsaturated and saturated phospholipids segregate into the ordered (Io) and disordered (Id) phases. The addition of cholesterol to the model membranes promotes the formation of ordered phase. The existence of ordered and disordered phases in cellular membranes remains a topic of discussion. However, it is posited that cellular membranes show assemblies of small dynamic nanometer sized ordered phases, which are enriched in cholesterol and saturated phospholipids. Early “T cell activation” events are initiated in and around the lipid microenvironment of the plasma membrane that has co-existing Io and Id-like phases. We have examined the role of membrane order/disorder in antigen-specific CD4+ T cell activation and clonal expansion by first creating membrane disorder by inserting 7-ketocholesterol, an oxysterol, into the membrane, and then reconstituting membrane order of the disordered plasma membrane by inserting cholesterol into it. Membrane anisotropy in T cells was assessed by flow cytometry after labeling with Di-4-ANEPPDHQ, a fluorescent probe, and antigen-specific clonal expansion was examined by MTT assays. Significant revival of antigen-specific CD4+ T cell proliferative response was observed after reconstituting the disrupted membrane order with cholesterol. These findings demonstrate that cholesterol-dependent membrane order (Io) is critical for responses generated by CD4+ T cells and point to the importance of membrane order and the lipid microenvironment in signaling processes through the antigen receptor. We are currently examining the mechanisms underlying the inhibitory responses promoted by the disordered membrane lipid microenvironment.
Pathogenic role of CD4+ T cells in the progression of neurotropic mouse hepatitis virus induced neuroinflammation
Authors: Chakravarty Debanjana , Saadi Fareeha , Kundu Soumya , Bose Abhishek , Khan Reas , Dine Kimberly , Kenyon Lawrence C , Shindler Kenneth S , Sarma Jayasri Das 
Published: January 2023

Abstract
Neurotropic Mouse hepatitis virus (MHV) induced demyelination serves as a model to understand the mechanisms of demyelination and concomitant axonal loss in CNS, which mimics the pathological symptoms of the human neurological disease Multiple Sclerosis (MS). Inflammation triggered by MHV consists of mixed population of inflammatory cells, predominantly microglia/macrophages, which differs from autoimmune model of MS, where infiltrating T cells are the major contributors to the pathology. Though the acute phase of MHV inflammation is controlled by microglia/microglia, the role of T and B cells in viral induced axonal degeneration and demyelination is controversial. In order to explore the role of CD4+ T cells during transition from an early protective innate response to a highly regulated adaptive response following MHV infection, MHV-infected CD4−/− mice were compared with MHV-infected CD4+/+ (wildtype) mice at days 5/6, 10, 15 and 30 post infection. Viral titre estimation and nucleocapsid gene amplification confirm enhanced replication of the virions in the absence of functional CD4 + T cells in brain tissue. Viral anti-nucleocapsid antigen staining further shows the persistence of virus at day 30 p.i. in CD4−/− mice unlike CD4+/+ mice. Moreover, histopathological analysis of liver, brain and spinal cord showed an elevated susceptibility of CD4−/− mice to encephalitis and axonal degeneration with augmented progression of acute poliomyelitis, bulbar vacuolation, and dorsal root ganglionic inflammation rarely observed in CD4+/+ infected mice. In summary, current study suggests that CD4 T cell is critical for viral clearance, resolving microglial activation, and controlling chronic progressive axonal degeneration.
Macrophage subsets determine sex differences between male and female immune responses to Francisella tularensis
Authors: Sanchez Michelle A , Martinez Danielle , Spencer Charles 
Published: January 2023

Abstract
Francisella tularensisis the causative agent of the human disease tularemia. F. tularensisinfects a variety of cells, including macrophages, in order to cause pathogenicity. As few as 10 inhaled microorganisms cause a lethal infection by over-activating the host’s own inflammatory response. Differences in the intensity of the inflammatory response exist between the sexes which leads to differences in sensitivity to autoimmune and infectious disease. Males tend to be more susceptible to infectious diseases whereas females tend to be more susceptible to autoimmune diseases. However, our preliminary data unexpectedly demonstrated that female mice were more susceptible to F. tularensis-mediated disease than male mice. We hypothesize that the elevated inflammatory state of females may make them more susceptible to F. tularensis disease and that the M1 and M2 macrophage subsets may determine this differential inflammatory response. Naïve M1 and M2 macrophages will be purified from male and female mice and infected in vitro to directly compare cellular responses between male and female mice. In parallel, M0 macrophages will be differentiated in vitro prior to infection for similar comparison.
Immunomodulatory capability of VCG in Chlamydia immunity
Authors: Eko Francis , Pais Roshan , Richardson Shakyra , Omosun Yusuf Omosun , Black Carolyn M , Igietseme Joseph 
Published: January 2023

Abstract
Immunization with UV-inactivated Chlamydia trachomatis elementary bodies (UV-EB), the infectious form of Chlamydia, does not protect against infection with live Chlamydia. Vibrio cholerae ghosts (VCG), which are empty V. cholerae cell envelopes derived by genetic inactivation, constitute an effective delivery vehicle for cloned vaccine antigens and promotes the induction of protective immunity in the absence of added adjuvants. In this study, we sought to investigate the ability of VCG to enhance the innate and adaptive immune responsesinduced by UV-EB. Thus, bone marrow-derived dendritic cells (BMDC) were pulsed with UV-EB in the presence or absence of VCG and the induction of innate immune responses, T cell proliferation and ability to afford protection against Chlamydia following adoptive transfer into susceptible mice was evaluated. The results show that VCG efficiently modulated the immunostimulatory properties of DCs as indicated by increased secretion of proinflammatory cytokines and expression of toll-like receptors and co-stimulatory molecules associated with DC maturation. Also, UV-EB-pulsed DCs that were exposed to VCG and adoptively transferred into mice resulted in effective chlamydial antigen presentation and protective immunity. The results demonstrate that VCG activate the maturation of DCs leading to enhancement of innate and adaptive immunity to an otherwise non-protective antigen, suggesting their utility as adjuvants for enhancement of protective immunity to inactivated vaccine antigens.
Analysis of mGBPs in host defense against the obligate parasite Toxoplasma gondii
Authors: Steffens Nora , Legewie Larissa , Beuter-Gunia Cornelia , Hanisch Philipp , Weidtkamp-Peters Stefanie , Hänsch Sebastian , Degrandi Daniel , Pfeffer Klaus 
Published: January 2023

Abstract
Toxoplasma gondii (T. gondii) is an obligate, intracellular parasite. During invasion of target cells, T.gondii creates a parasitophorous vacuole (PV). Members of the mGBP (murine guanylate binding protein) family assemble at the cytoplasmatic side of the PV and interact with membrane compartments via yet uncharacterized mechanisms. This analysis aims at unravelling the molecular mechanisms by which mGBPs impair the vital functions of T.gondii. Therefore stable cell lines expressing fluorescent mGBPs were generated and infected with GFP- or mCherry-expressing T.gondii to analyze the dynamics of mGBPs via Confocal Live Cell Imaging. Additionally, super-resolution microscopy technologies were used to analyze the doubly transduced cell lines during infections in detail. Giant unilamellar vesicles were used to investigate the binding capacity of mGBP2 and mGBP7 to lipids and their modulation capacities on membrane integrity. Furthermore, cytosolic compartments of mGBPs and the T.gondii PV are in progress to be characterized by electron microscopy. The different mGBP7-domains will be analyzed to determine the responsible domain for membrane binding. The first results suggest that mGBP7 colocalizes with mGBP3 in vesicle like structures, but only partially with mGBP6 and not with mGBP2. However, mGBP2 influences mGBP7 recruitment to the PV. Additionally, mGBP7, mGBP3, mGBP6 and mGBP2 are able to accumulate at the plasma membrane of T.gondii inside the PV. With unique properties for membrane binding, mGBP2 and mGBP7 interact with specific lipids whereby modulating membrane integrity. Elucidation of the functions of mGBPs will help to counteract toxoplasmosis and to possibly find new treatment opportunities in the long term.
Differential effects of glycerophospholipids versus glycosphingolipids on dendritic cell subsets
Authors: Singh Ram Raj , Halder Ramesh 
Published: January 2023

Abstract
Self-glycerophospholipids, such as phosphatidic acid (PA), bind CD1d, and activate phospholipid-reactive T cells (PLT) (Eur J Immunol 2018). Glycosphingolipids, such as α-GalCer (αGC), activate iNKT cells and exhibit many immune effects, including dendritic cell (DC) maturation. Here, we investigated the effect of glycerophospholipids on DC. Immunization with PA led to a rapid and persistent increase in the proportions and total numbers of plasmacytoid DC (pDC, CD11c+PDCA1+B220+ cells). In contrast, pDCs were initially reduced after αGC injection, but the total numbers recovered later. PA also caused an increase, albeit delayed as compared to increase in pDC, in myeloid DC (mDC)/non-pDC (CD11c+PDCA1− cells). mDC were increased at later timepoints with αGC. Further, PA increased expression of MHCII, CD86 and CD40 on pDC, but only a minimal increase in these on mDC. In contrast, αGC caused a minimal increase in these on pDC, but increased CD80 and CD86 expression on mDC. Finally, only pDC, but not mDC, produced IFNα after αGC or PA. Intriguingly, αGC that caused a less profound pDC maturation than PA induced more IFNα by pDC than PA. αGC, but not PA, also increased TNFα production by pDC. Overall, the two lipid Ag elicited different, complex effects on DC subsets: PA led to rapid expansion and maturation of pDC but did not increase their production of pro-inflammatory cytokines. In contrast, αGC that had little effects on pDC maturation and expansion increased IFNα and TNFα production by pDC. mDC were increased with both PA and αGC, but their costimulatory molecules’ expression increased more with αGC than with PA. Such differential effects of different lipids on DC subsets may have important immune and pathogenetic implications.
CD4+ T cells regulate Mouse Hepatitis Virus induced activation of microglia
Authors: Saadi Fareeha , Chakravarty Debanjana , Sarma Jayasri Das 
Published: January 2023

Abstract
Multiple Sclerosis (MS) is a human neurological disease characterised by neuroinflammatory demyelination and axonal loss. Studies in MS are focussed to understand the process of demyelination driven by B/T lymphocytes, but we have limited knowledge about direct virus-induced neural cell dystrophy and the role of innate immunity in MS. Our studies employ Mouse Hepatitis Virus (MHV) induced neuroinflammatory model to understand microglia-mediated myelin stripping as a mechanism of demyelination. Microglia are the CNS resident macrophages that lie at the intersection of immune response and neurodegenerative process. They control the initiation, progression and resolution of neuroinflammation in the CNS. One of our studies in MHV model demonstrated that in the absence of CD4+ T cells, mice are more susceptible to acute encephalitis and chronic demyelination. In order to understand the mechanism of anti-viral immune response, we have investigated the role of microglia upon CD4+ T cell modulation. Results from our studies showed that a higher number of Iba1+ microglial cells persist in the brain parenchyma of CD4−/− mice at the chronic infection stage in comparison to the WT mice. Real-time qPCR screening of inflammatory markers like IL6, IL10, IL12, CXCL10, CCL5, CD86 and CD163 presented a consistent proinflammatory microenvironment in the CNS and comparative lower expression of Btk1 and Arg1 in the brains of CD4−/− mice. In conclusion, our findings propose that further in vitro and in vivo studies are necessary to understand the role of CD4+ T cell activation and maturation which might help in favouring a shift towards adaptive immunity, differential microglial activation, viral clearance and maintaining neural homeostasis.
STAT2 is a determinant of yellow fever virus host tropism
Authors: Morrison Juliet , Miorin Lisa , Laurent-Rolle Maudry , Pisanelli Giuseppe , Co Pierre , Albrecht Randy , García-Sastre Adolfo 
Published: January 2023

Abstract
The recent yellow fever virus (YFV) epidemic in Brazil in 2017 and Zika virus (ZIKV) epidemic in 2015 serve to remind us of the importance of flaviviruses as emerging human pathogens. With the current global flavivirus threat, there is an urgent need for antivirals and vaccines to curb the spread of these viruses. However, the lack of suitable small animal models limits the research questions that can be answered. A common trait of all flaviviruses studied thus far is their ability to antagonize interferon (IFN) signaling so as to establish infection and subsequent dissemination. Previously, we reported that YFV NS5 requires the presence of type I IFN (IFNα/β) for its engagement with human Signal Transducer and Activator of Transcription 2 (hSTAT2). We now report that like the NS5 proteins of ZIKV and dengue virus (DENV), YFV NS5 protein is able to bind hSTAT2 but not murine STAT2 (mSTAT2). Contrary to what has been demonstrated with ZIKV NS5 and DENV NS5, replacing mSTAT2 with hSTAT2 cannot rescue the YFV NS5-STAT2 interaction, as YFV NS5 is also unable to interact with hSTAT2 in murine cells. We show that the IFNα/β-dependent ubiquitination of YFV NS5 that is required for STAT2 binding in human cells is absent in murine cells. In addition, we demonstrate that mSTAT2 restricts YFV replication in vivo. These data serve as further impetus for the development of an immunocompetent mouse model that can serve as a disease model for multiple flaviviruses.
The role of Blimp-1 in adipose Treg differentiation and effector function
Authors: Beppu Lisa , Frias Adolfo , Hyzny Eric , Poholek Amanda , D’Cruz Louise 
Published: January 2023

Abstract
Visceral adipose tissue regulatory T cells (VAT Tregs) protect against systemic inflammation and metabolic disease by limiting expansion of pro-inflammatory Th1 cells and M1 macrophages, and by preserving insulin sensitivity and glucose tolerance. Although their basic markers and roles have been studied, less is known about the transcriptional machinery regulating their differentiation and function. B lymphocyte-induced maturation protein-1 (BLIMP-1) is a transcriptional regulator known to be involved in the development, polarization, and maintenance of various immune cells including CD4+ T cells. Using BLIMP-1 reporter mice, we have discovered that BLIMP-1 is constitutively expressed in a subset of VAT Tregs compared to lymphoid Tregs, and that BLIMP-1+ VAT Tregs are phenotypically distinct from their BLIMP-1-counterparts. Blimp-1 is not required for VAT Treg development, however Treg-specific deletion of BLIMP-1 led to unique changes in VAT Treg markers in lean versus obese adipose tissue. Based on these preliminary data, our project aims to elucidate the role of BLIMP-1 in shaping the VAT Treg compartment and to explore a possible role for BLIMP-1+ VAT Tregs in metabolic co-morbidities such as obesity and Type II diabetes.
Immunodominant and cryptic tumor neoantigen-specific immune responses activated by an armed oncolytic virus expressing a PD-L1 inhibitor
Authors: Wang Guan 
Published: January 2023

Abstract
Tumor neoantigens are exclusively expressed in malignant cells representing an ideal target for tumor immunotherapy. Oncolytic virus selectively infects and lyses tumor cells releasing a full-array tumor antigens and danger factors. Combined with PD1 checkpoint blockade, oncolytic virus triggered tumor neoantigen-specific T cell immune responses through local treatments. The present study developed a novel therapeutic regimen that combines ddVV, GM-CSF, and a PD-L1 inhibitor into a single therapeutic agent by engineering ddVV to co-express GM-CSF and a PD-L1 inhibitor. The novel therapeutic regimen has triple functions: ddVV-mediated oncolysis, GM-CSF-mediated enhancement of dendritic cell recruitment and function, and PD-L1 inhibitor-mediated interruption of PD-1/PD-L1 interaction. As a result, the double-armed oncolytic virus eradicated primary tumor and prevented tumor recurrence more efficiently after local administration. Analyses of underlying mechanisms revealed that the double-armed ddVV possessed a superior capability of improving tumor environment and triggering systemic T cell immune responses against not only dominant but also cryptic tumor neo-antigens in tumor mouse models.
Influenza vaccination administered in the tumor induces an inflamed tumor microenvironment and reduces tumor growth
Authors: Newman Jenna H , Chesson Brent , Herzog Nora , Bommareddy Praveen , Aspromonte Salvatore , Pepe Russell , Estupinian Ricardo , Aboelatta Mones , Buddhadev Stuti , Schenkel Jason , Thomas Paul , Rudra Jai , Silk Ann , Zloza Andrew 
Published: January 2023

Abstract
Immunotherapy has revolutionized cancer treatment; however, a significant fraction of patients exhibit resistance to immunotherapy, in part due to the lack of an inflamed (“hot”) tumor microenvironment. Seeking to recruit immune cells to tumors lacking immune cell infiltration (“cold” tumors), we observed that intratumoral injection of heat-inactivated influenza, but not live influenza, slows growth of B16-F10 melanoma in C57BL/6 mice (p&lt;0.001). With clinical translation in mind, we next tested whether FDA-approved seasonal influenza vaccines could likewise reduce tumor growth. Mice administered influenza vaccines by intratumoral injection exhibited smaller tumors than PBS-injected controls (p&lt;0.001) and, importantly, were protected against future live influenza challenge in the lung. Vaccinated mice harbored a greater proportion of intratumoral dendritic cells, overall T cells, and tumor-reactive CD8+ T cells, and exhibited a more inflamed tumor signature associated with clinical response to immunotherapy. Furthermore, we observed that intratumoral influenza vaccination results in systemic responses, reduces metastasis, and synergizes with PD-L1 blockade to induce tumor regression. While all unadjuvanted vaccine formulations tested slowed tumor growth, a formulation containing a squalene-based adjuvant failed to do so due to induction of B regulatory cells in the tumor. Adjuvant removal or B cell or IL-10 depletions rendered anti-tumor effects to the adjuvanted vaccine (p&lt;0.01, p&lt;0.01, and p&lt;0.001, respectively). Future research will focus on further understanding underlying mechanisms and translating these findings to the clinic as an immunotherapy for cancer.
Targeting DAMP-induced inflammation to prevent breast cancer metastasis and improve anti-tumor immunity
Authors: Frazier Victoria N , Holl Eda , Boczkowski David , Sullenger Bruce , Nair Smita K 
Published: January 2023

Abstract
Biomarkers associated with systemic inflammation correlate with poor prognosis in cancer patients. Circulating cell-free DNA (cfDNA) is released passively and actively by both tumor cells and host cells and cfDNA levels in blood correlate with tumor burden in many tumor types. Notably, studies in breast cancer have shown that inhibition of cfDNA has a significant effect in reducing invasion and migration in vitro and metastatic disease in vivo. We have previously demonstrated that nucleic acid binding polymers (NABPs) bind and inhibit the proinflammatory effects of cfDNA in a murine model of pancreatic cancer.
We observed that levels of cfDNA in blood increase with tumor burden in an orthotopic immunocompetent murine model of breast cancer. Moreover, treatment of mice with the NABP, PAMAM-G3, following surgical removal of primary tumor results in decreased lung metastasis. This decrease in lung metastasis is associated with reduction in the levels of cfDNA in blood.
In addition, treatment of mice with NABPs in an intravenous experimental metastasis breast cancer model results in reduced seeding of tumor cells in lungs and lung metastasis. Analysis of immune infiltrates in lungs of PAMAM-G3- and control-treated mice demonstrates NABP-mediated transition of immune cell composition in lungs from innate to adaptive immune cells. Collectively, these data suggest that NABPs can be used to target cfDNA and inhibit DAMPs associated pathological inflammation. The use of NABPs is an innovative approach to treat cancer progression and metastasis, particularly in a clinical setting following standard of care surgical tumor resection.
This work is funded by the Department of Defense Breast Cancer Research Program award (PI, Smita Nair).
Glucocorticoid signaling regulates CD8+T cell responses in cancer
Authors: Acharya Nandini , Madi Asaf , Zhang Huiyuan , Klapholz Max , Christian Elena , Dixon Karen O , Mangani Davide , Xia Junrong , Singer Meromit , Rozenblatt-Rosen Orit , Regev Aviv , Kuchroo Vijay K , Anderson Ana C 
Published: January 2023

Abstract
Identifying signals in the tumor microenvironment (TME) that promote CD8+T cell dysfunction can inform the development of novel approaches to improve anti-tumor T cell responses. Here, we identified Nr3c1, the gene encoding the glucocorticoid receptor (GR), as one of the genes preferentially expressed by dysfunctional CD8+TILs. Glucocorticoids (GCs) are steroid hormones and ligands for the GR. Despite their widespread use, surprisingly little is known regarding the molecular circuitry by which glucocorticoids suppress immune responses. We demonstrate that glucocorticoids are synthesized de novo in the TME and activation of glucocorticoid signaling promotes features of dysfunction, including increased expression of checkpoint receptors like Tim3, PD1, Lag3 and TIGIT, and dampened effector function including decreased production of pro-inflammatory cytokines in both murine and human CD8+T cells. Deletion of GR in CD8+T cells in vivo resulted in loss of dysfunctional phenotype in CD8+TILs concomitant with improved tumor growth control. We thus identified glucocorticoid signaling as a component of immune suppression within the TME and uncovered a molecular mechanism by which it suppresses T cell responses. Glucocorticoids are the mainstay for treating the immune-related adverse events (IRAEs) that develop in patients receiving immune checkpoint blockade. Thus, having a better understanding of the mechanisms downstream of GCs could inform the application of glucocorticoids for suppressing immune responses.