bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Involvement of BLK in Development of Splenic B Cells and B Cell Adhesion and Migration (69.11)
Authors: Wu Ying-Yu , Haque Mohammad , Da Huining , Alarcon-Riquelme Marta 
Published: January 2023

Abstract
The BLK gene has been identified as genetically associated with systemic lupus erythematosus (SLE). BLK genetic variants involved in risk for SLE correlate with reduced expression of BLK in human B-cells. Recent studies have found that BLK deficiency dampened MZ B cell development, but enhanced its functional response to BCR stimulation. However, reduction of MZ B cells cannot explain why decreased expression of BLK is associated with SLE and why the TI-humoral response is increased in BLK-KO mice. In light of these recent discoveries, we performed a more comprehensive characterization of splenic B cell subsets and their biological functions. We report that BLK-KO mice have accumulated numbers of T1 B cells and splenic B1 B cells. B1 B cells from BLK-KO mice express higher levels of VLA4. Mature B cells and transitional B cells have normal in vitro adhesion to VCAM1 in the absence of stimulation. Nevertheless, BCR-engaged BLK-KO MZ B cells adhered less to VCAM1, whereas BCR-crosslinked BLK-KO T1 B cells had increased adhesion to VCAM1. Moreover, BLK-KO MZ B cells showed a reduced CXCR5-mediated chemotaxis, while BLK-KO T1 B cells had an increased CXCR5-mediated chemotaxis. Thus, this study demonstrates that BLK may have a novel role in the development of splenic B1 B cells and implies a previously unappreciated role for the involvement of BLK in B-cell adhesion and migration.
Molecular analysis of age-associated B cells (ABCs) (69.7)
Authors: Scholz Jean , Hao Yi , Russell Lisa , Maul Robert , Paley Michael , Wherry E. , Gearhart Patricia , Cancro Michael 
Published: January 2023

Abstract
Age-associated B cells (ABCs) are a phenotypically and functionally distinct mature B cell subset that accumulates with age. Unlike follicular (FO) B cells, ABCs do not rely on B lymphocyte stimulator (BLyS) to survive, and are likely derived from mature B cells that exhaustively expand throughout the animal’s lifespan. Because ABCs respond to innate but not adaptive stimuli, produce cytokines, and potentiate Th17 polarization, they may alter the quality of immune responses in aged animals, thereby contributing to age-associated increases in susceptibility to infection and inflammation. In order to further investigate ABC origins, relationships to other B cell subsets, and roles in immunosenescence, we have undertaken detailed gene expression and BCR repertoire analyses. Microarray results show striking differences in gene expression patterns between ABCs and FO B cells from aged and young mice. Heavy-chain gene analysis indicates that ABCs display a diverse VH repertoire, with a mutation frequency ~6-fold higher than that observed among FO B cells, indicating previous activation and concomitant somatic hypermutation. Despite this, the ratio of CDR to FWR mutations indicates a lack of antigen-mediated selection. Taken together, our results suggest that ABCs are derived from a diverse progenitor pool and reflect prior activation; however, expansion of the ABC subset either does not include selection based on CDR specificity, or involves aberrant selection.
Antigen density determines the pattern of pMHC cross-reactivity of CD4+ T cell responses during viral infection(69.8)
Authors: Vanguri Vijay , Smith Rebecca , Shah Shivanee , Paczosa Michelle , Huseby Eric 
Published: January 2023

Abstract
The activation of the CD4+ T cell immune response to pathogens is determined by the interaction between the T cell receptor and its cognate pathogen-derived peptide presented by MHC-II molecules on antigen-presenting cells (APCs). In vitro, whether a given CD4+ T cell will undergo activation is determined by the potency and density of the activating ligand. We created an in vivo murine model to identify how ligand potency and ligand density impact the overall cross-reactivity of an anti-viral CD4+ T cell response. We observed graded CD4+ T cell responses after immunization by strong, medium, or weak affinity ligands, with phenotypic differences evident within 24 hours and with long-term effects on the repertoire and clonal expansion. In addition, vaccinia viruses that expressed a high density ligand on the surface of APCs generated an expanded profile of CD4+ T cell specificities compared to that generated in response to lower density antigen. This occurred because medium affinity CD4+ T cells were able to be activated and expanded in the presence of high but not low antigen density.
Differential requirement for CCR7 expression in primary and secondary CD8 T cell responses to infection (69.9)
Authors: Sharma Naveen , Lefrançois Leo 
Published: January 2023

Abstract
Since naïve and memory T cells localize in both red and white pulp of the spleen, we wished to test the relative contribution of priming in each location. To do so, we employed TCR transgenic CD8 T cells (OT-I) that either lacked CCR7 or constitutively expressed CCR7 (CD2-CCR7). After Listeria infection, CCR7-/- CD8 T cells did not enter the T cell zone (PALS) while CD2-CCR7 OT-I cells were confined nearly exclusively to the PALS. The response of CCR7-/-CD8 T cells was blunted compared to WT and CD2-CCR7 OT-I cells and was characterized by skewing toward KLRG1highCD127low short-lived effector cells (SLEC) and away from KLRG1lowCD127high memory precursor effector cells (MPEC). Transfer studies showed that CCR7-/- OT-I cells competed with endogenous ova-specific CD8 T cells, suggesting that some priming occurred in the red pulp in normal conditions. Interestingly, CCR7-/-, CD2-CCR7 and WT OT-I memory cells responded equally well to challenge infection indicating a low stringency for localization for memory CD8 T cell activation. These results suggested that antigen presentation in the red pulp promoted SLEC generation while white pulp priming promoted MPEC development, perhaps due to differences in the inflammatory milieu. Along with our demonstration that naïve and memory CD8 T cell activation exhibited distinct anatomical requirements, our findings implied that local environmental cues regulated the development of primary and secondary CD8 T cell responses to infection.
Identifying third signal cytokines for development of differently functioning CD8 T cells in Mycobacterium tuberculosis infection (70.4)
Authors: Sun Tao , Einarsdottir Thorbjorg , Flynn JoAnne 
Published: January 2023

Abstract
Mycobacterium tuberculosis (Mtb), causing tuberculosis (TB), is estimated to infect one third of the human population, and kills about 1.8 million people per year. CD8 T cells are the essential components in the adaptive immunity against Mtb. We previously demonstrated that Mtb-specific CD8 T cell populations are divided into two distinct types: either cytotoxic or IFN-γ secreting. However, the third cytokine signals that prime CD8 T cells to evolve into these phenotypes, or to develop capability to have both cytotoxic and IFN-γ producing functions are not known. We found that naïve CD8 T cells adoptively transferred into mice during Mtb infection were primed into more IFN-γ+ IL-2+ TNFα+ and CD107+ IFN-γ+ phenotypes, compared with cells transferred before infection. We also observed dynamic changes in levels of multiple cytokines within tissues over the course of infection. We hypothesize that the relative balances between pro- and anti-inflammatory cytokines contribute to the different phenotypes of CD8 T cells. Here we are using an in vitro OT-I T cell priming system together with lung and lymph node homogenates, as well as individual cytokines identified in those homogenates for effects on CD8 T cell priming and phenotypes. We will also examine the cytokine effects on CD8 T cells in vivo. In summary, our study contributes to a better understanding in how CD8 T cell responses are modulated during Mtb infection, which will help with design of better therapies or vaccines.
STAT4 deficiency impairs CD4 T cell responses, yet enhances pathogen-specific antibody production during Pneumocystis murina lung infection (70.7)
Authors: Myers Riley , Trevor Jennifer , Nelson Michael , Dunaway Chad , Steele Chad 
Published: January 2023

Abstract
Although it is clear that the loss of CD4+ T cells is a predisposition to Pneumocystis pneumonia, the underlying mechanism for host defense is not well understood. Mice deficient in IFN-αR, IL-12p35, or IL-23p19 have delayed clearance of Pneumocystis murina, all of which activate the pro-Th1 transcription factor STAT4. In order to investigate the role of STAT4 in host defense against P. murina, C57BL/6 wild-type (WT) and STAT4-/- mice were infected intratracheally with P. murina cysts and fungal burden was assessed 28 days later. Despite a reduction in the total number of leukocytes in the lung on day 14 after infection in STAT4-/- mice, P. murina clearance at day 28 was not affected by the absence of STAT4. On day 14 after P. murina infection, STAT4-/- mice showed increased production of the Th2-type cytokine IL-5 relative to WT mice. In addition to CD4+ T cells, humoral immune responses are also critical for the clearance of P. murina, and because IL-5 has been shown to be important in antibody (Ab) production, we examined pathogen-specific Ab production in WT and STAT4-/- mice. STAT4-deficient mice had increased production of anti-P. murina IgG1, IgG2b, and IgG2c leading to enhanced opsonic killing by alveolar macrophages ex vivo compared to serum of WT mice. These data suggest that increased anti-P. murina Ab production, which enhances alveolar macrophage-mediated killing, may overcome T cell defects in the absence of STAT4, resulting in unimpaired clearance of P. murina.
Pregnancy establishment depends on a pre-existent population of thymic-derived uterine Foxp3+ cells while pregnancy maintenance relies on de novo converted regulatory T cells (71.1)
Authors: Zenclussen Ana , Teles Ana , Leber Anne , Tadokoro Carlos 
Published: January 2023

Abstract
Pregnancy represents a challenge for the maternal immune system; it has to be alert against pathogens while tolerating paternal alloantigens in fetal structures. The maternal immune system is aware of these alloantigens, actively tolerating them to ensure the survival of the fetus. Regulatory T cells (Treg) are reportedly involved in allotolerance towards paternal antigens. In mouse models, the transfer of antigen-specific Treg can protect from immunological rejection of the fetuses. However, Treg generation and indispensability for pregnancy remained unclear. Treg accumulate during the receptive phase of the estrous cycle as documented by in vivo imaging using a 2-photon microscope. Treg depletion prior to and during very early pregnancy (foxp3.DTR mice) leads to impaired implantation, while their depletion at later time points does not interfere with gestation. Helios+ cells leave the thymus and accumulate in blood and uterus-draining lymph nodes during early pregnancy. At later stages, Foxp3+ Treg are generated de novo in the periphery as we demonstrated in a Rag-model of cell transfer. While naturally occurring Treg are needed for pregnancy establishment, their absence at later stages is compensated by the generation of Foxp3+ cells from Foxp3- cells. Our data provides new insights in the generation/ function of Treg during pregnancy, which is essential to understand natural mechanisms of tolerance acquisition.
Molecular characterization of wheat antigens involved in celiac disease (71.13)
Authors: Srinivasan Bharani , Focke-Tejkl Margit , Swoboda Ines , Constantin Claudia , Mittermann Irene , Pahr Sandra , Vogelsang Harald , Huber Wolf-Dietrich , Valenta Rudolf 
Published: January 2023

Abstract
Wheat gliadins trigger a hypersensitive immune response in genetically susceptible individuals causing celiac disease (CD). The small intestinal mucosa of CD patients is characterised by presence of numerous infiltrating CD4+ T cells. These T cells proliferate and secrete IFN-γ when stimulated with gliadin extracts and are implicated in the mucosal damage and production of anti-gliadin antibodies. Peptide sequences in the Pro(P) and Glub(Q) rich regions of gliadins are known to be T cell-stimulatory but due to the heterogeneity of gliadin sequences, several potential stimulatory epitopes and the individual protein antigens are yet to be identified and characterized. Thus our aim was to identify and characterize wheat antigens with ability to initiate and sustain celiac disease. Due to their complex biochemistry the three subtypes of gliadins α/β, γ, and ω-gliadins are difficult to isolate into pure fractions. Hence, we developed a method wherein the alcohol extracted gliadins was sub-fractionated ion-exchange chromatography and each sub-fraction’s reactivity to serum IgA, from clinically well defined CD (active/diet) patients and non-CD patients was analyzed. We identified and generated recombinant gliadins that were CD specific. Epitope mapping studies revealed major immune-reactive regions. Recombinant gamma-gliadins will be useful for characterizing the immune response to wheat antigens and to develop reliable diagnostic and therapeutic strategies.
Increased small intestinal and colonic permeability, and loss of villus tip surface area, correlates with microbial translocation and immune activation in HIV (71.5)
Authors: Stubblefield Park Samantha , Sung Hannah , Funderburg Nicholas , Meddings Jon , Levine Alan 
Published: January 2023

Abstract
As early diagnosis and viremic control of HIV becomes more prevalent, the clinical focus has turned to preventing co-morbidities that include cardiovascular, hepatic, neurological, and metabolic abnormalities and immune exhaustion. Immune activation, as measured by leukocyte activation and soluble inflammatory mediators in circulation, is increased in HIV patients, even those on effective HAART therapy, and is a better predictor of disease progression and of all-cause mortality than viral load. Intestinal permeability, which often leads to microbial products in the bloodstream, may provide a cause for chronic inflammation in HIV patients. Here, we provide corroborating evidence of small intestinal and colonic permeability in a cohort of HIV patients with increased LPS, determined by measuring the excretion of various saccharides. Levels of lactulose and mannitol (small intestinal permeability) and sucralose (colonic permeability) were elevated (p=0.0014 and p&lt;0.001, respectively) in the urine of HIV patients, independent of HAART status. Further analysis of the saccharide excretion profile revealed that HIV patients have a loss of villus tip surface area in the small intestine as compared to controls (p&lt;0.001). These results were correlated to markers of bowel damage and microbial translocation (LPS Binding Protein, EndoCAb, sCD14, I-FABP) and immune activation (CRP, IL-6, IFN-α) and to clinical parameters in hopes of identifying key risk factors for disease progression.
IL-12 induced Fas expression in myeloid-derived cells within tumors delivers a co-stimulatory signal for adoptively transferred CD8+ T cells (74.10)
Authors: Kerkar Sid , Restifo Nicholas 
Published: January 2023

Abstract
Engineering CD8+ T cells to deliver IL-12 to the tumor site can lead to striking improvements in the ability of adoptively transferred T cells to induce the regression of established murine cancers. We have recently shown that IL-12 triggers an acute- inflammatory environment that reverses dysfunctional antigen presentation by myeloid- derived cells within tumors and leads to an increase in the infiltration of adoptively transferred antigen-specific CD8+ T cells. Here, we find that local delivery of IL-12 increased the expression of Fas within tumor-infiltrating macrophages, dendritic cells, and myeloid-derived suppressor cells and that these changes were abrogated in mice deficient in IL-12 receptor signaling. Importantly, up- regulation of Fas in host mice played a critical role in the proliferation and anti-tumor activity of adoptively transferred IL-12 engineered CD8+ T cells. We also observed higher percentages of myeloid-derived cell populations within tumors in Fas deficient mice, indicating the resistance for stromal collapse in the absence of signaling through the death receptor Fas. Taken together, these results describe the requirement for co-stimulatory reverse signaling through Fasl on T cells that successfully infiltrate tumors, a mechanism likely triggered by the induction of Fas expression on myeloid-derived cells by IL-12 and the subsequent collapse of the tumor stroma.
Oncogenic collaboration with IL-6 in the induction of spontaneous germinal centers (74.11)
Authors: Rosean Timothy , Tompkins Van , Waldschmidt Thomas , Janz Siegfried 
Published: January 2023

Abstract
Multiple myeloma (MM) is the second most common hematological malignancy in the United States, and represents one percent of all cancers. Despite ongoing research, MM remains incurable, with an average life expectancy of five to eight years after diagnosis. In order to better understand MM development, our lab has created a novel mouse model of plasmacytoma (PCT) which mimics key features of MM. This mouse model contains two transgenes. The first recapitulates a T(12:15) Myc translocation, while the second is a copy of human IL-6. The resultant mouse, designated iMyc/IL-6, develops PCT around three months of age with full tumor penetrance. Interestingly, both IL-6 and iMyc/IL-6 mice develop robust spontaneous germinal centers (GC) by two months of age. Notably, the addition of the iMyc oncogene in iMyc/IL-6 mice results in an increased frequency of GC B cells. Correlating with the development of spontaneous GCs, both IL-6 and iMyc/IL-6 mice develop a robust follicular T helper (Tfh) cell response which becomes more pronounced as mice develop tumors. These results may provide important clues into the role of the T cell response in the development of MM. Our current research is focused on elucidating the role of the Tfh response in the development of PCT.
TSLP driven inflammation fosters breast tumor development (74.2)
Authors: Marches Florentina , Wu Te-Chia , Xu Kangling , Pedroza Alexandro , Zurawski Sandy , Banchereau Jacques , Zurawski Gerard , Liu Yong-Jun , Palucka Karolina 
Published: January 2023

Abstract
Solid tumors are often associated with aseptic inflammation. There are two types of inflammation that have opposing effects on tumors, chronic inflammation that promotes cancer survival and metastasis, and acute inflammation which triggers cancer destruction. Chronic inflammation is often linked with the presence of type 2-polarized macrophages induced by Th2 cytokines, IL-4 and IL-13. Our studies have demonstrated the presence in breast cancer tumors of inflammatory Th2 cells, which produce IL-13, IL-4, and TNF. These CD4+ T cells appear to play a key role in the disease as they accelerate breast tumor development in a xenograft model through the production of IL-13. Breast tumors appear to play a critical role in conditioning the infiltrating myeloid DCs (mDCs) to induce such inflammatory Th2 cells. Our recent results suggest that thymic stromal lymphopoetin (TSLP) plays a role in mDCs conditioning. Breast cancer cell lines and primary tumors from patients show TSLP protein expression. TSLP-neutralizing antibodies block the upregulation of OX40L by mDCs exposed to tumor supernatant and consequently block mDCs capacity to generate inflammatory Th2 cells in vitro. Targeting pattern recognition receptors on mDCs renders them resistant to TSLP signal. These mDCs don't phosphorylate STAT6, don't express OX40L and turn on the secretion of IL12p70. The final outcome is the block of inflammatory Th2 and tumor rejection. Thus, TSLP could serve as therapeutic target in breast cancer.
Involvement of Toll-like Receptor 2 (TLR2) in self-renewal of mouse mammary cancer initiating cells (CIC) (74.8)
Authors: Cavallo Federica , Conti Laura , Lanzardo Stefania , Arigoni Maddalena , Forni Guido , Calogero Raffaele 
Published: January 2023

Abstract
CIC are a subpopulation of cancer cells with stem cell properties that may be responsible for tumor progression, metastasis, resistance to therapy, and tumor recurrence. It is thus conceivable that the identification of the molecular pathway and antigens directly involved in the maintenance of the stem-cell like features of CIC could open a new and promising therapeutic opportunity for anti-cancer interventions. We enriched CIC from a mammary carcinoma cell line derived from a tumor of ErbB2 transgenic mice (TuBo cells) generating subsequent passages of mammospheres. We compared their transcriptional profiling with that of the bulk population of TUBO cells and focused our attention on a cluster of 183 up-regulated transcripts. Among them there were growth factors and immune system-related genes, including toll-like receptor 2 (TLR2). The inhibition of TLR2 signaling strongly impaired in vitro mammospheres generation and in vivo tumorigenicity, demonstrating the involvement of TLR2 in CIC self-renewal. In conclusion, this study provides a genomic characterization of mammary CIC and shows that TLR2 might have a role in initiation and progression of breast cancers.
Dysregulation in p38 signalling contributes to altered phenotype and function in Nrf2 deficient dendritic cells (P5025)
Authors: Aw Yeang Han Xian , Al-Huseini Laith , Sethu Swaminathan , Hamdam Junnat , Goldring Christopher , Park Kevin , Sathish Jean 
Published: January 2023

Abstract
Nrf2 is a redox sensitive transcription factor vital for the maintenance of cellular homeostasis. Dendritic cells (DCs) are potent APCs responsible for the initiation of an immune response. Our previous study highlights the role of Nrf2 in DC function (increased costimulatory receptors expression and T cell stimulatory capacity) and intracellular signaling (such as ROS, NFκB and MAPKs). The p38 MAPK pathway plays a pivotal role in the up regulation of costimulatory receptors (CD86 & MHC II). However, it is unclear how Nrf2 affects the integrity of this pathway. In the current study using bone marrow-derived immature DCs from Nrf2 deficient (KO) and wild type mice, we investigate the effect of Nrf2 on various signaling events in the p38 pathway and associated functional responses. Our results indicate that the loss of Nrf2 in DCs resulted in elevated basal p38 phosphorylation. Furthermore, an increase in basal phosphorylation of CREB and ATF-1 - downstream targets of p38, was also observed. This was coupled with increased IL-10 cytokine production at basal conditions and also upon exposure to LPS. Increased costimulatory receptor expression, antigen specific T cell activation propensity and LPS stimulated IL-10 production observed in the KO DCs can be reversed by pharmacological inhibition of p38. These results suggest that deficiency of Nrf2 in DCs leads to dysregulation of the p38 signaling pathway contributing to the altered phenotype and function of these DCs.