bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dendritic Cells from Aged Subjects Display Impaired Responses to Retinoic acid
Authors: Agrawal Anshu , Agrawal Sudhanshu , Ganguly Sreerupa , Tran Alexander 
Published: January 2023

Abstract
Aged subjects display increased susceptibility to mucosal diseases. Infections and diseases of the respiratory, gastrointestinal and urinary tract are prevalent in this population. Sterile inflammation of the mucosa is considered a major culprit. Retinoic Acid (RA) secreted by mucosal epithelial cells plays a major role in inducing tolerance in the mucosa. RA acts on Dendritic cells (DCs) to induce mucosal tolerance. Here we compared the response of DCs from aged and young individuals to RA with a view to understand the mechanisms underlying chronic sterile inflammation in aged mucosa. Our investigations revealed that compared to young DCs, RA stimulated DCs from aged subjects are defective in inducing T regulatory cells. Examinations of the underlying mechanisms indicated that impaired upregulation of CD141 expression on aged DCs by RA was a major factor in reduced induction of T regulatory cells. In summary, reduced response of aged DCs to RA enhances mucosal inflammation in the elderly, increasing their susceptibility to mucosal diseases. In addition, our data also suggests a novel mechanism of immunosuppression by RA in tumor microenvironment.
Controlling Leukocyte Migration in Autoimmune Encephalomyelitis by the TIPE Family of Phospholipid Transfer Proteins.
Authors: Sun Honghong , Li Ning , Porturas Thomas , Boggs Amanda , Chen Youhai H 
Published: January 2023

Abstract
Leukocyte migration is essential for immune organ development, immune surveillance, and autoimmune diseases. A common pathogenic mechanism of multiple sclerosis (MS) is the infiltration of the central nervous system (CNS) by activated leukocytes. The CNS is an immunologically privileged site to which access of circulating leukocytes is tightly controlled by the blood-brain barrier (BBB). How leukocytes cross the BBB during MS is not well understood. We report here that members of the TNFAIP8 (TNF-alpha-induced protein 8-like) family control leukocyte migration during experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Using single or double TIPE deficient mice generated in our lab, we found that TNFAIP8 and TIPE2 were required for the development of EAE. Although TIPE2-deficient myelin-specific TH1 and TH17 cells were hypersensitive to myelin antigens, they had an intrinsic defect in migration into CNS. Further analysis indicated that TIPE family members affected cell polarization. The molecular mechanisms underlying these abnormalities are under investigation. These findings establish that TIPE family plays important roles in EAE and could be a potential therapeutic target for treating MS. Supported by NIH grant.
Serotonin Receptor Regulation of Eosinophil Transendothelial Migration
Authors: Walker Matthew T , Green Jeremy , Ferrie Ryan , Cook-Mills Joan M 
Published: January 2023

Abstract
The tryptophan amino acid metabolite, 5-hydroxytryptophan (5HTP), is a metabolic precursor of serotonin. 5HTP reduces allergic inflammation in the lung by inhibiting eosinophil migration across endothelial monolayers. Blocking the metabolic conversion of 5HTP to serotonin decreases inhibition of eosinophil migration, indicating that its metabolism is required for inhibition. Currently it is unknown if serotonin receptors are involved in mediating 5HTP function. We determined which serotonin receptors are expressed by endothelial cells and eosinophils by western blot and qPCR. There was expression of the serotonin receptors 1A, 1B, 3A, and 6. Function of the receptors in transendothelial migration was addressed. Selective receptor inhibitors for serotonin receptors 1A and 1B blocked 5HTP inhibition of migration. Current data suggests serotonin receptors are involved in 5HTP inhibition of transendothelial migration and thus may serve as a target for intervention during allergic inflammation. These results will help design ongoing clinical studies addressing whether 5HTP supplementation reduces allergic asthmatic responses.
FCRL4 and FCRL5 expression distinguishes three human memory B cell subsets in tonsils.
Authors: Li Huifang , Tolnay Mate 
Published: January 2023

Abstract
FCRL4 and FCRL5 are two members of the human Fc receptor like family with the capacity to regulate antigen receptor signaling. FCRL4 was shown to bind IgA, whereas FCRL5 binds IgG. Although the expression of FCRL4 and FCRL5 on human B cell subsets has each been individually evaluated, no study thus far addressed their potential co-expression. Here we report that three distinct subpopulations of CD38lowIgD-memory B cells exist in human tonsils, one that co-expresses FCRL4 and FCRL5, another that is FCRL5 single-positive, and a third that lacks both proteins. We found that the FCRL5+FCRL4+ subset expresses the highest levels of surface FCRL5, CD11c, FAS, PD-1, CD32, CCR1, CCR5 and CCR6 protein, as well as the lowest levels of LAIR-1 and CD21 among the three memory B cell populations. Furthermore, microarray analysis demonstrated that the three memory B cells subsets each possess distinct gene expression profiles. The FCRL5+FCRL4− memory B subset overexpressed dozens of immunoglobulin variable genes compared to the other two subsets, in addition to the transcription factors XBP1, PRDM1 and IRF4 that drive plasmablast and plasma cell differentiation. These results suggest that the FCRL5+FCRL4− memory B subset is committed to become plasmablast. Using KREC assay we established that the FCRL5+FCRL4+ subset underwent more rounds of cell divisions than the other two subsets. The low number of cell divisions measured in the FCRL5+FCRL4− subset suggests that the cells bypassed the germinal center. The surprising association of FCRL4 and FCRL5 expression with distinct memory B cell subsets could point to the functional role of these FCRL proteins and their immunoglobulin ligands to drive B cell development.
Visualizing mucosal resident memory CD8 T cell reactivation dynamics reveals in situ division and bystander resident memory T cell development
Authors: Beura Lalit K , Thompson Emily A , Mitchell Jason , Fife Brian T , Masopust David 
Published: January 2023

Abstract
CD8 T cells survey tissues for the presence of abnormal cells. The parameters of CD8 T cell search patterns and immunosurveillance determines outcome of infections and cancer (elimination, controlled persistence, or death). We established a two-photon intravital microscopy model to visualize resident memory CD8 T cell (TRM) behavior and recall responses within the female reproductive tract (FRT) mucosa of living mice. Unlike what has been described in skin epidermis, FRT TRM were highly motile (10 μm/min). Local antigen recognition induced pausing and initiation of in situ TRM division, and this appeared CD4 T cell and dendritic cell independent. Expansion by dividing TRM dominated the local recall response compared to recruitment of recirculating cells or progeny of reactivated central memory T cells. TRM reactivation also triggered recruitment of Ag-specific and bystander recirculating memory cells, and these underwent a de novo TRM differentiation program in situ. These results demonstrate that 1) T cell migration patterns and differentiation may be permanently altered by unrelated infectious experience, 2) that cognate antigen within the FRT is not required to induce local TRM differentiation, 3) TRM undergo in situ division upon recall that 4) may dominate the local secondary effector and memory response.
Elucidating the role of the Mst1/Foxo1 axis in CD8+ memory T cell development
Authors: Hills L Benjamin , Huang Yina H 
Published: January 2023

Abstract
The Foxo1 transcription factor is required for naïve T cell homeostasis and trafficking, T regulatory cell development, and CD8 memory T cell differentiation. Two kinases, Akt1 and Mst1 differentially control Foxo1 activity. Akt1-induced Foxo1 phosphorylation at T24, S256, and S319 causes association with 14-3-3 adapters, nuclear export, and degradation, resulting in decreased transcription of Foxo1 targets. Akt1-mediated control of Foxo1 activity in CD8 T cells promotes terminal differentiation into effector cells. In contrast, Mst1 may prevent Foxo transcription factors from binding 14-3-3, promoting Foxo nuclear localization and transcriptional activity. These data suggest that Akt1 and Mst1 have opposing effects on Foxo1 activity in T cells. However, how Mst1 regulates Foxo1 activity to impact CD8 memory T cell differentiation has not been directly evaluated. We hypothesize that, while phosphorylation of Foxo1 by Akt1 causes cytosolic localization and promotes effector CD8 differentiation, phosphorylation of Foxo1 by Mst1 increases Foxo1 stability and promotes CD8 central memory differentiation. To test this hypothesis, we have generated Mst1 phospho-null and phospho-mimetic Foxo1 variants (S209A and S209D). Surprisingly, Foxo1 mutations at the Mst1 phosphorylation site differentially altered Foxo1 subcellular localization. Current studies utilizing Lm--Ova to study the antigen-specific memory response of OT-I CD8 T cells expressing WT, S209A, or S209D Foxo1 variants in vivo revealed skewed effector and central memory differentiation. Together, these studies indicate that coordinated regulation of Foxo1 by Akt1 and Mst1 kinases determine the extent of CD8 terminal effector and memory cell differentiation.
Crucial signaling pathways in regulatory B lymphocytes
Authors: Taitano Sophina Horne 
Published: January 2023

Abstract
Regulatory B cells are critical players in immune regulation, protecting against autoimmune and allergic diseases. Regulatory B cells possess a several mechanisms for this purpose, including production of the anti-inflammatory cytokine interleukin 10 (IL-10) and the expression of the death inducing molecule Fas ligand (FasL). Despite the importance of these cells, what governs their activation and regulatory abilities is not fully understood. Our lab has developed in vitro cultures using CD40L and IL-5 stimulation to grow mouse regulatory B cells which produce IL-10 and display FasL associated killing abilities. To elucidate the signaling pathways involved in regulatory B cell activation and function, cultures were treated with inhibitors to specific signaling molecules. Inhibitor effects on IL-10 production, FasL killing ability, and cell growth of the B cells were evaluated. Through these inhibitor studies we have identified certain pathways imperative to regulatory B cell growth and function. Interestingly, regulatory B cells seem to use unique signaling pathways to respond to CD40L and IL-5 stimulation. Regulatory B cells can be activated by multiple stimuli in addition to CD40L and IL-5, but which stimuli are most important in vivo is still to be determined. Using the results from the in vitro studies we are now examining these pathways as potential targets for expansion and activation of regulatory B cells in vivo.
Resident Memory T cells in the liver Receive the Local Survival factors from the Specialized microenvironments in Response to Acute Viral Infection
Authors: Kim Hyun Gyung , Jung Yong Woo 
Published: January 2023

Abstract
Memory T (TM) cells provide long-term protection against the same infectious agents by maintaining their cell number and responding vigorously upon rechallenge. However, it remains to be investigated which type of TM cells are formed in the liver and how they maintain their homeostasis in response to systemic acute infections. Here, we show that virus-specific TM precursors were clustered in specialized anatomic microenvironments, called lymphoid aggregates. These cells did not circulate in the steady state, suggesting that they are resident in the lymphoid aggregates. We confirmed that TM cells in the liver did not migrate into the secondary lymphoid organs during recall responses. We further characterized the phenotypes of cells found in the lymphoid aggregates using immunofluorescent microscope. TM cells localized in these microenvironments are CXCR3+ and surrounding macrophages (Mø) showed the expression of CX3CR1. These Mø were purified based on the intensity of CX3CR1 expression and examined for expression of potential factors important for the homeostasis of TM cells. Compared to CX3CR1lo cells, CX3CR1hi or CX3CR1int Mø expressed inhibitory receptors, programmed death (PD) protein 1 and PD-ligand 1, and higher mRNA levels of chemokines, CXCL9 and CXCL10, which can induce the recruitment of CXCR3+ cells. These Mø also transcribed high level of interleukin (IL)-15 which is well-defined survival factors for TM cells, and the size of lymphoid aggregates decreased in IL-15-deficient mice. Therefore, we propose that CXCR3+ resident TM cells develop in the liver during acute viral infection, and the specialized Mø in the lymphoid aggregates provide important factors for the homeostasis of these TM cells.
Reduced TGF‑βR signaling results in increased T cell activation without autoinflammatory disease
Authors: Weissler Katherine Ann , Kinard Jessica , Laky Karen , Guerrerio Pamela 
Published: January 2023

Abstract
Transforming growth factor-β receptor (TGF-βR) signaling is important in regulating the proliferation and differentiation of CD4+ T cells, but how modulating the level of signaling can affect T cell fate remains unclear. We have created a mouse model of Loeys-Dietz syndrome (LDS), an autosomal dominant disease caused by mutations in genes encoding the TGF-βR, by targeting a missense mutation (M318R) to the endogenous murine Tgfbr1 locus. LDS patients exhibit an increased propensity for allergic disease, but no overt immunodeficiency or autoimmune disease. A higher percentage of CD4+ T cells in Tgfbr1M318R/+ mice exhibited a memory phenotype and produced enhanced levels of cytokines including IFN-γ, IL-13, IL-17, and IL-10 upon stimulation, but no autoimmunity was observed. In contrast, mice lacking TGF-βR2 specifically in T cells demonstrate exaggerated IFN-γ production and widespread autoinflammatory disease. While naïve CD4+ T cells from Tgfbr1M318R/+ mice were less likely to upregulate Foxp3 during in vitro culture with recombinant TGF-β, paradoxically, increased percentages and numbers of suppressive Foxp3+ regulatory T cells (Tregs) were observed in vivo, which may indicate a role for increased proliferation or survival of thymically-derived Tregs. The effects of the Tgfbr1M318R/+on T cells appear to be cell intrinsic. We observed no differences in T cells derived from WT bone marrow used to reconstitute irradiated Tgfbr1M318R/+ or WT hosts, while Tgfbr1M318R/+ bone marrow co-transferred with WT bone marrow into WT hosts gave rise to more activated CD4+ T cells and a higher frequency of Foxp3+ cells. These data suggest that partially abrogated TGF-β signaling leads to unexpected effects on T cell development and function.
CD28 induces survival in long-lived plasma cells through NFκB mediated Irf4 upregulation and mitochondrial respiration-dependent reactive oxygen species production.
Authors: Cooper James J. M. , Utley Adam , Peng Peng , Mahpour Amin , Carlson Louise M , Carle Sigrid A , Lee Kelvin P 
Published: January 2023

Abstract
Durable humoral immunity is dependent upon sustained antibody production by long-lived plasma cells (LLPCs). We have published that CD28 is required for LLPC survival and antibody production in vivo; however, the mechanistic basis for this is unclear. In T cells, CD28 is known to induce glycolysis at the expense of respiration. Surprisingly, CD28 induces mitochondrial respiration and biogenesis in LLPCs while also increasing glucose uptake. Paradoxically, respiration-dependent reactive oxygen species (ROS) are required for CD28-mediated survival. Using knock-in mice with mutations in the CD28 cytoplasmic tail, we demonstrate that CD28-Grb2-Vav-Slp76 signaling is required for the survival of LLPCs with high mitochondrial mass and ROS in vivo. Mechanistically, CD28 induces Irf4 in an NFκB-dependent manner. CD28-ROS drive cRel translocation, an NFκB subunit, which can bind directly to the Irf4 promoter. We also describe a super enhancer element further upstream of Irf4 driven by the NFκB subunit p65, induced by CD28 specifically in LLPCs. Furthermore, inhibition of NFκB abrogates CD28-mediated glucose uptake, mitochondrial respiration and biogenesis. Irf4 heterozygous LLPCs have lower mitochondrial mass in vivo, and knock-down of Irf4 decreases the mitochondrial mass. This leads to a model wherein CD28, through Grb2-Vav-Slp-76, reinforces LLPC survival through the induction of mitochondrial biogenesis and respiration. Respiration-dependent ROS then augment NFκB-mediated Irf4 expression through direct promoter activity and a previously undescribed super enhancer element. CD28, therefore, makes an attractive target for the augmentation of vaccine design and in the alleviation of antibody-mediated autoimmunity.
TGFβ Receptor mutations alter mast cell development and function
Authors: Turfkruyer Mathilde , Dugan Philip A , Kinard Jessica L. , Frischmeyer-Guerrerio Pamela 
Published: January 2023

Abstract
Mutations in TGFBRI, encoding the receptor for TGFβ, cause Loeys-Dietz syndrome (LDS), a Mendelian disorder associated with an increased risk of developing nearly all forms of allergic disease, including food allergy. To better understand the mechanisms responsible for this association, knock-in mice harboring LDS mutations have been developed, which recapitulate nearly all aspects of the human phenotype. Mast cells are the main effector cells of allergic disease and several studies have identified TGFβ as a critical mediator of mast cell development and function. We hypothesized that LDS mast cells are altered in a manner that would promote greater susceptibility to allergic outcomes. To address this possibility, in vitro assays were performed with peritoneal mast cells (pMCs) cultured in IL-3 and stem cell factor and stimulated with IL-33, TGFβ, or IgE crosslinking agents. LDS pMCs expressed higher levels of ST2, the receptor for IL-33, and greater secretion of IL-9 following IL-33 stimulation. Furthermore, LDS pMCs were more resistant to apoptosis, exhibited greater degranulation following IgE receptor crosslinking, and showed less downregulation of FcɛRI and c-kit following exposure to recombinant TGFβ1. This was associated with reduced pSmad2/3 levels, a key signaling molecule in the TGFβ pathway. Furthermore, we demonstrated that following food allergy induction, LDS mice exhibited greater MC hyperplasia in the small intestinal lamina propria as well as in the peritoneum where LDS peritoneal mast cells showed enhanced secretion of IL-9. In vivo studies are ongoing to further examine the role of altered mast cell frequency and/or function resulting from altered TGFβ signaling in promoting food-induced anaphylaxis.
Sphingosine Kinase Inhibitors Effectively Inhibit Growth of Mast Cells with D816V-KIT Mutations
Authors: AGEITOS ARACELI TOBIO , BANDARA GEETHANI , MUNOZ-CANO ROSA , YIN YUZHI , DESAI AVANTI , METCALFE DEAN , OLIVERA ANA 
Published: January 2023

Abstract
Sphingosine-1-phosphate (S1P) is a lipid mediator that promotes cell proliferation and prevents apoptosis in a variety of cells and its increased synthesis by Sphingosine Kinase (SphK) has been associated with oncogenesis and cancer prognosis. Mastocytosis is a disorder characterized by excessive mast cell (MC) proliferation and accumulation in tissues. Treatment therapies for aggressive mastocytosis have to date been partially effective, and thus the search of new pharmacological targets is warranted. We thus investigated the involvement of SphK isoforms (SphK1 and SphK2) and generation of S1P in the regulation of abnormal MC growth. The specific SphK1 and SphK2 inhibitors, SKI-178 and ABC294640, respectively, were used in this study. The effect of SphK1 and SphK2 inhibition on human (LAD2, HMC1.1 and HMC1.2) and murine (P815) neoplastic MC proliferation and survival was evaluated. SphK2 inhibition retarded entry into the cell cycle in all MC lines with no significant effect on cell survival. However, SphK1 inhibition led to cell cycle arrest in G2/M and apoptosis predominantly in MCs carrying D816V-KIT mutation. The effect of SKI-178 was associated with an alteration in the damage response cascade. This included activation of checkpoint kinase 2 (chk2) combined with a depletion of chk1, leading respectively to p53- and caspase2-induced apoptosis and cell cycle arrest mediated by cdc25c depletion. Both SphK inhibitors reduced MC accumulation in an in vivo mouse model of aggressive mastocytosis and the number of cultured bone marrow MCs and MC progenitors from a patient with systemic mastocytosis. These results support further consideration for SphK inhibitors as a cytoreductive strategy in proliferative MC disorders.
Mast cells are required for allergy-driven changes in senstivity to touch and pressure in oxazolone challenged skin in sensitized ND4 female mice.
Authors: Chatterjea Devavani , Landry Jasmine 
Published: January 2023

Abstract
Vulvodynia is a chronic vulvar pain condition affecting up to 8–16% of 18–60 year-old women. Epidemiological studies have demonstrated an increased risk of developing vulvodynia for women with histories of seasonal and insect allergies. We show that 10 exposures to the hapten oxazolone on the labiar skin of previously sensitized outbred ND4 female mice provokes increased sensitivity to touch and pressure that lasts for 3 weeks or longer. This persistent sensitivity is accompanied by local labiar mast cell accumulation and overgrowth of cutaneous neurites both of which persist for at least 3 weeks after the final allergen exposure. Oxazolone-challenged mice also show local labiar increases in inflammatory cytokine and neuro-immune signaling transcripts, infiltration of resident memory CD8 cells and CD4+CD25+ regulatory T cells. Local depletion of mast cells via intra-dermal injections of basic secretagogue compound 48/80 reduces the sensitivity to touch and pressure suggesting that persistent accumulation of mast cells in allergen-exposed tissue is necessary for the development of long-lasting painful responses in these mice. Our findings suggest that mast cell-targeted therapies may be a novel area of intervention for the management and treatment of chronic pain conditions associated with allergic and hyper-inflammatory states.