bluuebunny/crossref_metadata_2025_split huggingface dataset:
Down-regulation of CD73 expression favors host protection during Intracellular foodborne bacterial infections (IRC8P.496)
Authors: Alam Mohammad , Costales Matthew , Williams Kristina 
Published: January 2023

Abstract
Salmonella & Listeria infections cause foodborne illness. Adenosine is an immunomodulatory molecule produced by the enzymes CD39 & CD73. We examined the effect of bacterial infections on the host’s ecto-enzyme (CD73) expression & its role in regulating immune responses. After oral infection of B6 mice with Salmonella or Listeria, we tested the expression of CD39/CD73 in tissues, in T-cell & in RAW cells treated with antigen (Ag=bacterial-sonicate) & inflammatory cytokine expression. The function of CD73 was tested in Ag-activated RAW cells after addition of 5’-AMP with or without CD73 inhibition (APCP) & in splenocytes from CD73-KO mice after treatment of Ag in vitro. Inflammatory cytokine mRNA was tested by RT-PCR & cytokine proteins were tested from supernatant by ELISA. Infection, or Ag treatment, markedly downregulated CD73 mRNA in tissue with concomitant rise of the inflammatory cytokine TNF-α. In Th cells, Ag treatment or infection significantly reduced expression of CD73+ & CD39+CD73+ double positive cells compared to unstimulated/uninfected cells. Ag-treated & CD73-inhibited cells produced more anti-bacterial mediators (NO). Splenocyte derived Th cells from CD73-KO mice produced significantly more IL17A than wildtype mice when Ag treated. Also, Treg cells from Salmonella-infected wildtype mice expressed reduced CD73. CD73 downregulation during intracellular bacterial infection modulates host responses & may favor host protection.
Formation of mucosal resident memory CD8 T cells is controlled by mTOR. (IRC9P.705)
Authors: Marzo Amanda , Sowell Ryan , Rogozinska Magdalena , Nelson Christine , Vezys Vaiva 
Published: January 2023

Abstract
Mucosal tissues are sites of frequent pathogen exposure and major routes for the transmission of infectious diseases. Migration of virus-specific memory CD8 T cells into mucosal tissues such as the small intestine and vaginal mucosa is highly restricted to non-circulating tissue resident memory CD8 T cells. Resident mucosal memory CD8 T cells are sufficient to protect against the establishment of mucosa-acquired viral infections, and thus it is essential to develop vaccine strategies that elicit long-lived mucosal CD8 T cells. CD8 T cells residing in mucosal tissues are phenotypically distinct from those in secondary lymphoid tissues and factors critical for their formation are poorly defined. It is also unclear whether mucosal CD8 T cells possess a unique requirement for their generation and maintenance from that of circulating memory CD8 T cells. We report that unlike in the secondary lymphoid tissues, the formation of virus-specific memory CD8 T cells in the small intestine and vaginal mucosa is dependent on mTOR signaling. In addition, we demonstrate using a CD8 T cell mediated model of intestinal autoimmune disease that inhibiting mTOR results in a loss of CD8 T cells in the small intestine and protects mice from lethality. Furthermore, we will discuss data that targets mTOR signaling intrinsically within the CD8 T cells to provide mechanistic insight into how the mTOR pathway specifically controls the generation of mucosal CD8 T cells in response to viral infections.
Overexpression of suppressor of cytokine signaling-4 impairs T cell development and homeostasis (LYM7P.723)
Authors: Park Jung-Hyun , Feigenbaum Lionel , Luckey Megan 
Published: January 2023

Abstract
Suppressor Of Cytokine Signaling molecules (SOCS) are key players in regulating cytokine signaling. SOCS inhibits cytokine-induced JAK/STAT signaling by directly binding to JAK or by competing with cytokine receptor downstream signaling molecules. So far, eight SOCS family members have been identified, but only a few are known to play roles in the immune system. Here we identified SOCS4 as a SOCS family member whose expression is regulated during thymocyte development, with high mRNA and protein expression at the CD4, CD8 double positive stage and downregulation upon positive selection. To assess the role of SOCS4 during thymocyte development, we generated transgenic mice overexpressing a murine SOCS4 cDNA under the control of a human CD2 mini-cassette. Interestingly, SOCS4 overexpression resulted in reduced thymocyte numbers but did not affect CD4/CD8 lineage choice. Surprisingly, SOCS4 overexpression did not inhibit cytokine signaling. Instead, we found that SOCS4 transgenic T cells showed decreased ability to upregulate CD69 and CD5 following TCR stimulation. Moreover, we found that SOCS4 overexpression impaired positive selection in the thymus and interfered with T cell homeostasis in HY TCR transgenic mice. These results suggest a new role for SOCS4 in T cell development and homeostasis, independent of cytokine signaling.
Essential role of Cavβ2 in T Cell development and homeostasis. (LYM7P.715)
Authors: Jha Mithilesh , Jha Archana , Singh Ashish , Weissgerber Petra , Freichel Marc , Flockerzi Veit , Flavell Richard 
Published: January 2023

Abstract
Although many of the molecular components that regulate TCR signaling and thymocyte development are well characterized, the interactions between these molecules and their assembly in signaling complexes have remained elusive. Here, we report a novel and intriguing role of β2 regulatory subunit of voltage gated calcium channels (Cavβ2) during T cells development in thymus. We found that the T cell specific ablation of Cavβ2 resulted in severe reduction in thymocytes. Cavβ2-deficient DN and DP thymocytes were prone to die spontaneously. Consequently, the lack of Cavβ2 led to substantially lower peripheral T cell numbers, which became even more prominent in a competitive environment, thus emphasizing the crucial function of Cavβ2 in maintaining the peripheral T cell pool. Nicardipine, a selective Cav1 channel blocker, abolished the constitutive Lck phosphorylation in thymocytes and impacted the sustained calcium influx upon TCR-stimulation. The in vivo treatment of nicardipine resulted in a dramatic reduction in number of thymocytes and T cells but not bone marrow cells. Our findings demonstrate that Cavβ2 and Cav1 channels are critical components required during development and homeostasis of T cells.
Understanding Plasmodium-specific B cell dynamics during blood stage malaria infection (MPF6P.742)
Authors: Krishnamurty Akshay , Perez-Mazliah Damian , Pepper Marion 
Published: January 2023

Abstract
Immunity to malaria is acquired gradually and comes at the expense of 1 million deaths per year. Antibodies help confer clinical immunity and longitudinal studies of those in endemic areas show that B cell mediated protection develops slowly and is maintained only with constant re-exposure. These studies, however, do not give insight to the types of B cells responding and which are most protective. Using an antigen based enrichment method we observed the dynamics of Plasmodium-specific B cells in response to blood stage Plasmodium infection against Merozoite Surface Protein 1 (MSP1), a blood stage specific protein. We find at the peak of infection the emergence of short-lived plasmablasts and as parasitemia begins to decline later arising germinal center (GC) B cells form that seed a GC-derived memory B cell population. Surprisingly, there is an emergence of GC-independent B cells, which also form a stable memory population to levels similar to that of GC-derived cells. Together these data show that in response to infection, three heterogeneous populations of Plasmodium-specific B cells emerge with two stable memory populations maintained over time. We are currently assessing the functional contributions of each of these memory populations to protective immunity. These studies represent the first glimpse of the endogenous B cell response to Plasmodium with the hopes of defining optimally protective B cell responses.
IL-10R blockade enhances effector and memory CD4+ T cell responses during persistent bacterial infection (MPF6P.733)
Authors: Singh Abinav , Thirumalapura Nagaraja 
Published: January 2023

Abstract
Several bacterial pathogens have evolved to establish persistent infection in their hosts through suppression of host immune responses. IL-10 has emerged as a key immune-regulator during infection with various pathogens. Ehrlichia are tick transmitted bacteria that establish persistent infection in their natural reservoir hosts. In the present study, we analyzed the role of IL-10 in the development of immune responses and subsequent long-term protection against persistent ehrlichial infection in a murine model. We demonstrate that IL-10 secretion leads to reduced inflammatory responses and bacterial clearance and it also inhibits antigen-specific effector and memory CD4+ T cell responses during persistent bacterial infection. We also found that IL-10 secretion had no significant effect on the antigen-specific CD8+ T cell population. We observed that therapeutic blockade of IL-10R enhanced the magnitude and functional capacity of antigen-specific effector CD4+ T cells that translated into increased and more effective memory responses and secondary recall response after bacterial re-challenge. Our results provide new insights into the mechanisms of bacterial persistence and support the idea that alternative immune-based strategies may have applications in persistent bacterial infections.
TNF receptor 2 on CD8 T cells and TNF receptor 1 on non-CD8 T cells mediate upper genital tract pathology following primary genital Chlamydia muridarum infection (MUC7P.764)
Authors: Li Weidang , Manam Srikanth , Thomas Joshua , Schripsema Justin , Ramsey Kyle , Murthy Ashlesh 
Published: January 2023

Abstract
We recently demonstrated that pathogenesis in the upper genital tract (UGT) following primary vaginal Chlamydia muridarum infection in mice is dependent upon TNF-alpha production and antigen-specific CD8 T cells. In this study, we evaluated the contribution of TNF receptor 1 (TNFR1) and TNFR2 to UGT pathogenesis following primary intravaginal C. muridarum infection (5X104 IFU/mouse), using depo-provera ® treated mice deficient in TNFR1 (TNFR1 KO), TNFR2 (TNFR2 KO), or TNFR1 and 2 (TNFR1/2 DKO), and the corresponding C57BL/6J wild type (WT) mice. All groups (n=8) of mice displayed comparable chlamydial clearance, antigen-specific cytokine response, and serum anti-chlamydial antibody following primary bacterial inoculation. On day 80 after primary inoculation, TNFR1 KO, TNFR2 KO, and TNFR1/2 DKO mice displayed significantly reduced oviduct pathology (hydrosalpinx), when compared to WT mice, suggesting that both TNFR1 and TNFR2 contribute significantly to oviduct pathology. Repletion of wild type or TNFR1 KO CD8 T cells did not enhance pathology significantly in TNFR1 KO mice. On the other hand, repletion of WT, but not TNFR2 KO, CD8 T cells enhanced oviduct pathology to WT levels in TNFR2 KO mice. Collectively, these results suggest that TNFR2 on CD8 T cells and TNFR1 on non-CD8 T cells mediate UGT pathology following primary genital chlamydial infection.
Programmed death-ligand 1 expressed on corneal epithelium inhibits the local innate and adaptive immune response in the herpes simplex virus-1-infected cornea (MUC7P.751)
Authors: Jeon Sohyun , Harvey Stephen , Hendricks Robert 
Published: January 2023

Abstract
Constitutive expression of the PD-L1/B7-H1 ligand for the inhibitory receptor Programmed Death-1 (PD-1) appears to help protect the cornea from damaging inflammation, but might also limit clearance of pathogens from this mucosal surface. Indeed, mice lacking B7-H1 expression or those treated locally in the cornea with anti-PD-L1 mAb exhibited enhanced clearance of herpes simplex virus type 1 (HSV-1) from the cornea from 1 - 4 days post infection (dpi). PD-L1 expression peaked in the cornea on both CD45+ and CD45- cells at 4 dpi. Increased early viral clearance (1 dpi) was associated with significantly increased infiltration of CD45+ Gr-1+(presumed neutrophils) and increased production of the neutrophil chemokines CCL3 and CXCL1. Bone marrow chimeras that expressed PD-L1/B7-H1 only on bone marrow derived cells exhibited enhanced late viral clearance at 4 dpi in association with increased numbers of CD69+ CD3+ cells, but did not show enhanced early viral clearance at 1 dpi. Our findings suggest that PD-1 interacting with PD-L1/B7-H1 on CD45+ cells impairs early viral clearance from the cornea by inhibiting neutrophilic infiltration at 1 dpi, whereas PD-1 interacting with parenchymal cells (presumably corneal epithelial cells) inhibits late viral clearance by inhibiting T cell infiltration and/or activation at 3 dpi. Importantly, increasing viral clearance by inhibiting PD-1/PD-L1 interaction did not result in observable inflammatory damage to the cornea.
Renal monocyte-derived dendritic cells extend processes into the intravascular lumen (MUC7P.754)
Authors: Yatim Karim 
Published: January 2023

Abstract
Dendritic cells (DCs) have been shown to extend cellular processes that sample antigen (Ag) at barrier surfaces such as the epidermis and gut mucosa. Here, we tested the hypothesis that DCs in the kidney, a non-barrier organ, extend cellular processes into the blood vessel lumen, potentially allowing them to sample intravascular Ag. Flow cytometric analysis of the mouse kidney revealed multiple DC subsets (Lineage-(CD19,CD90,NK1.1,Ly-6G)CD45+CD11c+MHCII+cells). Among these, monocyte-derived DCs (mono-DC: CD11b+F4/80- DC) were the majority at ~68%. Two-photon intravital microscopy (2-PIM) of CD11c-eYFP (DCs express YFP) and CX3CR1-GFP (monocytic-lineage cells express GFP) mouse kidneys showed identical cellular networks located between the endothelial and epithelial cell layers. 2-PIM of CD11c-eYFP x CX3CR1-GFP mouse kidneys, where mono-DCs express GFP and YFP, revealed that this network is mainly composed of mono-DCs. The mono-DC network encased renal post-capillary venules. High-resolution image stacks of mouse kidneys showed DCs extending processes into the lumina of post-capillary venules. Intravascular filling defects, as well as capture of intravascularly retained, anti-CD11c-coated beads by mono-DCs, confirmed the above finding. Our data indicate that in the kidney, mono-DCs extend processes into the lumina of postcapillary venules. This suggests a role for the kidney in immune surveillance of the blood.
Regulation of plasma cell IgA production through the B cell maturation antigen receptor (MUC8P.802)
Authors: Wade Nekeithia , Loo William , Erickson Loren 
Published: January 2023

Abstract
B Cell Maturation Antigen (BCMA) is a receptor expressed on plasma cells (PCs) and is important for the survival of long-lived PCs in the bone marrow. Our laboratory has shown that autoimmune-prone mice deficient in BCMA (lpr.BCMA-/-) develop an exacerbated autoimmune phenotype, including increased numbers of PCs, T cells, and serum autoantibody IgG titers. We recently determined that these mice also have increased total and auto-antigen specific serum IgA titers. Because IgA is normally produced in the mucosa-associated lymphoid tissue, this observation suggests a loss of tolerance in the intestinal mucosa. Based on these data, we hypothesized that BCMA signaling regulates homeostasis between commensal bacteria and the protective intestinal IgA response. We found that lpr.BCMA-/- mice have increased serum secretory IgA and commensal-specific IgA levels compared to controls. However, this was not due to increased intestinal permeability as assessed by a serum FITC dextran assay. To determine if commensal bacteria regulate peripheral IgA responses, lpr.BCMA-/- mice were placed on a one month antibiotic regimen. This regimen ameliorated autoimmune disease and reduced IgA-producing PCs, including both autoantibody and commensal-specific IgA. These results suggest that BCMA is important for the regulation of intestinal mucosal tolerance in our models, elucidating a previously unknown role for BCMA in maintaining the balance between commensals and the adaptive immune response.
T-bet controls intestinal chronic inflammation via regulation of IL-10 production by CD4 T cells (MUC8P.806)
Authors: Shin Boyoung , Poholek Catherine , Yeh Wen-I , Harrington Laurie 
Published: January 2023

Abstract
The dynamics of pro- and anti-inflammatory cytokine secretion by CD4 T cells is critical for the maintenance of intestinal homeostasis. Disruption of this equilibrium can result in chronic inflammation in the intestine, causing inflammatory bowel disease (IBD). Among the various subsets of CD4 T cells, the Th1 and Th17 subsets are increased in IBD patients and are proposed to be pathogenic. Therefore, understanding the mechanisms by which these cells are regulated is important to expand current treatments of IBD. Using the CD4 T cell dependent adoptive transfer model of colitis, we have investigated the Th1-associated transcription factor, T-bet, in the context of intestinal inflammation. Loss of T-bet results in Th17 skewed immune responses; however, despite wild-type Th17 CD4 T cells being colitogenic, transfer of T-bet deficient naïve CD4 T cells fails to induce colitis in a lymphopenic recipient. Surprisingly, we show that IL-10 production is significantly increased in CD4 T cells in the absence of T-bet. Furthermore, deficiency of both T-bet and IL-10 negates the protective effects of T-bet deficiency alone, as recipients of T-bet-/-IL-10-/- CD4 T cells develop colitis with similar weight loss and histological damage to recipients of wild-type CD4 T cells. Therefore, our data suggests that T-bet plays crucial role in the maintenance of intestinal homeostasis by regulating the intricate balance of effector and regulatory cytokines, in particular IL-10 levels.
Homeostatic IL-23R signaling limits TH17 response through IL-22-mediated containment of commensal microbiota (MUC9P.818)
Authors: Ghilardi Nico , Cox Jennifer , Shih Vincent 
Published: January 2023

Abstract
Mammalian hosts are colonized with commensal microbes in various mucosal and epithelial tissues, including the intestinal tract. In mice, the presence of segmented filamentous bacteria (SFB) is required for TH17 differentiation and the development of autoimmune disease. Here we demonstrate that the IL-23 pathway dynamically regulates the abundance of SFB as well as mucosal barrier function in the adult animal. Genetic or pharmacological inactivation of the pathway selectively perturbs abundance of a small group of commensals, including SFB, and results in an impaired mucosal barrier, leading to systemic microbial dissemination. Conversely, microbial dissemination leads to induction of the IL-23 pathway with dual consequences: IL-23 drives IL-22 production to reinforce mucosal barrier function and elicit antimicrobial activities. It also drives the differentiation of TH17 cells in an attempt to combat escaped microbes in the lamina propria and in distal tissues. Thus barrier defects generate a systemic environment that facilitates TH17 development.
In vivo miR-146a administration reverses Pristane-induced pulmonary hemorrhage in C57BL/6 mice (THER5P.836)
Authors: Liang Dong , Zhou Shiyu , Liu Zheng , Shan Zhengyuan , Brohawn Philip , Yao Yihong , Harley John , Shen Nan 
Published: January 2023

Abstract
Purpose: MiR-146a as a lupus susceptibility gene plays a critical role in resolving acute inflammation. This study explored a therapeutic potential of miR-146a to treat Pristane-induced pulmonary hemorrhage in a murine model of lupus. Methods: The C57BL/6 (B6) mice were intravenously injected with PBS or miR-146a via lateral tail veins. The peripheral bloods from 3, 7 and 14 days post Pristane injection were evaluated by real time PCR or gene expression profile analysis. For comparison, the B6 mice were categorized into 3 groups, receiving respectively 3 consecutive injections of PBS (control group) or miR-146a either 3 days before (prevention group) or 7 days after (treatment group) a single intraperitoneal injection of Pristane. The pulmonary hemorrhage was histologically investigated by HE staining. Results: The injections of miR-146a mimic (agomir) increased its peripheral blood expression in both the prevention and treatment groups. HE staining showed that miR-146a administration reduced the prevalence of complete pulmonary hemorrhage from 56% in control group to 25% in treatment group and further to 0% in prevention group. Gene expression profile analysis showed that miR-146a treatment substantially suppressed multiple inflammatory signaling pathways. Conclusion: MiR-146a plays a suppressive role in the Pristane-induced pulmonary hemorrhage in B6 mice. Interference with miR-146a may constitute a useful therapeutic intervention for SLE patients with pulmonary hemorrhage.
Metabolic inhibitors normalize CD4 T cell metabolism and functions, and reverse disease in a murine model of lupus (THER5P.839)
Authors: Yin Yiming , Brusko Todd , Perry Daniel , Seay Howard , Mathews Clayton , Sobel Eric , Morel Laurence 
Published: January 2023

Abstract
Autoreactive CD4 T cells are key effectors in Systemic Lupus Erythematosus (SLE). Cell metabolism is an important checkpoint for T cell activation, proliferation, and differentiation. We hypothesized that 1) SLE T cells have metabolic defects that cause abnormal T cell functions; 2) Targeting T cell metabolism may abrogate T cell inflammatory functions and reduce disease symptoms in SLE mice. Metabolism of CD4 T cells from lupus-resistant B6 mice and the congenic lupus model B6.Sle1.Sle2.Sle3 (B6.TC) were studied. Here it was observed that compared to B6, CD4 T cells from B6.TC mice have a stronger glycolysis and a higher mitochondrial oxygen consumption, as well as an enhanced mTOR activity. To normalize T cell metabolism in B6.TC mice, we used metformin, which activates the AMPK pathway and inhibits mitochondrial oxygen consumption, and 2-DG, an inhibitor of glycolysis. In vitro, metformin blocks IFNγ production by CD4 T cells and facilitates Treg development. 2-DG also blocks IFNγ production, but only after T cell activation. In vivo, a combined treatment with metformin and 2-DG of B6.TC mice normalized T cell metabolism and reversed disease phenotypes, including T cell activation and autoantibody production. Further, CD4 T cells from SLE patients have an enhanced metabolism as compared to healthy controls, and excessive IFNγ production was significantly reduced by metformin. Our research suggests that T cell metabolism is a novel target for SLE treatment.