bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-4 upregulates Igα and Igβ protein, resulting in augmented IgM maturation and amplified BCR-triggered B cell activation in vitro and in vivo (P6230)
Authors: Guo Benchang , Rothstein Thomas 
Published: January 2023

Abstract
Interleukin 4 (IL-4) is critical for optimal B cell activation in T-dependent responses; however, the underlying mechanism remains elusive. In the present study, we demonstrate that IL-4-pretreatment markedly up-regulates STAT6-dependent Igα and Igβ protein expression in a translational manner in primary B cells. Elevated Igα and Igβ protein significantly promotes IgM maturation and IgM surface expression as evidenced by isolated overexpression of Igα and Igβ in a B cell line and this increased surface IgM is associated with augmented BCR-initiated ERK phosphorylation. In vivo, Tfh-derived IL-4 is critical for germinal center B cell expansion as shown by significant reduction of germinal center B cells in SRBC-immunized IL-4 receptor alpha deficient mice relative to wild type control mice. We find that IL-4 facilitates BCR-initiated pre-germinal center B cell activation by up-regulating Igα, Igβ, surface IgM expression and BCR-triggered pERK, all of which were reversed by administration of neutralizing anti-IL-4 antibody. In sum, this study elucidates a novel mechanism for crosstalk between the IL-4 receptor and B cell receptor.
IL-12 is required for mTOR regulation of memory CTLs during virus infection (P6232)
Authors: Garcia Karla , Xiao Zhengguo 
Published: January 2023

Abstract
Inflammatory cytokines are critical in the induction of memory CTLs, and inhibition of mTOR by rapamycin can enhance memory CTL generation. However, it is unknown if important inflammatory cytokines such as IL-12 are involved in the regulation of memory CTLs by mTOR during infection. We show here that inhibition of mTOR by rapamycin represses CTLs expansion and enhances memory CTL generation during vaccinia virus infection in mice. In addition, rapamycin promotes central memory phenotype in CTLs. However, the absence of IL-12 signal in CTLs diminishes rapamycin regulation on both CTL expansion and subsequent memory CTL formation, despite that rapamycin substantially increases memory CTLs when IL-12 signal is missing. Moreover, rapamycin-regulated memory CTLs in the absence of IL-12 are impaired in secondary expansion upon pathogen challenge, and subsequently form abolished secondary memory. In conclusion, IL-12 contributes to the strength of rapamycin regulation on primary memory CTLs, and lack of IL-12 signal leads to impaired secondary expansion of memory CTLs. Thus, the IL-12 signal is required for mTOR regulation on functional memory CTLs.
Novel CX3CR1+hi monocyte-derived dendritic cell subtype with inflammatory properties (P6244)
Authors: Beceiro Susana , Cortado Hanna , Partida-Sanchez Santiago 
Published: January 2023

Abstract
Blood monocyte-derived macrophages (MØ) and dendritic cells (DCs) are essential for effective control of infections. Exacerbated recruitment of these cells, in the other side, contributes to the pathogenesis of chronic inflammatory diseases. The main blood monocyte subsets differ in the expression of the differentiation marker Ly6C and the chemokine receptors CCR2 and CX3CR1. We recently found a subset of Ly6Clow/CCR2low/CX3CR1hi associated to inflammatory responses induced by urinary tract infection in the mouse. Therefore, here we analyzed monocyte-derived inflammatory cell subsets in a model of non-bacterial peritonitis using CCR2 and CX3CR1 KO mice. We found that CCR2 is not required for tissue recruitment of monocyte-derived MØ under homeostatic conditions. In contrast, CCR2 expression is required for the recruitment of two Ly6Chi/CX3CR1low and Ly6Clow/CX3CR1hi subpopulations of inflammatory cells. Furthermore, sorted Ly6Clow/CX3CR1hi cells produced high levels of IL-6, MIP-1 and TNF-α cytokines. These cells showed dendritic cell morphology, low levels of F4/80 but CD11c expression, as well as Class-II, CD80, and CD86 DC markers. In addition, Ly6Clow/CX3CR1hi cells were capable of picking-up antigen and trafficked to lymph nodes demonstrating specific DC functions. In summary, our studies indicate that blood monocytes expressing Ly6Clow/CX3CR1hi give rise to a novel inflammatory DC subset recruited to tissue during infectious or non-infectious inflammatory conditions.
CCR2 blockade of monocyte migration is less potent at higher CD11b integrin levels in HIV-1 infection (P6213)
Authors: D'Antoni Michelle , Jalbert Emilie , Shikuma Cecilia , Barbour Jason 
Published: January 2023

Abstract
Monocytes are a key contributor to HIV inflammation and HIV-associated neurocognitive disorders by migrating into the brain in response to chemokine gradients, such as MCP-1 (a CCR2 ligand). We sought to characterize the migration capacity of monocytes from HIV infected adults. Cryopreserved peripheral blood mononuclear cells from HIV-1 infected adults (n=6) were incubated with BMS-22 (blocks MCP-1 binding to CCR2) and transferred to a transwell migration system, and put under an MCP-1 gradient. Migrated cells were collected and stained for CD3, CD14, CD16, HLA-DR, CCR2, CCR5 and CD11b. Cells were acquired on a Fortessa flow cytometer and analyzed using FlowJo. MCP-1 caused a significant increase in migration compared to baseline (3.0 fold change, p = 0.01) in the absence of BMS-22. There was a significant inverse correlation between CD11b mean fluorescence intensity (MFI) and degree of inhibition of migration by BMS-22 (rho = -0.88, p = 0.03). A trend between higher CCR2 and CCR5 MFI and lower migratory rates was also observed. Higher CD11b rates associated with poorer inhibition of migration by BMS-22, a CCR2 but not CD11b antagonist. Blocking MCP-1 is being pursued as a novel treatment method in HIV. The incomplete inhibition of monocyte migration at higher CD11b expression levels by a CCR2 antagonist highlights compensatory mechanisms between CCR2 and integrins, and indicates CD11b levels could guide effective use of CCR2 antagonist based therapies in humans.
An in vivo induced membrane antigen of Lyme disease pathogen triggers murine joint inflammation (P6258)
Authors: Yang Xiuli , Pal Utpal 
Published: January 2023

Abstract
Borrelia burgdorferi bba57 is a plasmid-encoded gene-product of unknown function. Here we show that bba57 is induced in vivo and facilitates early murine infection. While BBA57 is not required for pathogen persistence during later phases of infection, unlike wild type isolate, the mutants failed to induce severe disease. We show that BBA57 is an outer membrane and surface-exposed antigen that is essential for the genesis of murine joint inflammation. Using a PCR array, we further identified that deficiency of BBA57 reduces the expression of selected “neutrophil-recruiting” chemokines and associated receptors in the joints that ultimately results in severe impairment of neutrophil infiltration. Similarly, using an established chemotaxis assay we demonstrated that BBA57 is directly involved in neutrophil migration in vitro. Taken together, our data suggest that BBA57 is a major trigger of murine Lyme arthritis, and that interfering with BBA57 may contribute to the development of new therapeutic strategy to prevent Lyme arthritis.
Hantaan virus induces high expression levels of CXCL10 via TLR3, RIG-I, and MDA5 pathways. (P6221)
Authors: Zhang Yusi , Liu Bei , Ma Ying , Zhang Chunmei , Yi Jing , Zhang Yun , Zhuang Ran , Jin Boquan 
Published: January 2023

Abstract
Hantaan virus is a major agent causing hemorrhagic fever with renal syndrome, a high-mortality-rate disease. However, the pathogenesis of HFRS remains to be elucidated. We found that CXCL10 expresses highly in the HFRS-patients’ sera and the increased CXCL10 is positively correlated with the severity of HFRS. To clarify the molecular mechanisms of HTNV infection inducing CXCL10 expression, the HTNV-infected human umbilical vein endothelial cells model has been used. The results indicated that the dsRNA, produced in the process of HTNV replication, could activate TLR3, RIG-I, and MDA5 pathways, which facilitated the translocation of IRF7 and NF-κB. Afterwards, the two transcription factors bound directly to the CXCL10 promoter region and promoted the transcription and expression of CXCL10. Furthermore, we found that the expression levels of CXCR3, the receptor of CXCL10, increased on the surface of monocytes at the early stage of HFRS. It suggested that CXCL10 may recruit monocytes, which may be involved in the cytokine storm and the pathogenesis of HFRS. Further studies are still needed to reveal the function of CXCL10 in the pathogenesis of HFRS. In conclusion, we reported that the increased CXCL10 level was associated with the state of the HFRS. The activation of innate immunity induced by HTNV replication may be of importance in the regulation of CXCL10 expression and the abundant CXCL10 may play an important role in the pathogenesis of HFRS.
Flowcytometric evaluation of T lymphocyte suppression by Euphorbia hirta (P6226)
Authors: Albakheet Saleh , Ahmad Sheikh 
Published: January 2023

Abstract
Euphorbia hirta is a tree locally used as a traditional medicine in Africa and Australia to treat numerous diseases such as hypertension, respiratory ailments, tumors, anti-inflammatory activities etc. The objective of the study was to investigate immunomodulatory effects of the ethanol extract of E. hirta on humoral antibody & delayed-type hypersensitivity (DTH) immune responses, graft rejection, T-lymphocytes (CD3+, CD4+ and CD8+ receptors), B- lymphocyte (CD19+ receptor) and Th1 cytokines (IL-2, TNF-α & IFN-γ) in dose dependent manner in mice. Assessment of T and B cell receptors and their intracellular content of (Th1) cytokines was carried out by flowcytometric analysis in Balb/c mice. E. hirta ethanol extract at 25-200 mg/kg doses was given orally for seven days from the day of immunization with sheep red blood cells (SRBC) as an antigen. Cyclosporine 5 mg/kg and levamisole 2.5 mg/kg was used as standard drug. E. hirta maximum inhibition at 100 and 200 mg/kg p.o was found to significantly block the production of the cell mediated immune response, (CD3+, CD4+, CD8+ and CD19+ receptors) and Th1 (IL-2, TNF-α & IFN-γ) and also prolongs graft rejection. E. hirta also showed a decrease of DTH response and dose related decrease in the primary antibody response. Based on the data, it can be suggested that E. hirta is a potent and non-toxic immunosuppressor, which can be further explored for the development of potent immunosuppressor.
Nitric oxide inhibits the NLRP3 inflammasome (P1270)
Authors: Tsuchiya Kohsuke , Hernandez-Cuellar Eduardo , Hara Hideki , Fang Rendong , Sakai Shunsuke , Kawamura Ikuo , Mitsuyama Masao 
Published: January 2023

Abstract
Activation of the inflammasome leads to caspase-1 activation and maturation of pro-inflammatory cytokines, IL-1β and IL-18. The inflammasome plays a pivotal role in host defense against microbial pathogens. However, its uncontrolled activation is associated with inflammatory disorders, suggesting that regulation of inflammasome activation is important to prevent detrimental effects. In this study, we found that endogenous and exogenous NO inhibits the NLRP3 inflammasome. iNOS was involved in the regulation of NLRP3 inflammasome activation by either IFN-β pretreatment or long-term LPS stimulation. Furthermore, the NO donor SNAP markedly inhibited NLRP3 inflammasome activation, while the AIM2 and NLRC4 inflammasomes were only partially inhibited by SNAP. An increase in mitochondrial reactive oxygen species induced by ATP was only modestly affected by SNAP treatment. S-nitrosylation of NLRP3 was detected in macrophages treated with SNAP, and this modification may account for the NO-mediated mechanism controlling inflammasome activation. Taken together, these results revealed a novel role of NO in regulating the NLRP3 inflammasome.
Memantine modulation of LPS-induced NLRP3 inflammasome and pro-inflammatory cytokine expression (P1278)
Authors: Chang Sulie , Mao Xin , Sarkar Sraboni 
Published: January 2023

Abstract
The bacterial endotoxin, lipopolysaccharide (LPS), can induce the production of pro-inflammatory cytokines. Pro-inflammatory signaling is partly mediated through multiprotein complexes known as inflammasomes, including the NLRP3. Recent studies report that systemic treatment with low doses of the drug, memantine, decreases cytokine levels. In this study, LPS induction of several pro-inflammatory cytokines and the NLRP3 inflammasome were examined, with and without memantine treatment. Male F344 rats were treated with LPS (500 μg/kg) or saline intraperitoneally (i.p). Thirty minutes after treatment, the rats were given (i.p.) either memantine (0.2, 5, or 10 mg/kg) or saline. Blood and spleen were collected 1.5 h after treatment. Serum cytokine levels were measured using electrochemiluminescent assays; IL-1β and NLRP3 expression in the spleen was determined using real-time PCR. LPS-induced IL-1β, IL-5, and KC/GRO serum levels were significantly increased, and reduced by only the 5 and 10 mg/kg doses of memantine. LPS-induced IL-1β expression in the spleen was also significantly increased, but reduced only following a 10 mg/kg memantine dose. NLRP3 expression in the spleen was significantly increased after LPS, and decreased significantly by all doses of memantine. Our findings suggest that inhibition of the NLRP3 inflammasome may be one of the mechanisms underlying memantine’s anti-inflammatory actions.
The PYHIN family member IFI205 regulates immune signaling via transcriptional regulation of the inflammasome adapter ASC (P1280)
Authors: Ghosh Sreya , Carpenter Susan , Fitzgerald Katherine 
Published: January 2023

Abstract
Members of the PYHIN protein family such as AIM2 and IFI16, function as DNA sensors in innate immunity. Here we investigated the role of Ifi205, a murine PYHIN family member in innate immunity by generating murine macrophages lacking Ifi205 and monitoring immune signaling in these cells. Macrophages lacking Ifi205 had abrogated caspase-1 dependent processing and production of the pro-inflammatory cytokine IL-1β in response to cytosolic double stranded DNA and Nigericin, that activate the AIM2 and NLRP3 inflammasomes, respectively. Surprisingly, expression of the inflammasome adapter ASC was completely abolished at both the protein and mRNA levels in all Ifi205 knockdown cells generated. Reconstitution of the knockdown cells with ASC rescued IL-1β production attributing the knockdown phenotype to the loss of ASC expression. We observed a similar defect in ASC expression in cell lines lacking Ifi205 by targeting the 3’-UTR of the ifi205 gene. Reconstitution of these cells with Ifi205 rescued ASC mRNA expression. We also found that ectopic expression of Ifi205 augmented the activation of an ASC promoter-luciferase reporter gene in a dose-dependent manner in HEK 293T cells. The data suggest that ASC expression might be controlled at the transcriptional level. Thus, Ifi205 regulates inflammasome activation by controlling transcriptional regulation of ASC.
Gardnerella vaginalis causes inflammasome recruitment and inflammatory cytokine release in human monocytes (P1282)
Authors: Vick Eric , Huff Krista , Ouellette Corbett , Park Erin , Farone Mary , Farone Anthony 
Published: January 2023

Abstract
Intrauterine inflammation during pregnancy can cause prenatal brain injury, and is associated with preterm birth. Gardnerella vaginalis (GV) is a gram variable rod associated with bacterial vaginosis, pelvic inflammatory disease, bacteremia, and preterm birth. Bacterial vaginosis samples demonstrate up-regulation of Toll-like Receptor 2 and 4 mRNA and secretion of IL-1β in cultured trophoblasts. It has not been clearly demonstrated that isolated GV specimens are capable of the characteristic inflammatory downstream effectors in monocytes. We set out to determine if GV causes inflammatory effector recruitment and expression of proinflammatory cytokines in a human monocyte cell line, THP-1. An ASC-YFP overexpression system was used for immunofluorescent detection of inflammasome components, the Annexin-V apoptosis assay was used for viability, and cytokine levels were quantified by ELISA. Immunofluorescent detection showed co-localization of both NLRP3 and NLRC4 with ASC-YFP in GV-treated and LPS/ATP-treated cells. GV-treated cells exhibited a statistically significant IL-1β, IL-18, and TNFα response over untreated cells, however, IL-18 was significantly increased compared to LPS/ATP treatment. GV-treated cells remained viable through 24 h which demonstrates that GV causes significant cytokine elevation in THP-1 cells, without significant cell death. These results suggest that GV infection may lead to significant sequelae by production of proinflammatory cytokines.
Foxo1 is essential for effector-to-memory transition in CD8+ T cells (P1420)
Authors: Hess Michelini Rodrigo , Doedens Andrew , Goldrath Ananda , Hedrick Stephen 
Published: January 2023

Abstract
The forkhead DNA binding domain, O subgroup of transcription factors (FOXO) integrate a range of extracellular signals including growth factor and nutrient availability, and assimilate these to subsequent downstream FOXO TF activity to modulate cell survival, cell cycle progression, and a multitude of cell-type specific responses yet to be unraveled. CD8+ T lymphocytes are essential for the clearance of intracellular pathogens, and they undergo a rapid expansion and arming of effector function within days of pathogen exposure. Upon pathogen clearance, most cells die off while a subset remain with short-term or long-term memory function; this contraction is thought to depend on availability of growth factors/inflammatory cytokines and TCR stimulation, all of which regulate FOXO TFs. Using LCMV Armstrong as an infection model, we found that upon the transition from effector to memory FOXO1-/- CD8+ T cells contract slowly. In addition, memory precursors KLRG1lo CD8+ T cells retain higher GranzymeB and display an enhanced effector phenotype. Consistent with this phenotype, FOXO1-/- CD8+ T cells fail to upregulate memory-associated Tcf7, Eomesodermin, Bcl2, and a multitude of lesser known memory signature genes. As a result, FOXO1-/- CD8+ T cells were unable to properly respond to a secondary infection. Our results demonstrate an intrinsic role for FOXO1 in regulating the post-antigenic crash of CD8+ T cells, and is essential for the transition from effector to true memory.
Progressive memory differentiation of CD8 T cells is regulated by de novo DNA methylation (P1426)
Authors: Youngblood Benjamin , Hale Jeffery , Xu Xiaojin , Ahn Eunseon , Araki Koichi , West Erin , Konieczny Bogumila , Ahmed Rafi 
Published: January 2023

Abstract
Memory CD8 T cells generated from acute infection or vaccination have the potential to provide the host with life-long immunity against re-infection, yet one of the least understood and most remarkable attributes of memory T cells is their ability to progressively regain select naïve cell functions following the effector stage of the response. Presently debated is whether or not CD8 T cell memory arises through progressive modification of effector programs. To ascertain if effector programs are progressively modified during the effector to memory stage of the response, we performed longitudinal analyses of acquired epigenetic programs at the L-selectin (CD62L) promoter in virus-specific CD8 T cells during acute LCMV infection of mice. We observed that the CD62L promoter acquires a repressive de novo DNA methylation program in both terminal (TE) and memory precursor (MP) effector CD8 T cells. Demethylation of the de novo program in MP effector cells results in re-expression of CD62L at the memory stage of differentiation and occurs in the absence of cell division. Conditional deletion of the DNA methyltransferase 3a blocks methylation of the CD62L promoter in effector cells resulting in faster CD62L re-expression during effector to memory cell conversion. These data provide proof-of-principle that progressive modification of epigenetic programs in CD8 T cells undergoing memory differentiation is utilized to re-acquire naïve-like properties to enhance the recall response.
Determining molecular mechanisms of Tc17 plasticity in vitro and in vivo (P1414)
Authors: Ceccato Christina , Nirschl Christopher , Durham Nicholas , Alme Angela , Jackson Christopher , Drake Charles 
Published: January 2023

Abstract
We and others have shown that CD8+ T cells cultured in the presence of IL-6 and TGF-β acquire the capacity to secrete IL-17 (Tc17). Several in vivo tumor models have shown that adoptively transferred Tc17s have an equivalent if not superior anti-tumor response compared to adoptively transferred cells activated in the presence of IL-12 (Tc1). Since the efficacy of Tc17s correlates to conversion to an IFN-γ secreting phenotype, we sought to understand the mechanism of IL-17+ to IFN-γ+ conversion (plasticity). In this report, we show that antigen-specific, sorted IL-17+IFN-γ- (pure Tc17) cells that are re-cultured in vitro can convert to an IFN-γ secreting phenotype. Surprisingly, this conversion occurs not in the presence of Tc1 skewing cytokines but rather in the presence of IL-2 or IL-7. This conversion in vitro appears to be controlled by the balance of the transcription factors Tbet and RORγT. When ova-specific Tc17s are adoptively transferred in vivo they maintain a stable phenotype, but convert during re-stimulation with Vaccinia-Ova. The balance of the transcription factors Eomesodermin and RORγT likely controls this in vivo conversion, where IL-17 is not expressed in Eomesodermin positive CD8 T cells. Our data provide insight into the nature of these cells that could be important in clinical scenarios such as chronic infectious diseases or adoptive T cell immunotherapy.
CD8 T cells express randomly selected KIRs with distinct specificities compared to NK cells (P1418)
Authors: Björkström Niklas , Beziat Vivien , Cichocki Frank , Liu Lisa , Levine Jeffrey , Larsson Stella , Koup Richard , Anderson Stephen , Ljunggren Hans-Gustaf , Malmberg Karl-Johan 
Published: January 2023

Abstract
Epistatic interactions between killer cell immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands have important implications for reproductive success, anti-viral immunity, susceptibility to autoimmune conditions and cancer, as well as for graft-versus-leukemia reactions in settings of allogeneic stem cell transplantation. Although CD8 T cells are known to acquire KIRs when maturing from naïve to terminally differentiated cells, little information is available about the constitution of KIR repertoires on human CD8 T cells. Here, we have performed a high-resolution analysis of KIR-expression on CD8 T cells. The results show that most CD8 T cells possess a restricted KIR expression-pattern, often dominated by a single activating or inhibitory KIR. Furthermore, the expression of KIR, and its modulation of CD8 T cell function, was independent of expression of self-HLA class I-ligands. Finally, despite similarities in the stochastic regulation of KIRs by the bi-directional proximal promoter, the specificity of inhibitory KIRs on CD8 T cells was often distinct from that of NK cells in the same individual. The results provide new insight into the formation of KIR repertoires on human T cells.