bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of NPRA in MDSC mediated suppression in cancer (P2071)
Authors: Nagaraj Srinivas , Nelson Allison , Mohapatra Subhra , Mohapatra Shyam 
Published: January 2023

Abstract
It is now evident that inadequate function of the host immune system is due to suppressive factors such as myeloid derived suppressor cells (MDSC). In our study we found that MDSCs isolated from tumor bearing mice expressed high levels of natriuretic peptide receptor A (NPRA) a receptor for atrial natriuretic peptide (ANP). Since MDSCs play a pivotal role in tumorigenesis, we addressed whether NPRA signaling may be linked with altered differentiation of myeloid cells and their suppressive function. We examined the wild type and NPRA deficient mice for MDSC differentiation, and the results showed that NPRA deficient mice exhibited restricted tumor growth and altered differentiation of MDSCs. Next we investigated the link between ANP levels and accumulation of MDSCs. Increase in ANP levels triggered expansion of MDSC. MDSCs suppressed T cells via reactive oxygen species (ROS), and increase in NPRA expression was associated with decreased miR150 as well as increased expression of Nox. NPRA KO mice showed increased expression of miR150 compared to WT mice.Our experiments suggested that activation of NPRA and was regulated by a key micro RNA, miR-150. Taken together, these results suggest a key role to NPRA signaling in myeloid cell differentiation and cancer progression.
Escape of myeloma cells from CD4 T-cell-driven immunoprotection (P2015)
Authors: Tveita Anders , Schjesvold Fredrik , Haabeth Ole Audun , Bogen Bjarne 
Published: January 2023

Abstract
Background: CD4+ T cells can mediate efficient immunosurveillance against MHC class II-negative cancer cells through indirect presentation of tumor-specific antigens on antigen-presenting cells (APCs). A CD4+ T cell response against an epitope on the immunoglobulin light chain of the Id peptide of MOPC315 myeloma cells can mediate an antitumor immune response that induces long term tumor dormancy, followed by eventual tumor escape. Interestingly, this escape occurs despite continued secretion of the tumor-specific antigen. Objective: To identify the immunoediting mechanisms underlying the loss of T-cell-mediated immunoprotection against MOPC315 myeloma cells Method: Mice injected with fluorescently labeled MOPC315 tumor cells were monitored using in vivo imaging. Parental and escape tumor cell clones were obtained, and gene- and protein expression characterized. Results: Escape tumor cells secrete an intact M315 Id peptide, but secretion of free light chains is selectively down-regulated. This limits exposure of the inciting antigen in a form that permits efficient antigen display by tumor-infiltrating APCs, despite preserved T cell reactivity within draining lymph nodes. Our study defines a novel mechanism of tumor immunoevasion by modified secretion of a natural tumor-specific antigen, which emphasizes the importance of antigen presentation within the tumor microenvironment, and has implications for the design of effective CD4+ T cell-based immunotherapy.
Fc receptor-targeting of immunogen as a strategy for enhanced antigen loading, vaccination, and protection using intranasally-administered ex vivo antigen-pulsed dendritic cells (P4292)
Authors: Pham Giang , Iglesias Bibiana , Rosa Sarah , Gosselin Edmund 
Published: January 2023

Abstract
Dendritic cells play a critical role in the generation of an effective adaptive immune response. This is primarily due to their ability to capture, process, and present Ag to naïve T cells. Administration of Ag-pulsed DCs has proven to be an effective strategy for enhancing immunity to both tumors and infectious disease organisms. In addition, our own studies using an F. tularensis infectious disease vaccine model have demonstrated that targeting immunogens to FcγR via intranasal administration of inactivated F. tularensis-mAb complexes enhances protection against F. tularensis challenge. Therefore, we sought to determine if ex vivo targeting of Ag to FcγR would enhance the potency of intranasally administered Ag-pulsed DCs. In this study, bone marrow-derived DCs were pulsed ex vivo with inactivated F. tularensis alone or complexed to mAb. Immunization of mice, via intranasal injection of F. tularensis-mAb-pulsed DCs, enhanced humoral and cellular immune responses, as well as protection against F. tularensis infection. These observations correlated with increased loading of Ag on the DCs as a consequence of FcR targeting. Importantly, engagement of the inhibitory receptor FcγRIIB had no impact on this enhancement. In conclusion, targeting Ag ex vivo via FcγR on DCs provides a method for enhanced Ag loading of DCs, while bypassing the inhibitory impact of FcγRIIB. Thus, this represents an important strategy for increasing the potency of ex vivo-pulsed DC vaccines.
Induction of central memory to BCG vaccine in mice through rapamycin (P4300)
Authors: Jagannath Chinnaswamy , Khan Arshad , Bakhru Pearl , Soudani Emily , Lewis Dorothy 
Published: January 2023

Abstract
BCG vaccine induced Th1 immunity protects against childhood tuberculosis failing to protect adults. BCG induces short lived effector T cells (SLECs) but poor memory precursor effector T cells (MPECs) in mice. Rapamycin prolongs antigen presentation by macrophages and also affects MTOR of CD8 T cells. Thus, we examined whether rapamycin co-treatment with BCG enhances MPECs. Methods: C57Bl/6 mice were immunized with BCG alone or BCG-rapamycin. Mice were challenged 4 weeks later (primary challenge) with an aerosol dose of virulent Mtb and T cell responses were evaluated using flow cytometry and correlated with protection measured as a decline in the number of challenged Mtb. T cells were typed using tetramers, intracellular IFNγ, T-bet and Eomes transcription factors. Mice were then cleared of mycobacteria through drug treatment and rested before rechallenge (secondary challenge) with virulent Mtb. Results: Following primary challenge, rapamycin enhanced the efficacy of BCG vaccine through a better expansion of both CD4 SLECs and CD8 T SLEC/MPECs. Only rapamycin-BCG treated mice showed a robust recall response of CD8 T cells in the lungs of rechallenged mice, with a 1-log10 better decline in the numbers of Mtb organisms. The lungs also contained a high number of TB10.4 tetramer-IFNγ positive CD8 T cells, and CD8 T cells expressing perforin and granzyme. Thus, enhancing the ability of BCG vaccine to induce MPECs, leads to a vaccine that can induce long term immunity.
Pertussis toxin-dependent inhibition of trafficking receptors on plasmacytoid dendritic cells and delay in the polarization of Th17 cells expressing mucosal-associated trafficking receptors during B. pertussis infection. (P3031)
Authors: Nguyen Tuan , Ferguson Ryan , Wu Victoria , Sequeira Christopher , Niknam Shahryar , Wan Judy , Taylor Marlene , Abramson Tzvia 
Published: January 2023

Abstract
Via murine infection models of B. pertussis (Bp) and BpΔPTX (Bp strain devoid of pertussis toxin [PTX]), we tested the hypothesis that PTX inhibits the expression of G-protein coupled receptors (GPCR) on dendritic cells (DC) and of mucosal-associated trafficking receptors (MATR) on CD4+ effector memory T cells. Lung plasmacytoid DC (pDC) increased during early infection with both strains. However, a reduced percentage of pDC from Bp infected lung expressed co-stimulatory molecules and the GPCR required for migration to secondary lymph nodes. Additionally, a modest rise of circulating Th1 cells was observed during early Bordetella infections. However, in Bp infection, a reduced number expressed MATR compared to those from BpΔPTX infection. Interestingly, at 10-25 days post infection, blood Th17 cells rose dramatically, followed by accumulation in the lung and a gradually elevated display of MATR. Lung T-regulatory cells arose in tandem with increased lung Th17 level, perhaps controlling the rise in lung inflammation. The temporal correlation between pDC and memory responses suggests that pDC responses, driven perhaps by opsonized Bordetella antigens, may interfere with the imprinting of MATR on CD4+ effector memory T cells. We conclude that the PTX-dependent defective MATR imprinting on Th1 cells and delayed polarization into Th17 cells expressing MATR during Bp infection in mice may be responsible for the prolonged disease and suggest a role of pDC in this mechanism.
Circulating plasmablasts of HIV-infected individuals dominantly produce polyreactive antibodies including anti-NMDAR antibodies contributing to HAND and HAD (P3037)
Authors: Liao Hongyan , Yu Yangsheng , Li Song , Yue Yinshi , Sandkovsky Uriel , Swindells Susan , Su Kaihong , Zhang Zhixin 
Published: January 2023

Abstract
In the post-HAART stage, a substantial percent of HIV patients develop HIV-Associated Neurocognitive Dysfunction and HIV-Associated Dementia. Finding early biomarkers is essential to diagnose and prevent these diseases. HIV infection causes B cell dysfunctions. To evaluate the functional antibody repertoire during HIV infection, we cloned the paired IgH and IgL genes from single circulating plasmablasts of 5 HIV patients and expressed 80 recombinant antibodies to determine their functions. We also expressed 80 antibodies from 5 donors without HIV infection as control. Analyses of antibodies from HIV-infected individuals showed that 30% of them weakly bind to gp120. Surprisingly, about 72% of the antibodies cloned from HIV-infected individuals were polyreactive, which is sharp contrast to the 16% of polyreactive antibodies from control donors. Up to 60% of them cross-reacted with the DWDYS peptide present in NMDA receptor. We found 17% of antibodies bound to SH-SY5Y or U251 cell surface antigens. Detailed analyses of one such antibody HIV201P5B2 derived from HIV patients showed that it induced NMDAR clustering and internalization and eventually caused neuronal cell apoptosis. Taken together, the dominant production of polyreactive antibodies in the plasmablasts of HIV patients revealed an abnormal alteration of B cell function during HIV infection. Anti-NDMAR antibodies generated in HIV patients may provide a new diagnostic biomarker for HAND and HAD in AIDS patient.
Aerosolized influenza infection during late gestation pregnancy results in severe clinical outcomes in the ferret model (P3004)
Authors: Cole Kelly , Gage Emily , Reed Doug , Trichel Anita , Oury Tim , Beigi Richard 
Published: January 2023

Abstract
In 2009, the emergence of pandemic A influenza virus (pH1N1) demonstrated greater severity in pregnant women compared to prior influenza pandemics. The Centers for Disease Control and Prevention reported a death rate of 20% in pregnant women in the United States hospitalized with influenza-like symptoms. To understand the immunological basis for the enhanced influenza-associated morbidity and mortality observed in pregnant women, pregnant and nonpregnant ferrets were challenged with aerosolized pH1N1 strain A/California/04/09. Pregnant ferrets had poorer gestational outcomes and a more fulminant disease course than nonpregnant controls. Viral load and tissue tropism were similar for both groups as determined by quantitative RT-PCR. Influenza virus was detected in the brains of both groups. Gross pathological analysis and H&E stains identified interstitial pneumonia in the lungs, with no significant pathology in any other tissues. Virus was also detected in placental tissue and kits of the pregnant ferrets suggesting transmission across the placental barrier. Pro-inflammatory cytokine analysis using semi-quantitative RT-PCR showed a disparity in cytokine profile in the pregnant versus the nonpregnant ferret tissues suggesting possible cytokine dysregulation. Both cohorts demonstrated comparable influenza-specific IgG responses by 5 dpi. This model will be useful in discerning the differences in host responses associated with greater morbidity and mortality during pregnancy.
Young and elderly patients with type 2 diabetes have optimal B cell responses to the seasonal influenza vaccine (P3007)
Authors: Blomberg Bonnie , Diaz Alain , Romero Maria , Landin Ana Marie , Frasca Daniela 
Published: January 2023

Abstract
We evaluated immune response to the seasonal influenza vaccine in young and elderly patients with type 2 diabetes (T2D). Immune measures included the in vivo serum response to the vaccine by hemagglutination inhibition (HAI) and ELISA in 22 patients (14 young, 8 elderly) and 65 healthy age-matched controls (37 young, 28 elderly). B cell-specific biomarkers of optimal vaccine response were measured ex vivo by switched memory B cells and plasmablasts and in vitro by activation-induced cytidine deaminase (AID) in stimulated cells. Markers of systemic and B cell-intrinsic inflammation were also measured. Results show that in vivo responses, as well as B cell-specific markers identified above, decrease with age in healthy individuals but not in T2D patients. This occurred despite high levels of B cell-intrinsic inflammation (TNF-α) in T2D patients, which was surprising as we had previously demonstrated this negatively impacts B cell function. We have preliminary data to indicate that the innate immune system of T2D patients is beneficially hyperactivated and we suggest that this may induce a direct stimulation of B cells. These results altogether suggest that valid protection against influenza can be achieved in T2D patients and proposed mechanisms are discussed.
Induction of neural guidance molecule expression in macrophages and dendritic cells by Mycobacterium tuberculosis. (P3017)
Authors: Bracho-Sanchez Edith , Ramkhelawon Bhama , Desvignes Ludovic , Moore Kathryn , Ernst Joel 
Published: January 2023

Abstract
Cellular immunity to Mycobacterium tuberculosis (Mtb) requires coordinated cell migration and localization to form granulomas. In addition to chemokines and adhesion proteins, we found that Mtb infection of mouse bone marrow-derived DC or MØ upregulated expression of members of a family of neuronal guidance molecules: netrins, semaphorins, slits, and ephrins, which have been implicated in inflammation and immunity. Since netrin-1 and its receptor Unc5b cause immobilization of MØ in atherosclerotic lesions, we hypothesized that up-regulation of these molecules during Mtb infection contributes to MΦ and DC sequestration in granulomas. Using RT-qPCR, we found that netrin-1 and its receptors: Unc5b, Adora 2a, and Adora2b are up-regulated in Mtb-infected cells. Immunoblotting revealed that netrin-1 is secreted by Mtb-infected MΦ, and immunofluorescence showed netrin-1 is expressed in the lungs of Mtb infected mice. Since netrin-1 is secreted, we studied the migration of peritoneal macrophages in response to CCL19 in the presence of supernatants from Mtb-infected or uninfected MΦ and DCs. Supernatants from Mtb-infected cells inhibited MΦ migration in a netrin-1-dependent fashion. Based on these results, we hypothesize that neuronal guidance molecules contribute to granuloma formation and/or maintenance in tuberculosis.
Chemerin is an antimicrobial agent in human epidermis. (P1257)
Authors: Cichy Joanna , Banas Magdalena , Zabieglo Katarzyna , Kasetty Gopinath , Kapinska-Mrowiecka Monika , Borowczyk Julia , Drukala Justyna , Murzyn Krzysztof , Zabel Brian , Butcher Eugene , Schroeder Jens , Schmidtchen Arthur 
Published: January 2023

Abstract
Chemerin is a chemoattractant ligand for chemokine like receptor 1 (CMKLR1). CMKLR1-positive human plasmacytoid dendritic cells and NK cells can be recruited to diseased skin in a chemerin-dependent manner. Chemerin is predicted to share similar tertiary structure with antibacterial cathelicidins, and recombinant chemerin has antimicrobial activity. Here we show that endogenous chemerin protein is abundant in human epidermis, and that inhibition of bacteria growth by exudates from organ cultures of primary human skin keratinocytes is largely chemerin-dependent. Using a panel of overlapping chemerin derived synthetic peptides, we demonstrate that the highly positively-charged chemerin domain Val66-Pro85 embodies the majority of the anti-microbial activity, which is comparable in potency to other antimicrobial proteins. Finally, we demonstrate that Val66-Pro85 likely functions by direct bacterial lysis. Therefore, chemerin may operate at multiple levels in skin defense, as a chemoattractant and an antimicrobial agent.
Toll-like receptor 10 mediates the inflammatory response to Listeria monocytogenes infection (P1263)
Authors: Regan Tim , Nally Kenneth , Brint Elizabeth , MacSharry John 
Published: January 2023

Abstract
Intestinal epithelial cells (IECs) represent the initial point of invasion for the pathogen Listeria monocytogenes however; the role of epithelial pattern recognition receptors (PRRs) engagement and subsequent inflammatory cascades remains poorly characterised. The aim of our study was to determine which PRRs are involved in initiating the immune response to L. monocytogenes in IECs. We performed a PRR siRNA library screen of 50 PRRs in the HT-29 IEC prior to infection with L. monocytogenes and then measured immune gene expression by qRT-PCR. Silencing of TLR1, TLR2, TLR10 and NLRP2 resulted in reductions in CCL20 and IL8 induction following infection, while silencing of NLRP7 and NLRP10 increased expression levels. Silencing of TLR10 gave the most significant effect and subsequent stable lentivirus knockdown of TLR10 in HT-29s yielded similar results upon infection. Similarly, silencing of TLR10 in macrophage-like THP-1 cells resulted in markedly reduced cytokine production in response to L. monocytogenes infection. Moreover, TLR10 silencing resulted in greater viability of L. monocytogenes in both THP-1 macrophages and HT-29 epithelia. Using an NF-κB reporter HEK cell line we found that TLR10 requires TLR2 for efficient NF-κB activation following L. monocytogenes infection. These data indicate a previously unknown role for TLR10 in sensing of pathogenic infection and moreover have potentially identified L. monocytogenes as a specific ligand for the orphan receptor TLR10.
Cathelicidin LL-37 bloodstream surveillance is down regulated during septic shock (P1267)
Authors: Pinheiro da Silva Fabiano , Barbeiro Denise , Barbeiro Hermes , Zampieri Fernando , Machado Marcel , Torggler Filho Francisco , Cunha Debora , Goulart Alessandra , Velasco Irineu , Cruz Neto Luiz , Souza Heraldo 
Published: January 2023

Abstract
Antimicrobial peptides are ancient weapons of the innate immunity. Cathelicidin antimicrobial peptides (AMPs) support the epithelial barrier against infection and are constitutively secreted in the bloodstream by immune cells. Current knowledge claims that cathelicidins are up regulated upon infection. Directly bactericidal, cathelicidins possess many additional immunomodulatory properties. Here, we show that LL-37, the human cathelicidin, is down regulated during septic shock. Furthermore, we show that these effects are not related to vitamin D serum levels, a potent inducer of LL-37 gene expression, pointing out that the mechanisms that control antimicrobial peptides activity involve multiple pathways.
MARCH1 regulates macrophage polarization and host responses against parasite infections (P1271)
Authors: Galbas Tristan , Raymond Maxime , Bourgeois-Daigneault Marie-Claude , Moffat Jessica , Ishido Satoshi , Villadangos Jose , Stäger Simona , Thibodeau Jacques 
Published: January 2023

Abstract
Aim: Polarization of macrophages to M1 or M2 phenotypes will dictate the effectiveness of host responses against specific infections. Membrane-associated RING-CH (MARCH1) has been shown to be implicated in the activation of antigen presenting cells and is readily induced by the anti-inflammatory cytokine IL-10. Here, we set out to investigate the role of MARCH1 in the activation of macrophages and its implication in host responses. Results: We show that MARCH1-deficient bone-marrow-derived macrophages exhibit a bias toward M1 polarization as assessed by quantitative real-time PCR, cytometric bead array (CBA) and flow cytometry. Furthermore, a macrophage population showing intermediate surface markers (CD11bint and F4/80int) between M1 and M2 was observed in the peritoneal cavity of MARCH1-deficient mice. In addition, these mice were found to be more susceptible to LPS-induced shock and exhibited higher pro-inflammatory cytokine production in their serum as monitored by CBA. Finally, MARCH1-deficient mice showed an enhanced clearing of leishmania parasites in the spleen at 21 and 28 days post infection. Conclusion: These results show that MARCH1 contributes to the polarization and functional plasticity of macrophages. Conflict of Interest disclosure: No conflict to declare.
Osteopontin supports neutrophil survival and function in polymicrobial infection. (P1281)
Authors: Matsui Aritsune , Rittling Susan 
Published: January 2023

Abstract
Oral infections are among the most prevalent bacterial infections: they are polymicrobial and refractory to antibiotic treatment. Understanding the host response to these infections is critical for their ultimate control. Osteopontin (OPN), a secreted phosphorylated integrin binding protein, has been previously shown to protect against inflammation in a mouse model of endodontic infection. The objective of this work was to determine the mechanism by which OPN protects against polymicrobial infection. Here we have used a titanium chamber model to analyze the innate immune response to polymicrobial infection in mice in the presence or absence of OPN. Chambers were implanted subcutaneously in WT and OPN-deficient mice, and inoculated with a mixture of four endodontic pathogens. The fluid within the chamber was sampled at different times after infection. 80-90% of the cells appearing in the chamber fluid were Ly6G+ neutrophils. At early times, there were significantly lower numbers of cells in the absence of OPN and the viability of these cells was lower than in WT mice. In addition, there were significantly higher numbers of live bacteria in the absence of OPN. These results suggest that OPN functions to protect neutrophils from apoptosis and is required for maximal bacterial killing during bacterial infection. Our results are also consistent with a role for OPN in neutrophil function. Analysis of the integrins responsible for these effects is underway.
Evasion of innate immunity by Yersinia pseudotuberculosis: LPS biosynthesis genes play a key role in inhibiting the antimicrobial effects of chemokines and other antimicrobial peptides (P1241)
Authors: Wilson Eric , Lew Cynthia , Kartchner Brittany , Sullivan Shea , Porter Nathan , Jones Nathan , Erickson David 
Published: January 2023

Abstract
Host defense peptides, including antimicrobial chemokines, play an essential role in protecting a wide variety of organisms from bacterial infection. In an effort to identify bacterial genes involved in resistance to antimicrobial chemokine mediated cell death we performed random transposon mutagenesis on a population of Yersinia pseudotuberculosis. Through the use of a novel flow cytometric assay these mutant bacteria were then screened for mutations which led to increased binding to the antimicrobial chemokine to the bacterium. Using this strategy we have screened thousands of mutant bacteria and identified several genes that when mutated lead to increased antimicrobial chemokine binding to and killing of bacteria. These genes, which when interrupted lead to increased susceptibility to antimicrobial chemokine mediated cell death, fall into several functional categories including efflux pups, transcriptional regulators and LPS biosynthesis related genes. Understanding how chemokines and other host defense peptides recognize and bind bacteria and how bacteria evade the antimicrobial activity of host defense peptides, could lead to novel drug targets that enhance the innate immune system. In short, the therapeutic use of AMCs to fight infections may be significantly enhanced by simultaneously targeting processes, such as lipopolysaccharide biosynthesis, that are required for resistance to these peptides.