bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute symptomatic influenza A virus (IAV) infection in humans leads to expansion of highly diverse CD8 T cell repertoires crossreactive with persistent Epstein Barr virus (EBV) (HUM8P.344)
Authors: Gil Anna , Mishra Rabinarayan , Aslan Nuray , Selin Liisa 
Published: January 2023

Abstract
The competence of T cell responses predominantly depends on how efficient T cell receptors (TCRs) are at recognizing antigenic epitopes. We show here that during acute severely symptomatic IAV infection there was an expansion of IAV-M1/EBV-BRLF1 and IAV-M1/EBV-BMLF1 double-tetramer+ cells directly ex-vivo in 5 HLA-A2+ patients. We questioned whether this expansion specific to these two different crossreactive responses would lead to alterations in the TCR repertoire of the IAV-M1-58, EBV-BRLF1-109 and BMLF1-280 from before, during and following acute IAV infection. Using staining with Vb MAb we found that T cell responses generated to these epitopes became surprisingly more polyclonal, with the sharing of Vb between M1, BMLF1 and BRLF1 populations which is not seen in healthy donors and which decreased 2 months later consistent with crossreactive expansion. Furthermore, by using single-cell analysis of TCRα and TCRβ repertoire of tetramer sorted IAV-M1 cells we showed dramatic changes in specific clonotype usage and in JA and JB family usage during acute IAV infection compared to before infection. In summary, these changes in TCR repertoire during acute symptomatic IAV infection suggest that during severe infection there is a preferential expansion of highly diverse crossreactive responses between IAV and the persistent virus, EBV, which leads to permanent changes in TCR repertoires to both of these two viruses.
Kinetics of antibodies against major pneumococcal proteins in mother and child (HUM8P.348)
Authors: Mendy Awa , Aderonke Adutola , Sutherland Jayne , Ota Matrin , Mendy Awa 
Published: January 2023

Abstract
Invasive pneumococcal diseases (IPD) are responsible for almost 1 million deaths per year among children under five years. Streptococcus pneumoniae has over 90 serotypes yet the current conjugate vaccine only includes 13 serotypes. Pneumococcal proteins are conserved across all serotypes and therefore hold potential as vaccine candidates. Study aimed to investigate the transfer of antibodies against major pneumococcal antigens from pregnant mothers to their infants, and to correlate antibody concentrations with nasopharyngeal carriage (NPC).We analysed plasma from mother’s (3 months post-birth) and infants(cord blood) to determine antibody concentrations and avidity to recombinant pneumolysin (rPly), Pneumococcal surface protein A (PspA) and choline-binding protein A (CbpA) using an in-house IgG ELISA. Antibody transfer was antigen-dependent with significantly higher levels of antibodies against PspA and CbpA in mothers compared to cord blood but similar levels for rPly. PspA and CbpA were better transferred than rPly from mother to child (p=0.0001 and p=0.0024 respectively). Antibodies to PspA and CbpA but not rPly were retained up to 3 months in mothers with no significant difference in the avidity index at any time-point. Our data shows that transfer of antibodies against major pneumococcal proteins from mother to child is antigen-dependent. Further work will explore the relationship with NPC.
Functional IGH V polymorphism is frequent in humans: implications for immunity and vaccination (HUM8P.349)
Authors: Carlson Chris , Luning Prak Eline , Dagloria Jeanne , Utsugi Heidi , Chen Christina , Alvendia Melissa , Rieder Mark , Makar Karen , Robins Harlan 
Published: January 2023

Abstract
Antibody heavy chain variable region genes (VH) are important for antigen binding, as evidenced by the dominant usage of particular VHs, such as the VH3b subfamily, in the immune responses to the capsular polysaccharide of H. influenza b. The presence or absence of particular VH alleles may be important for immunity. To screen for polymorphic VH alleles in humans, we sequenced functionally rearranged VH from 500K circulating B cells in each of 100 healthy young adults. We focused on the naïve repertoire (0-1 mutations compared to the closest known germline allele), and analyzed the proportion of rearrangements that were in-frame without stop codons (IF). In mice, low IF VHs have not undergone robust selection and are often pseudogenes. We confirmed several polymorphically functional VH genes with variable IF fractions, including V3-20, V5-a, V3-f, V1-8, and V3-9. We also identified homozygous individuals carrying novel, non-functional alleles at V7-4-1, V6-1, V3-66 and V2-70. Comparison of VH usage patterns between individuals revealed significant variation in the number of functional VH contributing to the naïve repertoire, with between 36 and 43 functional VH segments observed in each individual. These data demonstrate a significant level of functional allelic diversity and VH copy number variation between individuals, which could contribute to differential disease susceptibility, as well as influence vaccine efficacy.
Regulation of B7-H1 (PD-L1) expression by gastric epithelial cells and development of Treg cells during Helicobacter pylori infection (HUM8P.328)
Authors: Lina Taslima , Shatha Alzahrani , Pinchuk Irina , Reyes Victor 
Published: January 2023

Abstract
Helicobacter pylori (H. pylori) infects &gt;50% of the world’s population and is linked to peptic ulcers and gastric cancer. We have previously shown that H. pylori upregulates B7-H1 expression on GEC, which, in turn, suppress T cell proliferation and induction of Treg cells in vitro, but the mechanism was unknown. Herein, we investigated the underlying mechanisms behind H. pylori-mediated upregulation of B7-H1 expression by GEC and its functional relevance to chronic infection. Using H. pylori wild type and isogenic mutant strains we showed that H. pylori requires its type 4 secretion system (T4SS) component cytotoxin associated gene A (CagA) and peptidoglycan for B7-H1 upregulation in GEC. In vivo confirmation was obtained when infection of C57BL/6 mice with H. pylori PMSS1 strain, containing a functional T4SS, but not with H. pylori SS1 strain lacking this delivery system, led to upregulation of B7-H1 expression, increased bacterial load, induction of Treg cell in the stomach and increased IL-10 in the serum. Interestingly, B7-H1 knock out mice showed less Treg cells and reduced bacterial loads. We also showed that H. pylori uses p38 MAPK pathway to upregulate B7-H1 expression in GEC. Our observations suggest that H. pylori T4SS contributes to the ability to evade immune-mediated clearance by modulating expression of B7-H1 in GEC. These observations may have important implications in vaccine efforts directed at H. pylori.
Chronic infectious exposures during pregnancy shift the distribution of cord blood fetal memory B cell subpopulations in a Kenyan cohort (HUM8P.332)
Authors: Dent Arlene , Yeo Kee Thai , Embury Paula , Anderson Timothy , Mungai Peter , Holding Penny , Malhotra Indu , King Christopher , Kazura James 
Published: January 2023

Abstract
Chronic infections during pregnancy can expose the fetus to foreign antigens leading to cytokine responses that affect fetal B cell development. We hypothesize that this exposure shifts the distribution of B cell subpopulations. Using flow cytometry, we examined the proportions of various B cell subpopulations in cord blood from North American (Nam) and Kenyan neonates. NAm neonates had no prenatal infectious exposures whereas Kenyan neonates examined had prenatal HIV, CMV, or P falciparum exposure, or no infectious exposures. We also measured the plasma levels of pro-inflammatory biomarkers and BAFF in NAm and Kenyan cord plasma. We found that Kenyan neonates exposed to prenatal infections had greater proportions of memory B cells (CD19+CD27+), especially the activated (CD19+CD27+CD21-IgD-) memory B cells compared to NAm neonates. HIV exposed neonates had greater proportions of atypical MBC compared to the other Kenyan infectious exposed groups. Kenyan neonates had higher levels of IP-10, TNFa, CRP, sCD14 and BAFF than NAm neonates. Among the Kenyan groups, those with prenatal infectious exposures had higher levels of INFg, IL-7, sTNFR1 and sTNFR2 compared to Kenyan neonates with no infectious exposures. These results suggest that the presence of chronic infections during pregnancy affects B cell development including activated memory B cells, some pro-inflammatory biomarkers, and BAFF levels. The functional significance of these differences needs to be further investigated.
Intranasal interleukin-12 treatment for protection against respiratory infection with methicillin-resistant Staphylococcus aureus. (INC7P.413)
Authors: Nguyen Quang Tam , Furuya Yoichi , Roberts Sean , Metzger Dennis 
Published: January 2023

Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) represents the most common pathogen associated with nosocomial pneumonia. In the present study, the role of interleukin-12 (IL-12) in inducing protective immunity in the lungs against intranasal infection of mice with MRSA was investigated. It was found that IL-12-deficient mice showed a lower survival rate, a higher bacterial burden in both the lung and spleen, and a lower level of interferon gamma (IFN-γ) in the lung than wild-type (WT) mice. These effects were completely reversed by replacement therapy with recombinant IL-12. Furthermore, exogenous IL-12 treatment of WT mice 24 h before intranasal infection with a lethal dose of MRSA significantly improved bacterial clearance and resulted in protection from death. These IL-12 treated-mice had a greater number of the lung natural killer (NK) cells and neutrophils, and had higher levels of IFN-γ in the lung and serum compared to control mice. The majority of IFN-γ-producing cells detected in IL-12-treated mice were NK cells. IL-12-induced protection against MRSA infection was abolished in NK cell-depleted, IFN-γ deficient, and MIIG mice. In addition, we found that combination therapy with linezolid and IL-12 following intranasal infection with MRSA significantly increased survival compared to mice receiving linezolid or IL-12 alone. Our results indicate that IL-12 can play an important role in protection against MRSA infection.
Mannose receptor (CD206)-mediated signaling in human macrophages in the context of tuberculosis (INC7P.418)
Authors: Rajaram Murugesan , Ni Bin , Carlson Tracy , Schlesinger Larry 
Published: January 2023

Abstract
The mannose receptor (MR, CD206) is abundantly expressed on alveolar and monocyte-derived macrophages (MDMs), recognizes several pathogens, mediates phagocytosis and endocytosis, and regulates inflammatory signaling pathways. It is a major human macrophage phagocytic receptor for Mycobacterium tuberculosis (M.tb). We have shown that MR-mediated phagocytosis of M.tb by MDMs up-regulates PPARγ expression, a negative regulator of NF-kB activation. However, the associated receptor-specific downstream signaling molecules are unknown. Thus, we investigated the signaling molecules involved in MR-mediated phagocytosis and other immune functions in MDMs. M.tb infection of MDMs leads to phosphorylation of tyrosine residues in the MR cytoplasmic tail that enable the recruitment of tyrosine kinases (e.g. Syk) which transmit the signals downstream. To identify MR-mediated signaling proteins, we assayed for MR-associated proteins by MALDI-TOF and Western blot using a pull down assay with macrophage lysates and phosphorylated and un-phosphorylated MR cytoplasmic tail peptides. We have identified several proteins bound to the phosphorylated peptides and linked to signaling pathways involved in MR-mediated phagocytosis and related immune funtions. In conclusion, we are identifying key signaling molecules and pathways used by the MR to transmit signals that initiate phagocytosis and other immune-related functions in human macrophages.
NK cell differential activation induced by Mycobacterium bovis BCG substrains and nontuberculous mycobacteria. (INC7P.420)
Authors: Salazar-Lopez Luis , Castillo-Rodal Antonia , Llorente-Peter Luis , Lopez-Vidal Yolanda 
Published: January 2023

Abstract
Mycobacterium bovis BCG is the only available vaccine against tuberculosis. Although widespread used, it is effectiveness is variable and protection conferred might be limited as following factors; BCG substrains used for vaccination, exposure to Nontuberculous mycobacteria and different components innate immune response interaction are not yet completely understood. When NK cells, are stimulated with BCG substrains proliferate and IFNγ production is induced, but recognition pathway and actual activation profiles existence remain obscure. To evaluate the activation profile of human NK cells isolated from PBMC of 20 healthy individuals. The NK cells were cultured and stimulated with BCG substrains or Nontuberculous mycobacteria species to induce an activation profile, assessed by flow cytometry. The activated NK cells were differentially recognized and induced by each BCG substrains used. Five different BCG substrains and Nontuberculous mycobacteria were included but, only BCG Mexico, M. avium and M. scrofulaceum were able to induce NK cells activation. We have shown that the differential recognitions to BCG substrains or Nontuberculous mycobacteria on NK cells occurred this could imply highly tuned response regarding cytokines promoting and enhanced impact in the regulation of immune response.
Pro-inflammatory response and defective bactericidal activity by Mycobacterium tuberculosis/HIV-1 co-infected human macrophages (INC7P.421)
Authors: Huante Matthew , Nusbaum Rebecca , Vijayakumar Sudhamanthi , Calderon Veronica , Sutjita Putri , Goez-Rivillas Yenni , Hunter Robert Hunter , Actor Jeffrey , Cirillo Jeffrey , Ferguson Monique , Valbuena Gustavo , Endsley Janice 
Published: January 2023

Abstract
Mycobacterium tuberculosis (M.tb), the etiological agent of tuberculosis (TB), is the leading cause of death in people living with Human Immunodeficiency Virus (HIV). In contrast to most other opportunistic infections, susceptibility to M.tb occurs prior to significant loss of peripheral CD4+T cells in people with HIV. The molecular basis for pathogen synergy that leads to an aggressive course of TB in those with HIV-1 infection is poorly defined. The primary objective of this study is to determine how HIV-1 alters the host macrophage innate immune response to M.tb infection. Primary human monocyte-derived macrophages, alveolar macrophages from human donor bronchoalveolar lavage, and our recently developed humanized mouse model of M.tb/HIV co-infection were used for in vitro and in vivo studies. Preliminary results demonstrate that HIV-1 (JR-CSF)/M.tb (H37Rv) co-infection results in greater cell death and increased expression of pro-inflammatory cytokines and chemokines (e.g. IL-1β, IL-6, MCP) compared to mono-infection with either HIV-1 or M.tb. A corresponding increase in leukocyte recruitment into the lungs of M.tb-infected humanized mice was observed in animals with HIV-1 infection and coincided with greater mycobacterial dissemination. These studies suggest that inappropriate inflammatory responses by host macrophages may contribute to dysfunctional host immunity to M.tb in those with concurrent HIV-1 infection.
Escherichia coli Nissle 1917 colonization upregulates innate immunity and partially protects against human rotavirus infection in a neonatal gnotobiotic pig model (INC7P.422)
Authors: Saif Linda , Vlasova Anastasia , Kandasamy Sukumar , Shao Lulu , Rauf Abdul , Fischer David , Chattha Kuldeep , Kumar Anand , Rajashekara Gireesh 
Published: January 2023

Abstract
We evaluated how colonization with gram-positive or gram-negative commensal bacteria (alone or combined) modulates virulent human rotavirus (VirHRV) infection and innate immunity in a neonatal gnotobiotic (Gn) pig model. Gn pigs were colonized with Escherichia coli Nissle 1917 (EcN), Lactobacillus rhamnosus GG (LGG) or both (EcN+LGG) and challenged with VirHRV 15 days later. Non-colonized VirHRV challenged pigs served as controls. Colonization with each bacteria alone or combined, decreased VirHRV shedding and diarrhea scores post-challenge. Among the colonized pigs, those were lowest in the EcN-, intermediate in EcN+LGG- and highest in the LGG-colonized pigs. EcN colonization induced the highest plasmacytoid dendritic cell (DC) frequencies (EcN or EcN+LGG, all tissues), significantly increased natural killer (NK) cell activity (EcN, spleen and blood) and decreased frequencies of VirHRV-induced apoptotic and TLR4+ mononuclear cells (MNCs) (EcN, all tissues). Consistent with the highest NK cell activity, SWC3a+ MNCs (DC enriched fraction) from spleen of EcN colonized Gn pigs produced the highest levels of IL12 (essential for NK cell activation) in vitro. LGG colonization had less effect on VirHRV induced innate immune responses, and those of EcN+LGG colonized pigs were intermediate, suggesting that LGG and EcN modulate each other’s effects. Our results indicate that EcN partially protects against VirHRV infection and diarrhea by modulating innate immune responses.
TLR2 and ERK signaling control macrophage responses to Mycobacterium tuberculosis and the balance of inflammatory mechanisms and Th1 activation (INC7P.402)
Authors: Richardson Edward , Wearsch Pamela , Boom W. , Harding Clifford 
Published: January 2023

Abstract
Tuberculosis is one of the leading causes of death and morbidity worldwide. The causative agent, Mycobacterium tuberculosis, has co-evolved with humanity and developed numerous immune evasion strategies to establish chronic, latent infection. These strategies include modification of anti-microbial responses and antigen processing and presentation by cells that harbor the pathogen, such as macrophages. In these studies, we demonstrate that inhibition of MHC class II, expression of the anti-inflammatory cytokine IL-10, and inhibition of maximal production of the Th1-inducing cytokine IL-12 are dependent on TLR2 and ERK signaling in macrophages following M. tuberculosis infection in vitro. Furthermore, macrophages deficient in the TLR2-ERK signaling pathway (macrophages deficient in Tpl2, the kinase that activates MEK/ERK downstream of TLR signaling) are more potent at activating antigen-specific CD4 T cells, enhance T cell expression of T-bet, a marker of Th1 differentiation, and induce more IFN-γ from activated T cells. These results collectively suggest that M. tuberculosis uses the TLR2-ERK signaling pathway in macrophages to facilitate its intracellular survival and prevent efficient elimination by antigen-specific, IFN-γ-producing T cells.
The role of innate stimulation of CD4 T cells in multiple infection models (INC7P.404)
Authors: Pham Oanh , O'Donnell Hope , McSorley Stephen 
Published: January 2023

Abstract
Salmonella-specific CD4 T cells acquire the ability to produce IFN-γ in response to non-cognate innate stimuli. CD4-Cre/Myd88-floxed mice with CD4 T cells lacking the ability to generate non-cognate responses are more susceptible to Salmonella infection, demonstrating the importance of non-cognate stimulation in vivo. Treatment of Salmonella-infected mice with LPS caused increased production of IFN-γ, IL-12, IL-18, and IL-33 mRNA in the spleen and liver and significantly higher concentrations of IFN-γ and IL-18 were detected in the serum. These cytokines were responsible for inducing large non-cognate responses in Salmonella-specific CD4 and CD8 T cells. We are currently testing whether non-cognate activation of CD4 T cells can provide cross-protection in mouse models of Chlamydia, Listeria, and Plasmodium infection. Together these data suggest an unappreciated role for non-cognate T cell activation in response to bacterial infection.
MOV10 provides antiviral activity against RNA viruses by enhancing IFN induction through IKKε and IRF3. (INC8P.441)
Authors: Cuevas Rolando , Hornung Veit , Coyne Carolyn , Sarkar Saumendra 
Published: January 2023

Abstract
MOV10 (Moloney leukemia virus 10, homolog) is an interferon-inducible putative DEAG-containing RNA helicase, which has been known to be associated with the RNA-induced silencing complex (RISC). Although, it is known to inhibit HIV-1 replication, analysis of its border antiviral activity and the mechanism has not been explored. Here, we report that MOV10 exhibits antiviral activity against a number of RNA viruses including EMCV, CVB, SeV and VSV by enhancing IFN induction. The antiviral activity of MOV10 is dependent on IFN signaling, and stable expression of MOV10 enhances IRF3 dimerization and IFN/ISG induction. Using various knockout cells combined with siRNA knockdowns, we show that MOV10-mediated IRF3 activation and IFN/ISG induction is not dependent on RIG-I/MAVS-mediated RNA sensing. Upon virus infection MOV10 specifically interacts and activates IKKε to induce IRF3 activation without involving TBK1. The important role of MOV10 in mediating antiviral signaling is further supported by our findings that CVB 3Cpro protease specifically targets MOV10 for degradation as a possible innate immune evasion mechanism. Taken together, these results establish MOV10, an evolutionary conserved protein, as an antiviral gene that uses a novel signaling pathway to enhance IFN response.
Functionally distinct subsets of natural killer cells help shape and regulate the immune response during viral infection (INC8P.429)
Authors: Zamora Anthony , Sungur Can , Aguilar Ethan , Baumgarth Nicole , Murphy William 
Published: January 2023

Abstract
Natural killer (NK) cells are innate lymphocytes that play an important role in the immune response against certain viral infections and transformed cells. Historically, NK cells have been recognized for their direct antiviral defense; however, a more complex view of NK cell function has recently emerged highlighting their ability to direct the balance between viral infection and host immunity. While the diverse effector functions of NK cells are increasingly seen as vital components of host immunity, the specific populations of NK cells that mediate these differential effects have not been identified. In this study, we provide evidence for distinct NK cell subsets that differ in their effector and immunoregulatory functions during influenza infection. We show here that during the early stages of the host immune response to viral infection, a population of effector NK cells directly contributes to viral resistance at the site of infection, while a separate helper NK subset concurrently functions to prime the adaptive immune response by expanding dendritic cells in the lymph nodes. Conversely, at the later stages of viral infection, a subset of suppressor NK cells dampens the adaptive immune response by directly regulating antigen-specific T cells. These results suggest that adoptive transfer of specific NK subsets may serve as a useful therapeutic strategy to modulate the immune response during viral infection.