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  1. Article ; Online: Interleukin-4 downregulates transcription factor BCL6 to promote memory B cell selection in germinal centers.

    Shehata, Laila / Thouvenel, Christopher D / Hondowicz, Brian D / Pew, Lucia A / Pritchard, Gretchen Harms / Rawlings, David J / Choi, Jinyong / Pepper, Marion

    Immunity

    2024  Volume 57, Issue 4, Page(s) 843–858.e5

    Abstract: Germinal center (GC)-derived memory B cells (MBCs) are critical for humoral immunity as they differentiate into protective antibody-secreting cells during re-infection. GC formation and cellular interactions within the GC have been studied in detail, yet ...

    Abstract Germinal center (GC)-derived memory B cells (MBCs) are critical for humoral immunity as they differentiate into protective antibody-secreting cells during re-infection. GC formation and cellular interactions within the GC have been studied in detail, yet the exact signals that allow for the selection and exit of MBCs are not understood. Here, we showed that IL-4 cytokine signaling in GC B cells directly downregulated the transcription factor BCL6 via negative autoregulation to release cells from the GC program and to promote MBC formation. This selection event required additional survival cues and could therefore result in either GC exit or death. We demonstrate that both increasing IL-4 bioavailability or limiting IL-4 signaling disrupted MBC selection stringency. In this way, IL-4 control of BCL6 expression serves as a tunable switch within the GC to tightly regulate MBC selection and affinity maturation.
    MeSH term(s) B-Lymphocytes ; Germinal Center ; Interleukin-4/metabolism ; Memory B Cells ; Proto-Oncogene Proteins c-bcl-6/genetics ; Proto-Oncogene Proteins c-bcl-6/metabolism ; Transcription Factors/metabolism
    Chemical Substances Interleukin-4 (207137-56-2) ; Proto-Oncogene Proteins c-bcl-6 ; Transcription Factors
    Language English
    Publishing date 2024-03-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1217235-2
    ISSN 1097-4180 ; 1074-7613
    ISSN (online) 1097-4180
    ISSN 1074-7613
    DOI 10.1016/j.immuni.2024.02.018
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: IL-4 downregulates BCL6 to promote memory B cell selection in germinal centers.

    Shehata, Laila / Thouvenel, Christopher D / Hondowicz, Brian D / Pew, Lucia A / Rawlings, David J / Choi, Jinyong / Pepper, Marion

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Germinal center (GC)-derived memory B cells (MBCs) are critical for humoral immunity as they differentiate into protective antibody-secreting cells during re-infection. GC formation and cellular interactions within the GC have been studied in detail, yet ...

    Abstract Germinal center (GC)-derived memory B cells (MBCs) are critical for humoral immunity as they differentiate into protective antibody-secreting cells during re-infection. GC formation and cellular interactions within the GC have been studied in detail, yet the exact signals that allow for the selection and exit of MBCs are not understood. Here, we show that IL-4 signaling in GC B cells directly downregulates BCL6 via negative autoregulation to release cells from the GC program and promote MBC formation. This selection event requires additional survival cues and can therefore result in either GC exit or death. We demonstrate that both increasing IL-4 bioavailability or limiting IL-4 signaling disrupt MBC selection stringency. In this way, IL-4 control of BCL6 expression serves as a tunable switch within the GC to tightly regulate MBC selection and affinity maturation.
    Language English
    Publishing date 2023-10-04
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.01.26.525749
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: In Vivo CD4

    Ruterbusch, Mikel / Pruner, Kurt B / Shehata, Laila / Pepper, Marion

    Annual review of immunology

    2020  Volume 38, Page(s) 705–725

    Abstract: The discovery of ... ...

    Abstract The discovery of CD4
    MeSH term(s) Animals ; B-Lymphocytes/immunology ; B-Lymphocytes/metabolism ; CD4-Positive T-Lymphocytes/cytology ; CD4-Positive T-Lymphocytes/immunology ; CD4-Positive T-Lymphocytes/metabolism ; Cell Differentiation/genetics ; Cell Differentiation/immunology ; Cytokines/metabolism ; Humans ; Lymphocyte Activation/immunology ; Receptors, Antigen, T-Cell/metabolism ; T-Lymphocyte Subsets/immunology ; T-Lymphocyte Subsets/metabolism ; Th1 Cells/immunology ; Th1 Cells/metabolism ; Th2 Cells/immunology ; Th2 Cells/metabolism
    Chemical Substances Cytokines ; Receptors, Antigen, T-Cell
    Language English
    Publishing date 2020-05-18
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 604953-9
    ISSN 1545-3278 ; 0732-0582
    ISSN (online) 1545-3278
    ISSN 0732-0582
    DOI 10.1146/annurev-immunol-103019-085803
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Site-Directed Mutagenesis to Improve Sensitivity of a Synthetic Two-Component Signaling System.

    Olshefsky, Audrey / Shehata, Laila / Kuldell, Natalie

    PloS one

    2016  Volume 11, Issue 1, Page(s) e0147494

    Abstract: Two-component signaling (2CS) systems enable bacterial cells to respond to changes in their local environment, often using a membrane-bound sensor protein and a cytoplasmic responder protein to regulate gene expression. Previous work has shown that ... ...

    Abstract Two-component signaling (2CS) systems enable bacterial cells to respond to changes in their local environment, often using a membrane-bound sensor protein and a cytoplasmic responder protein to regulate gene expression. Previous work has shown that Escherichia coli's natural EnvZ/OmpR 2CS could be modified to construct a light-sensing bacterial photography system. The resulting bacterial photographs, or "coliroids," rely on a phosphotransfer reaction between Cph8, a synthetic version of EnvZ that senses red light, and OmpR. Gene expression changes can be visualized through upregulation of a LacZ reporter gene by phosphorylated OmpR. Unfortunately, basal LacZ expression leads to a detectable reporter signal even when cells are grown in the light, diminishing the contrast of the coliroids. We performed site-directed mutagenesis near the phosphotransfer site of Cph8 to isolate mutants with potentially improved image contrast. Five mutants were examined, but only one of the mutants, T541S, increased the ratio of dark/light gene expression, as measured by β-galactosidase activity. The ratio changed from 2.57 fold in the starting strain to 5.59 in the T541S mutant. The ratio decreased in the four other mutant strains we examined. The phenotype observed in the T541S mutant strain may arise because the serine sidechain is chemically similar but physically smaller than the threonine sidechain. This may minimally change the protein's local structure, but may be less sterically constrained when compared to threonine, resulting in a higher probability of a phosphotransfer event. Our initial success pairing synthetic biology and site-directed mutagenesis to optimize the bacterial photography system's performance encourages us to imagine further improvements to the performance of this and other synthetic systems, especially those based on 2CS signaling.
    MeSH term(s) Bacterial Outer Membrane Proteins/genetics ; Bacterial Outer Membrane Proteins/physiology ; Bacterial Proteins/genetics ; Bacterial Proteins/physiology ; Escherichia coli/genetics ; Escherichia coli/physiology ; Escherichia coli Proteins/genetics ; Escherichia coli Proteins/physiology ; Gene Expression Regulation, Bacterial/genetics ; Lac Operon/genetics ; Lac Operon/physiology ; Light ; Multienzyme Complexes/genetics ; Multienzyme Complexes/physiology ; Mutagenesis, Site-Directed/methods ; Organisms, Genetically Modified/genetics ; Organisms, Genetically Modified/physiology ; Photography ; Signal Transduction/genetics ; Trans-Activators/genetics ; Trans-Activators/physiology ; beta-Galactosidase/metabolism
    Chemical Substances Bacterial Outer Membrane Proteins ; Bacterial Proteins ; Escherichia coli Proteins ; Multienzyme Complexes ; Trans-Activators ; osmolarity response regulator proteins ; envZ protein, E coli (EC 2.7.3.-) ; beta-Galactosidase (EC 3.2.1.23)
    Language English
    Publishing date 2016
    Publishing country United States
    Document type Journal Article
    ISSN 1932-6203
    ISSN (online) 1932-6203
    DOI 10.1371/journal.pone.0147494
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Structure-specific DNA recombination sites: Design, validation, and machine learning-based refinement.

    Nivina, Aleksandra / Grieb, Maj Svea / Loot, Céline / Bikard, David / Cury, Jean / Shehata, Laila / Bernardes, Juliana / Mazel, Didier

    Science advances

    2020  Volume 6, Issue 30, Page(s) eaay2922

    Abstract: Recombination systems are widely used as bioengineering tools, but their sites have to be highly similar to a consensus sequence or to each other. To develop a recombination system free of these constraints, we turned ... ...

    Abstract Recombination systems are widely used as bioengineering tools, but their sites have to be highly similar to a consensus sequence or to each other. To develop a recombination system free of these constraints, we turned toward
    Language English
    Publishing date 2020-07-24
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.aay2922
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Systematic comparison of respiratory syncytial virus-induced memory B cell responses in two anatomical compartments.

    Shehata, Laila / Wieland-Alter, Wendy F / Maurer, Daniel P / Chen, Eunice / Connor, Ruth I / Wright, Peter F / Walker, Laura M

    Nature communications

    2019  Volume 10, Issue 1, Page(s) 1126

    Abstract: Respiratory syncytial virus (RSV) is a leading cause of hospitalization in infants and young children. Although it is widely agreed that an RSV vaccine should induce both mucosal and systemic antibody responses, little is known about the B cell response ... ...

    Abstract Respiratory syncytial virus (RSV) is a leading cause of hospitalization in infants and young children. Although it is widely agreed that an RSV vaccine should induce both mucosal and systemic antibody responses, little is known about the B cell response to RSV in mucosa-associated lymphoid tissues. Here, we analyze this response by isolating 806 RSV F-specific antibodies from paired adenoid and peripheral blood samples from 4 young children. Overall, the adenoid-derived antibodies show higher binding affinities and neutralization potencies compared to antibodies isolated from peripheral blood. Approximately 25% of the neutralizing antibodies isolated from adenoids originate from a unique population of IgM
    MeSH term(s) Adenoids/immunology ; Adenoids/virology ; Antibodies, Neutralizing/biosynthesis ; Antibodies, Viral/biosynthesis ; Antibody Affinity ; Antibody Specificity ; B-Lymphocytes/immunology ; B-Lymphocytes/virology ; Biomarkers/metabolism ; Child, Preschool ; Cloning, Molecular ; Female ; Gene Expression ; Genetic Vectors/chemistry ; Genetic Vectors/metabolism ; Humans ; Immunity, Mucosal ; Immunoglobulin D/biosynthesis ; Immunoglobulin M/biosynthesis ; Leukocytes, Mononuclear/immunology ; Leukocytes, Mononuclear/virology ; Male ; Mutation ; Organ Specificity ; Recombinant Proteins/biosynthesis ; Recombinant Proteins/immunology ; Respiratory Syncytial Virus, Human/immunology ; Saccharomyces cerevisiae/genetics ; Saccharomyces cerevisiae/metabolism
    Chemical Substances Antibodies, Neutralizing ; Antibodies, Viral ; Biomarkers ; Immunoglobulin D ; Immunoglobulin M ; Recombinant Proteins
    Language English
    Publishing date 2019-03-08
    Publishing country England
    Document type Comparative Study ; Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-019-09085-1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Environmental contaminant mixtures modulate in vitro influenza infection.

    Desforges, Jean-Pierre / Bandoro, Christopher / Shehata, Laila / Sonne, Christian / Dietz, Rune / Puryear, Wendy B / Runstadler, Jonathan A

    The Science of the total environment

    2018  Volume 634, Page(s) 20–28

    Abstract: Environmental chemicals, particularly organochlorinated contaminants (OCs), are associated with a ranged of adverse health effects, including impairment of the immune system and antiviral immunity. Influenza A virus (IAV) is an infectious disease of ... ...

    Abstract Environmental chemicals, particularly organochlorinated contaminants (OCs), are associated with a ranged of adverse health effects, including impairment of the immune system and antiviral immunity. Influenza A virus (IAV) is an infectious disease of major global public health concern and exposure to OCs can increase the susceptibility, morbidity, and mortality to disease. It is however unclear how pollutants are interacting and affecting the outcome of viral infections at the cellular level. In this study, we investigated the effects of a mixture of environmentally relevant OCs on IAV infectivity upon in vitro exposure in Madin Darby Canine Kidney (MDCK) cells and human lung epithelial cells (A549). Exposure to OCs reduced IAV infectivity in MDCK and A549 cells during both short (18-24h) and long-term (72h) infections at 0.05 and 0.5ppm, and effects were more pronounced in cells co-treated with OCs and IAV than pre-treated with OCs prior to IAV (p<0.001). Pre-treatment of host cells with OCs did not affect IAV cell surface attachment or entry. Visualization of IAV by transmission electron microscopy revealed increased envelope deformations and fewer intact virions during OC exposure. Taken together, our results suggest that disruption of IAV infection upon in vitro exposure to OCs was not due to host-cell effects influencing viral attachment and entry, but perhaps mediated by direct effects on viral particles or cellular processes involved in host-virus interactions. In vitro infectivity studies such as ours can shed light on the complex processes underlying host-pathogen-pollutant interactions.
    MeSH term(s) Animals ; Dogs ; Environmental Pollutants/toxicity ; Host-Pathogen Interactions ; Humans ; Influenza A virus/drug effects ; Influenza A virus/physiology ; Influenza, Human ; Madin Darby Canine Kidney Cells
    Chemical Substances Environmental Pollutants
    Language English
    Publishing date 2018-09-01
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2018.03.321
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: TGFβ restricts expansion, survival, and function of T cells within the tuberculous granuloma.

    Gern, Benjamin H / Adams, Kristin N / Plumlee, Courtney R / Stoltzfus, Caleb R / Shehata, Laila / Moguche, Albanus O / Busman-Sahay, Kathleen / Hansen, Scott G / Axthelm, Michael K / Picker, Louis J / Estes, Jacob D / Urdahl, Kevin B / Gerner, Michael Y

    Cell host & microbe

    2021  Volume 29, Issue 4, Page(s) 594–606.e6

    Abstract: CD4 T cell effector function is required for optimal containment of Mycobacterium tuberculosis (Mtb) infection. IFNɣ produced by CD4 T cells is a key cytokine that contributes to protection. However, lung-infiltrating CD4 T cells have a limited ability ... ...

    Abstract CD4 T cell effector function is required for optimal containment of Mycobacterium tuberculosis (Mtb) infection. IFNɣ produced by CD4 T cells is a key cytokine that contributes to protection. However, lung-infiltrating CD4 T cells have a limited ability to produce IFNɣ, and IFNɣ plays a lesser protective role within the lung than at sites of Mtb dissemination. In a murine infection model, we observed that IFNɣ production by Mtb-specific CD4 T cells is rapidly extinguished within the granuloma but not within unaffected lung regions, suggesting localized immunosuppression. We identified a signature of TGFβ signaling within granuloma-infiltrating T cells in both mice and rhesus macaques. Selective blockade of TGFβ signaling in T cells resulted in an accumulation of terminally differentiated effector CD4 T cells, improved IFNɣ production within granulomas, and reduced bacterial burdens. These findings uncover a spatially localized immunosuppressive mechanism associated with Mtb infection and provide potential targets for host-directed therapy.
    MeSH term(s) Adaptive Immunity ; Animals ; CD4-Positive T-Lymphocytes ; Cell Death ; Cytokines ; Disease Models, Animal ; Female ; Granuloma/immunology ; Granuloma/microbiology ; Inflammation ; Interferon-gamma ; Lung/microbiology ; Macaca mulatta ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mycobacterium tuberculosis ; T-Lymphocytes/immunology ; Th1 Cells ; Transforming Growth Factor beta/metabolism ; Tuberculosis/immunology
    Chemical Substances Cytokines ; Transforming Growth Factor beta ; Interferon-gamma (82115-62-6)
    Language English
    Publishing date 2021-03-11
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2278004-X
    ISSN 1934-6069 ; 1931-3128
    ISSN (online) 1934-6069
    ISSN 1931-3128
    DOI 10.1016/j.chom.2021.02.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Affinity Maturation Enhances Antibody Specificity but Compromises Conformational Stability.

    Shehata, Laila / Maurer, Daniel P / Wec, Anna Z / Lilov, Asparouh / Champney, Elizabeth / Sun, Tingwan / Archambault, Kimberly / Burnina, Irina / Lynaugh, Heather / Zhi, Xiaoyong / Xu, Yingda / Walker, Laura M

    Cell reports

    2019  Volume 28, Issue 13, Page(s) 3300–3308.e4

    Abstract: Monoclonal antibodies (mAbs) have recently emerged as one of the most promising classes of biotherapeutics. A potential advantage of B cell-derived mAbs as therapeutic agents is that they have been subjected to natural filtering mechanisms, which may ... ...

    Abstract Monoclonal antibodies (mAbs) have recently emerged as one of the most promising classes of biotherapeutics. A potential advantage of B cell-derived mAbs as therapeutic agents is that they have been subjected to natural filtering mechanisms, which may enrich for B cell receptors (BCRs) with favorable biophysical properties. Here, we evaluated 400 human mAbs for polyreactivity, hydrophobicity, and thermal stability using high-throughput screening assays. Overall, mAbs derived from memory B cells and long-lived plasma cells (LLPCs) display reduced levels of polyreactivity, hydrophobicity, and thermal stability compared with naive B cell-derived mAbs. Somatic hypermutation (SHM) is inversely associated with all three biophysical properties, as well as BCR expression levels. Finally, the developability profiles of the human B cell-derived mAbs are comparable with those observed for clinical mAbs, suggesting their high therapeutic potential. The results provide insight into the biophysical consequences of affinity maturation and have implications for therapeutic antibody engineering and development.
    MeSH term(s) Antibodies, Monoclonal/immunology ; Antibody Specificity/immunology ; Humans ; Molecular Conformation
    Chemical Substances Antibodies, Monoclonal
    Language English
    Publishing date 2019-08-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2649101-1
    ISSN 2211-1247 ; 2211-1247
    ISSN (online) 2211-1247
    ISSN 2211-1247
    DOI 10.1016/j.celrep.2019.08.056
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  10. Article ; Online: Antigen- and scaffold-specific antibody responses to protein nanoparticle immunogens.

    Kraft, John C / Pham, Minh N / Shehata, Laila / Brinkkemper, Mitch / Boyoglu-Barnum, Seyhan / Sprouse, Kaitlin R / Walls, Alexandra C / Cheng, Suna / Murphy, Mike / Pettie, Deleah / Ahlrichs, Maggie / Sydeman, Claire / Johnson, Max / Blackstone, Alyssa / Ellis, Daniel / Ravichandran, Rashmi / Fiala, Brooke / Wrenn, Samuel / Miranda, Marcos /
    Sliepen, Kwinten / Brouwer, Philip J M / Antanasijevic, Aleksandar / Veesler, David / Ward, Andrew B / Kanekiyo, Masaru / Pepper, Marion / Sanders, Rogier W / King, Neil P

    Cell reports. Medicine

    2022  Volume 3, Issue 10, Page(s) 100780

    Abstract: Protein nanoparticle scaffolds are increasingly used in next-generation vaccine designs, and several have established records of clinical safety and efficacy. Yet the rules for how immune responses specific to nanoparticle scaffolds affect the ... ...

    Abstract Protein nanoparticle scaffolds are increasingly used in next-generation vaccine designs, and several have established records of clinical safety and efficacy. Yet the rules for how immune responses specific to nanoparticle scaffolds affect the immunogenicity of displayed antigens have not been established. Here we define relationships between anti-scaffold and antigen-specific antibody responses elicited by protein nanoparticle immunogens. We report that dampening anti-scaffold responses by physical masking does not enhance antigen-specific antibody responses. In a series of immunogens that all use the same nanoparticle scaffold but display four different antigens, only HIV-1 envelope glycoprotein (Env) is subdominant to the scaffold. However, we also demonstrate that scaffold-specific antibody responses can competitively inhibit antigen-specific responses when the scaffold is provided in excess. Overall, our results suggest that anti-scaffold antibody responses are unlikely to suppress antigen-specific antibody responses for protein nanoparticle immunogens in which the antigen is immunodominant over the scaffold.
    MeSH term(s) HIV Antibodies ; Antibody Formation ; HIV-1 ; Nanoparticles ; Glycoproteins ; Vaccines
    Chemical Substances HIV Antibodies ; Glycoproteins ; Vaccines
    Language English
    Publishing date 2022-09-26
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 2666-3791
    ISSN (online) 2666-3791
    DOI 10.1016/j.xcrm.2022.100780
    Database MEDical Literature Analysis and Retrieval System OnLINE

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