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Title: Organoid Polymer Functionality and Mode of Klebsiella pneumoniae Membrane Antigen Presentation Regulates Ex Vivo Germinal Center Epigenetics in Young and Aged B Cells
Abstract

Antibiotic‐resistant bacteria are a major global health threat that continues to rise due to a lack of effective vaccines. Of concern areKlebsiella pneumoniae(K. pneumoniae) that fail to induce in vivo germinal center B cell responses, which facilitate antibody production to fight infection. Immunotherapies using antibodies targeting antibiotic‐resistant bacteria are emerging as promising alternatives, however, they cannot be efficiently derived ex vivo, necessitating the need for immune technologies to develop therapeutics. Here, polyethylene glycol (PEG)‐based immune organoids are developed to elucidate the effects of polymer end‐point chemistry, integrin ligands, and mode ofK. pneumoniaeantigen presentation on germinal center‐like B cell phenotype and epigenetics, to better define the lymph node microenvironment factors regulating ex vivo germinal center dynamics. Notably, PEG vinyl sulfone or acrylate fail to sustain primary immune cells, but functionalization with maleimide (PEG‐4MAL) leads to B cell expansion and germinal center‐like induction. RNA sequencing analysis of lymph node stromal and germinal center B cells shows niche associated heterogeneity of integrin‐related genes. Incorporation of niche‐mimicking peptides reveals that collagen‐1 promotes germinal center‐like dynamics and epigenetics. PEG‐4MAL organoids elucidate the impact ofK. pneumoniaeouter membrane‐embedded protein antigen versus soluble antigen presentation on germinal centers and preserve the response across young and aged mice.

 
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NSF-PAR ID:
10452646
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Advanced Functional Materials
Volume:
30
Issue:
48
ISSN:
1616-301X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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    Basic Protocol 1: Isolation of bone marrow progenitor cells

    Basic Protocol 2: In vitro differentiation of dendritic cells with GM‐CSF

    Support Protocol 1: Preparation of conditioned medium from GM‐CSF producing J558L cells

    Basic Protocol 3: In vitro differentiation of dendritic cells with Flt3L

    Support Protocol 2: Preparation of Flt3L containing medium from B16‐Flt3L cells

    Basic Protocol 4: Expansion of cDC1s in vivo for use in ex vivo experiments

    Basic Protocol 5: Characterizing resting and activated dendritic cells

    Basic Protocol 6: Dendritic cell stimulation, antigenic cargo, and fixation

    Support Protocol 3: Preparation of model antigen coated microbeads

    Support Protocol 4: Preparation of apoptotic cells

    Support Protocol 5: Preparation of recombinant bacteria

    Basic Protocol 7: Immunocytochemistry immunofluorescence (ICC/IF)

    Support Protocol 6: Preparation of Alcian blue‐coated coverslips

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