title: Tracking human antigen-specific memory B cells: a sensitive and generalized ELISPOT system.
abstract: In the interest of better understanding the role of human memory B cells in protection against disease, we developed an assay to quantitate antigen-specific memory B cells in human blood. This assay utilizes a 6-day polyclonal stimulation of PBMC followed by an antigen-specific ELISPOT for the detection of memory B cells that have differentiated into antibody secreting cells (ASC) in vitro. We have used this assay to demonstrate that the anthrax vaccine (AVA; BioThrax) elicits a substantial population of protective-antigen (PA) specific memory B cells, and these B cells satisfy the canonical surface phenotype of human memory B cells: CD19(+)CD20(+)Ig(+)CD27(+). These anti-PA antigen-specific memory B cells are IgG(+) and represent up to 2% of circulating IgG(+) B cells. Furthermore, these results confirm that vaccine-elicited memory B cells reside in the CD27(+) B cell population. This ELISPOT-based system has been designed in a generalized manner, such that the assay can be rapidly adapted to detect human antigen-specific memory B cells of any given specificity. This method should be useful for quantitatively assessing the potency of vaccines and the longevity of B cell immunological memory to various vaccines or infectious diseases.
authors.affiliation: Emory Vaccine Center and Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Road, Rm G-211, Atlanta, GA 30322, USA. shane@liai.org
authors.forename: Shane
authors.initials: S
authors.lastname: Crotty
authors.forename: Rachael D
authors.initials: RD
authors.lastname: Aubert
authors.forename: John
authors.initials: J
authors.lastname: Glidewell
authors.forename: Rafi
authors.initials: R
authors.lastname: Ahmed
mesh_terms: D022122:Anthrax Vaccines / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D007156:Immunologic Memory / Q000276:immunology*; D018189:Immunomagnetic Separation; D016130:Immunophenotyping; D011043:Pokeweed Mitogens / Q000276:immunology; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000276:immunology
chemical_list: D022122:Anthrax Vaccines; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D018985:Epitopes, B-Lymphocyte; D011043:Pokeweed Mitogens; C030325:anthrax toxin