title: Antigen-specific B memory cell responses to lipopolysaccharide (LPS) and invasion plasmid antigen (Ipa) B elicited in volunteers vaccinated with live-attenuated Shigella flexneri 2a vaccine candidates.
abstract: We evaluated B memory responses in healthy adult volunteers who received one oral dose of live-attenuated Shigella flexneri 2a vaccine. LPS-specific B(M) cells increased from a median of 0 at baseline to 20 spot forming cells (SFC)/10(6) expanded cells following vaccination (p=0.008). A strong correlation was found between post-vaccination anti-LPS B(M) cell counts and peak serum anti-LPS IgG titers (rs=0.95, p=0.0003). Increases in B(M) specific for IpaB approaching significance were also observed. In sum, oral vaccination with live-attenuated S. flexneri 2a elicits B(M) cells to LPS and IpaB, suggesting that B(M) responses to Shigella antigens should be further studied as a suitable surrogate of protection in shigellosis.
authors.affiliation: Division of Infectious Disease and Tropical Pediatrics, Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, United States. jsimon@medicine.umaryland.edu
authors.forename: J K
authors.initials: JK
authors.lastname: Simon
authors.forename: R
authors.initials: R
authors.lastname: Wahid
authors.forename: M
authors.initials: M
authors.lastname: Maciel
authors.forename: W L
authors.initials: WL
authors.lastname: Picking
authors.forename: K L
authors.initials: KL
authors.lastname: Kotloff
authors.forename: M M
authors.initials: MM
authors.lastname: Levine
authors.forename: M B
authors.initials: MB
authors.lastname: Sztein
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004405:Dysentery, Bacillary / Q000517:prevention & control; D005260:Female; D006801:Humans; D007114:Immunization; D007156:Immunologic Memory; D008070:Lipopolysaccharides / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010957:Plasmids; D012763:Shigella flexneri / Q000235:genetics / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014838:Volunteers; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D008070:Lipopolysaccharides; D014613:Vaccines, Attenuated