Generation of B cell memory to the bacterial polysaccharide alpha-1,3 dextran.
B1b B cells generate a novel form of memory and provide Ab mediated-protection to persisting bacterial pathogens. To understand how B1b B cells establish memory to polysaccharide Ags, we studied an oligoclonal B cell response to alpha-1,3 dextran (DEX) expressed on Enterobacter cloacae. B cells specific for DEX enrich in the marginal zone (MZ) and B1b B cell populations. After E. cloacae immunization, MZ B cells were responsible for the generation of initial peak DEX-specific Ab titers, whereas, DEX-specific B1b B cells expanded and played an important role in boosted production of DEX-specific Ab titers upon E. cloacae rechallenge. Cell transfer experiments demonstrate that B1b B cells possess the capacity for both robust proliferation and plasma cell differentiation, thus distinguishing themselves from MZ B cells, which uniformly commit to plasma cell differentiation. These results define B1b B cells as the principal reservoir for memory to bacterial-associated polysaccharide Ags.
Foote
Jeremy B
JB
Department of Microbiology, The University of Alabama, Birmingham, AL 35294-2182, USA.
Kearney
John F
JF
D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D003911:Dextrans / Q000276:immunology* / Q000378:metabolism; D016972:Enterobacter cloacae / Q000276:immunology; D005260:Female; D007156:Immunologic Memory; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013154:Spleen / Q000276:immunology / Q000378:metabolism
D003911:Dextrans; D011135:Polysaccharides, Bacterial; C040834:alpha-1,3-dextran