Faculty Opinions recommendation of Germinal center B cell and T follicular helper cell development initiates in the interfollicular zone.

We identify the interfollicular (IF) zone as the site where germinal center B cell and T follicular helper (Tfh) cell differentiation initiates. For the first 2 days postimmunization, antigen-specific T and B cells remained confined within the IF zone, formed long-lived interactions, and upregulated the transcriptional repressor Bcl6. T cells also acquired the Tfh cell markers CXCR5, PD-1, and GL7. Responding B and T cells migrated to the follicle interior directly from the IF zone, T cell immigration preceding B cells by 1 day. Notably, in the absence of cognate B cells, Tfh cells still formed and migrated to the follicle. However, without such B cells, PD-1, ICOS, and GL7 were no longer expressed on follicular Bcl6(hi) T cells that nevertheless persisted in the follicle. Thus, Ag-specific B cells are required for the maintenance of the PD-1(hi)ICOS(hi)GL7(hi) Tfh cell phenotype within the follicle, but not for their initial differentiation in the IF zone.Copyright © 2011 Elsevier Inc. All rights reserved. PMID: 21636295 Funding information This work was supported by: NIAMS NIH HHS, United States Grant ID: P30AR053495 NIAID NIH HHS, United States Grant ID: R01AI080850 Canadian Institutes of Health Research, Canada NIAMS NIH HHS, United States Grant ID: P30 AR053495 NIAID NIH HHS, United States Grant ID: R01 AI080850 NIAID NIH HHS, United States Grant ID: R01 AI080850-01A1 More Less keyboard_arrow_down