Details

Autor(en) / Beteiligte

• Victora, Gabriel D.
• Schwickert, Tanja A.
• Fooksman, David R.
• Kamphorst, Alice O.
• Meyer-Hermann, Michael
• Dustin, Michael L.
• Nussenzweig, Michel C.

Titel

Germinal Center Dynamics Revealed by Multiphoton Microscopy with a Photoactivatable Fluorescent Reporter

Ist Teil von

• Cell, 2010-11, Vol.143 (4), p.592-605

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2010

Quelle

MEDLINE

Beschreibungen/Notizen

• The germinal center (GC) reaction produces high-affinity antibodies by random mutation and selective clonal expansion of B cells with high-affinity receptors. The mechanism by which B cells are selected remains unclear, as does the role of the two anatomically defined areas of the GC, light zone (LZ) and dark zone (DZ). We combined a transgenic photoactivatable fluorescent protein tracer with multiphoton laser-scanning microscopy and flow cytometry to examine anatomically defined LZ and DZ B cells and GC selection. We find that B cell division is restricted to the DZ, with a net vector of B cell movement from the DZ to the LZ. The decision to return to the DZ and undergo clonal expansion is controlled by T helper cells in the GC LZ, which discern between LZ B cells based on the amount of antigen captured and presented. Thus, T cell help, and not direct competition for antigen, is the limiting factor in GC selection. [Display omitted] [Display omitted] ► Photoactivation reveals phenotypic differences between light and dark zone B cells ► Interzonal migration is bidirectional, with a net vector from dark to light zone ► T cell help triggers B cell return from light to dark zone ► Return to dark zone is accompanied by clonal expansion