Germinal centers in human lymph nodes contain reactivated memory B cells

RJ Bende, F Van Maldegem, M Triesscheijn… - The Journal of …, 2007 - rupress.org
RJ Bende, F Van Maldegem, M Triesscheijn, TAM Wormhoudt, R Guijt, CJM Van Noesel
The Journal of experimental medicine, 2007rupress.org
To reveal migration trails of antigen-responsive B cells in lymphoid tissue, we analyzed
immunoglobulin (Ig) M-VH and IgG-VH transcripts of germinal center (GC) samples
microdissected from three reactive human lymph nodes. Single B cell clones were found in
multiple GCs, one clone even in as many as 19 GCs. In several GCs, IgM and IgG variants of
the same clonal origin were identified. The offspring of individual hypermutated IgG memory
clones were traced in multiple GCs, indicating repeated engagement of memory B cells in …
To reveal migration trails of antigen-responsive B cells in lymphoid tissue, we analyzed immunoglobulin (Ig)M-VH and IgG-VH transcripts of germinal center (GC) samples microdissected from three reactive human lymph nodes. Single B cell clones were found in multiple GCs, one clone even in as many as 19 GCs. In several GCs, IgM and IgG variants of the same clonal origin were identified. The offspring of individual hypermutated IgG memory clones were traced in multiple GCs, indicating repeated engagement of memory B cells in GC reactions. These findings imply that recurring somatic hypermutation progressively drives the Ig repertoire of memory B cells to higher affinities and infer that transforming genetic hits in non-Ig genes during lymphomagenesis do not have to arise during a single GC passage, but can be collected during successive recall responses.
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