| |
|
|
|
|
|
|
|||
|
Blood, 1 December 2007, Vol. 110, No. 12, pp. 3917-3925. Prepublished online as a Blood First Edition Paper on July 20, 2007; DOI 10.1182/blood-2007-05-087767.
IMMUNOBIOLOGY CD45RO enriches for activated, highly mutated human germinal center B cells1 Molecular Immunogenetics Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK To date, there is no consensus regarding the influence of different CD45 isoforms during peripheral B-cell development. Examining correlations between surface CD45RO expression and various physiologic processes ongoing during the germinal center (GC) reaction, we hypothesized that GC B cells, like T cells, that up-regulate surface RO should progressively acquire phenotypes commonly associated with activated, differentiating lymphocytes. GC B cells (IgD–CD38+) were subdivided into 3 surface CD45RO fractions: RO–, RO+/–, and RO+. We show here that the average number of mutations per IgVH transcript increased in direct correlation with surface RO levels. Conjunctional use of RO and CD69 further delineated low/moderately and highly mutated fractions. Activation-induced cytidine deaminase (AID) mRNA was slightly reduced among RO+ GC B cells, suggesting that higher mutation averages are unlikely due to elevated somatic mutation activity. Instead, RO+ GC B cells were negative for Annexin V, comprised mostly (93%) of CD77– centrocytes, and were enriched for CD69+ cells. Collectively, RO+ GC B cells occupy what seems to be a specialized niche comprised mostly of centrocytes that may be in transition between activation states. These findings are among the first to sort GC B cells into populations enriched for live mutated cells solely using a single extracellular marker.
Related Article in Blood Online:
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2007 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||