The BLNK adaptor protein has a nonredundant role in human B-cell differentiation.
Lagresle-Peyrou C, Millili M, Luce S, Boned A, Sadek H, Rouiller J, Frange P, Cros G, Cavazzana M, André-Schmutz I, Schiff C.
Source : J Allergy Clin Immunol
2014 Jul 1
Pmid : 24582315
METHODS: B-cell development, including IgVH and Vk chain repertoires analysis, was studied in the bone marrow of a new case of BLNK deficiency in vitro and in vivo.
RESULTS: Here, we report on a patient with agammaglobulinemia, with a total absence of circulating B cells. We detected a homozygous mutation in BLNK, which leads to the complete abrogation of BLNK protein expression. In the bone marrow, we identified a severe differentiation blockade at the pre-BI- to pre-BII-cell transition. IgVH gene rearrangements and selection of the IgH repertoire were normal, whereas the patient's pre-BI cells showed very restricted usage of the IgVκ repertoire. Complementation of bone marrow progenitors from the patient with the BLNK gene and transplantation into NOD/SCID/γcko mice allowed the complete restoration of B-cell differentiation and a normal usage of the IgVκ genes.