An unusual Fc receptor-related protein expressed in human centroblasts

AUTOR(ES)

Facchetti, Fabio

FONTE

The National Academy of Sciences

RESUMO

Here, we report the identification of Fc receptor homolog expressed in B cells (FREB), a unique B cell-specific molecule that is distantly related to FcγRI (receptor I for the Fc fragment of IgG) and is encoded on human chromosome 1q, within the FcγR gene region. FREB has an intracellular distribution and lacks a canonical transmembrane domain. In addition, FREB lacks bona fide Fc fragment binding regions and does not bind immunoglobulins. By using specific monoclonal antibodies, we show that FREB is preferentially expressed in germinal center centroblasts, which undergo affinity maturation and class-switch recombination. Together, these characteristics indicate that FREB may have a unique role in B cell differentiation. FREB is also expressed in some B cell lymphomas, most of which have centroblast origin. Remarkably, FREB is expressed in a subset of diffuse large B cell lymphomas, providing a unique marker for the characterization of this B cell malignancy.

Documentos Relacionados

• Heterogeneous expression of poliovirus receptor-related proteins in human cells and tissues.
• Expression of alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein and scavenger receptor in human atherosclerotic lesions.
• 39 kDa receptor-associated protein is an ER resident protein and molecular chaperone for LDL receptor-related protein.
• Low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor is an hepatic receptor for tissue-type plasminogen activator.
• Functional expression of low density lipoprotein receptor-related protein is controlled by receptor-associated protein in vivo.