Content area
Full Text
Cellular & Molecular Immunology (2012) 9, 373374 2012 CSI and USTC. All rights reserved 1672-7681/12 $32.00 http://www.nature.com/cmi
Web End =www.nature.com/cmi
RESEARCH HIGHLIGHT
The origin of IgE memory and plasma cells
Malou Zuidscherwoude and Annemiek B van Spriel
Cellular & Molecular Immunology (2012) 9, 373374; doi:10.1038/cmi.2012.21; published online 13 August 2012
I gEantibodiesareinvolvednotonlyintheimmunedefenseagainstparasites,but
also in the pathogenesis of allergic diseases and anaphylaxis. Allergen-induced crosslin-king of IgE bound to FceR1 on mast cells triggers degranulation and may initiate an allergic reaction.1 Although IgE is a major player in allergic responses, IgE regulation and the molecular pathway underlying IgE1 B-cell maturation remains elusive. In an exciting report published in the April issue of Nature Immunology, Talay and colleagues demonstrate a new model for IgE switching and memory in vivo.2 In contrast to the current paradigm, IgE1 memory B cells and plasma cells develop through a germinal-center (GC) IgE1 intermediate, without the need of a transitional IgG1 phase.Furthermore, IgE1 memory B cells, and not IgG11 memory B cells, are the source of cellular IgE memory.
The typical immune response to T cell-dependent antigens starts with B-cell differentiation into short-lived plasma cells that produce low-affinity antibodies, followed by the formation of GCs that are the origin of both memory B cells and long-lived plasma cells that produce high-affinity antibodies.3 Previous studies reported a pathway of IgE B-cell maturation that is distinct from the classical model of B-cell differentiation.4,5 IgE1 B cells were
not found in GCs nevertheless differentiated into high-affinity plasma cells. It was proposed that GC IgG11 intermediates switched to IgE1 plasma cells outside the GCs.4 This model was strengthened by the
observation that IgG1-deficient mice were impaired in producing high-affinity IgE.5 Moreover, cellular IgE memory was reported to reside in IgG11 memory B cells which undergo a sequential switch to IgE after re-exposure to antigen.4
IgE differentiation is difficult to study since IgE-expressing...