Intestinal bacteria trigger T cell-independent immunoglobulin A(2) class switching by inducing epithelial-cell secretion of the cytokine APRIL.
Immunity
; 26(6): 812-26, 2007 Jun.
Article
in En
| MEDLINE
| ID: mdl-17570691
ABSTRACT
Bacteria colonize the intestine shortly after birth and thereafter exert several beneficial functions, including induction of protective immunoglobulin A (IgA) antibodies. The distal intestine contains IgA(2), which is more resistant to bacterial proteases than is IgA(1). The mechanism by which B cells switch from IgM to IgA(2) remains unknown. We found that human intestinal epithelial cells (IECs) triggered IgA(2) class switching in B cells, including IgA(1)-expressing B cells arriving from mucosal follicles, through a CD4(+) T cell-independent pathway involving a proliferation-inducing ligand (APRIL). IECs released APRIL after sensing bacteria through Toll-like receptors (TLRs) and further increased APRIL production by activating dendritic cells via thymic stromal lymphopoietin. Our data indicate that bacteria elicit IgA(2) class switching by linking lamina propria B cells with IECs through a TLR-inducible signaling program requiring APRIL. Thus, mucosal vaccines should activate IECs to induce more effective IgA(2) responses.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacteria
/
Immunoglobulin A
/
B-Lymphocytes
/
Immunoglobulin Class Switching
/
Tumor Necrosis Factor Ligand Superfamily Member 13
/
Intestinal Mucosa
Limits:
Humans
Language:
En
Journal:
Immunity
Journal subject:
ALERGIA E IMUNOLOGIA
Year:
2007
Type:
Article
Affiliation country:
United States