A distinct Toll-like receptor repertoire in human tonsillar B cells, directly activated by PamCSK, R-837 and CpG-2006 stimulation.
Immunology
; 118(4): 539-48, 2006 Aug.
Article
em En
| MEDLINE
| ID: mdl-16780564
ABSTRACT
Toll-like receptors (TLRs) recognize specific pathogen-associated molecular patterns (PAMPs), which subsequently trigger innate immunity. Recent data also suggest a role for TLRs in the direct activation of adaptive immune cells. In the present study, the expression and function of TLR1-TLR10 were characterized in purified human tonsillar B cells, focusing on differences among CD19+ CD38- CD27- (naïve B cells), CD19+ IgD- CD27-[germinal centre (GC) B cells] and CD19+ CD38- CD27+ (memory B cells) cells. The study was also designed to compare the TLR expression in B cells obtained from infected and hyperplastic tonsils that served as controls. The results demonstrated a distinct repertoire of TLRs, in which TLR1, TLR2, TLR7, TLR9 and TLR10 predominated. No differences were found among naïve, GC and memory B cells. Tonsillar infection did not substantially alter the TLR expression profile in ex vivo-isolated B-cell subsets. Purified CD19+ B cells stimulated with Pam3CSK4, R-837 and CpG oligodeoxynucleotide (ODN) 2006, via TLR1/TLR2, TLR7 and TLR9, respectively, showed an induction of interleukin-6 secretion and an up-regulated expression of human leucocyte antigen (HLA)-DR. Collectively, the present study demonstrates that B cells exhibit constitutively high levels of specific TLRs, which are not developmentally regulated during the B-cell differentiation process. Ongoing microbial infections, such as chronic tonsillitis, do not appear to affect the TLR profile in B cells. Furthermore, the distinct expression of TLRs allows B cells to respond directly to the cognate PAMPs. This further emphasizes the role of TLRs in directly activating adaptive immune cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tonsila Palatina
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Tonsilite
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Subpopulações de Linfócitos B
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Receptores Toll-Like
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Humans
Idioma:
En
Revista:
Immunology
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Suécia