In:
Blood, American Society of Hematology, Vol. 120, No. 25 ( 2012-12-13), p. 4992-5001
Abstract:
We studied the distribution of peripheral B-cell subsets in patients deficient for key factors of the TLR-signaling pathways (MyD88, TIRAP/MAL, IL-1 receptor–associated kinase 4 [IRAK-4], TLR3, UNC-93B, TRIF). All TLRs, except TLR3, which signals through the TRIF adaptor, require MyD88 and IRAK-4 to mediate their function. TLR4 and the TLR2 heterodimers (with TLR1, TLR6, and possibly TLR10) require in addition the adaptor TIRAP, whereas UNC-93B is needed for the proper localization of intracellular TLR3, TLR7, TLR8, and TLR9. We found that IgM+IgD+CD27+ but not switched B cells were strongly reduced in MyD88-, IRAK-4-, and TIRAP-deficient patients. This defect did not appear to be compensated with age. However, somatic hypermutation of Ig genes and heavy-chain CDR3 size distribution of IgM+IgD+CD27+ B cells were not affected in these patient s. In contrast, the numbers of IgM+IgD+CD27+ B cells were normal in the absence of TLR3, TRIF, and UNC-93B, suggesting that UNC-93B–dependent TLRs, and notably TLR9, are dispensable for the presence of this subset in peripheral blood. Interestingly, TLR10 was found to be expressed at greater levels in IgM+IgD+CD27+ compared with switched B cells in healthy patients. Hence, we propose a role for TIRAP-dependent TLRs, possibly TLR10 in particular, in the development and/or maintenance of IgM+IgD+CD27+ B cells in humans.
Type of Medium:
Online Resource
ISSN:
0006-4971
,
1528-0020
DOI:
10.1182/blood-2012-07-440776
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2012
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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