Chemokines CCL19 and CCL21 promote activation-induced cell death of antigen-responding T cells.
Blood
; 109(2): 449-56, 2007 Jan 15.
Article
in En
| MEDLINE
| ID: mdl-16973962
ABSTRACT
Secondary lymphoid organs (SLOs) provide a niche for the initiation and regulation of T-cell responses, but the mechanisms have been poorly understood. We investigated the influence of chemokines CCL19 and CCL21 constitutively expressed in SLOs on activation-induced cell death (AICD) of CD4+ T cells. When paucity of lymph node T cells (plt) mutant mice lacking expression of CCL19/CCL21 were primed with OVA/CFA, both expansion of OVA-responding CD4+ T cells in the draining lymph nodes and an in vitro recall response were prolonged as compared with responses in wild-type (WT) mice. The apoptotic cell frequency among OVA-responding CD4+ T cells was similarly low in plt/plt and WT mice during the clonal expansion phase. However, during the clonal contraction phase, the frequency never increased in plt/plt mice, whereas in WT mice it continuously increased to a peak 18 days after immunization. The presence of CCL19/CCL21 during the in vitro stimulation of CD4+ T cells with anti-CD3 plus anti-CD28 significantly enhanced in vitro AICD induction of the restimulated T cells, partially through enhancing expression of Fas ligand. Our results suggest that CCL19/CCL21 produced by stromal cells and antigen-presenting cells regulate CD4+ T-cell immune responses in SLOs by promoting AICD.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
CD4-Positive T-Lymphocytes
/
Chemokines, CC
/
Lymphoid Tissue
Type of study:
Diagnostic_studies
Limits:
Animals
Language:
En
Journal:
Blood
Year:
2007
Document type:
Article
Affiliation country:
Japón