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Blood, Vol. 109, Issue 2, 449-456, January 15, 2007
Chemokines CCL19 and CCL21 promote activation-induced cell death of antigen-responding T cells
Blood Yasuda et al.
109: 449
Supplemental materials for: Yasuda et al, Vol 109, Issue 2, 449-456
Files in this Data Supplement:
- Figure S1. Phenotypic analysis of OVA-reactive Vβ14+CD4+ T cells in the d-LNs (PDF, 291 KB) -
(a) Annexin V, CD44, CD45RB, CD62L, or CXCR5 expression in V14+CD4+ T cells in the draining popliteal LN cells from BALB/c or plt/plt mice was analyzed by flow cytometry. Representative results at day 16 for CD44, CD45RB and CD62L and at day 18 for CXCR5 are shown. (b, c) Percentage of CD44hi, CD45RBlow, CD62Llow, or CXCR5+ cells among Annexin V+ apoptotic V 14+CD4+ T cells (b) or annexin V– viable V14+CD4+ T cells (c) in the draining popliteal LNs from BALB/c (open circle) or plt/plt (closed circle) were kinetically analyzed. Mean ± SD for 3 mice is indicated at each time point. Decreased induction of apoptosis in plt/plt mice may be due to differential activation of antigen-specific CD4+ T cells, despite similar proliferative responses in plt/plt and BALB/c mice (Figures 2 and 4). To address this possibility, expression of the surface markers CD44, CD45RB, CD62L, or CXCR5 on annexin V– viable or annexin V+ apoptotic V14+CD4+ cells in the draining LNs was estimated. Naive T cells, TCM cells, and effector memory T (TEM) cells are reportedly CD44lowCD45RBhighCD62Lhigh, CD44highCD45RBlowCD62Lhigh, and CD44highCD45RBlowCD62Llow, respectively.1,2 In BALB/c mice, the frequency of CD44high cells in both apoptotic and viable V14+ CD4+ cell populations increased after immunization, sharply peaked at day 16, and declined thereafter (b, c). About 70% of apoptotic cells were CD44high at day 16 (b), suggesting that these V14+CD4+ T cells responded to OVA, increased expression of CD44, and then underwent activation-induced cell death (AICD). The frequency of CD62Llow cells following immunization also increased in the viable cell fraction and peaked at day 16 (c), but the frequency in the apoptotic fraction was steadily elevated (70%) irrespective of immunization (b), demonstrating that most apoptotic V14+CD4+ T cells acquired a CD62Llow phenotype. The frequency of CD45RBlow or CXCR5+ cells in V14+CD4+ T cells also increased transiently in annexin V– and V+ cells, although that of CXCR5+ cells in apoptotic cells at day 18 was higher than at day 9 (b, c). Among V14+CD4+ T cells from plt/plt mice, the representation of CD44high or CD45RBlow cells in the viable population increased after immunization and, unlike in BALB/c mice, never decreased during the observation period, whereas their representation in the apoptotic population was already high at day 0 and changed little after immunization (b, c). The CD62Llow cell population increased and peaked at day 9 and declined thereafter in viable cells, whereas in apoptotic cells the percentage was quite high, about 70%, irrespective of immunization, the same as in BALB/c mice (b, c). A population of CXCR5+ cells in plt/plt mice followed a similar time course to that in BALB/c mice, although the percentages in annexin V– and V+ cells were higher in plt/plt mice than in BALB/c mice (b, c). Thus, the ratio of cells with each phenotype at the peak in plt/plt mice was quite similar to, or rather higher than, in BALB/c mice, suggesting that immunization-induced activation was not different in these two mouse strains.
REFERENCES
1. Sallusto F, Lenig D, Forster R, Lipp M, Lanzavecchia A. Two subsets of memory T lymphocytes with distinct homing potentials and effector functions. Nature. 1999;401:708-712.
2. Wherry EJ, Teichgraber V, Becker TC, et al. Lineage relationship and protective immunity of memory CD8 T cell subsets. Nat Immunol. 2003;4:225-234.
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