Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster, Ohio, United States of America.
PLoS One. 2012;7(3):e33970. doi: 10.1371/journal.pone.0033970. Epub 2012 Mar 27.
Thymic CD4(+)CD25(+) cells have regulatory-T-cell-like properties in chickens. This study examined the ontogeny of CD4(+)CD25(+) cells in the thymus and in peripheral compartments in chickens. CD4(+)CD25(+) cells started to appear in the thymus at day 15 of incubation (E15), although at low percentages. Expressed as a percentage of CD4(+) cells, CD4(+)CD25(+) cells increased (P<0.01) from 1.7% at E20 to 7.3% at 0 d post-hatch (D0). CD4(+)CD25(+) cells did not appear in the spleen or cecal tonsils of embryos. Expressed as a percentage of CD4(+) cells, CD4(+)CD25(+) cells increased (P<0.01) from 0% at D0 to 27% at D1 in cecal tonsils and from 0% at D0 to 11% at D1 in the spleen. Expressed as a percentage of all mononuclear cells, cecal tonsils at D1 had approximately 3.5-fold higher percentage of CD4(+)CD25(+) cells than the spleen at D1. CD4(+)CD25(+) cells from cecal tonsils of chicks at D1 were suppressive. CD4(+)CD25(+) cells from D0 thymus, when injected back into MHC-compatible chicks, migrated to cecal tonsils and lungs and were detected until 10 d post-injection. CD4(+)CD25(+) cells from cecal tonsils had a higher (P = 0.01) relative amount of CCR9 mRNA than CD4(+)CD25(+) cells from the thymus. It could be concluded that in chickens CD4(+)CD25(+) cells migrate from the thymus immediately post-hatch and preferentially colonize the gut associated lymphoid tissues. CD4(+)CD25(+) cells' preferential migration to cecal tonsils is likely directed through the CCR9 pathway in chickens.
胸腺中的 CD4(+)CD25(+) 细胞具有调节性 T 细胞样特性。本研究检测了鸡的胸腺和外周组织中 CD4(+)CD25(+) 细胞的发生情况。尽管 CD4(+)CD25(+) 细胞在孵化第 15 天（E15）时就已经开始出现在胸腺中，但比例较低。以 CD4(+) 细胞的百分比表示，CD4(+)CD25(+) 细胞从 E20 时的 1.7%增加（P<0.01）至孵化后第 0 天（D0）的 7.3%。胚胎的脾脏或盲肠扁桃体中未出现 CD4(+)CD25(+) 细胞。以 CD4(+) 细胞的百分比表示，CD4(+)CD25(+) 细胞从 D0 时的 0%增加（P<0.01）至盲肠扁桃体的 D1 时的 27%，以及从 D0 时的 0%增加（P<0.01）至脾脏的 D1 时的 11%。以所有单核细胞的百分比表示，盲肠扁桃体在 D1 时的 CD4(+)CD25(+) 细胞比例约为脾脏的 3.5 倍。盲肠扁桃体的 CD4(+)CD25(+) 细胞在 D1 时具有抑制性。D0 时的胸腺 CD4(+)CD25(+) 细胞，当回注到 MHC 相容的小鸡中时，迁移到盲肠扁桃体和肺部，并在注射后 10 天被检测到。来自盲肠扁桃体的 CD4(+)CD25(+) 细胞比来自胸腺的 CD4(+)CD25(+) 细胞具有更高（P = 0.01）的相对 CCR9 mRNA 量。可以得出结论，在鸡中，CD4(+)CD25(+) 细胞在孵化后立即从胸腺迁移，并优先定植于肠道相关淋巴组织。CD4(+)CD25(+) 细胞优先迁移到盲肠扁桃体可能是通过鸡中的 CCR9 途径来实现的。
