Vγ9Vδ2 T cells are a major human blood γδ T cell population that respond in a T cell receptor (TCR)-dependent manner to phosphoantigens which are generated by a variety of microorganisms. It is not clear how Vγ9Vδ2 T cells react toward the sudden microbial exposure early after birth. We found that human Vγ9Vδ2 T cells with a public/shared fetal-derived TCR repertoire expanded within 10 wk postpartum. Such an expansion was not observed in non-Vγ9Vδ2 γδ T cells, which possessed a private TCR repertoire. Furthermore, only the Vγ9Vδ2 T cells differentiated into potent cytotoxic effector cells by 10 wk of age, despite their fetal origin. Both the expansion of public fetal Vγ9Vδ2 T cells and their functional differentiation were not affected by newborn vaccination with the phosphoantigen-containing bacillus Calmette–Guérin (BCG) vaccine. These findings suggest a strong and early priming of the public fetal-derived Vγ9Vδ2 T cells promptly after birth, likely upon environmental phosphoantigen exposure.

Vγ9Vδ2 T 细胞是主要的人类血液 γδ T 细胞群，它们以 T 细胞受体 (TCR) 依赖性方式对由多种微生物产生的磷酸抗原作出反应。目前尚不清楚 Vγ9Vδ2 T 细胞如何对出生后早期的突然微生物暴露做出反应。我们发现具有公共/共享的胎儿衍生 TCR 库的人类 Vγ9Vδ2 T 细胞在产后 10 周内扩展。在拥有私有 TCR 库的非 Vγ9Vδ2 γδ T 细胞中未观察到这种扩增。此外，只有 Vγ9Vδ2 T 细胞在 10 周龄时分化为有效的细胞毒性效应细胞，尽管它们起源于胎儿。公共胎儿 Vγ9Vδ2 T 细胞的扩增及其功能分化均不受新生儿接种含磷酸抗原的卡介苗 (BCG) 疫苗的影响。