Bovay Amandine, Speiser Daniel E, Fuertes Marraco Silvia A
Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), University of Lausanne , Epalinges, Switzerland.
Hum Vaccin Immunother. 2020 Dec 1;16(12):3103-3110. doi: 10.1080/21645515.2020.1750249. Epub 2020 Apr 29.
Lymphocyte recirculation within the human body is essential for efficient pathogen detection and immune responses. So far, immune cell migration has been investigated largely using ovine and murine models, with little evidence in humans. Here, we analyzed peripheral blood of healthy individuals following primary vaccination with the Yellow Fever vaccine YF-17D. We found that the number of leukocytes was transiently and sharply reduced in blood as detected on day 7 after vaccine administration. The T cell drop was restricted to cells expressing the lymph node-homing chemokine receptor CCR7. Interestingly, the vaccine-induced drop positively correlated with the expression of CD69 by the T cells before vaccination. This suggests that CCR7 T cells are being trapped within the lymph nodes through CD69-induced suppression of egress. Strikingly, we further found that the T cell drop negatively correlated with CD8 T cell activation and with production of neutralizing antibodies. In conclusion, early and transient T cell depletion in blood negatively correlated with protective immune response events induced by YF-17D vaccination. Our data highlight baseline CD69 expression and early drop in T cells as potential biomarkers of the Yellow Fever vaccine response.
淋巴细胞在人体内的再循环对于高效检测病原体和免疫反应至关重要。到目前为止，免疫细胞迁移的研究主要使用绵羊和小鼠模型，在人类中的证据很少。在这里，我们分析了健康个体初次接种黄热病疫苗YF-17D后的外周血。我们发现，在接种疫苗后第7天检测到血液中的白细胞数量短暂且急剧减少。T细胞的减少仅限于表达淋巴结归巢趋化因子受体CCR7的细胞。有趣的是，疫苗诱导的减少与接种疫苗前T细胞上CD69的表达呈正相关。这表明CCR7 T细胞通过CD69诱导的出芽抑制而被困在淋巴结内。引人注目的是，我们进一步发现T细胞减少与CD8 T细胞活化以及中和抗体的产生呈负相关。总之，血液中早期和短暂的T细胞耗竭与YF-17D疫苗接种诱导的保护性免疫反应事件呈负相关。我们的数据突出了基线CD69表达和T细胞早期减少作为黄热病疫苗反应的潜在生物标志物。
