Andrade W N, Johnston M G, Hay J B
Department of Pathology, University of Toronto, Toronto, North York, Ontario, Canada.
Blood. 1998 Mar 1;91(5):1653-61.
Lymphocyte recirculation facilitates the detection and elimination of pathogens and the dissemination of immunologic memory. It is generally assumed that all small lymphocytes in the blood are actively recirculating, yet there is little quantitative data directly comparing the migration of this population with actively recirculating, lymph-derived lymphocytes. In this study blood lymphocytes were labeled with fluorescein isothiocyanate (FITC), and lymph lymphocytes were labeled with CM-DiI, reinfused intravenously, and monitored in blood and lymph. After equilibration the concentration of blood lymphocytes was several times higher in blood than in lymph, whereas lymph lymphocytes displayed the opposite behavior. This suggested that blood lymphocytes did not recirculate as efficiently as lymph lymphocytes, so we examined the following blood lymphocyte subsets in greater detail: B cells, CD4+, CD8+, and gammadelta T cells. Within 4 hours postinjection the percentage of FITC+ CD8+ and CD4+ lymphocytes fell in the blood and remained significantly lower than the injected sample. In contrast, the concentration of FITC+ gammadelta T cells did not change, and the percentage of FITC+ B cells increased. These data suggest that subpopulations of B and perhaps gammadelta T lymphocytes in the blood do not recirculate efficiently through lymph nodes.
淋巴细胞再循环有助于病原体的检测与清除以及免疫记忆的传播。一般认为血液中的所有小淋巴细胞都在积极地进行再循环，然而，几乎没有定量数据能直接比较这群细胞与源自淋巴且积极进行再循环的淋巴细胞的迁移情况。在本研究中，血液淋巴细胞用异硫氰酸荧光素（FITC）标记，淋巴淋巴细胞用CM-DiI标记，静脉回输后，对血液和淋巴中的细胞进行监测。平衡后，血液中血液淋巴细胞的浓度比淋巴中的高几倍，而淋巴淋巴细胞则表现出相反的情况。这表明血液淋巴细胞的再循环效率不如淋巴淋巴细胞，因此我们更详细地检查了以下血液淋巴细胞亚群：B细胞、CD4 +、CD8 +和γδ T细胞。注射后4小时内，血液中FITC + CD8 +和CD4 +淋巴细胞的百分比下降，且仍显著低于注射样本。相反，FITC +γδ T细胞的浓度没有变化，FITC + B细胞的百分比增加。这些数据表明，血液中的B淋巴细胞亚群以及可能的γδ T淋巴细胞亚群不能有效地通过淋巴结进行再循环。
