Hilmo A, Howard T H
Blood. 1987 Mar;69(3):945-9.
We utilized flow cytometric analysis of NBDphallacidin-stained cells to measure F-actin content, expressed as fluorescent channel numbers, and we compared the microfilamentous cytoskeletal organization in neutrophils from healthy neonates (36 to 38 weeks gestational age) and adults. Basal F-actin content in neonate cord blood neutrophils is higher than that of adults. The elevation is intrinsic to the cell and not related to parturition because basal F-actin content of neonatal cells obtained by venipuncture (days 1 to 8 of age) is also elevated (38 +/- 10, N = 15) when compared to adults (21 +/- 7.0, N = 27). The rate of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced actin polymerization is similar in adult and neonatal neutrophils and is maximal by 30 to 45 seconds at 25 degrees C. Adult, neonatal cord, and neonatal venipuncture neutrophils increase F-actin content to a similar extent following 0.5 mumol/L fMLP activation (52 +/- 18, N = 27; 58.7 +/- 18, N = 18; 51.5 +/- 7.0, N = 15, respectively). However, the relative increase in F-actin content following fMLP activation is much greater in adult (2.37-fold) than neonatal neutrophils (1.28-fold). This difference is due to the elevated basal F-actin content of neonatal cells. Comparison of distribution of F-actin content among basal, neonatal neutrophils reveals two subpopulations of neutrophils with respect to F-actin content--approximately 25% with F-actin content similar to that of adult neutrophils and 75% with F-actin content greater than that of adult cells. Following fMLP activation, the subpopulations disappear. The results suggest that abnormalities in microfilamentous cytoskeletal organization of neonatal cells may, in part, be responsible for decreased chemotactic response of neonatal neutrophils.
我们利用对NBD鬼笔环肽染色细胞的流式细胞术分析来测量F-肌动蛋白含量，以荧光通道数表示，并比较了健康新生儿（胎龄36至38周）和成人中性粒细胞中的微丝细胞骨架组织。新生儿脐带血中性粒细胞中的基础F-肌动蛋白含量高于成人。这种升高是细胞固有的，与分娩无关，因为与成人（21±7.0，N = 27）相比，通过静脉穿刺获得的新生儿细胞（出生后1至8天）的基础F-肌动蛋白含量也升高（38±10，N = 15）。在成人和新生儿中性粒细胞中，N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸（fMLP）诱导的肌动蛋白聚合速率相似，在25℃下30至45秒时达到最大值。成人、新生儿脐带血和新生儿静脉穿刺中性粒细胞在0.5μmol/L fMLP激活后，F-肌动蛋白含量增加的程度相似（分别为52±18，N = 27；58.7±18，N = 18；51.5±7.0，N = 15）。然而，fMLP激活后F-肌动蛋白含量相对增加在成人（2.37倍）中比新生儿中性粒细胞（1.28倍）大得多。这种差异是由于新生儿细胞基础F-肌动蛋白含量升高所致。比较基础新生儿中性粒细胞中F-肌动蛋白含量的分布，发现中性粒细胞在F-肌动蛋白含量方面有两个亚群——约25%的F-肌动蛋白含量与成人中性粒细胞相似，75%的F-肌动蛋白含量高于成人细胞。fMLP激活后，亚群消失。结果表明，新生儿细胞微丝细胞骨架组织的异常可能部分导致新生儿中性粒细胞趋化反应降低。
