Lee E K, Kehrli M E
Department of Microbiology, Iowa State University, Ames 50011, USA.
Am J Vet Res. 1998 Jan;59(1):37-43.
To determine expression of the beta 2-integrin (CD18) family of adhesion molecules and L-selectin (CD62L) on neutrophils from periparturient cows and calves.
8 periparturient Holstein cows and 9 Holstein calves.
Constitutive CD18 and CD62L expression on neutrophils was determined by flow cytometry, using specific monoclonal antibodies. Platelet-activating factor was used to activate neutrophils in vitro to measure down-regulation of CD62L and up-regulation of CD18 on activated neutrophils.
Mean values for constitutive and platelet-activating factor-stimulated CD18 expression on neutrophils from cows and calves were highest at parturition, then decreased during the first 24 hours after parturition on calf neutrophils, whereas CD62L expression decreased markedly by 9 to 24 hours after parturition on cow and calf neutrophils. Constitutive amounts of CD18 and CD62L on cow neutrophils returned to prepartum values by day 3 after parturition. Amounts of CD18 expression on calves' neutrophils recovered by 1 week of age, but did not reach original birth values, whereas CD62L expression exceeded birth values by day 3 after parturition. Cows had leukocytosis (neutrophilia), with a doubling of circulating neutrophils 9 hours after calving that was inversely correlated with CD62L expression on neutrophils.
Low amounts of CD62L and CD18 on calf neutrophils and of CD62L on neutrophils from cows for several days after parturition may result in impaired inflammatory response. Low CD62L expression may contribute to increased susceptibility to disease.
测定围产期奶牛和犊牛中性粒细胞上β2整合素（CD18）家族黏附分子和L选择素（CD62L）的表达。
8头围产期荷斯坦奶牛和9头荷斯坦犊牛。
使用特异性单克隆抗体，通过流式细胞术测定中性粒细胞上组成性CD18和CD62L的表达。体外使用血小板活化因子激活中性粒细胞，以测量活化中性粒细胞上CD62L的下调和CD18的上调。
奶牛和犊牛中性粒细胞上组成性及血小板活化因子刺激后的CD18表达平均值在分娩时最高，犊牛中性粒细胞在分娩后最初24小时内下降，而奶牛和犊牛中性粒细胞上的CD62L表达在分娩后9至24小时显著下降。奶牛中性粒细胞上CD18和CD62L的组成性含量在分娩后第3天恢复到产前值。犊牛中性粒细胞上CD18表达量在1周龄时恢复，但未达到出生时的原始值，而CD62L表达量在分娩后第3天超过出生时的值。奶牛出现白细胞增多（中性粒细胞增多），产犊后9小时循环中性粒细胞数量翻倍，这与中性粒细胞上的CD62L表达呈负相关。
犊牛中性粒细胞上低水平的CD62L和CD18以及奶牛中性粒细胞上低水平的CD62L在分娩后数天可能导致炎症反应受损。低水平的CD62L表达可能导致疾病易感性增加。
