Gröndahl G, Johannisson A, Demmers S, Jensen Waern M
Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
Vet Microbiol. 1999 Mar 12;65(3):241-54. doi: 10.1016/s0378-1135(98)00299-5.
The aim of this study was to evaluate the influence of age and plasma treatment on neutrophil phagocytosis, CD18 expression and serum opsonic capacity in foals in field settings. Microbial infections constitute a large threat in young foals and neutrophil functions are crucial for the defense. Blood samples were obtained from 13 foals at seven time points between the ages of 2 and 56 days and once from 16 adult horses. Six of the foals were treated with adult plasma at the age of 1 week. Neutrophil phagocytosis of yeast after various opsonizations and the expression of complement adhesion receptor CD18 were analysed by flow cytometry. Autologous serum opsonization resulted in 52+/-6.1% phagocytic neutrophils in 2-day-old foals (n = 12), a significantly lower rate than in adult horses (mean 84+/-3.1%; n = 16). In foals, yeast ingestion per neutrophil was also lower than in adults. Opsonic capacity increased with age (p < 0.05), reaching adult levels at 3-4 weeks. An increase in serum opsonic capacity followed plasma treatment (p < 0.05). The phagocytic capacity of foal neutrophils at the time-points studied was equal to or higher than that in the adults, when pooled adult horse serum or anti-yeast IgG was used as opsonin. In foals, serum IgG concentration was negatively correlated to serum opsonic capacity. CD18 receptor expression was higher in neutrophils from foals (<21 days old) than in those from adult horses (p < 0.05). The results indicate that foals are transiently deficient in serum opsonic capacity, which negatively affects their capacity for neutrophil phagocytosis. These changes in serum opsonins, unrelated to IgG, may be important factors in susceptibility to infections in foals.
本研究的目的是评估年龄和血浆处理对野外环境下驹中性粒细胞吞噬作用、CD18表达及血清调理素能力的影响。微生物感染对幼驹构成巨大威胁，中性粒细胞功能对防御至关重要。在2至56日龄的7个时间点从13匹驹采集血样，另从16匹成年马采集一次血样。其中6匹驹在1周龄时接受成年马血浆治疗。通过流式细胞术分析各种调理作用后酵母的中性粒细胞吞噬作用及补体黏附受体CD18的表达。自体血清调理导致2日龄驹（n = 12）中52±6.1%的中性粒细胞发生吞噬，这一比例显著低于成年马（平均84±3.1%；n = 16）。在驹中，每个中性粒细胞的酵母摄取量也低于成年马。调理素能力随年龄增加（p < 0.05），在3至4周时达到成年水平。血浆治疗后血清调理素能力增加（p < 0.05）。当使用成年马混合血清或抗酵母IgG作为调理素时，所研究时间点驹中性粒细胞的吞噬能力等于或高于成年马。在驹中，血清IgG浓度与血清调理素能力呈负相关。<21日龄驹的中性粒细胞中CD18受体表达高于成年马（p < 0.05）。结果表明驹血清调理素能力暂时不足，这对其中性粒细胞吞噬能力产生负面影响。这些与IgG无关的血清调理素变化可能是驹易感染的重要因素。
