Kozel T R, Pfrommer G S, Redelman D
Department of Microbiology, School of Medicine, University of Nevada, Reno 89557.
Clin Exp Immunol. 1987 Oct;70(1):238-46.
We studied the effect of agents that activate neutrophils on phagocytosis of C. neoformans. The amount of CR3 on the surface of neutrophils was used as a marker for neutrophil activation. Surface CR3 was estimated by flow cytometry using phycoerythrin-labelled anti-CR3 (anti-Leu-15) monoclonal antibody. Phagocytosis was determined by incubation of neutrophils with cryptococci that had been preincubated with normal human serum. We found that treatment of neutrophils with (i) the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine, (ii) zymosan activated serum, (iii) supernatant fluid from a mixed leucocyte culture, or (iv) supernatant fluid from human leucocytes cultured with phytohaemagglutinin produced a dose-dependent increase in CR3 density. These agents also markedly enhanced phagocytosis of opsonized cryptococci in a parallel dose-dependent fashion. These results indicate that phagocytosis of cryptococci opsonized with normal human serum is markedly enhanced by treatment of neutrophils with reagents that stimulate neutrophils. Our results demonstrate that neutrophils activated in an appropriate manner are capable of efficient phagocytosis of encapsulated cryptococci. This potential phagocyte activity may account in part for the high natural resistance to cryptococcosis.
我们研究了激活中性粒细胞的试剂对新型隐球菌吞噬作用的影响。中性粒细胞表面CR3的量被用作中性粒细胞激活的标志物。使用藻红蛋白标记的抗CR3（抗-Leu-15）单克隆抗体通过流式细胞术估计表面CR3。吞噬作用通过将中性粒细胞与已用正常人血清预孵育的隐球菌一起孵育来确定。我们发现用以下物质处理中性粒细胞：（i）趋化肽N-甲酰甲硫氨酰亮氨酰苯丙氨酸，（ii）酵母聚糖激活的血清，（iii）混合白细胞培养物的上清液，或（iv）用植物血凝素培养的人白细胞的上清液，会使CR3密度呈剂量依赖性增加。这些试剂还以平行的剂量依赖性方式显著增强了调理隐球菌的吞噬作用。这些结果表明，用刺激中性粒细胞的试剂处理中性粒细胞可显著增强用正常人血清调理的隐球菌的吞噬作用。我们的结果表明，以适当方式激活的中性粒细胞能够有效吞噬被包裹的隐球菌。这种潜在的吞噬细胞活性可能部分解释了对隐球菌病的高天然抵抗力。
