In vitro assessment of chemotaxis by peripheral blood neutrophils from adult and senescent C57BL/6 mice: correlation with in vivo responses to pulmonary infection with type 3 Streptococcus pneumoniae.
In vitro assessment of chemotaxis by peripheral blood neutrophils from adult and senescent C57BL/6 mice: correlation with in vivo responses to pulmonary infection with type 3 Streptococcus pneumoniae.
复制标题
成年和衰老 C57BL/6 小鼠外周血中性粒细胞趋化性的体外评估：与 3 型肺炎链球菌肺部感染的体内反应的相关性。
作者：
Esposito,AL;Poirier,WJ;Clark,CA
To assess the effects of advanced age on the ability of circulating neutrophils to respond to biologically relevant chemoattractants, cells were isolated from the peripheral blood of pathogen and disease-free C57BL/6 mice and evaluated in a microchemotaxis chamber. The responses of granulocytes obtained from senescent mice (26–28 months) to the chemotactic peptide, FMLP, and to leukotriene B4 were similar to those found with cells from the younger animals (8–10 months). In contrast, the migration of neutrophils in response to sonicated type 3Streptococcus pneumoniaewas significantly greater with cells from the older animals. Similarly, the chemotactic response of neutrophils to zymosan-activated serum was greater with cells and serum from the senescent animals; however, the enhanced chemotaxis exhibited by granulocytes from the aged mice was a consequence of serum factors. Following the deposition of viable type 3 S.pneumoniaeinto the lower respiratory tract, the neutrophil influx at 24 h after challenge was significantly greater in the senescent mice; however, age-related differences in survival rates and LD50were not detected. Thus, in the C57BL/6 mouse, senescence is not associated with deficiencies in the response of neutrophils in vitro to chemoattractants that contribute to lung host defense against the pneumococcus; further, in this murine strain, advanced age does not result in an attenuation of the pulmonary inflammatory reaction to infection with type 3 S.pneumoniae.
