Relation between activity control of neutrophils and ingestion in inflammation

吞噬、细胞因子产生和趋化是中性粒细胞在急性炎症中发挥的主要功能。随着炎症急性期的结束，浸润的中性粒细胞大部分很快发生凋亡。本研究旨在探讨嗜中性粒细胞的吞噬作用对其凋亡、细胞因子产生和趋化等功能的影响。注射蛋白蛋白胨后，从腹腔渗出细胞中分离出大鼠中性粒细胞。通过DNA的断裂和中性细胞核的形态来评估细胞凋亡。吞噬作用是由摄入油颗粒引起的。采用夹心ELISA法和荧光法分别测定中性粒细胞中的TNF-α和活性氧。中性粒细胞的凋亡被细菌产物脂多糖（LPS）或炎症细胞因子IL-1β剂量依赖性地抑制。这种对中性粒细胞凋亡的抑制作用被它们摄入油颗粒所消除。摄入油颗粒抑制了lps诱导的中性粒细胞产生TNF-α和活性氧。中性粒细胞对酶解酶处理血清的趋化活性在Boyden室测定。当中性粒细胞与LPS放置在上腔中时，它们的趋化活性被极大地抑制。通过摄入油颗粒，这种情况恢复到控制水平。综上所述，我已经证明，中性粒细胞的吞噬作用削弱了LPS或IL-1β诱导的中性粒细胞自身的已知功能，如抑制凋亡倾向、增加细胞因子产生和改变趋化活性。结果表明，早期感染后出现的嗜中性粒细胞的吞噬可能通过促进细胞凋亡、抑制细胞因子和活性氧的产生以及抑制趋化活性来帮助周围正常组织从脓性炎症的自毁性中拯救出来。少

Phagocytosis, cytokine production and chemotaxis are the major function carried out by neutrophils in an acute inflammation. Infiltrating neutrophils soon undergo in the most part apoptosis with cessation of an acute phase of inflammation. The present study was attempted to investigate how phagocytosis of neutrophils causes effects on their function such as apoptosis, cytokine production and chemotaxis.Rat neutrophils were separated from cells exudated in the peritoneal cavity after injection of proteosepeptone. Apoptosis was evaluated by fragmentation of DNA and morpholpgy of neutrophilic nuclei. Phagocytosis was brought about by ingestion of oil particles. TNF-α and active oxygen species from neutrophils were determined by a sandwich ELISA and a fluorometric assay, respectively. Apoptosis of neutrophils was inhibited dose-dependently by treatment with a bacterial product, lipopolysaccharide (LPS) or an inflammatory cytokine, IL-1β. This inhibitory effect on apoptosis of neutrophils w … More as abrogated by their ingestion of oil particles. The ingestion of oil particles suppresed a LPS-induced production of TNF-α and reactive oxygen species from neutrophils. Chemotactic activity of neutrophils in response to zymosan-treated serum was assayed in a Boyden chamber. When neutrophils were placed onto an upper chamber with LPS, their chemotactic activity was greatly inhibited. This was reverted to a control level by ingestion of oil particles.In summary I have shown that phagocytosis of neutrophils diminished a known function of their own induced by either LPS or IL-1β such as suppressed apoptotic propensity, increased cytokine production and altered chemotactic activity. Results suggest that phagocytosis of neutrophils emerging after an early phase of infection may help rescue surrounding normal tissues from a self-destructive nature of purulent inflammation by facilitating their apoptosis, inhibiting production of cytokine and active oxygen species, and by suppressing chemotactic activity. Less