Effect Of Reactive Nitrogen Metabolites And Their Scavengers To NK Cell-mediated Killing Of K562 Cell

Objective:To explore the influence of RNM(reactive nitrogen metabolites) as supressor and the effect of Tiopronin(TIP),Glutamylcysteinylglycine (GSH),dihydrochloride(DHT) immunoadjuvant to reverse RNM's suppressing influence in NK cell-mediated killing of K562 cell line.Methods:1.Exogenous ONOO- was administered in the NK cell and K562 cell culture system, Then TIP,GSH and DHT were administered in the cultivated systems espectively.The concentrations of RNM were measured at the sixth hour and the corresponding changes of TNF-βand IFN-γand K562 cell inhibition rate(KIR) were observed at the 24rd hour 2.IL-2 and PHA were administered as reactivator in the system of monocytes plus NK cells and K562 cells(E/T=10/1,E/MO=10/2) to increase RNM ROM,Different concentrations of TIP,GSH and DHT were administered in the cultivated systems then the Parameters of NK cell activity include KIR,productions of TNF-βand IFN-γwere measured on schedule.Results:1.After exogenous ONOO- was administered in the NK cell and K562 cell culture system, RNM productions increased while NK cell population and NK cell activity degraded significantly. When The TIP,GSH and DHT were administered in the systems,RNM productions dropped from 260.30±9.51umom/L umom/L to 178.65±10.00 umom/L umom/L,185.02±8.166umom/L espectively, The DHT can not clear RNM. The Percentage of live NK cell increase form 79.87±1.027% to 91.133±0.67%,88.03±1.46%,82.6±0.76%respectively,KIR increase from 43.84±0.178% to 59.35±1.078%,56.64±0.827%,51.41±1.47%respectively;TNF-β,IFN-γproductions increased correspondingly.When TIP,GSH and DHT were administered in the cultivated systems mixing with NK cells,K562 cells,monocytes,IL-2 and PHA,the trend of various parameter variety we measured is like the result of part 1. With higher concentration of TIP and GSH,the RNM and ROM productions decreased accordingly, TNF-βand IFN-γproductions as well as KIR increased at the same time,DHT can not clear RNM.Conclusions: Exogenous ONOO- is deleterious to NK cells and K562 cells.Monocytes are the major resources of RNM and ROM.Bothes of RNM and ROM can disable NK cells in killing neoplasm cells(K562 cells).Bothes of TIP and GSH can protect NK cells via scavenging RNM and ROM,and enhance the anti-neoplasm activity of NK cells.At the same time,there shows a dose-effect relationship between the doses of TIP and GSH and their capability of scavenging RNM and ROM.While DHT can not scavenge RNM. In scavenging RNM and ROM and up-regulating KIR,TIP is as good as GSH,but bothes of them are better than DHT.With less side effect,TIP and GSH may take the place of DHT as immunoadjuvant during the adoptive immunotherapy in leukemia.