Study On The Phenotype, Phagocytosis For Peritoneal Macrophages And The Changes Of Cytokine Secretion For Peritoneal Fluid In Mice Infected With Plerocercoids

Objective:To observe the phenotype,phagocytic function of peritoneal macrophages?M??and the changes of cytokine secretion of peritoneal fluid in mice infected with plerocercoids,and exploring the role of M?in resisting plerocercoids infection in host response.Methods:1.80 Kunming mice were randomly divided into 10 groups,including 5 experimental groups and 5 control groups?8 mice/caeh group?.Mice in the experimental group were orally infected with plerocercoids?5 worms/per mouse?.8 infected mice as a group were randomly sacrificed at designed time points from 6 hours to 28 days and mouse peritoneal mononuclear cell suspension was collected.The control group mice were not infected,and the method and time of collecting peritoneal suspension were the same as those of the experimental group.2.Flow cytometry was used to detect the proportion of M?and the expression of surface molec?les CD40,CD86 and major histocompatibility complex II?MHCII?.3.Neutral red phagocytosis test was used to detect the absorbance(A₅₄₀ value)when the density of M?was 1×10⁵,and their phagocytic ability was evaluated.4.After intervention by cysteine protease inhibitor,ELISA was used to detect the changes of TNF-?,IL-6,IL-10 and NO in peritoneal fluid.Results:1.From 6h to 18 days after infection,the proportion of M?in the experimental group was[?35.86±3.16?%^70.72±3.56%],which was significantly different?P<0.01?from that in the control group[?21.68±3.31?%^28.03±4.07)%]and with the prolongation of infection time,the proportion of M?increased.Compared with the control group,the proportion of CD40,CD86 and MHCII on the surface of M?was down-regulated from 6h to 28d after infection?P<0.01?.3.When the density of the experimental group M?was 1×10⁵,the A₅₄₀ value at 6h²8d after infection was significantly different from that of the control group?P<0.05?,which increased from 6h to 14d after infection,28d after infection to lower than the control group.4.The detection values of TNF-?,IL-6 and IL-10 at 6 h²8 d after infection were[?178.99±15.93⁵45.18±59.63?pg/mL],[?350.78±7.25⁵105.21±266.28?pg/mL]and[?55.22±4.43²31.55±14.46?pg/mL],which were higher than the control group?P<0.01?,and increased with the prolongation of infection time;The detection values of NO at 6h-28d after infection were[?18.90±2.08-49.21±4.54??mol/L],and the trend was increased from 6h to 14d,then decreased.After intervention by cysteine protease inhibitors,the detection values of TNF-?,IL-6,IL-10 and NO molecules at6h-24d after infection were[?80.90±9.70-361.02±48.93?pg/mL],[?164.48±5.17³509.11±315.06?pg/mL],[?18.14±3.06¹15.52±15.76?]pg/mL and[?7.63±1.39³0.65±4.46??mol/L],and compared with the experimental group,the decrease was observed?P<0.01?.Conclusion:1.The infection of the plerocercoids can affect the non-specific immunity and specific immune function of M?,and M?can play a certain role in the host response to the invasion,migration and settlement of the plerocercoids.2.Cysteine protease inhibition has an inhibitory effect on M?secretion in the peritoneal cavity of mice.