ABSTRACT
This study examined endogenous cannabinoid (ECB)-anandamide (AEA) and its can-nabinoid receptors (CBR) in mice liver with the development of schistosomajaponicum.Mice were infected with schistosoma by means of pasting the cercaria onto their abdomens.Liver fibrosis was pathologically confirmed nine weeks after the infection.High performance liquid chromatography (HPLC) was employed to determine the concentration of AEA in the plasma of mice.Immunofluorescence was used to detect the expression of CBR 1 and CBR2 in liver tissue.Morphological examination showed typical pathological changes,with worm tubercles of schistosoma deposited in the liver tissue,fibrosis around the worm tubercles and infiltration or soakage ofinfiammatory cells.Also,CBRI and CBR2 were present in hepatocytes and hepatic sinusoids of the two groups,but they were obviously enhanced in the schistosoma-infected mice.However,the average optical density of CBR1 in the negative control and fibrosis group was 13.28±7.32 and 30.55±7.78,and CBR2 were 28.13±6.42 and 52.29±4.24 (P<0.05).The levels of AEA in the fibrosis group were significantly increased as compared with those of the control group.The concentrations of AEA were (0.37±0.07) and (5.67±1.34) ng/mL (P<0.05).It is concluded that the expression of endocannabinoids AEA and its cannabinoid receptor CBR were significantly increased in schistosoma-infected mice.Endogenous endocannabinoids may be involved in the development of schistosoma-induced liver fibrosis.
ABSTRACT
Objective To evaluate the diagnostic value of the recombinant protein Sj_Ts4 in immunodiagnosis of Schistosomiasis japonica.Methods Seventy-four blood samples of schistosomiasis japonica patients(acute, chronic and advanced)were used for evaluating the sensitivity.Blood samples from 24 Clonorchiasis patients,8 patients with hookworm infections and 30 normal persons from the areas without Schistosomiasis were used ror patients.Results The positivity rates were 97.1%(33/34),100.0%(16/16),87.5%(21/24)in rSj-Ts4-ELISA and 100%(34/34),100.0%(16/16),75.0%(18/24)in SjAWA-ELISA in acute,chmnic and advanced Schistosomiasis. respectively.Statistical analysis revealed no significant difference in sensitivity(X2=1.23,P＞0.05)between both recombinant and crude antigens.The false positive reaction was found to be 6.7%(2/30)in rSj-Ts4-ELISA and 3.3%(1/30)in SjAWA-ELISA when detected in 30 cases of normal control sera.but no statisticallv significant difference was noted(x2=0.35,P＞0.05).Twelve point five percent(3/24),20.8%(5/24)and 12.5%(1/8),37.5% (3/8),of cross-reactions were observed between rSj-Ts4-ELISA and SjAWA-ELISA for detecting the sera of patients with clonorehiasis and hookworms.There was no significant difference of cross-reaction in two parasitic infections (x2=0.60,1.33,P＞0.05)with the two tests.Conclusions The rSj-Ts4 antigen shows higher sensitivity and specificity for the diagnosis of Schistosomiasis japonica,which is helpful in the serological diagnosis of Schistosomiasis japonica in endemic areas.
ABSTRACT
Objective To compare a potential role of dendritic cells (DCs) and macrophages in inducing protective immunity against infection with Schistosoma japonicum. Methods DCs and macrophages were pulsed in vitro with soluble egg antigen (SEA) of S. japonicum. BALB/c mice were injected three times with DCs or macrophages, either antigen-pulsed or not,and challenged with 40 ± 2 cercariae of S. japonicum per mouse. Worms were collected 42 days later by portal perfusion of the mice and egg number of liver was calculated. To evaluate whether protective immunity had been induced by preparations of DCs or macrophages, the worm burden and fertility ( eggs per female per mouse liver) were compared between the groups of mice. The antibody level against SEA was detected by ELISA. Results With respect to mice injected with untreated cells, numbers of worms and eggs per female worms were significantly reduced in the groups of mice having received pulsed DCs (26. 3% and 37.9%, respectively), or pulsed macrophages (22. 0% and 30.7%). Untreated DCs and macrophages induced no significant effects. The antibody level against SEA rose in sera of all groups of mice up to 42 days after the challenge, but most pronounced in those immunized with pulsed DCs, although this was not significantly different from other groups. Conclusion The results suggest that the protective immunity against S. japonicum might be induced by DCs to a higher extent than by macrophages after in vitro pulsing with egg antigen.
ABSTRACT
The expression of TNF-α in the liver at different periods post Schistosoma japonica infection and the effect on liver fibrosis after supplementary injection of these eytokines were investigated. The mice infected with schistosome cercariae were divided into 3 groups: normal control group, TNF-α-untreated infection group and TNF-α-treated infection group. ABC immunohistochemistry and pathologic image multimedia quantification system were applied to dynamically detect the activity of TNF-α. The results showed that the levels of TNF-α in the liver in TNF-α-untreated infection group were slowly decreased with prolongation of infection time (from 8th, 11th, 14th to 18th week), while in the TNF-α-treated infection group, those were increased significantly after intraperitoneal injection of TNF-α at 6th week after infection. At first to 8th week after the final injection of TNF-α, the intrahepatic TNF-α levels in the TNF-α-treated infection group were significantly higher than in the other two groups (P＜0.01), and the granulomatous inflammation and fibrosis in the liver were also milder in the normal control group. It was concluded that at the early stage of Schistosoma japonica infection mouse liver mainly released Th1 cytokine and TNF-α from Th1 activated macrophages. Six weeks after infection (post egg deposition), exogenous supplement with intraperitoneal injection of TNF-α could induce the enhanced expression of Th1 cytokines and alleviate the liver granulomatous inflammation and fibrosis.