Effect and mechanism of CD4+CD25+regulatory T cells on protective effica-cy of protein vaccine against Schistosoma japonicum in mice / 中国血吸虫病防治杂志

Objective To explore the effect and mechanism of CD4+CD25+Tregs(Tregs)on the protective efficacy of glutha?tione?S?transferase(GST)against Schistosoma japonicum in mice. Methods Female BALB/c mice were divided randomly into five groups:a normal control group,an infected control group,an anti?CD25mAb group,a GST immunization group and a com?bination group with GST immunization and anti?CD25 mAb. The GST group and combination group were injected percutaneously with GST 50μg each mouse,the other two groups were injected with equal volume PBS. The immunization was performed for 3 times for two?week interval,and 2 weeks after the last immunization,each mouse was challenged with 40 S. japonicum cercaria. Two weeks post?infection,the combination group and anti?CD25 mAb group were injected intraperitoneally with 300μg anti?CD25 mAb each mouse. The mice were succumbed 2 weeks,3 weeks,4 weeks and 5 weeks post?infection respectively. The per?centages of CD4+CD25+Tregs in splenocytes of mice were measured with flow cytometer. The levels of IFN?γ,IL?2,IL?4,IL?5 and TGF?βin cell cultural supernatants were determined by sandwich?ELISA after stimulation with Con A. The liver sections were stained with hematoxylin and eosin. Results The worm burden in the combination group(15.80 ± 2.74)was significantly lower than those of the infected control group(27.78 ± 3.15),anti?CD25 mAb group(21.50 ± 4.21),and GST group(20.84 ± 6.46). Compared to those of the infected control group,the percentages of CD4+CD25+Tregs were significantly higher in the GST group,while the percentages of CD4+CD25+Tregs were significantly lower post?anti?CD25 mAb?administration. Regardless of GST administration,the levels of IFN?γ,IL?2,IL?4 and IL?5 after anti?CD25 mAb were significantly higher than those of the in?fected control groups. There were no significant differences of egg granuloma and the level of TGF?βbetween each group. Con?clusion CD4+CD25+Tregs could be partially blocked by anti?CD25 mAb while Th1 and Th2 type immunization response could be enhanced,which plays a role in improving the protective efficacy of GST against of S. japonicum.

Research progress of immunoregulation of B cells to schistosome infection / 中国血吸虫病防治杂志

Recent studies found that B cell subsets and their factors have double effects on anti-and aiding schistosome infec-tion. This article summarizes the research progress of positive and negative immunoregulation of schistosome infection involving B lymphocytes antibody and regulatory B cells Bregs relating cytokines IL-10 IL-7 and TGF-β .

Signaling Role of Exogenous Arachidonic Acid in the Invasion of Macrophages by Toxoplasma gondii / 中国寄生虫学与寄生虫病杂志

Objective To investigate the signaling role of arachidonic acid in the invasion of RAW264.7 macrophage by Toxoplasma gondii . Methods Rate of infection was calculated by both light microscope and flow cytometer. Fluorescent emission spectra were recorded using a microspectrofluometer for the concentration of cytoplasmic free calcium. Results Calcium concentration in macrophages and rate of infection increased with a higher concentration of exogenous arachidonic acid in a dose-dependent manner. The invasion was dependent on the mobilization of calcium from the extracellular medium and from intracellular stores and followed the influx of calcium into the parasitized cell. Conclusion Arachidonic acid may enhance the rate of infection via calcium transduction pathway.

Biological Features of Mouse Macrophage Transfected with Toxoplasma gondii GRA-1 Gene / 中国寄生虫学与寄生虫病杂志

Objective To investigate the change of biological features of macrophages after transfected by Toxoplasma gondii GRA 1 genes (P24). Methods The transfected cells Cyto P24 RAW264.7, Nuc P24 RAW264.7, Mito P24 RAW264.7 and ER P24 RAW264.7 were studied by RT PCR to determine the P24 mRNA expression. Growth features of the cells were examined with microscopy and the cell growth curve was developed. Results In four cell lines, expression of ER P24 RAW 264.7 was found to be higher than the other three, and there was no P24 mRNA expression in either of the cells without P24 insert. The attachment and the proliferation of ER-P24-RAW264.7 were more rapid than normal RAW264.7. Conclusion Transfection of mouse macrophages ER RAW264.7 strain with T. gondii P24 gene leads to a prominent change of biological features in the studied cell line.

Study on screening simulated epitopes of protective antigens of Schistosoma japonicum and their immuno-protective effect / 中国血吸虫病防治杂志

Objective To study the immuno-protective effect against Schistosoma japonicum challenge of the positive monoclonal phages which were screened from the 12 mers-phage random peptide library by the new model rabbit serum. Methods The new model was established by injecting the Schistosoma japonicum infection rabbits with inhibitor of phenol oxidose. Positive clones immunoscreened with the new model rabbit sera were absorbed by SEA immune rabbit sera, and 14 clones selected randomly from them were compared and their antigenic ability was identified by ELISA. The two best positive monoclonal phages (No.8, No.13) recognized by the new model rabbit sera were selected to immunize Kunming mice by subcutaneously injecting 1?10~15 pfu positive phages at 0, 2nd, 4th week respectively. After 4 weeks of the last immunity,each mouse was challenged with 40?1 S.japonicum cercariae. All mice were sacrificed after 42 days and the reduction rates of adult worms and the liver eggs were investigated. Results The positive phage clones after immune absorption were weakly recognized by the SEA immune rabbit sera. The 14 monoclonal phages were recognized by the rabbit sera of the new model and the normal model. Especially No.8, No.13 were strongly recognized by the rabbit sera of the new model,while weakly recognized by the SEA immune rabbit sera. The reduction rates of adult worms and liver eggs induced by the monoclonal phage No.13, the monoclonal phage No.8 and the original peptide library were 35.81% and 63.32%, 32.09% and 52.02%, 14.90% and 30.64%, respectively. Conclusion Most clones of simulated epitopes of SEA can be removed by absorbing positive clones with SEA immune rabbit serum .The 14 monoclonal phages from the new model contain the simulated S.japonicum epitope. The two monoclonal phages have higher reduction rates of adult worms and eggs than original 12 mers-phage random peptide library and the positive polyclonal phages.[

EFFECT OF PHENOL OXIDASE PROTEIN ANTIGEN ON LIVER PATHOLOGIC CHANGE IN MICE INFECTED WITH SCHISTOSOMA JAPONICUM / 中国血吸虫病防治杂志

Objective To explore the effect of phenol oxidase antigen on liver pathologic change in mice infected with Schistosoma japonicum. Methods 42d-aged adult worms were incubated in RPMI 1640 containing 0.05% sodium phenobarbital for 8 h. The worms were washed three times with PBS (pH 6.8) and homogenized with a Teflon pestle. The homogenate was then centrifuged at 3000 g for 20 min at 4 ℃. Supernatant fractions containing phenol oxidase (PO) were analyzed by means of polyacrylamide gel electrophoresis (PAGE). The rude antigen of PO was obtained by cutting the corresponding gel of PO activities. Three groups were set up to observe whether PO could induce protective immunity: experiment group, adjuvant control group and water control group. On day 42 post infection with (40?1) cercariae of Schistosoma japonicum, the mice were sacrificed to observe liver pathologic changes. Results The liver surface of PO immunized group was rather smooth and the liver color was slightly gray. A few pale nods were seen indistinctly but not clearly. Necrosis and inflammatory cell infiltration were not clear. There were many immature eggs without granuloma reaction. The mean diameter and area of the granuloma in the experiment group were less than those in the control group. There were significant differences among the 3 groups (P

PRELIMINARY STUDY ON SCREENING OF PHAGE RANDOM PEPTIDE LIBRARY USING RABBIT SERUM FROM A NEW MODEL INFECTED WITH SCHISTOSOMA JAPONICUM / 中国血吸虫病防治杂志

Objective To screen the 12 mers-phage random peptide library using the serum from the new model rabbit and to identify the immuno-protection of the positive phages. The new model infected with Schistosoma japonicum was proved that has a high protection against the challenge infection. Methods After being absorbed by E.coli antibody, the serum of the new model rabbit was used to screen the peptide library. Through three rounds of biopaning and enriching, lots of positive phages were obtained and their antigenic ability was tested. Every mouse was immunized by subcutaneously injecting 1?10 14 pfu positive phages from the new model rabbit serum respectively at 0-2-4 th week. After 4 weeks of the last immunization, the challenge infection was performed. At the same time, several control groups including the group immunized with the phages from the rabbit serum of the normal model infected with Schistosoma japonicum, the group immunized with the original 12 mers-phage random peptide library and the control group of challenge infection were arranged. Results ①The positive clones of phage(1?10 14) from the new model rabbit serum were strongly recognized by the rabbit serum of the new model, weakly recognized by the rabbit serum of the normal model infected with Schistosoma japonicum,but not recognized by the serum of healthy rabbit. ②The reduction rate of adult worms and liver eggs induced by phages screened with the rabbit serum of the new model group and the nomal model group and that induced by the original peptide library were respectively 27 2% and 38 8 %, 17 8% and 35 0%, 4 5% and 6 0% Conclusion The new model group obtained a higher reduction rate of adult worms than the nomal model group (P

TOXOPLASMA GONDII INDUCES PROSTAGLANDIN E_2 SYNTHESIS IN MACROPHAGES VIA CYCLOOXYGENASE-2 PATHWAY / 中国血吸虫病防治杂志

Objective To explore prostaglandin E 2 (PGE 2) production pathway in Toxoplasma gondii-infected macrophage RAW264.7 cell line.Methods Cells were incubated with Toxoplasma gondii tachyzoites and lipopolysaccharides (LPS). Prostaglandin synthesis and arachidonic acid in supernants were detected with ELISA and gas chromatogram. Expression of cyclooxygenase-1/cyclooxygenase-2 (COX-1/COX-2) mRNA and protein following stimulation with LPS or infection of Toxoplasma gondii were evaluated with RT-PCR and Western blot in presence or absence of peculiar antagonists of PGE 2 production. Results PGE 2 synthesis of macrophages began at 4-8 h after invasion with Toxoplasma gondii and saturated at 12-16 h. Expression of COX-2 mRNA peaked at 4-8 h, and diminished in presence of both indomethacin and nimesulide, COX-2 protein expression was not affected by them. Expression of COX-1 mRNA and protein were constant and not affected by either indomethacin or nimesulide. Conclusion Toxoplasma gondii may induce macrophages prostaglandin E 2 synthesis via cyclooxygenase-2 pathway.

DETERMINATION OF INTERCELLULAR FREE Ca~(2+) CONCENTRATION IN TH E CULTURED CELLS FROM SCHISTOSOMA JAPONICUM BY USING FURA-2/A M / 中国血吸虫病防治杂志

0 05), being ( 187 0?10 7) nmol/L in average. Moreo ver, it was not significantly different from the cells cultured at day 0, ei ther . However, [Ca 2+ ]i increased significantly(P

Effect of Chronic Toxoplasma Infection on the Spatial Learning and Memory Capability in Mice / 中国寄生虫学与寄生虫病杂志

Objective To investigate the effect of chronic infection of Toxoplasma gondii on the spatial learning and memory capability in mice.Methods Toxoplasma tachyzoites(RH strain)were reanimated at 37 ℃ after 15 days' storage at-20 ℃,and injected intraperitoneally to mice of the experimental group each with 7.7?105.Normal saline was given to the control group,0.5 ml per mouse.Two months later,all mice were tested in the Morris Water Maze.Smears of the mice brain homogenate and pathological sections were examined.Results ① The density of cysts in the brain homogenate was 15/HP,and there was no evident pathological change in the hippocampus and adjacent areas of mice in the brain in the experimental mice.② Latency to platform,cumulative distance to the platform,total distance traveled in both experimental and control groups decreased significantly with the increase of training days(P

Proteomics and Its Application in Parasitology / 中国寄生虫学与寄生虫病杂志

Proteomics is an important high throughout method in modern life science.In this paper,the definition,background and methods used in proteomics were introduced,and the last part was focused on its application in parasitology.

Intra-cellular Signal Pathway and Synthesis of Prostaglandin E_2 During Invasion of Macrophage by Toxoplasma gondii / 中国寄生虫学与寄生虫病杂志

Objective To investigate the signal transduction pathway of arachidonic acid(AA) and prostaglandin E-2(PGE-2) synthesis in macrophage invaded by Toxoplasma gondii. Methods Synthesis of AA and PGE-2, expression of COX_2 mRNA and protein following stimulation infection by Toxoplasma gondii were evaluated in RAW264