Effect of mice Taenia crassiceps WFU cysticerci infection on the ovarian folliculogenesis, enzyme expression, and serum estradiol.

The murine infection with Taenia crassiceps WFU (T. crassiceps WFU) cysticerci has been widely used as an experimental model to better understand human cysticercosis. Several reports have established that the host hormonal environment determines the susceptibility and severity of many parasite infections. Female mice are more susceptible to infection with T. crassiceps cysticerci suggesting that a rich estrogen environment facilitates their reproduction. Ovarian androgens and estrogens are synthesized by key enzymes as P450-aromatase and 17α-hydroxilase/17, 20 lyase (P450C17). The aim of this study was to determine the effect of chronic intraperitoneal infection of T. crassiceps WFU cysticerci on mice ovarian follicular development, ovulation, the expression of ovarian P450-aromatase and P450C17, and serum 17ß-estradiol, key enzymes of the ovarian steroidogenic pathway. To perform this study ovaries and serum were obtained at two, four and six months from T. crassiceps WFU cysticerci infected mice, and compared to those of healthy animals. The ovaries were fixed and processed for histology or lysed in RIPA buffer for Western blot using specific antibodies for P450C17 and P450-aromatase. 17ß-estradiol serum concentration was measured by ELISA. The results showed that the infection with T. crassiceps WFU cysticerci significantly reduced the number of primordial and primary follicles after two months of infection. Through the course of the study, the corpus luteum number began to decrease, whereas atretic follicles increased. The expression of ovarian P450C17 and P450-aromatase as well as serum E2 concentration were significantly increased in the infected group compared to control. These findings show that chronic infection with Taenia crassiceps WFU may alter the reproductive functions of the female mice host.

Anti-oxidant activity of superoxide dismutase and glutathione peroxidase enzymes in skeletal muscles from slaughter cattle infected with Taenia saginata.

It is known that highly reactive oxygene species produced during normal cellular metabolism represent a powerful effector mechanism against parasites. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) belong to the main defense anti-oxidants that prevent the formation of new free radical species. The aim of this study was to assess the activities of SOD and GPx in cattle tissues infected with Taenia saginata. We observed a statistically significant increase in the SOD and GPx activities (p=0.00003, 0.00008, respectively, Student's t-test) in skeletal muscles infected with T. saginata in spectrophotometric analysis. With the use of western blot technique, SOD synthesis stimulation has appeared in the host tissues containing cysticerci in contrast with the control samples. There was no statistically significant increase in the GPx band intensity observed in the studied samples in comparison to controls (Gene Tools Version 4.01 program). These results support the significance of anti-oxidant processes in host defense mechanism during parasitic infections.

Reactive oxygen species and 12/15-lipoxygenase contribute to the antiproliferative capacity of alternatively activated myeloid cells elicited during helminth infection.

Understanding the role of CD11b(+)GR-1(+) myeloid suppressor cells in the immune suppression and immunoregulation associated with a variety of diseases may provide therapeutic opportunities. In this article, we show, in a model of helminth infection, that CD11b(+)GR-1(+) myeloid suppressor cells but not CD11b(+)F4/80(high) mature macrophages expanded in the peritoneal cavity of BALB/c mice implanted with Taenia crassiceps. Peritoneal cell populations from early stage-infected animals impaired T cell proliferation by secreting NO. Yet, they lost their ability to secrete NO in the late stage of infection. Concomitantly, their capacity to exert arginase activity and to express mRNAs coding for FIZZ1 (found in inflammatory zone 1), Ym, and macrophage galactose-type C-type lectin increased. Furthermore, cells from early stage-infected mice triggered T cells to secrete IFN-gamma and IL-4, whereas in the late stage of infection, they only induced IL-4 production. These data suggest that CD11b(+)GR-1(+) myeloid suppressor cells displaying an alternative activation phenotype emerged gradually as T. crassiceps infection progressed. Corroborating the alternative activation status in the late stage of infection, the suppressive activity relied on arginase activity, which facilitated the production of reactive oxygen species including H(2)O(2) and superoxide. We also document that the suppressive activity of alternative myeloid suppressor cells depended on 12/15-lipoxygenase activation generating lipid mediators, which triggered peroxisome proliferator-activated receptor-gamma. IL-4 and IL-13 signaling contributed to the expansion of myeloid suppressor cells in the peritoneal cavity of T. crassiceps-infected animals and to their antiproliferative activity by allowing arginase and 12/15-lipoxygenase gene expression.

Taenia taeniaeformis: early inflammatory response around developing metacestodes in the liver of resistant and susceptible mice II. Histochemistry and cytochemistry.

Female BALB/cJ (resistant), C3H/HeJ (intermediate resistant), and C3H/HeDub (susceptible) inbred mice, 4-5 wk old, were infected with Taenia taeniaeformis. Liver sections were stained for the enzymes acid phosphatase, beta-glucuronidase, and peroxidase. Eosinophils present around the parasite were identified by the ethanolic Congo red method. Possible gross changes in lipid metabolism in the hepatocytes surrounding the parasite were investigated with the Sudan black B method. The results of observations made by light microscopy were: (1) beta-glucuronidase activity above background levels was observed only in the hepatocytes around the parasite in BALB/cJ mice at 4, 5, and 6 days postinfection (PI); no reaction was observed in the other 2 strains of mice studied; (2) acid phosphatase activity was very strong at 2, 3, and 4 in the 3 strains of mice while this reactivity was weak at 5 and 6 days PI; (3) the cytoplasm of the hepatocytes around the metacestode stained more heavily with Sudan black B than other hepatocytes; and (4) the presence of eosinophils appearing at 3 days PI around the parasite in all 3 strains of mice was demonstrated by staining with Sudan black B, the substrate of peroxidase, and Congo red. Infected C3H/HeJ and BALB/cJ mice had higher numbers of liver eosinophils than infected C3H/HeDub mice throughout the observation time. The present results suggest 2 conclusions: (1) a parasite-liver interaction occurs as is evident by hepatocyte changes in beta-glucuronidase activity and Sudan black B staining, and (2) resistance to the early stages of T. taeniaeformis is associated with the appearance of eosinophils.

Changes in serum enzyme activities in pigs naturally infected with the metacestodes of Taenia solium.

The serum enzymes of pigs naturally infected with the metacestodes of Taenia solium and of uninfected pigs were assayed. Aspartate aminotransferase, alanine aminotransferase, ornithine carbamyl transferase, sorbitol dehydrogenase, lactate dehydrogenase, isocitrate dehydrogenase, alkaline phosphatase and ceruloplasmin activities were significantly increased in the serum of the infected pigs.