A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth Parasite Taenia crassiceps

MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasite Taenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host and T. crassiceps, and may be considered as target for anti-helminth drugs design

La señalización a través de los receptores FcyRI y FcyRII en células monocíticas es determinada por el estado de diferenciación celular /

\ua0tesis que para obtener el grado de Doctor en Ciencias Biomédicas, presenta Claudia Hallal Calleros ; asesor Enrique Ortega Soto. 85, [11] páginas :\ua0ilustraciones. Doctorado en Ciencias Biomédicas\ua0UNAM, Instituto de Investigaciones Biomédicas,\ua0200

In Vitro Ovicidal and Cestocidal Effects of Toxins from Bacillus thuringiensis on the Canine and Human Parasite Dipylidium caninum

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. is bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 g/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. e lethal concentration of toxins on eggs was 600 g/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. e motility was inhibited by 100% aer 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. us, B. thuringiensis is proposed as a potential biological control agent against this zoonosis

In Vitro Ovicidal and Cestocidal Effects of Toxins from Bacillus thuringiensis on the Canine and Human Parasite Dipylidium caninum

Bacillus thuringiensis is a gram-positive soil-dwelling bacterium that is commonly used as a biological pesticide. This bacterium may also be used for biological control of helminth parasites in domestic animals. In this study, we evaluated the possible ovicidal and cestocidal effects of a total protein extract of B. thuringiensis native strains on the zoonotic cestode parasite of dogs, Dipylidium caninum (D. caninum). Dose and time response curves were determined by coincubating B. thuringiensis proteins at concentration ranging from 100 to 1000 μg/mL along with 4000 egg capsules of D. caninum. Egg viability was evaluated using the trypan blue exclusion test. The lethal concentration of toxins on eggs was 600 μg/ml, and the best incubation time to produce this effect was 3 h. In the adult stage, the motility and the thickness of the tegument were used as indicators of damage. The motility was inhibited by 100% after 8 hours of culture compared to the control group, while the thickness of the cestode was reduced by 34%. Conclusively, proteins of the strain GP526 of B. thuringiensis directly act upon D. caninum showing ovicidal and cestocidal effects. Thus, B. thuringiensis is proposed as a potential biological control agent against this zoonosis