CABRERIZO Franco Martin
congresos y reuniones científicas
Direct and photosensitized attenuation of Toxoplasma gondii tachyzoites
JUAN G. YAÑUK; M. LIS ALOMAR; M. MICAELA GONZALEZ; ANDRÉS M. ALONSO; SERGIO O. ANGEL; VERÓNICA M. COCERES; FRANCO M. CABRERIZO
Villa Carlos Paz
Encuentro; XIII Encuentro Latinoamericano de Fotoquímica y Fotobiología (XIII ELAFOT); 2017
Toxoplasma gondii is a protozoan obligate intracellularparasite that can infect a wide range of animals including approximately one-thirdof the human population. Infectioncan result in severe clinical diseases. In addition,infection in domestic animals is a threat to public health from food-borneoutbreaks and causes a great economic loss as it may lead to abortion,stillbirth and neonatal loss. Therefore, toxoplasmosis is of great medicaland veterinary importance. Treatment of this disease is difficult since theavailable drugs have severe side effects and reactivation may occur at anytime. Under the present scenario, therefore, developing an effective vaccineagainst T. gondii infection is the need of the hour. The vaccines based on live-attenuated parasites are more efficient thanvaccines based on dead-parasites, because the former ones emulates the naturalinfection.  In this regard, γ, X-ray andUVC radiation have been used as attenuation sources of a remarkably wide rangeof parasite species [5,6]. In every case, irradiatedparasites induce protective immunity against subsequent challenge ofexperimental hosts. Regarding UVC irradiation, parasite?s attenuation may occur either dueto direct absorption of the incident radiation by molecular targets or mediatedby reactive oxygen species leading to a highly oxidant environment. Such anenvironment can certainly induce unspecific and uncontrollable damage on bothmorphological and functional aspects of the parasites. Thus, the type and/orextent of damage and, consequently, the immunogenicity, would depend on the UVCdoses applied. Therefore, otherattenuation sources such as UVA and visible radiation, viaphotosensitization, should be taken into account and further evaluated.In the present work, a systematic and comparativeevaluation of the effect of three different types of radiation (UVC, UVA andvisible) as attenuation sources of T. gondii tachyzoites has beencarried out. In particular, we have evaluated the effect on morphological(structure and proteins stability, etc.), intracellular Reactive Oxygen Species(ROS) production and physiological functions (invasion and replicationcapability) of T. gondii tachyzoites.