P12- Direct and photosensitized attenuation of Toxoplasma gondii tachyzoites

*JUAN G. YAÑUK; *MARIA. L ALOMAR; MARIA M GONZALEZ; ANDRES M. ALONSO; ANGEL SERGIO. O; VERONICA M. COCERES; CABRERIZO, FRANCO M.

Villa Carlos Paz, Cordoba

Congreso; XIII Encuentro Latinoamericano de Fotoquímica y Fotobiología (XIII ELAFOT); 2017

P12- Direct and photosensitized attenuation of Toxoplasma gondii tachyzoitesJuan G. Yañuk, Maria L. Alomar, Maria M. Gonzalez, Andrés M. Alonso, Sergio O. Angel, Verónica M.Coceres and Franco M. CabrerizoIIB-INTECH-UNSAM-CONICET (sede Chascomús). Av. Intendente Marino km 8,2. CC 164. (7130). Chascomús.Buenos Aires, Argentina; E-mail: gabrielyanuk@intech.gov.arToxoplasma gondii is a protozoan obligate intracellular parasite that can infect a wide range ofanimals including approximately one-third of the human population. Infection can result in severeclinical diseases.[1] In addition, infection in domestic animals is a threat to public health from foodborneoutbreaks and causes a great economic loss as it may lead to abortion, stillbirth and neonatalloss.[2] Therefore, toxoplasmosis is of great medical and veterinary importance. Treatment of thisdisease is difficult since the available drugs have severe side effects and reactivation may occur atany time.[3] Under the present scenario, therefore, developing an effective vaccine against T. gondiiinfection is the need of the hour.The vaccines based on live-attenuated parasites are more efficient than vaccines based on deadparasites,because the former ones emulates the natural infection. [4] In this regard, γ, X-ray andUVC radiation have been used as attenuation sources of a remarkably wide range of parasitespecies [5,6]. In every case, irradiated parasites induce protective immunity against subsequentchallenge of experimental hosts.Regarding UVC irradiation, parasite?s attenuation may occur either due to direct absorption of theincident radiation by molecular targets or mediated by reactive oxygen species leading to a highlyoxidant environment. Such an environment can certainly induce unspecific and uncontrollabledamage on both morphological and functional aspects of the parasites. Thus, the type and/or extentof damage and, consequently, the immunogenicity, would depend on the UVC doses applied.[7]Therefore, other attenuation sources such as UVA and visible radiation, via photosensitization,should be taken into account and further evaluated.In the present work, a systematic and comparative evaluation of the effect of three different typesof radiation (UVC, UVA and visible) as attenuation sources of T. gondii tachyzoites has been carriedout. In particular, we have evaluated the effect on morphological (structure and proteins stability,etc.), intracellular Reactive Oxygen Species (ROS) production and physiological functions (invasionand replication capability) of T. gondii tachyzoites.