FUNCTIONAL CHARACTERIZATION OF T. CRUZI MUCINS IN THE INFECTION OF THE INVERTEBRATE HOST

CAMARA MARIA DE MILAGROS; PASSOS DE MATOS DEBORA; SALABERT MARCELO; CARLOS BUSCAGLIA

Buenos Aires

Congreso; Reunion Conjunta de Biocienciass; 2017

Sociedad Argentina de Parasitologia

Trypanosoma cruzi, the etiological agent of Chagas diseases iscovered in different glycoconjugates which contribute to parasite protectionand to the establishment of a persistent infection. TcSMUGL is a group of genes coding for small T. cruzi mucins anchored toand secreted from the surface of replicative, insect-dwelling developmentalforms (i.e. epimastigotes). The objective of this work wasthe functional characterization of TcMUGL mucin family and theirrole in the infection of Rhodnius prolixus. We analyzed TcSMUGLexpression levels in different T. cruzi strains observing not only differencesin expression levels but also in glycosylation patterns. Inorder to characterize epimastigote mucin function we generated T.cruzi strains overexpressing TcSMUGL and TcTSSA (tripomastigotestage mucin) in two different genetic backgrounds CL Brener(high TcSMUGL levels) and Y strain (low TcSMUGL levels and isunable to infect Rhodnius prolixus). Transgenic lines were used toperform in vivo infection assays in Rhodnius prolixus. TcSMUGLCL overexpressing parasites presented higher infection rates thancontrol lines. Furthermore TcSMUGL lines belonging to the Y strainwere able to stablish the infection in the insect host, presenting highinfectivity rates. In order to further characterize mucin function weperformed in vitro adhesion using different sections of Rhodniusprolixus nymph?s digestive tract. Our results indicate that TcSMUGLwould be involved in parasites adhesion to the posterior midgut, asboth transgenic TcSMUGL lines presented 4 times more adhesionpercentages than control lines. Finally we performed in vitro lysisexperiments with digestive contents observing that TcSMUGL overexpressionenhances parasites survival towards stomach and intestinalcontents. Together, these data indicate that TcSMUG L mucinsare key determinants of the infectivity of T. cruzi towards the insectpopulation and, hence, on T. cruzi epidemiology