Gene expression modification of the autophagic pathway during the innate immune phase of the zebrafish during mycobacterial infection.

GIAI C; ORTEGA, M; ZARELLI VE; COLOMBO, MI

San Luis

Congreso; XXXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2019

Gene expression modification of the autophagic pathway during the innate immune phase of the zebrafish during mycobacterial infection.Ortega M, Giai C, Colombo MI, Zarelli, VEP.Instituto de Histología y Embriología de Mendoza, (IHEM-CONICET). Facultad de Ciencias Médicas, Universidad Nacional de Cuyo. E-mail:vzarelli@mendoza-conicet.gob.arAutophagy is involved in various physiological and pathological processes. One of the key functions of the autophagic pathway is to participate in the first line of defense against the invasion of intracellular pathogens, as part of the innate immune response, acting as an effector mechanism of the host cell for protection against such invasion. However, many intracellular bacterial pathogens have developed very advanced mechanisms, both to evade the recognition of autophagy and to manipulate it for their own benefit.Mycobacterium tuberculosis (Mtb) is an intracellular pathogen that colonizes and multiplies in the host macrophages. The success of Mycobacterium as a pathogen is based on its ability to modulate the intracellular environment, persisting within phagosomes through interference with the biogenesis of phagolysosomes. M. marinum (Mm) is a close relative of Mtb that causes a disease similar to tuberculosis in fish and is widely used as an alternative to study mycobacteria.In addition, since infectious diseases are often the result of the coevolution between pathogen and host, the use of a host-pathogen substitute pair may provide a certain level of understanding that could be difficult to achieve when using a non-native host. Therefore, we use the zebrafish (Danio rerio) as an in vivo model for the study of autophagic response against Mm infection. Zebrafish 6 days post fertilization (dpf) larvae were infected by immersion with 225 cfu during 3 hours. After that, infection medium was removed and larvae were washed three times with sterile embryo water. Fresh embryo medium was added per larvae and let them develop until 7 dpf. The samples were collected for cfu counting, RNA extraction and RT-PCR. Our results suggest that some autophagy and innate immune genes expression profile are modified in zebrafish against Mm infection. Further studies are carried out to better understand these observations.