Novel approaches of vaccine development against bovine cryptosporidiosis

SCHNITTGER L; TOMAZIC ML; MONTE G; ELGUERA E; POKLEPOVITCH T; NUSBLAT AD; GARRO C; FLORIN-CHRISTENSEN M

Conferencia; Vaccines R&D 2016; 2016

Abstract Bovine cryptosporidiosis, caused by Cryptosporidiumparvum, is responsible for significant morbidity and mortality of neonatalcalves, resulting in substantial economic loss in dairy farming. No drugs orvaccines against this disease are currently available and treatment ispalliative. An immunotherapeutic control strategy is considered preferable; asit would have the additional advantage to prevent dissemination of theinfective oocyst into water and food avoiding human outbreaks. Calves are bornwithout protective antibodies, and are immediately exposed to ubiquitous and highlyinfective Cryptosporidium oocysts;passive immunity is usually transferred via the uptake of maternal antibodiesvia colostrum. Our group will test two control strategies aimed to reinforcethe provision of calves with protective antibodies (i) immunization of calf-in dams ensuring the acquisition of protectivematernal antibodies via colostrum or (ii) the administration of protective anti-CryptosporidiumIgY, raised in eggs of immunized hens, as a food supplement of milk. Whilestrategy (i) may have the benefit of lifelong protection, (ii) can be appliedon demand when preventive measures have been neglected, as is often the case inveterinary settings. Identification of antigens capable of the generation ofprotective antibodies is essential for the development of vaccine formulations.We have identified the C. parvum glycosylphosphatidylinositol (GPI)-anchoredsurface proteome involved in host cell invasion, containing promising vaccine candidates. Expression in E. coliand the ciliate Tetrahymena are being compared, the latter having theadvantage of adding GPI as a posttranslational modification. Financed by:FonCyt (PICT-2013-1708 and PICT 0695-2012); INTA (PNBIO-1131034 andPNSA-1115053); Fundación Universidad de Morón (PID8-2015)