Immunotherapy in lambs using specific antibodies against the recombinant 24kDa excretory-secretory protein of Haemonchus contortus.

• Grant number: 24/09500-0
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2024
• End date: September 30, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Cintia Hiromi Okino
• Grantee: Cintia Hiromi Okino
• Host Institution: Embrapa Pecuária Sudeste. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). São Carlos , SP, Brazil
• Associated researchers: Adriana Mércia Guaratini Ibelli ; Alessandro Francisco Talamini Do Amarante ; Alessandro Pelegrine Minho ; Ana Carolina de Souza Chagas ; Ana Claudia Alexandre de Albuquerque ; César Cristiano Bassetto ; Helio Jose Montassier ; Raquel Rubia Rech ; Roselene Ecco ; Sergio Novita Esteves ; Simone Cristina Méo Niciura
• Associated scholarship(s): 25/10380-2 - Production and purification of Haemonchus contortus ES24 protein-specific immunoglobulins from chicken eggs for immunotherapy in naturally infected lambs., BP.MS; 25/10259-9 - Investigating the effect of passive immunization, mediated by colostrum from ewes vaccinated with Haemonchuscontortus ES24 antigen on haemonchosis resistance in suckling lambs., BP.PD; 24/21238-0 - Passive immunotherapy using specific anti-ES24 antibodies for the control of Haemonchus contortus in lambs., BP.DR

Abstract

Haemonchus contortus is the most economically important and prevalent parasite worldwide. Populations of this parasite are already resistant to all anthelmintic classes commercially available, highlighting the need of new methods for this parasite control. In this sense, secretory-excretory products (ES) are antigens continuously secreted by parasites and that have been already associated with the development of immune protection against H. contortus. Antibodies of the IgM isotype against ES24 of H. contortus showed a moderate negative correlation with eggs per gram of feces (OPG), and a positive correlation with globular volume in lambs infected with this parasite, indicating an important role of these antibodies in host response to this parasite infection. Therefore, the present project aims to develop and test passive immunotherapy protocols through the oral administration of anti-H. contortus ES24 protein antibodies in lambs submitted to experimental and natural parasitic challenges. The antibodies will be produced in sheep or in chicken eggs. Furthermore, this study also aims to implement a method for monitoring specific antibodies in lambs from birth to weaning and predict the requirement of animal treatment based on a tool to be developed. (AU)