Increased Lytic Efficiency of Bovine Macrophages Trained with Killed Mycobacteria.
Innate immunity is evolutionarily conserved in multicellular organisms and was considered to lack memory until very recently. One of its more characteristic mechanisms is phagocytosis, the ability of cells to engulf, process and eventually destroy any injuring agent. We report the results of an ex vivo experiment in bovine macrophages in which improved clearance of Mycobacterium bovis (M. bovis) was induced by pre-exposure to a heat killed M. bovis preparation. The effects were independent of humoral and cellular adaptive immune responses and lasted up to six months. Specifically, our results demonstrate the existence of a training effect in the lytic phase of phagocytosis that can be activated by killed mycobacteria, thus suggesting a new mechanism of vaccine protection. These findings are compatible with the recently proposed concept of trained immunity, which was developed to explain the observation that innate immune responses provide unspecific protection against pathogens including other than those that originally triggered the immune response.
Animal Health Department, NEIKER-Tecnalia, Berreaga, 1, 48160 Derio, Bizkaia, Spain.
Ramon A
RA
Juste
Animal Health Department, NEIKER-Tecnalia, Berreaga, 1, 48160 Derio, Bizkaia, Spain.
Marta
M
Alonso-Hearn
Animal Health Department, NEIKER-Tecnalia, Berreaga, 1, 48160 Derio, Bizkaia, Spain.
Joseba M
JM
Garrido
Animal Health Department, NEIKER-Tecnalia, Berreaga, 1, 48160 Derio, Bizkaia, Spain.
Naiara
N
Abendaño
Animal Health Department, NEIKER-Tecnalia, Berreaga, 1, 48160 Derio, Bizkaia, Spain.
Iker A
IA
Sevilla
SaBio, Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo, 13071, Ciudad Real, Spain.
Christian
C
Gortazar
SaBio, Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo, 13071, Ciudad Real, Spain.|Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, OK, 74078, United States of America.
José
J
de la Fuente
Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense, Avenida Puerta de Hierro, 28040, Madrid, Spain.
Lucas
L
Dominguez
D000818:Animals; D002417:Cattle; D016207:Cytokines / Q000378:metabolism; D006358:Hot Temperature; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D008264:Macrophages / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D050296:Microbial Viability / Q000528:radiation effects; D009000:Monocytes / Q000166:cytology; D009163:Mycobacterium bovis / Q000502:physiology* / Q000528:radiation effects; D010587:Phagocytosis
D016207:Cytokines