Bovine macrophages responses to the infection with virulent and attenuated Leptospira interrogans serovar Pomona.

ETULAIN, JULIA; GÓMEZ, RICARDO MARTÍN; NAGEL, ARIEL; BLANCO, FEDERICO CARLOS; CAIMI, KARINA; VÁZQUEZ, CRISTINA LOURDES; GRAVISACO, MARIA JOSÉ

VETERINARY MICROBIOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 233 p. 124 - 132

0378-1135

Leptospirosis is a zoonosis, caused by pathogenic spirochetes of the genus Leptospira. Although cattle are usually themaintenance hosts of serovar Hardjo, Pomona is the most frequent serovar circulating in Argentina. Theunderstanding of bovine innate immune response and the virulence of this serovar is important for future controlmeasures. This work compares infection of bovine macrophages with the virulent L. interrogans sv Pomona strainAKRFB (P1) and its attenuated counterpart (P19). First, we confirmed attenuation in the hamster model. Mortality andlung hemorrhages occurred after P1 inoculation, while the survival rate was 100% in P19-infected animals. Cellsinfected with both strains showed statistically upregulated gene expression of pro-inflammatory cytokines, IL-1β, IL-6and TNFα. The level of expression of anti-inflammatory cytokine IL-10 was statistically different between strains.Increased expression of IL-10 was observed only in P1-infected cells. For the first time, we describe macrophagesextracellular traps induced by infection of bovine macrophages (bMETs) with both, the virulent and attenuatedLeptospira interrogans Pomona strains. P1 was found higher internalized when the phagocytosis was inhibited,suggesting a cell entrance of this strain also by an independent-phagocytosis pathway. Furthermore, P1 was highercolocalized with acidic and late endosomal compartments compared with P19. This data emphasizes the importanceto deepen in Leptospira bovine macrophages particular invasion mechanisms and, furthermore, underline the value ofstudying the main hosts.