INVESTIGADORES
GARCIA Veronica Edith
congresos y reuniones científicas
Título:
In vivo and in vitro bactericidal effects of Secretory Leukocyte Protease Inhibitor (SLPI) on Mycobacterium bovis Bacillus Calmette-Guerin (BCG).
Autor/es:
GÓMEZ SA; ARGUELLES C; GUERRIERI D; SLIMOVICH R,; TATEOSIAN N,; PASQUINELLI V; CHULUYAN E; GARCÍA V
Lugar:
Rio de Janeiro, Brazil
Reunión:
Congreso; 13 th International Congress of Immunology; 2007
Resumen:
SLPI is a proteinase inhibitor produced mainly by epithelial cells. Several studies demonstrate that SLPI has bactericidal activity against Streptococcus species and Escherichia coli but its role against mycobacterial species has never been reported. Our objective was to study the effect of recombinant human SLPI (rhSLPI) on Mycobacterium bovis BCG viability in vitro and in vivo. rhSLPI (5 mM) was incubated overnight with equal volumes of mid-log grown bacterial suspension (105/ml), and survival percentage was determined with a colorimetric method. rhSLPI killed M. bovis BCG rendering 70% and 30% survival at 2.5mM and 5mM, respectively (p<0.05 and p<0.003 respectively; n = 3). A kinetic study was performed to evaluate the long term effects of rhSLPI on mycobaterial survival. We observed a time dependent decrease in bacterial survival with maximum killing at 72 h (17 % survival, p<0.001). To study the effects of rhSLPI in vivo, Balb/c female mice were infected with one intranasal instillation dose of 0.5-1x106 colony forming units (CFU) of BCG/mice. Viable BCG load in lung homogenates was determined at day 14 post infection on agar as well as percent of mycobacterial positive lung cells by Ziehl-Neelsen. Two-day intranasal rhSLPI treatment (four doses 150 mg/ml each) decreased the number of CFU recovered from lung homogenates vs control BCG (p<0.03, n=4/group). The same was observed after counting the number of acid fast positive infected lung cells (p<0.005 vs control). This is the first work to show effective bactericidal action of rhSLPI on a mycobacteria specie.