NF-kB activation and p38 phosphorilation in microglial cells infected with Leptospira or exposed to partially purified leptospiral lipoproteins.
Recently, we have shown a differential susceptibility of non-pathogenic vs. pathogenic leptospires to phagocytosis and killing by microglial cells. Although all ingested to some extent, only the pathogenic strains survived intracellularly while the non-pathogenic ones were killed in a time-dependent manner. By the same infection model, here we demonstrate that microglial cells respond to Leptospira infection with a time- and dose-dependent induction of molecular signals (p38 phosphorilation and NF-kB activation) and the production of soluble factors (cytokines and nitric oxide). Such bio-molecular response is predominantly observed against the pathogenic Leptospira; the phenomenon is reproduced by leptospiral lipoproteins and, to a lower extent, by leptospiral-derived LPS. These data provide initial evidence that Leptospira affects microglial cell response in a different manner depending upon the virulence of the infecting strain; specific bacterial components happen to be involved in the induction of such pathogen-induced immune response.
Blasi
Elisabetta
E
Dipartimento di Scienze di Sanità Pubblica, Università di Modena e Reggio Emilia, Via Campi 287, 41100 Modena, Italy. blasi.elisabetta@unimore.it
Ardizzoni
Andrea
A
Colombari
Bruna
B
Neglia
Rachele
R
Baschieri
Cristina
C
Peppoloni
Samuele
S
Cinco
Marina
M
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004306:Dose-Response Relationship, Immunologic; D007919:Leptospira / Q000378:metabolism / Q000472:pathogenicity; D007922:Leptospirosis / Q000276:immunology / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism; D008074:Lipoproteins / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D017628:Microglia / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D010587:Phagocytosis; D010766:Phosphorylation; D014774:Virulence; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D016207:Cytokines; D008070:Lipopolysaccharides; D008074:Lipoproteins; D016328:NF-kappa B; D009569:Nitric Oxide; D048051:p38 Mitogen-Activated Protein Kinases