Dendritic cell response after exposure to Salmonella enterica with different LPS structure.

Abstract:

Lipopolysaccharide (LPS) is a structure of the gram-negative bacteria that protect from chemicals and works as a stabilization component for the membrane. Studies show that LPS also may have a function to avoid immune defense. In this project we investigate two Salmonella enterica variants with different LPS conformation. The wild-type Salmonella got an originally LPS structure and the mutant form had a defect one. The bacteria were transfected with a green fluorescent protein (GFP) to allow measuring of phagocytosis. Monocytes were isolated from human blood and were incubated for several days with cytokines to give dendritic cells. The cells were exposed to each type of Salmonella and incubated for different times. After labeling with phalloidin and studies with fluorescent microscopy, phagocytosis and F-actin were measured. The results show that it is a difference in phagocytosis and F-actin depending on LPS conformation. That means that LPS may have a decisive role for the pathogenicity of Salmonella.