Bacterial endosymbiont-derived lipopolysaccharides and a protein on symbiosome membranes in newly infected amoebae and their roles in lysosome-symbiosome fusion.
Experimental results are presented to support the view that symbiont-derived lipopolysaccharides are involved in the prevention of lysosome-symbiosome fusion in xD amoebae harboring bacterial endosymbionts. Monoclonal antibodies against lipopolysaccharides and a 96-kDa protein present on symbiosome membranes of amoebae were used to monitor the appearance of the membrane-specific components in newly infected amoebae with endosymbionts from xD amoebae. The lipopolysaccharides and protein appeared on the newly forming symbiosome membranes within 3 to 7 days, as detected by indirect immunofluorescence staining with monoclonal antibodies. The lysosome-symbiosome fusion was followed by double staining of two antigens with different monoclonal antibodies applied to the same amoeba. Antilipopolysaccharide monoclonal antibodies were detected by staining with a fluorescein isothiocyanate-conjugated secondary antibody, and a biotinylated anti-lysosomal protein monoclonal antibody was detected by staining with Texas Red-conjugated streptavidin. In xD amoebae injected with an antilipopolysaccharide antibody, lysosomes fused with some of the symbiosomes that did not fuse with lysosomes in noninjected cells.
Kim
K J
KJ
Department of Zoology, University of Tennessee, Knoxville 37996.
Na
Y E
YE
Jeon
K W
KW
D000656:Amoeba / Q000382:microbiology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006090:Gram-Negative Bacteria / Q000254:growth & development*; D007425:Intracellular Membranes / Q000502:physiology; D008070:Lipopolysaccharides / Q000276:immunology / Q000378:metabolism; D008247:Lysosomes / Q000502:physiology; D008561:Membrane Fusion; D013559:Symbiosis; D014617:Vacuoles / Q000502:physiology
D000911:Antibodies, Monoclonal; D008070:Lipopolysaccharides