Detection of nitrosylated epitopes in Trypanosoma brucei gambiense by polyclonal and monoclonal anti-conjugated-NO-cysteine antibodies.
Activated macrophages with the Calmette/Guérin bacillus (BCG) have a cytotoxic/cytostatic effect on the extracellular parasite, Trypanosoma brucei gambiense. This effect was inhibited when the NO-synthase inhibitor NG-monomethyl-L-arginine (NMMA; 0.5 mM) was added to the culture media. Using an immunocytochemical method with rabbit polyclonal or mouse monoclonal antibodies directed against conjugated nitroso-epitopes (anti-conjugated-NO-cysteine), nitrosylated antigens were visualized in fixed trypanosomes. These results suggest that NO was synthesized by the activated macrophages and that it reacted with some parasitic proteins containing cysteine. The release of NO bound to parasitic proteins may cause the killing of trypanosomes. The immunoreactivity was positive when the trypanosomes were obtained from the supernatant of the BCG-activated macrophages that contains BSA (4 mg/mL). In contrast, the parasites cocultured with non-activated macrophages remained completely viable, and, the immunoreactivity was completely negative.
Mnaimneh
S
S
Laboratoire de physique des interactions ondes-matières, UMR 5501, CNRS, Talence, France. s_mnaimneh@hotmail.com
Geffard
M
M
Veyret
B
B
Vincendeau
P
P
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D000913:Antibodies, Protozoan / Q000737:chemistry / Q000276:immunology; D000915:Antibody Affinity; D000918:Antibody Specificity; D000953:Antigens, Protozoan / Q000032:analysis*; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism*; D007150:Immunohistochemistry; D008262:Macrophage Activation; D051379:Mice; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits; D014347:Trypanosoma brucei gambiense / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D009569:Nitric Oxide; D003545:Cysteine