Cross-reactivity of anti-galactocerebroside autoantibodies with a Trypanosoma brucei proteolipidic epitope.
Pathogenic mechanisms of the demyelinating encephalopathy featuring the nervous phase of human African trypanosomiasis (HAT) are largely unknown. They might include autoimmune disorders. A variety of autoantibodies is detected during the disease and we have previously evidenced anti-galactocerebroside (GalC) antibodies in the serum and cerebrospinal fluid (CSF) from patients in the nervous stage (stage II) of HAT. We now show that anti-GalC antibodies recognize an antigen located on the parasite membrane and common to different strains of trypanosomes. By using affinity chromatography with a rabbit anti-GalC antiserum, a 52-kD proteolipid was isolated from the membrane of Trypanosoma brucei (T. b.) brucei AnTat 1.9, AnTat 1. 1E, and T. b. rhodesiense Etat 1.2/R and Etat 1.2/S. Antibodies directed against this antigen were found in the CSF from patients with nervous stage HAT. These CSF also contained anti-GalC antibodies and adsorption with the proteolipid decreased anti-GalC reactivity. Immunization of mice with this antigen induced the production of antibodies which cross-reacted with GalC but no protection from experimental infection with T. b. brucei. These data support the hypothesis that anti-GalC antibodies detected in the CSF from HAT patients might be induced by molecular mimicry with a parasite antigen.
Girard
M
M
Institute of Tropical Neurology, Faculty of Medicine, Limoges, Laboratories of Immunology (University Hospital, Limoges and University Hospital, Poitiers), France.
Bisser
S
S
Buscher
P
P
Bouteille
B
B
Preud'homme
J L
JL
Jauberteau
M O
MO
D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D003429:Cross Reactions; D005699:Galactosylceramides / Q000276:immunology*; D006801:Humans; D051379:Mice; D011817:Rabbits; D014346:Trypanosoma brucei brucei / Q000276:immunology*; D014353:Trypanosomiasis, African / Q000276:immunology*
D001323:Autoantibodies; D005699:Galactosylceramides; C002454:galactocerebroside