Antibodies directed against nitrosylated neoepitopes in sera of patients with human African trypanosomiasis
Antibodies directed against nitrosylated epitopes have been found in sera from patients suffering from human African trypanosomiasis (HAT) but not in sera from control subjects living in the same endemic area or African control subjects living in France. We conjugated amino acids to albumin by glutaraldehyde (conjugates) and then nitrosylated the conjugates. Both conjugates and nitrosylated conjugates were analysed by enzyme-linked immunosorbent assay (ELISA). We detected antibodies directed against nitrosylatedl-cysteine andl-tyrosine conjugates; antibody levels were higher in stage II patients than in stage I. Patients with severe clinical signs had higher antibody levels, and antibody levels were highest in patients with major neurological signs. Antibody response was only associated with the IgM isotype. We evaluated antibody specificity and avidity by competition experiments using conjugates and nitrosylated conjugates. Avidity was around 2 ×10−6 mfor the S-nitroso-cysteine epitope and 2 × 10−8 mfor the S-nitroso-tyrosine epitope. Detection of circulating antibodies to S-nitroso-cysteine and S-nitroso-tyrosine epitopes provides indirect evidence for nitric oxide (NO) involvement in HAT and their levels are correlated with disease severity.
Document Type: Research Article
Affiliations: 1: Laboratoire de parasitologie, Université de Bordeaux II, Bordeaux cedex, France 2: Ecole nationale supérieure de chimie et de physique de Bordeaux, Talence cedex, France 3: Institut de recherche pour le développement, Montpellier, France
Publication date: 2004-10-01