myelin-basic-protein and Chagas-Disease

Most reports of autoimmune response during infection with the parasite Trypanosoma cruzi have dealt with the cardiomyopathic form of Chagas' disease, but little is known about the mechanisms of tissue damage involved in the gastrointestinal form, which was studied here. Chronically infected patients with a severe gastrointestinal form of Chagas' disease present increased antibody production and proliferative responses to peripheral myelin components, such as myelin basic protein (MBP), which is homologous to the P1 protein fraction of peripheral myelin. T lymphocytes preferentially recognize a region on the MBP molecule (1-30), which suggests that the MBP is a potential target on the peripheral nerve for autoimmune reactions in patients with gastrointestinal lesions resulting from Chagas' disease.

Topics: Adult; Animals; Autoantibodies; Autoantigens; Autoimmunity; Brain; Chagas Disease; Enteric Nervous System; Female; Gastrointestinal Diseases; Gastrointestinal Tract; Humans; Lymphocyte Activation; Male; Middle Aged; Myelin Basic Protein; Myelin Proteins; Myelin Sheath; Neurons; Peripheral Nerves; Polyradiculoneuropathy; T-Lymphocytes; Trypanosoma cruzi

Some autoimmune diseases are thought to arise after an infection. Infectious agents can initiate a chronic inflammatory response associated with autoimmune reactions. Chagas disease, caused by the intracellular parasite Trypanosoma cruzi, is an excellent model for autoimmune disease induced by an infection. The chronic disease is characterized by rich inflammatory infiltrate in myocardial and nervous tissues, with virtually no demonstrable parasites. We were able to demonstrate the presence of antibody to myelin basic protein (MBP) in the serum from T. cruzi chronically infected mice. Lymphocytes from mice immunized with T. cruzi-derived soluble extract antigen (TCSE) proliferate in response to MBP in vitro. Lymphocytes from animals immunized with MBP also were activated by TCSE in vitro. By studying the overlapping peptides from the MBP molecule, we were able to identify two regions responsible for the cross-reactivity.

Topics: Amino Acid Sequence; Animals; Antibodies, Protozoan; Antigens, Protozoan; Autoimmune Diseases; Chagas Disease; Chronic Disease; Cross Reactions; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Immunization; Lymph Nodes; Lymphocyte Activation; Mice; Mice, Inbred CBA; Molecular Sequence Data; Myelin Basic Protein; Peptide Fragments; Trypanosoma cruzi

The glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), S100 protein (S100), gamma gamma-enolase and neurofilament proteins were determined in the CSF of neurological patients. In Alzheimer's disease (AD), the GFAP values were very often increased but this was not specific to this disease. In 2 cases of familial AD, increases in neurofilament protein were detected. The determination of autoantibodies against neurofilament proteins in blood showed rather low values in AD, although they were higher than in subacute sclerosing panencephalitis (SSPE) and Chagas' disease. Increases were observed in diseases not related to AD such as vascular disorders and Parkinson's disease.

Topics: Aging; Alzheimer Disease; Brain Chemistry; Chagas Disease; Glial Fibrillary Acidic Protein; Humans; Intermediate Filament Proteins; Myelin Basic Protein; Neurofilament Proteins; S100 Proteins; Subacute Sclerosing Panencephalitis