Normally occurring human Anti-GM1immunoglobulin M antibodies and the Immune response to bacteria

• Autores: Alaniz, María E.; Lardone, Ricardo D.; Yudowski, Silvia L.; Farace, María Isabel; Nores, Gustavo A.
• Año de publicación: 2004
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Infection and Immunity 2004;72(4):2148-2151
• Materia: Inmunoglobulinas; Anticuerpos; Bacterias
• Institución: Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"

Fil: Alaniz, María E. Universidad Nacional de Córdoba. Departamento de Química Biológica Dr. Ranwel Caputto; Argentina.
Fil: Lardone, Ricardo D. Universidad Nacional de Córdoba. Departamento de Química Biológica Dr. Ranwel Caputto; Argentina.
Fil: Yudowski, Silvia L. Hospital Infantil Municipal. Servicio de Bacteriología; Argentina.
Fil: Farace, María Isabel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio Bacteriología Sanitaria; Argentina.
Fil: Nores, Gustavo A. Universidad Nacional de Córdoba. Departamento de Química Biológica Dr. Ranwel Caputto; Argentina.
Anti-GM1 antibodies of the immunoglobulin M (IgM) isotype are normal components of the antibody repertoire of adult human serum. Using a sensitive high-performance thin-layer chromatography (HPTLC) immunostaining assay, we found that these antibodies were absent in the umbilical vein and children <1 month of age but could be detected after 1 month of age. Although most of the children older than 6 months of age were positive, there were still a few negative children. The appearance of anti-GM1 IgM antibodies showed a perfect concordance with two well-characterized antibacterial antibodies, anti-Forssman and anti-blood group A, which indicates a similar origin. We also studied IgM reactivity with lipopolysaccharides (LPSs) from gram-negative bacteria isolated from stool samples from healthy babies and from Escherichia coli HB101 in serum from individuals of different ages. We found a positive reaction with both LPSs in all the children more than 1 month of age analyzed, even in those that were negative for anti-GM1 antibodies. Anti-GM1 IgM antibodies were purified from adult serum by affinity chromatography and tested for the ability to bind LPSs from different bacteria. This highly specific preparation showed reactivity only with LPS from a strain of Campylobacter jejuni isolated from a patient with diarrhea. We conclude that normally occurring IgM antibodies are generated after birth, probably during the immune defense against specific bacterial strains.