NATURALLY OCURRING ANTI-GM1 ANTIBODIES: CAMPYLOBACTER JEJUNI STRAINS COULD ACT AS IMMUNOGEN

ALANIZ MARÍA E; MOYANO ANA LIS; COMIN ROMINA; LARDONE RICARDO D; NORES GUSTAVO A

Rosario

Congreso; XLII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB); 2006

SAIB

In contrast with the large body of evidence supporting a primary role of anti-GM1 antibodies in neuropathies, very little information is available about their origin. Based in studies on the antigen structural requirements for their binding it has been proposed that they originate from naturally occurring anti-GM1 antibodies. Anti-GM1 antibodies of the IgM isotype are part of the normal repertoire of human serum. They are absent in day-old babies and can be detected after few months. Their appearance show a perfect concordance with well characterized anti-bacterial antibodies, an indication that they are part of the defence system toward these organisms.  On the other hand, sera from months-old children, devoid of anti-GM1 antibodies, have antibodies recognizing symbiotic bacteria.  All together these results indicated that the generation of anti-GM1 antibodies in normal human are originated during the immune response to specific bacteria. In the present study we develop a strategy to detect them. Normal occurring anti-GM1 IgM-antibodies were purified from healthy human sera by GM1 affinity chromatography. This highly specific antibody preparation was used for searching bacterium strains that could act as immunogen. For this purpose, lipopolisaccharides (LPS) from several bacteria species were purified and chased for antibody binding. Positive reactions were only obtained with LPS from Campylobacter jejuni (three of sixteen strains). These results indicate that subclinic infection with certain strains of these bacteria could trigger the production of naturally occurring anti-GM1 antibodies.