Protective activity of the antilipopolysaccharide antibodies from human cord serum

• Autor(a) principal: Pontes, Gerlandia Neres
• Data de Publicação: 2006
• Outros Autores: Massironi, Silvia Gomes, Arslanian, Christina, Friedlander-Del Nero, Dora Lisa, Sales Carneiro-Sampaio, Magda Maria, Nagao-Dias, Aparecida Tiemi [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/29056; http://dx.doi.org/10.1111/j.1574-695X.2006.00107.x
• topic: Escherichia coli O6; sepsis; maternally acquired immunity; proinflammatory cytokines; antilipopolysaccharide antibodies

We evaluated the ability of human maternal and cord serum antibodies to protect mice challenged with live Escherichia coli serotype O6:K2ac (E. coli O6). Mice received paired maternal or cord serum pools before a challenge with E. coli O6 to evaluate the mortality rate. All the pools were able to protect the animals challenged with bacteria except the test group from paired maternal and cord sera from preterm neonates containing less than 1.0 mg L-1 immunoglobulin G antibody levels. in liver, spleen and mesenteric lymph nodes from the control group (phosphate-buffered saline), more than 10(2) CFU mL(-1) bacteria were found at 30 min and more than 10(5) CFU mL(-1) after 120 min. the test group showed lower bacterial counts in the organs, and no bacteria in the mesenteric lymph nodes during the evaluated period. Tumor necrosis factor alpha and interleukin 6 were undetectable in serum from animals pretreated with paired maternal and cord serum pools from full-term neonates and pools from preterm neonates containing high antibody and avidity levels. Our findings suggest that placental transfer of antilipopolysaccharide O6 immunoglobulin G antibodies to neonates has a high capacity to prevent lethal infection with E. coli O6 in a mouse protection model and that the degree of protection is determined by the concentration and avidity of these IgG antibodies.