Antibody-independent binding of complement component C1q by Legionella pneumophila.

AUTOR(ES)

Mintz, C S

RESUMO

Incubation of Legionella pneumophila Philadelphia 1 in normal human serum depleted of either classical-pathway component C1q or alternative-pathway component factor B resulted in activation of the complement system. Experiments focused on the role of the classical pathway in complement activation revealed that legionellae bound C1q independently of antibody. Purified preparations of L. pneumophila major outer membrane protein but not serogroup 1 lipopolysaccharide bound C1q independently of antibody. This suggests that antibody-independent binding of C1q by L. pneumophila can result in activation of the classical pathway in normal human serum and that major outer membrane protein may be a C1q acceptor on the L. pneumophila cell surface.

Documentos Relacionados

• Antibody-independent binding of the first component of complement (C1) and its subcomponent C1q to the S and R forms of Salmonella minnesota.
• Electron microscopic study showing antibody-independent binding of C1q, a subcomponent of the first component of complement, to serum-sensitive salmonellae.
• Antibody-independent and -dependent opsonization of group B Streptococcus requires the first component of complement C1.
• Antibody-independent interaction of the first component of complement with Gram-negative bacteria.
• Antibody-independent interactions of fibronectin, C1q, and human neutrophils with Treponema pallidum.