Evaluation of adenyl cyclase toxin constructs from Bordetella pertussis as candidate vaccine components in an in vitro model of complement-dependent intraphagocytic killing.

Autor: Prior S; Division of Bacteriology, National Institute for Biological Standards and Control, NIBSC, Potters Bar, Hertfordshire EN6 3QG, UK. sprior@nibsc.ac.uk, Fleck RA, Gillett ML, Rigsby PR, Corbel MJ, Stacey GN, Xing DK
Jazyk: angličtina
Zdroj: Vaccine [Vaccine] 2006 May 29; Vol. 24 (22), pp. 4794-803. Date of Electronic Publication: 2006 Apr 03.
DOI: 10.1016/j.vaccine.2006.03.065
Abstrakt: Recombinant, genetically-detoxified adenylate cyclase toxin (CyaA) constructs from Bordetella pertussis have been developed as potential antigen delivery systems and as promising antigen candidates for inclusion in acellular pertussis vaccines. The major toxic effects of native CyaA are attributed to its enzymatic activity following delivery to cells of the innate immune system via the CD11b/CD18 (CR3) cell receptor. In view of the potential use of detoxified CyaA in vaccinology, a complement dependent in vitro model was used to investigate the potential effects of the interaction of detoxified CyaA with CD11b/CD18 (CR3) on phagocytic function. Interaction of CyaA with CD11b/CD18 (CR3) on human pro-myelocytic NB-4 cells differentiated to a neutrophil-like phenotype was measured as inhibition of binding of a monoclonal antibody to the receptor. This interaction was dose-dependent and required acylation of CyaA. Treatment of the cells with either acylated or non-acylated detoxified CyaA constructs inhibited their phagocytic function. Washing the cells allowed recovery of phagocytic function after treatment with non-acylated toxin but not for cells treated with acylated CyaA constructs. However, availability of CD11b/CD18 receptors on acylated CyaA-treated cells was restored after washing and further incubation. The results suggest that the interaction of detoxified CyaA constructs to the CD11b/CD18 (CR3) receptor may temporarily influence the complement-dependent phagocytic function in neutrophil leukocytes.
Databáze: MEDLINE