Characterization of new potential vaccine candidates identified by immune proteomics.

PEREZ VIDAKOVICS MARA LAURA ; ALVAREZ HAYES, JIMENA;; LAMBERTI, YANINA; RODRIGUEZ, MARIA EUGENIA.

Mar del Plata

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2007

The low efficacy in preventing colonization of pertussis vaccines in use have led to disease re-emergence. Opsonins and antibodies capable of blocking initial attachment are critical to prevent colonization. Antigens included in vaccines able to induce this kind of antibodies have varied along the years leading to circulating bacteria with different variants than vaccine strains. On top of this, since Bordetella pertussis (Bp) seems not to be transmitted in virulent phase antigens included in vaccines might not be present in the infective phenotype. Using a proteomic approach we screened for new immunogens that should be expressed under physiological conditions. Four proteins induced under iron limitation, the main nutritional stress in vivo, not included in any of the current vaccines though present in the infective phenotype, were differencially recognized by sera from infected individuals. Two of them with predicted bacterial surface location, proved antigenic in mice. Antibodies against these proteins recognized surface exposed antigens that were overexpressed under iron limitation as determined by whole cell ELISA. Furtheremore, they showed aggluttinin and opsonic activity as detected by microscopy and flowcytometry using iron straved Bp. Since these are key biological activities to prevent colonization these proteins may prepresent attractive vaccines candidates.