IMMUNIZATION OF MICE WITH ESCHERICHIA-COLI CONTAINING AN ANTIGEN OF THE MALARIA PARASITE PLASMODIUM-CHABAUDI CHABAUDI EXPRESSED IN LAMBDA-GT11 INDUCES HIGH ANTIBODY-TITERS

Escherichia coli containing a recombinant malarial protein expressed i n lambda gt11 have been evaluated as an antigen delivery system in viv o. They were generated by infecting non-suppressing E. coil cells with a clone from a cDNA library of Plasmodium chabaudi chabaudi in lambda gt11. This clone (termed clone 6) expresses part of a 93 kDa blood-st age antigen of P. c. chabaudi as beta-galactosidase fusion protein. Im munization of C57Bl/6 mice with these infected E. coli cells resulted in an antibody response to the malarial part of the fusion protein com parable to that obtained with purified fusion protein preparations. Th is method, therefore represents a rapid secondary screening of clones from lambda gt11 expression libraries for immunogenic and potentially protective components. In addition, the administration of whole infect ed E. coli obviates the need for an adjuvant.