Lactobacilli harboring aggregation gene as a vaccine delivery vehicle

DETAILED DESCRIPTION OF THE INVENTION As used herein and in the claims, the term "animal" means mammals and avians, with humans being the animal of greatest interest.
As used herein and in the claims, the term "L.
reuteri" means any Lactobacillus microorganism that is identified as L.
reuteri according to the method set forth in U.
S.
Pat.
No.
5,352,586.
As used herein and in the claims, the terms "transformed Lactobacilli or "transformed L.
reuteri" mean Lactobacilli or L.
reuteri into which foreign genes encoding antigenic products have been inserted.
Transformed L.
reuteri, or other similarly transformed bacteria particularly other Lactobacillus species, may be administered in the form of a capsule, tablet, yogurt, solution or the like.
Adequate dosages to establish transformed bacteria in the normal flora of an animal to effectuate vaccination is within the skill of the artisan.
All embodiments of the invention require the use of viable transformed non-virulent bacteria, preferably Lactobacilli and more preferably L.
reuteri, as the organism which provides for the production of antigenic products in the animal body at sites that elicit an immune response.
Vaccines according to the invention are prepared from live bacteria preferably Lactobacilli, and more preferably L.
reuteri, that have been transformed so as to express antigens of microorganisms pathogenic to the host.
The transformed bacteria, which serve as hosts for the expression of the antigen, can express the antigen in the cytoplasm which can then be translocated to the outer membrane of the microorganism or secreted to provide immunogens for an immunologic response by the animal host.
By employing live, non-virulent bacteria as carriers for an immunogen, a strong targeted stimulus can be provided to the immune system.
The antigen gene which is inserted into the host non-virulent bacteria may come from diverse sources, such as pathogenic bacteria, viruses, fungi, protozoa, or other biological material.
The antigen gene may encode envelope proteins, capsid proteins, surface proteins or toxins such as exotoxins or enterotoxins