Avirulent microbes and uses therefor: Salmonella typhi

• US 5,387,744 A
• Filed: 07/07/1993
• Issued: 02/07/1995
• Est. Priority Date: 06/04/1987
• Status: Expired due to Term

• Current Assignee: Mega Holdings, Inc.
• Original Assignee: Washington University In St Louis
• Inventors: Curtiss, Roy III, Kelly, Sandra M.
• Primary Examiner(s): Low, Christopher S. F.
• Application Number:
  US08/088,394
• Time in Patent Office: 580 Days
• Field of Search: 435/252.3, 435/252.8, 435/879, 435/172.1, 435/172.3, 435/320.1, 424/93 A, 424/93 D, 935/72, 536/23.1, 536/23.7, 536/24.1, 536/24.2
• US Class Current: 424/258.1
• CPC Class Codes: A61K 2039/522 avirulent or attenuated
• CPC Class Codes: A61K 2039/523 expressing foreign proteins
• CPC Class Codes: A61K 2039/552 Veterinary vaccine
• CPC Class Codes: A61K 39/0275 Salmonella
• CPC Class Codes: A61K 39/04 Mycobacterium, e.g. Mycobacterium tuberculosis
• CPC Class Codes: A61K 39/099 Bordetella
• CPC Class Codes: C07K 14/255 Salmonella (G)
• CPC Class Codes: C07K 14/315 from Streptococcus (G), e.g. Enterococci
• CPC Class Codes: C07K 14/35 from Mycobacteriaceae (F)
• CPC Class Codes: C12N 1/205 Bacterial isolates
• CPC Class Codes: C12N 15/00 Mutation or genetic engineering; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification; Use of hosts therefor mutants or genetically engineered microorganisms, per se C12N1/00, C12N5/00, C12N7/00; new plants per se A01H; plant reproduction by tissue culture techniques A01H4/00; new animals per se A01K67/00; use of medicinal preparations containing genetic material which is inserted into cells of the living body to treat genetic diseases, gene therapy A61K48/00
• CPC Class Codes: C12N 15/01 Preparation of mutants without inserting foreign genetic material therein; Screening processes therefor
• CPC Class Codes: C12N 15/68 Stabilisation of the vector
• CPC Class Codes: C12N 9/0008 acting on the aldehyde or oxo group of donors (1.2)
• CPC Class Codes: C12R 2001/42 Salmonella
• CPC Class Codes: C12Y 102/01011 Aspartate-semialdehyde dehydrogenase (1.2.1.11)
• CPC Class Codes: Y10S 435/879 Salmonella

Abstract

This invention provides immunogenic compositions for the immunization of a vertebrate or invertebrate comprising an avirulent derivative of S. typhi. The derivatives having a mutation of the cya and/or crp and/or cdt genes. The invention also provides immunogenic compositions for the immunization of a vertebrate and invertebrate comprising an avirulent derivative of the above type which is capable of expressing a recombinant gene derived from a pathogen of said vertebrate or invertebrate individual to produce an antigen capable of inducing an immune response against said pathogen. Other embodiments of the invention include methods of preparing immunogenic compositions from these strains, and strains useful in the preparation of the immunogenic compositions, as well as methods of stimulating the immune system to respond to an immunogenic antigen of S. typhi by administration of the immunogenic composition.

Claims

1. An immunogenic composition for the immunization of an individual comprising a live avirulent Salmonella having a mutation in a cdt gene said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

2. An immunogenic composition for the immunization of an individual according to claim 1, wherein said avirulent Salmonella expresses a recombinant gene from an agent pathogenic to said individual, to produce an antigen which induces an immune response in said vertebrate against said pathogen.

3. A method for stimulating the immune system of an individual to respond to an immunogenic antigen of Salmonella comprising administering to said individual an immunogenic composition comprising a live avirulent Salmonella having a mutation in a cdt gene said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

4. A method for stimulating the immune system to respond to an immunogenic antigen of a pathogen comprising administering to said individual an immunogenic composition comprising a live avirulent Salmonella having a mutation in a cdt gene said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

5. A biologically pure live avirulent strain of Salmonella said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

6. The avirulent strain of Salmonella of claim 5, which expresses a recombinant gene from an agent pathogenic to said individual, to produce an antigen which induces an immune response in said vertebrate against said pathogen.

7. A strain according to claim 6, wherein the Salmonella contains a chromosomal mutation which is lethal and which is balanced by a vector-borne gene which complements the lethal mutation to constitute a balanced lethal host vector system.

8. A strain according to claim 6, wherein cells of the strain:

a) lack a functioning native chromosomal gene encoding beta-aspartate semialdehyde dehydrogenase asd;

b) have present an exogenously introduced gene encoding a functional Asd polypeptide which phenotypically complements the chromosomal asd mutation, but which cannot replace the defective chromosomal gene by recombination; and

c) have a physical linkage between the recombinant genes encoding the functional Asd polypeptide and the immunogenic antigen, wherein the loss of the recombinant gene encoding the functional Asd polypeptide causes the cells to lyse when the cells are in an environment in which the lack of functional Asd causes the cells to lyse.

9. A live biologically pure strain of S. typhi having a mutation in a cdt gene said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

10. A vaccine for the immunization of an individual comprising:

a pharmaceutically effective mount of a live avirulent Salmonella which has a diminished ability to colonize deep tissue of said individual as a result of a mutation in a cdt gene said live avirulent Salmonella having the phenotype of failure to colonize deep tissue of Salmonella deposit strain ATCC no. 55113.

11. The vaccine of claim 10 wherein said avirulent Salmonella fails to colonize deep tissue of said individual. 2