David R Stephens

US Patent:

6403306, Jun 11, 2002

Filed:

Sep 23, 1997

Appl. No.:

08/936107

Inventors:

David S. Stephens - Stone Mountain GA
John S. Swartley - Westport CT

Assignee:

Emory University - Atlanta GA

International Classification:

C12Q 168

US Classification:

435 6, 536 237, 536 243, 536 2432, 4353201, 435975

Abstract:

The present invention is based on the discovery of meningococcal isolates having genetic markers of a particular serogroup but expressing a capsular polysaccharide of a different serogroup. These isolates and prototype serogroup A, B, C, Y and W-135 strains were used to define the capsular biosynthetic operon of the major meningococcal serogroups and to show that capsule switching occurs as a result of allelic exchange of, for example, the polysialyl-transferase gene. Findings of capsule switching in vivo indicate that closely related virulent meningococcal clones may not be recognized by traditional serogroup-based surveillance and can escape vaccine-induced or natural protective immunity by capsule switching. The invention provides recombinant meningococcal strains, recombinant DNA constructs and immunological preparations useful as diagnostic probes for detection and diagnosis of meningococcal diseases, screening for specific meningococcal serogroups and broad based immunizations with multivalent capsular polysaccharide conjugate vaccines.

US Patent:

6472518, Oct 29, 2002

Filed:

Aug 17, 1999

Appl. No.:

09/284926

Inventors:

Efrain M. Ribot - Atlanta GA
David S. Stephens - Stone Mountain GA
Nigel Raymond - Wellington, NZ
Frederick D. Quinn - Avondale Estates GA

Assignee:

Centers for Disease Control and Prevention, as represented by the Secretary, Department of Health and Human Services - Atlanta GA

International Classification:

C07H 2104

US Classification:

536 237, 536 2432, 536 2433, 536 241, 4242501, 435243, 4352523, 4353201, 435 691, 435 693

Abstract:

Genes isolated from , as well as isolated nucleic acids, probes, expression cassettes, polypeptides, antibodies, immunogenic compositions, antisense nucleic acids, amplification mixtures, and new invasion deficient swains of are provided Methods of detecting and nucleic acids, and methods of inhibiting the invasion of mammalian cells by are also provided.

US Patent:

7348161, Mar 25, 2008

Filed:

Mar 15, 2002

Appl. No.:

10/472801

Inventors:

Kathryn Gay - Atlanta GA, US
David S. Stephens - Stone Mountain GA, US

Assignee:

Emory University - Atlanta GA

International Classification:

C12Q 1/37
C12Q 1/14
C07K 14/325
C12N 1/20

US Classification:

435 237, 530350, 43525233, 435 72, 435 32

Abstract:

Macrolide resistance associated with macrolide efflux (mef) in has been defined with respect to the genetic structure and dissemination of a novel mefE-containing chromosomal insertion element. The mefE gene is found on the 5′-end of a 5. 5 kb or 5. 4 kb insertion designated mega (acrolide fflux enetic ssembly) found in at least four distinct sites of the pneumococcal genome. The element is transformable and confers macrolide resistance to susceptible. The first two open reading frames (ORFs) of the element form an operon composed of mefE and a predicted ATP-binding cassette homologous to msrA. Convergent to this efflux operon are three ORFs with homology to stress response genes of Tn5252. Mega is related to mefA-containing element Tn1207. 1. Macrolide resistance due to mega has been rapidly increased by clonal expansion of bacteria containing it and horizontally by transformation of previously sensitive bacteria.

US Patent:

7807181, Oct 5, 2010

Filed:

Mar 20, 2003

Appl. No.:

10/508309

Inventors:

David S. Stephens - Stone Mountain GA, US
Yih-Ling Tzeng - Atlanta GA, US
Susu Zughaier - Atlanta GA, US
Shanta Zimmer - Atlanta GA, US

Assignee:

Emory University - Atlanta GA

International Classification:

A61K 39/02
A61K 39/095
A61K 39/38
A01N 43/04
C07H 1/00

US Classification:

4242341, 4241841, 4242501, 4242491, 514 23, 5361231

Abstract:

Provided herein are mutant strains of which produce Kdo-free lipid A as well as the Kdo-free lipid A molecules and immunogenic compositions containing such Kdo-free lipid A molecules from a strain containing a genetically stable mutation which inactivates a gene selected from the group consisting of genes encoding arabinose-5-phosphate isomerase, CMP-Kdo synthetase and CMP-Kdo transferase. NMB206 is a specifically exemplified strain which harbors a stable insertion mutation in the gene (kpsF) encoding A5P isomerase; strain NMB-249 is a specifically exemplified strain with a stable insertion mutation in the gene (kdtA) encoding CMP-Kdo synthetase, and strain NMB259 is specifically exemplified strain with a stable insertion mutation in the gene (kdsB) encoding CMP-Kdo transferase. Also provided by the present invention are methods for the production of Lipid A flee of 3-keto-3-deoxyoctanoic acid using these genetically stable mutants. Also describes is pYT250, a plasmid functional in neisseriae and in enterics such as.

US Patent:

20060073168, Apr 6, 2006

Filed:

Aug 11, 2005

Appl. No.:

11/201774

Inventors:

David Stephens - Stone Mountain GA, US
Seshu Gudlavalleti - Atlanta GA, US
Yih-Ling Tzeng - Atlanta GA, US
Anup Datta - La Jolla CA, US
Russell Carlson - Athens GA, US

International Classification:

A61K 39/095
C07H 21/04
C12P 21/06
C12N 9/10
C12N 15/74
C12P 19/04
C12N 1/21

US Classification:

424249100, 435069100, 435252300, 435193000, 435471000, 536023200, 435101000

Abstract:

Provided are recombinant DNA molecules that do not occur in nature encoding an O-acetyltransferase, vectors that direct expression of an O-acetyltransferase, recombinant host cells which express an O-acetyltransferase, methods for recombinant production of an O-acetyltransferase, methods for acetylating capsular polysaccharides, especially those of a Serogroup A using a recombinant O-acetyltransferase, and immunogenic compositions comprising the acetylated capsular polysaccharide.

US Patent:

20090035827, Feb 5, 2009

Filed:

Aug 23, 2007

Appl. No.:

11/843933

Inventors:

David S. Stephens - Stone Mountain GA, US
Charlene Kahler - Perth, AU

International Classification:

C12P 19/04
C12N 1/21
C12N 9/10
C12N 15/54

US Classification:

435101, 536 232, 4352523, 435193

Abstract:

Provided are recombinant DNA molecules that do not occur in nature encoding a Lot3 O-acetyltransferase, vectors that direct expression of a Lot O-acetyltransferase, recombinant host cells which express a Lot3 O-acetyltransferase, methods for recombinant production of a Lot3 O-acetyltransferase, methods for acetylating lipooligosaccharides, especially those of a using a recombinant Lot O-acetyltransferase, and immunogenic compositions comprising the acetylated lipooligosaccharide.

US Patent:

20120053199, Mar 1, 2012

Filed:

Aug 24, 2011

Appl. No.:

13/216458

Inventors:

Susu Zughaier - Atlanta GA, US
Ritu Aneja - Lilburn GA, US
David S. Stephens - Stone Mountain GA, US

Assignee:

GEORGIA STATE UNIVERSITY RESEARCH FOUNDATION - Atlanta GA
EMORY UNIVERSITY - Atlanta GA

International Classification:

A61K 31/4355
A61P 37/00
A61P 25/28
A61P 19/02
A61P 11/06
A61P 9/10
A61P 1/00
A61P 17/00
A61P 31/14
A61P 19/04
A61P 25/16
A61P 11/00
A61P 11/08
A61P 37/06
A61P 1/16
A61P 29/00

US Classification:

514291

Abstract:

The invention relates to the innate immune pathway and anti-inflammatory molecules with therapeutic properties. In some embodiments, the invention relates to compounds and pharmaceutical compositions and methods of using the compounds and compositions to treat inflammatory diseases including inflammation associated with auto-immune diseases.

US Patent:

59765364, Nov 2, 1999

Filed:

Aug 9, 1995

Appl. No.:

8/512955

Inventors:

David S. Stephens - Stone Mountain GA
Charlene Marree Kahler - Decatur GA

Assignee:

Emory University - Atlanta GA

International Classification:

A61K 3900
A61K 3902
A61K 39095
A01N 6300

US Classification:

4241841

Abstract:

Provided herein are mutant strains of Neisseria meningitidis which produce lipooligosaccharide (LOS) differing from the wild-type LOS in structure as well as the mutant LOS molecules and immunogenic compositions containing truncated LOS molecules from a Neisseria strain containing a genetically stable in a gene selected from the group consisting of genes encoding. alpha. -1,2-N-acetylglucosamine transferase and a gene homology to an Escherichia coli gene encoding 1-acyl-sn-glycerol-3-phosphate acyltransferase. N. meningitidis NMB-559 harbors an insertion mutation in the gene encoding. alpha. -1, 2-N-acetylglucosamine transferase, and N. meningitidis NMB-469 harbors an insertion mutation in an nlaB gene, the protein product of which has significant amino acid sequence homology to the E. coli gene encoding 1-acyl-sn-glycerol-3-phosphate acyltransferase.