Rossi, Omar
(2014)
MODULATION OF REACTOGENICITY OF GENERALIZED MODULES FOR MEMBRANE ANTIGENS (GMMA)BY GENETIC LIPID A MODIFICATION.
[Tesi di dottorato]
Item Type: |
Tesi di dottorato
|
Lingua: |
English |
Title: |
MODULATION OF REACTOGENICITY OF GENERALIZED MODULES FOR MEMBRANE ANTIGENS (GMMA)BY GENETIC LIPID A MODIFICATION |
Creators: |
Creators | Email |
---|
Rossi, Omar | omar_rossi@hotmail.it |
|
Date: |
26 March 2014 |
Number of Pages: |
118 |
Institution: |
Università degli Studi di Napoli Federico II |
Department: |
Scienze Chimiche |
Scuola di dottorato: |
Biotecnologie |
Dottorato: |
Scienze biotecnologiche |
Ciclo di dottorato: |
26 |
Coordinatore del Corso di dottorato: |
nome | email |
---|
Sannia, Giovanni | giovanni.sannia@unina.it |
|
Tutor: |
nome | email |
---|
Sannia, Giovanni | UNSPECIFIED | Gerke, Christiane | UNSPECIFIED |
|
Date: |
26 March 2014 |
Number of Pages: |
118 |
Uncontrolled Keywords: |
Shigella, Vaccine, Endotoxin |
Settori scientifico-disciplinari del MIUR: |
Area 05 - Scienze biologiche > BIO/11 - Biologia molecolare |
Aree tematiche (7° programma Quadro): |
SALUTE e TUTELA DEL CONSUMATORE > Biotecnologie, strumenti e tecnologie generiche per la salute umana |
[error in script]
[error in script]
Date Deposited: |
08 Apr 2014 11:06 |
Last Modified: |
11 Apr 2017 01:00 |
URI: |
http://www.fedoa.unina.it/id/eprint/9677 |

Abstract
Outer membrane particles from Gram-negative bacteria are attractive vaccine candidates as they present surface antigens in their natural environment and orientation. We previously developed a high yield production process for genetically derived particles, called Generalized Modules for Membrane Antigens (GMMA), from Shigella. As GMMA are derived from the outer membrane and contain immune-stimulatory components, especially lipopoly-saccharide (LPS), we examined ways of reducing their reactogenicity by modifying lipid A, the endotoxic part of LPS, through deletion of late acyltransferase genes msbB or htrB in GMMA-producing S. sonnei and S. flexneri strains. GMMA with resulting penta-acylated lipid A from the msbB mutants showed a 600-fold reduction, GMMA from the S. sonnei ΔhtrB mutant a 60,000-fold reduced ability compared to GMMA with wild-type lipid A to stimulated human Toll-like receptor 4 (TLR4) in a reporter cell line. In contrast, in the S. flexneri ΔhtrB mutant, a compensatory palmitoleoylation occurs resulting in hexa-acylated lipid A with approximately 10-fold higher activity than the penta-acylated lipid A. In human PBMC, GMMA with penta-acylated lipid A showed a marked reduction in induction of inflammatory cytokines (800-fold for S. sonnei ΔhtrB, 300-fold for the msbB mutants) compared to a 50-fold reduction observed for GMMA with palmitoleoylated lipid A from the S. flexneri ΔhtrB strain. We demonstrated that the residual activity of GMMA with penta-acylated lipid A is largely due to non-lipid A related TLR2 activation whereas GMMA with palmitoleoylated hexa-acylated lipid A predominantly activate TLR4. These results identify the relative activation of TLR4 and TLR2 pathways by GMMA.
Downloads per month over past year
Actions (login required)
 |
View Item |