Naslov
The encapsulation of peptodglycans and adamantyltripeptides into liposomes and the interaction of peptidoglycans in liposomal bilayers

Autori
Tomašić, Jelka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
COST D27 Workshop

Mjesto i datum
Budimpešta, Mađarska, 12.12.2003. - 14.12.2003

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
peptidoglycan monomer; adamatyltripeptides; liposomes; EPR spectra

Sažetak
The lecture covered three main topics: a) peptidoglycans as components of bacterial cell walls and the interaction with mammalian organism b) encapsulation of peptidoglycan monomer, its derivatives and adamantyltripeptides into liposomes, and c) ESR studies of liposomal preparations. Peptidoglycans are the ubiquitous components of bacterial cell walls conferring physical integrity to bacterial cell, but also exhibiting various biological activities in mammals. Such molecules affect strongly the immune response of the host. We have developed an experimental model in mice for testing the immunostimulating (adjuvant) activity of potential adjuvants and have shown that peptidoglycan monomer and structurally related compounds that we tested stimulate the humoral immune response. In our experimental model the immune response was evaluated by determination of specific antibodies. The aim of present work was to compose a liposomal preparation containing peptidoglycans that would further strongly enhance the immune response. Our choice were multilamellar, negatively charged liposomes. Increased immune response was demonstrated in mice immunized with various liposomal preparations . Best results were always obtained when the adjuvant and antigen were both encapsulated into liposomes. The possible interaction of encapsulated peptidoglycans and adamantyltripeptides was studied by EPR spectra. In order to obtain EPR spectra spin label was introduced either in the fatty acids or in peptidoglycan molecule. Several parameters and information were obtained from EPR spetra and corresponding measurements and calculations. There was no difference in order parameters calculated for empty liposomes, liposomes with encapsulated PGM or adamantylacetyl-PGM indicating that there is no interaction between those adjuvants and phospholipids in the liposomal layers. On the other hand, an increase in order parameters was obtained for admantyltripeptides shown on the slide but also for Boc-Tyr-PGM (results not shown) this time indicating an interaction of these compounds with lipsomal layers. The explanation could be in increased lipophilicity and probably convenient conformation of these compounds.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Biologija, Temeljne medicinske znanosti

POVEZANOST RADA