Naslov
MCMV interference with disposal endocytic pathway of cell-surface MHC-I molecules at early stages of infection

Autori
Kučić, Natalia ; Ilić Tomaš, Maja ; Mahmutefendić, Hana ; Blagojević, Gordana ; Lučin, Pero

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts of the 10th Congress of the Croatian Society of Biochemistry and Molecular Biology /The secret life of biomolecules / Zrinka Kovarik, Jadranka Varljen (ur.). - Rijeka : Hrvatsko Društvo za Biotehnologiju, 2010, 73-73

Skup
10th Congress of the Croatian Society of Biochemistry and Molecular Biology with international participation

Mjesto i datum
Opatija, Hrvatska, 15.09.2010. - 18.09.2010

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
Murine cytomegalovirus; cell-surface MHC-I molecules; endocytic pathway

Sažetak
Murine cytomegalovirus (MCMV) down-regulates MHC class I molecules (MHC-I) from the cell surface at early stages of infection. Viral interference with both secretory and endocytic endosomal pathways of MHC-I contributes to viral strategy to evade immune recognition. The aim of our study was to investigate the endocytosis of the cell-surface MHC-I in MCMV-infected embryonic fibroblasts and to identify the compartment wherein virus transposes these molecules from the cell surface. Within that the possible role of MCMV m06/gp48 early protein residing in the compartment where internalized MHC-I are accumulated was analyzed. In order to investigate the internalization pathways of down-regulated MHC-I and their accumulation within m06+ retention compartment we used both the internalization assay including cell-surface Abs-labeling after cell-infection with FcR-MCMV and a palette of endosomal protein markers. Trafficking of Abs-labeled cell surface MHC-I was compared with well known internalization pathways of cell-surface control molecules. The early endosomal compartment was identified by the EEA1 or by the uptake of TfR while Golgi compartment by GM130 and entry of cholera toxin B subunit (CTxB). To determine the MHC-I degradation pathway the EGF and M6PR were used as a control and Lamp-1 for identification of late endosomes/lysosomes. The colocalization experiments were performed by immunofluorescent confocal microscopy. The fate of internalized MHC-I is determined by immunoprecipitation after cell-surface biotinylation following with chase period of 24 hrs. The cell-surface MHC-I are almost completely down-regulated 16 hrs post infection in MCMV-infected cells. Internalized MHC-I are backsorted in endocytic compartments or transported through early endosomes toward Golgi area and accumulated in the compartment where colocalization with viral protein MCMVm06/gp48 was observed. The retention compartment (m06+MHCI+) is accessible and transient for the control molecules (TfR, CTxB, LAMP). In addition, MHC-I and EGF traffic toward late compartments and lysosomes for degradation was maintained but postponed. In the cells infected with MCMV-deletion mutant (delta m06-MCMV) the degradation of cell-surface MHC-I was inhibited, indicating the m06 interference in MHC-I endocytic/degradative pathway.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA