Naslov
Endocitoza HLA-G molekula na nepolariziranoj staničnoj liniji (J-26)
(ENDOCYTOSIS OF HLA-G1 MOLECULES IN NON-POLARISED CELL LINE (J-26))

Autori
Blagojević, G. ; Mahmutefendić, H. ; Kučić, N. ; Lučin, P.

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

Skup
Second EMBIC Summer School

Mjesto i datum
Pečuh, Mađarska, 01.07.2006. - 04.07.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
endocitoza; HLA-G
(endocytosis; HLA-G)

Sažetak
The aim of our study was to investigate the endocytosis of HLA-G1 molecules, and to compare it with other HLA alleles (HLA-B7, HLA-Cw6 and HLA-E) as well as murine MHC class I alleles. We used murine fibroblastic J-26 cell line transfected with distinct HLA molecules (HLA-B7, HLA-Cw6 and HLA-E, HLA-G1). Constitutive internalization of MHC class I alleles was acheived after cyclohehimide treatment. Misfolding of MHC class I molecules was generated by short acidification (45 seconds in medium with pH 2.0) The kintetics of internalization and intracellular trafficking was followed by flow cytometry and confocal microscopy. The kinetics of degradation was determined by cell surface biotynilation and immunoprecipitation. To distinguish the intracellular localization of HLA molecules we used markers of intracellular compartments. We have found that conformed HLA-G1 molecules constitutively internalize from the cell surface with the half time of four hours, that is similar to other HLA alleles, whereas misfolded HLA-G1 molecules were internalized significantly faster. After internalization fully conformed HLA-G1 molecules partially colocalize with trensferrin receptor, but no colocalization with caveolin was observed. Chlorpromasine, an inhibitor of clathrin endocytosis, had no influence on internalization of HLA molecules whereas filipin, an inhibitor of cholesetrol dependent endocytosis, inhibited internalization of misfolded MHC class I molecules. Triton-X-100 treatment removed all conformed HLA molecules from the cell surface indicating for their localization in non-organized membrane domains, whereas misfolded MHC class I molecules were resistant to triton-X-100 extraction, indicating for their localization in the lipid rafts. Misfolded MHC class I molecules are targeted for degradation as determined by immunoprecipitaion.. Our results indicate that conformed HLA molecules are internalized via non-clathrin, non-caveolar pathway, whereas internalization of non-conformed is lipid raft dependent.

Izvorni jezik
Engleski

POVEZANOST RADA