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2‐D DIGE analyses of enriched secretory lysosomes reveal heterogeneous profiles of functionally relevant proteins in leukemic and activated human NK cells
Author(s) -
Schmidt Hendrik,
Gelhaus Christoph,
Nebendahl Melanie,
Lettau Marcus,
Watzl Carsten,
Kabelitz Dieter,
Leippe Matthias,
Janssen Ottmar
Publication year - 2008
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200800170
Subject(s) - microbiology and biotechnology , immunological synapse , biology , cytotoxic t cell , lymphokine activated killer cell , cell culture , immune system , t cell , interleukin 12 , immunology , biochemistry , t cell receptor , in vitro , genetics
As part of the innate immune system, natural killer (NK) cells detect and lyse tumor and virus‐infected cells without prior antigen‐dependent recognition and expansion. To this end, they utilize dual‐function organelles that combine properties of conventional lysosomes and exocytotic vesicles. Upon stimulation, these secretory lysosomes (SLs) release their cytotoxic molecules into the immunological synapse. In addition, several molecules associated with secretory vesicles become exposed on the plasma membrane. Recent studies often took advantage of the few established NK cell lines, for instance to analyze the exocytotic machinery associated with NK cell vesicles. NK cell lines and primary NK cells differ, however, substantially in the expression of “typical” surface receptors and their requirements to induce target cell lysis. Here, we directly compared the lysosomal compartments of different NK cell populations. We enriched SLs of two leukemic cell lines (YTS and NKL) and IL‐2‐expanded NK cells by subcellular fractionation and characterized their proteome by 2‐D difference gel electrophoresis and MS. Although the overall protein composition of the lysosomal preparations was very similar and more than 90% of the proteins were present at comparable levels, we define a cell line‐specific setup of functionally relevant proteins involved in antigen presentation and cytotoxic effector function.