Targeting proteins to secretory lysosomes of natural killer cells as a principle for immunoregulation.

Markus Hansson, Sofia Jönsson, Ann-Maj Persson, Jero Calafat, Hans Tapper, Inge Olsson

Research output: Contribution to journalArticlepeer-review

9 Citations (SciVal)

Abstract

Secretory lysosomes of natural killer (NK) cells combine storage, regulated secretion and lysosomal activity. We asked whether one could target exogenous proteins to the secretory lysosomes of NK-cells for final delivery into a tumor site upon degranulation. cDNAs for both soluble and transmembrane (tm) proteins were expressed in the human YT-Indy NK-cell line. Targeting of a soluble TNF receptor (sTNFR1) was achieved by expressing a cDNA construct with a transmembrane sequence to facilitate ER-export and by incorporating a cytosolic sorting signal (Y) from CD63 to overcome constitutive secretion. The resulting sTNFR1-tm-Y was targeted to secretory lysosomes as confirmed by results from biosynthetic radiolabeling in combination with subcellular fractionation, immunoelectron microscopy, and immunofluorescence microscopy. A soluble sTNFR1 form was generated in the secretory lysosome by endogenous proteolytic activity. Expression of exogenous normally secretory non-membrane proteins, such as alpha1-microglobulin (alpha1-m) and alpha1-antitrypsin (alpha1-at) resulted mostly in constitutive secretion although a small amount of alpha1-microglobulin was targeted to secretory lysosomes. Our results suggest a potential for delivery of pharmacologically active agents into tumor sites by use of the NK-cell secretory lysosome as a carrier. (C) 2003 Elsevier Ltd. All rights reserved.
Original languageEnglish
Pages (from-to)363-372
JournalMolecular Immunology
Volume40
Issue number6
DOIs
Publication statusPublished - 2003

Subject classification (UKÄ)

  • Immunology in the medical area

Fingerprint

Dive into the research topics of 'Targeting proteins to secretory lysosomes of natural killer cells as a principle for immunoregulation.'. Together they form a unique fingerprint.

Cite this