MicroRNA-150 regulates the cytotoxicity of natural killers by targeting perforin-1.
BACKGROUND
Perforin-1 (Prf1) is the predominant cytolytic protein secreted by natural killer (NK) cells. For a rapid immune response, resting NK cells contain high Prf1 mRNA concentrations while exhibiting minimal cytotoxicity caused by a blockage of Prf1 protein synthesis, implying that an unknown posttranscriptional regulatory mechanism exists.


OBJECTIVE
We sought to determine whether microRNA-150 (miR-150) posttranscriptionally regulates Prf1 translation in both mouse and human NK cells at rest and at various time points after activation.


METHODS
Mouse NK cells with a targeted deletion of miR-150 (miR-150(-/-) NK cells), primary human NK cells, and NK92 MI cells were used to investigate the role of miR-150 in NK cells. NK cell cytotoxicity assays and Western blotting proved that activated miR-150(-/-) NK cells expressed upregulated Prf1, augmenting NK cell cytotoxicity. When immunodeficient mice were injected with miR-150(-/-) NK cells, there was a significant reduction in tumor growth and metastasis of B16F10 melanoma.


RESULTS
We report that miR-150 binds to 3' untranslated regions of mouse and human Prf1, posttranscriptionally downregulating its expression. Mouse wild-type NK cells displayed downregulated miR-150 expression in response to IL-15, which led to corresponding repression and induction of Prf1 during rest and after IL-15 activation, respectively.


CONCLUSIONS
Our results indicate that miR-150 is a common posttranscriptional regulator for Prf1 in mouse and human NK cells that represses NK cell lytic activity. Thus the therapeutic control of miR-150 in NK cells could enhance NK cell-based immunotherapy against cancer, providing a better clinical outcome.
Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
Nayoung
N
Kim
School of Interdisciplinary Bioscience and Bioengineering (I-Bio), POSTECH, Pohang, Korea; Department of Mechanical Engineering, POSTECH, Pohang, Korea.
Miju
M
Kim
Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
Sohyun
S
Yun
School of Interdisciplinary Bioscience and Bioengineering (I-Bio), POSTECH, Pohang, Korea; Department of Mechanical Engineering, POSTECH, Pohang, Korea.
Junsang
J
Doh
Departments of Immunology and Medicine, University of Washington School of Medicine, and Fred Hutchinson Cancer Research Center, Seattle, Wash.
Philip D
PD
Greenberg
Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea; Department of Functional Genomics, University of Science and Technology (UST), KRIBB, Daejeon, Korea. Electronic address: tdkim@kribb.re.kr.
Tae-Don
TD
Kim
Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea; Department of Functional Genomics, University of Science and Technology (UST), KRIBB, Daejeon, Korea. Electronic address: ipchoi@kribb.re.kr.
Inpyo
I
Choi
D020413:3' Untranslated Regions; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics*; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology* / Q000637:transplantation; D008546:Melanoma, Experimental / Q000276:immunology / Q000473:pathology / Q000628:therapy; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000276:immunology; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics* / Q000276:immunology; D014176:Protein Biosynthesis; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy
D020413:3' Untranslated Regions; D019409:Interleukin-15; D035683:MicroRNAs; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; C533097:MIR150, human; C529101:Mirn150 microRNA, mouse; C510468:PRF1 protein, human; C510467:perforin 1, mouse
NK cell cytotoxicity; NK cells; immunotherapy; miR-150; perforin-1; post-transcriptional regulation; tumor growth and metastasis