Establishment of lal-/- myeloid lineage cell line that resembles myeloid-derived suppressive cells

• Published in: PloS one 2015-03, Vol.10 (3), p.e0121001-e0121001
• Main Authors: Ding, Xinchun, Wu, Lingyan, Yan, Cong, Du, Hong
• Format: Article
• Language: English
• Subjects: Animals; Antigen T (large); Blockage; Breeding; Cancer; CD4 antigen; Cell growth; Cell Proliferation; Comparative analysis; Energy metabolism; Enzymes; Fatty acids; Fatty Acids - metabolism; Genetic engineering; Glycolysis; Immunosuppression; Immunosurveillance; Immunotherapy; Inflammation; Laboratories; Lipase; Lymphocytes; Lymphocytes T; Lysosomes; Lysosomes - metabolism; Medicine; Membrane potential; Membrane Potential, Mitochondrial - physiology; Metabolism; Metastases; Metastasis; Mice; Mice, Knockout; Mitochondria; Mitochondrial DNA; Myeloid Cells - cytology; Myeloid Cells - metabolism; Myeloid Progenitor Cells - cytology; Myeloid Progenitor Cells - metabolism; Nuclear fuels; Oxidation; Pathology; Physiological aspects; Rapamycin; Reactive Oxygen Species - metabolism; Rodents; Signal Transduction - physiology; siRNA; Suppressor cells; T cells; TOR protein; Transgenic mice; Tumor antigens; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0121001

Myeloid-derived suppressor cells (MDSCs) in mouse are inflammatory cells that play critical roles in promoting cancer growth and metastasis by directly stimulating cancer cell proliferation and suppressing immune surveillance. In order to facilitate characterization of biochemical and cellular mechanisms of MDSCs, it is urgent to establish an "MDSC-like" cell line. By cross breeding of immortomouse (simian virus 40 large T antigen transgenic mice) with wild type and lysosomal acid lipase (LAL) knock-out (lal-/-) mice, we have established a wild type (HD1A) and a lal-/- (HD1B) myeloid cell lines. Compared with HD1A cells, HD1B cells demonstrated many characteristics similar to lal-/- MDSCs. HD1B cells exhibited increased lysosomes around perinuclear areas, dysfunction of mitochondria skewing toward fission structure, damaged membrane potential, and increased ROS production. HD1B cells showed increased glycolytic metabolism during blockage of fatty acid metabolism to fuel the energy need. Similar to lal-/- MDSCs, the mTOR signal pathway in HD1B cells is overly activated. Rapamycin treatment of HD1B cells reduced ROS production and restored the mitochondrial membrane potential. HD1B cells showed much stronger immunosuppression on CD4+ T cell proliferation and function in vitro, and enhanced cancer cells proliferation. Knockdown of mTOR with siRNA reduced the HD1B cell ability to immunosuppress T cells and stimulate cancer cell proliferation. Therefore, the HD1B myeloid cell line is an "MDSC-like" cell line that can be used as an alternative in vitro system to study how LAL controls various myeloid cell functions.