title: Ovarian cancer immunotherapy using PD-L1 siRNA targeted delivery from folic acid-functionalized polyethylenimine: strategies to enhance T cell killing.
abstract: Adoptive T cell immunotherapy is a promising treatment strategy for epithelial ovarian cancer (EOC). However, programmed death ligand-1 (PD-L1), highly expressed on EOC cells, interacts with programmed death-1 (PD-1), expressed on T cells, causing immunosuppression. This study aims to block PD-1/PD-L1 interactions by delivering PD-L1 siRNA, using various folic acid (FA)-functionalized polyethylenimine (PEI) polymers, to SKOV-3-Luc EOC cells, and investigate the sensitization of the EOC cells to T cell killing. To enhance siRNA uptake into EOC cells, which over express folate receptors, PEI is modified with FA or PEG-FA so that siRNA is complexed into nanoparticles with folate molecules on the surface. PEI modification with a single functional group lowers the polymer cytotoxicity compared to unmodified PEI. FA-conjugated polymers increase siRNA uptake into SKOV-3-luc cells and decrease unspecific uptake into monocytes. All polymers result in 40% to 50% PD-L1 protein knockdown. Importantly, SKOV-3-Luc cells treated with either PEI-FA or PEI- polyethylene glycol (PEG)-FA/PD-L1 siRNA complexes are up to twofold more sensitive to T cell killing compared to scrambled siRNA treated controls. These findings are the first to demonstrate that PD-L1 knockdown in EOC cells, via siRNA/FA-targeted delivery, are able to sensitize cancer cells to T cell killing.
authors: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore, 138669, Singapore.|Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
authors: Pei Yun
authors: PY
authors: Teo
authors: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore, 138669, Singapore.
authors: Chuan
authors: C
authors: Yang
authors: Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.|King's College London, Guy's Hospital, St Thomas Street, London, SE1 9RT, UK.
authors: Lynsey M
authors: LM
authors: Whilding
authors: King's College London, Guy's Hospital, St Thomas Street, London, SE1 9RT, UK.
authors: Ana C
authors: AC
authors: Parente-Pereira
authors: King's College London, Guy's Hospital, St Thomas Street, London, SE1 9RT, UK.
authors: John
authors: J
authors: Maher
authors: Brunel University, Kingston Lane, Uxbridge, Middlesex, UB8 3PH, UK.
authors: Andrew J T
authors: AJ
authors: George
authors: IBM Almaden Research Center, 650 Harry Road, San Jose, CA, 95120, USA.
authors: James L
authors: JL
authors: Hedrick
authors: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore, 138669, Singapore.
authors: Yi Yan
authors: YY
authors: Yang
authors: Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK.
authors: Sadaf
authors: S
authors: Ghaem-Maghami
mesh_terms: D060890:B7-H1 Antigen / Q000235:genetics* / Q000378:metabolism; D000077216:Carcinoma, Ovarian Epithelial; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005260:Female; D005492:Folic Acid / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D052118:Lysosomal-Associated Membrane Protein 1 / Q000235:genetics / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics* / Q000628:therapy; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000628:therapy; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D034741:RNA, Small Interfering / Q000235:genetics*; D013601:T-Lymphocytes / Q000378:metabolism
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human; D052118:Lysosomal-Associated Membrane Protein 1; D011108:Polymers; D034741:RNA, Small Interfering; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D005492:Folic Acid
keywords: PD-L1 knock-down; T cells; ovarian cancer; polyethylenimine; siRNA delivery