Silencing TNF-α in macrophages and dentritic cells for arthritis treatment. Chunting Ye

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1 Silencing TNF-α in macrophages and dentritic cells for arthritis treatment Chunting Ye Biomedical Sciences Department Paul L. Foster School of Medicine Texas Tech University Health Sciences Center

2 Targeting macrophages and dendritic cells Macrphages and dendritic cells are important targets in arthritis. They are the major source for proinflammatory cytokines elevated in many autoimmune diseases sirnas can be used to suppress inflammation as well as cytokine production Delivery to macrophages and dendritic cells in vivo is a major limitation for therapeutic use of sirna

3 A short peptide from Rabies virus envelope glycoprotein binds to acetylcholine receptor (AchR) Our studies suggest that acetylcholine receptor (AchR) α7 subunit is expressed by macrophages and DC cells Kim ss, Ye C et al. Mol Ther May;18(5): We have previously shown that a short 29 aa peptide derived from Rabies virus glycoprotein (RVG) binds to α7 subunit of AchR Kumar P et al Nature Jul 5;448(7149):39-43 We synthesized a RVG peptide with 9R residues added to its carboxy terminus. RVG-9R: YTIWMPENPRPGTPCDIFTNSRGKRASNGGGGRRRRRRRRR

4 Schematic of targeted sirna delivery to macrophages and dendritic cells AchR RVG 9R Macrophages or DCs sirna P W M R I P P T Y E N G poly-arginine R R R R R R R R R _ sirna

5 RVG-9R peptide binds sirna + RVG-9R: YTIWMPENPRPGTPCDIFTNSRGKRASNGGGGRRRRRRRRR

6 RVG-9R delivers sirna to macrophage RAW cell line AchR expression RVG-9R+FITCsiRNA Counts Counts AchR FITC uptake Raw macrophage cell line was tested for AchR expression and RVG-9R/FITC sirna uptake

7 RVG-9R delivers sirna to MDMs and MDDC that express AchR, but not T cells Isotype control AchR expression FITC sirna uptake MDM MDDC T cells AchR FITC sirna uptake

8 RVG-9R/siCyPB silences cyclophilin B in MDMs and MDDC CypB mrna expression MDMs MDMs CypB mrna expression MDDCs Lipofect/ siluc Lipofect/ sicypb RVG-9R/ siluc RVG-9R/ sicypb no sirna Lipofect/ siluc Lipofect/ sicypb RVG-9R/ siluc RVG-9R/ sicypb no sirna Human MDDCs and MDMs were tested for gene silencing: CyPB sirna/rvg-9r complex were transfected into the human MDMs and MDDCs, 24 hours later, CyPB mrna levels in the cell pellet were measured by RT-PCR.

9 RVG-9R/TNF-α sirna silences TNF-α production in mice in vivo Relative human TNF-α mrna expression siluci /RVG-9R sitnf-α /RVMAT-9R * * sitnf-α /RVG-9R Human TNF-α protein (ng/mg) siluci /RVG-9R sitnf-α /RVMAT-9R sitnf-α /RVG-9R no LPS no sirna siluci/rvg-9r sitnf-α/rvg-9r sitnf-α/rvmat-9r no LPS, no sirna mice were injected with RVG-9R peptide or RVMAT-9R complexed with sitnf-α 18 hours and 6 hours before LPS (5mg/Kg) injection and 1 h after LPS injection, sera were tested for TNF-α protein levels by ELISA and TNF- α mrna was tested by RT-PCR. spleen was tested for TNF-α expression in cells.

10 RVG-9R/TNF-α sirna reduce the murine arthritis Collagen-Antibody Induced Arthritis (CAIA) Model DBA/1 mice were injected i.v. with 2 mg cocktail of collagen type II cocktail of monoclonal antibodies on day 1. On day 3, mice were injected i.p. with 50 μg of LPS. Arthritis developed on day 4 and reached its peak on day 7-9. RVG-9R/siTNF-a complex was injected on day 1, 3, 5, 7, total 4 injections (i.v.). Mice were euthanized on day 10.

11 RVG-9R/TNF-α sirna reduce the murine arthritis Collagen-Antibody Induced Arthritis (CAIA) Model normal Dexamethason sitnf-a/rvg-9r sitnf-a/rvmat-9r

12 a RVG-9R+siTNF-α b * Paw thickness Score RVMAT-9R+siTNF-α Dexamethason TNF-α protein(pg/ml) sitnf-α/ RVG-9R sitnf-α/ RVMAT-9R Dex Normal Days mouse paw thickness measuring and synovia TNF-α testing. a) shows total score of the mouse paw thickness. Irrelavant peptide RVMAT-9R delivery of TNF-α sirna group had highest score that means mice had moderate to severe swelling paws. The others only had mild swelling paws. b) shows synovia TNF-α protein level tested by ELISA with ex vivo culture.

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14 Conclusions RVG-9R provides a tool for sirna delivery to macrophages and dendritic cells in vitro and in vivo. RVG-9R-mediated sirna delivery could have potential clinical implications with regard to the development of new therapeutics for the treatment of arthritis and other forms of inflammatory disease.

15 Acknowledgements Dr. N Manjunath Dr. Premlata Shankar Harvard Medical School, Massachusetts General Hospital Dr. Atul K. Bhan Dr. Vikram Deshpande