3058 - Nembaleukin a-Enhanced Dual Tumor Attack by Fas-4-1BB Engineered CD8⁺-T-Cell with CAND1 Pubic Neoantigen and Natural Killer Cell, Using Encapsulated Nanoparticles Directed by Radiation

Purpose/Objective(s):

The efficacy of radioimmunotherapy was tested by nembaleukina-enhanced dual tumor attack; 1) Fas-4-1BB engineered T CD-8⁺-T-cells that were primed with CAND1 pubic neoantigen and 2) nembaleukin a activated NK-cell, which was targeted by two radiation sessions, using computed tomography (CT) detectable nanocapsules (?545 ± 32 nm) that released their contents upon radiation exposure in 4TI^FasL+ tumor in BALB/c mice.

Materials/Methods:

Fas-4-1BB was transduced to PI4 CD8⁺ T-cells, using retroviral vector (RV), and 1 X 10⁷ stimulated engineered T-cells were intravenously administered to mice and used for experiments 27 days after treatment. For session 1, Polypoly lactic-co-glycolic acid (PLGA) AP-NPs were coated with 1.0 mg nembaleukin-a through a nanoprecipitation method. Nanocapsules (hyaluronate-alginate nanocapsules;HA-NCs) were generated by combining 1 X 10¹⁰ AP-NPs and15 µg IFN? with a 1.0 mL of 4.0% alginate, 3.0% hyaluronate, and 1 µg/mL P-selectin. This mixture was sprayed onto 0.5 mmol/L L FeCl₂ supplemented with 1 µg/mL anti-VEGFR-1/2 antibody (Ab). For session 2, 110 fmol of CAND1 and 1.0 mg nembaleukin-a were encapsulated into P-selectin Ab labelled HA-NCs through the same electrospray and Fe-polymerization as session 1. In session 1, 1 × 10¹⁰ HA-NCs were intravenously administered into mice. Tumor accumulation was monitored by CT. Subsequently, 10 or 20 Gy ⁶⁰Co ?-radiation was administered to primary tumors and lung metastasis. In session 2, 1 × 10¹⁰ HA-NCs were intravenously administered, subsequently, second radiation was likewise conducted.

Results:

In session 1, anti- VEGFR-1/2-Ab-HA-NCs were accumulated in the primary tumor and metastasis, which could be monitored by CT. In session 1, HA-NCs released P-selectin, IFN ?, and nembaleukin-a coated AP-NPs in response to session 1. P-selectin was deposited on tumor vessels. Radiation and released IFN ? heterogeneously induced MHC-I on tumor cells, Released nembaleukin-a AP-NPs discharged nembaleukin-a which gathered and activated Fas-4-1BB–IFP engineered T CD-8⁺-T-Cells and NK-cells. On second radiation session, the P-selectin Ab labelled HA-NCs were accumulated via Ag-Ab reaction of P-selectin and they released CAND-1 and nembaleukin-a. CAND-1 formed the MHC-I-CAND1-CD8⁺T-cell receptor (TCR)/Fas-4-1BB complex. Fas-4-1BB converted inhibitory/death signals into activating/survival signals in CD8⁺-T-cells, enhancing CD8⁺/ T-cell function and persistence, in collaboration with nembaleukin-a. Nembaleukin-a activated NK-cell, which attacked MHC-1 free tumor. These dual attack to primary tumor and metastasis resulted in EF 1.9 and 84% reduction of metastasis.

Conclusion:

Our targeted dual tumor attack by CD8⁺-T-cell and NK cell result to effective radioimmunotherapy.