NK‐Cell Biofactory as an Off‐the‐Shelf Cell‐based Vector for Targeted In Situ Synthesis of Engineered Proteins

Abstract

The NK‐92MI, a fast‐growing cytolytic cell line with a track record of exerting clinical efficacy, is transformed into a vector for synthesizing calibrated amounts of desired engineered proteins at our disease site, that is, NK‐cell Biofactory. This provides an allogeneic option to the previously published T‐cell‐based living vector that is limited by high manufacturing cost and product variability. The modularity of this pathway, which combines a “target” receptor with an “effector” function, enables reprogramming of the NK‐cell Biofactory to target diseases with specific molecular biomarkers, such as cancer, viral infections, or auto‐immune disorders, and overcome barriers that may affect the advancement of NK‐cell therapies.

Antiviral T-cell Biofactory platform for SARS-CoV-2

“…Figures 2A and 2B demonstrate the expression of type-I IFNs (IFN-β1) and type-III IFNs (IFN-λ2) by the T-cell Biofactory respectively and compares the results with the IFNs produced from the two T-cell Biofactories irradiated at 20 Gy. Consistent with our previous work on the anti-tumor T-cell Biofactory 16 and the anti-tumor NK-cell Biofactory 17 , the Effector protein (IFNs) expression was proportionate to the Target-Cell count and was observed in all Effector-Cell to Target-Cell (E:T) ratios. The IFN expression by the T-cell Biofactory was significantly elevated (p<0.00005 at all E:T) when stimulated by the target SARS-CoV-2-Sgp-cells, compared to when it was stimulated by the non-engineered negative control cells.…”

“…A T-cell Biofactory without Actuator/Secretor/Effector domains was used as a negative control. As expected, the therapeutic protection offered by the IFN-producing T-cell Biofactories was proportional to their number (indicating the amount of IFN produced 16,17 ) (see Figure 3C for IFN-β1 and Figure 3D for IFN-λ2). The therapeutic effect demonstrated by the type-I IFN-β1-producing T-cell Biofactory was higher (p<0.005 at all Effector-Cell counts) when compared to the control T-cell Biofactory ( Figure 3C ).…”

“…The results from IFN-α2 (type-I IFN) and IFN-λ1 (type-III IFN) are shown in supporting information ( Figure S2 ). Our assessment determined that 20-Gy dose of the gamma radiation, which renders the T-cell Biofactory non-proliferative without degrading our artificial cell-signaling pathway, is non-oncogenic 17,22 ( Figure S3 ).…”

“…We determined the prophylactic and therapeutic effects of the IFNs produced by the antiviral T-cell Biofactory platform on SARS-CoV-2 infected cells and investigated the expression profiles of ISGs in the host cells in response to these IFNs. We also determined the radiation dose (γ-radiation) needed to render the T-cell Biofactory non-proliferative making the cellular products suitable for clinical use 17,[20][21][22] , while conserving the cell-based IFN production. This process ensures safe administration of the T-cell Biofactory without potential oncogenesis.…”

“…Previously we reported on engineering immune cells with chimeric antigen receptors (CAR) that, upon engaging antigen-presenting target cells, produce non-endogenous proteins for exerting the desired effect locally, i.e., T-cell Biofactory 16 and NK-cell Biofactory 17 . Recently, we also directed this platform for antigen 18 and serology testing 19 for SARS-CoV-2.…”