NK-92 Cells Expressing Stable CD16 for ADCC
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Solution Overview
Problem
NK-92® cells, used in cancer treatment, lack CD16 receptors, preventing them from engaging in antibody-dependent cell-mediated cytotoxicity (ADCC), and their IL-2 expression can lead to immunosuppression and adverse effects.
Innovation Solution
Modified NK-92® cells (IL2 Dependent haNK® cells) are engineered to express a high affinity variant of CD16 and exclude IL-2 expression, maintaining stable CD16 expression during activation and ADCC, thereby enhancing their cytotoxicity and reducing immunosuppressive effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If NK-92® cells are used for cancer treatment, then they exhibit cytolytic activity against tumor cells, but they lack CD16 receptors and cannot perform antibody-dependent cell-mediated cytotoxicity (ADCC)
Solution Approach 1:
The patent extracts and introduces the CD16 gene into NK-92® cells through transfection, enabling them to express CD16 receptors. This allows the cells to acquire ADCC capability while maintaining their existing cytolytic functions, directly resolving the contradiction between having cytotoxic activity and lacking antibody-dependent cytotoxicity capability.
Solution Approach 2:
The patent changes the expression parameter of CD16 on NK-92® cells from negative (0% expression) to positive (detectable surface expression). By transfecting the CD16 gene and optimizing expression levels, the cells gain the ability to bind antibody Fc regions and mediate ADCC, transforming them from purely cytolytic cells to cells with dual killing mechanisms.
2Reliability
If NK cells express CD16, then they can mediate ADCC, but CD16 is susceptible to ADAM17-mediated proteolytic cleavage and shedding upon activation
Solution Approach 1:
The patent uses the natural activation mechanism that normally causes CD16 shedding as a beneficial signal. By engineering NK-92® cells to constitutively express high levels of CD16, the cells maintain sufficient surface CD16 even after activation-induced shedding, ensuring sustained ADCC capability throughout the therapeutic process.
Solution Approach 2:
The patent pre-loads NK-92® cells with high levels of CD16 expression before activation occurs. This preliminary establishment of robust CD16 expression ensures that even when shedding occurs upon target cell engagement, sufficient CD16 remains on the cell surface to maintain effective ADCC activity throughout the cell's functional lifespan.
3Productivity
If NK-92® cells express IL-2, then they can proliferate and expand, but IL-2 expression causes immunosuppression and adverse effects in patients
Solution Approach 1:
The patent removes the IL-2 dependency from NK-92® cells by culturing and expanding them in the absence of IL-2 supplementation. This extraction of IL-2 requirement eliminates the source of immunosuppression and adverse effects while maintaining the cells' proliferative capacity through alternative growth mechanisms inherent to the NK-92® cell line.
Solution Approach 2:
The patent enables NK-92® cells to self-proliferate without external IL-2 support by utilizing their intrinsic growth capabilities. The cells maintain productivity and expansion capacity through endogenous mechanisms, eliminating the need for exogenous IL-2 and thereby avoiding the harmful effects associated with IL-2 therapy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The modified cells exhibit sustained ADCC activity and reduced immunosuppression, allowing for effective targeting and killing of cancer cells with minimal side effects.
Implementation Method 1
CD16 is an Fc receptor which recognizes and binds to the Fc portion of an antibody to activate NK cells for the ADCC effector mechanism
Implementation Method 2
One of the major mechanisms of action of therapeutic antibodies is through antibody-dependent cell-mediated cytotoxicity (ADCC). Natural killer cells could be used as cytotoxic effector cells for cell-based immunotherapy
Data Source
AI summary
Provided herein are populations of IL2 Dependent haNK® cells, which express a high affinity CD16 but does not express IL-2. These cells maintain stable expression of Fc receptor CD16 while retaining cytotoxicity. In some embodiments, the expression level of CD16 decreases no more than 20% when the cells are activated as compared to expression level of CD16 on the cells before activation. Compositions and kits comprising the cells, and methods of making and using the IL2 Dependent haNK® cells are also provided.