Novel Chemokine-Based Immunotoxins for Potent and Selective Targeting of Cytomegalovirus Infected Cells

Figure 2

Design, binding, cell killing, and antiviral activity of FTPs with a modified CX₃CL1 domain. (a) Schematic representation of CX₃CL1-based FPTs created by fusion of CX₃CL1 variants to domains of PE. (b) Binding of the prototype CX₃CL1-FTP (grey symbols) and CX₃CL1-based FTPs on HEK-293 cells induced to express US28 (black circles) and CX₃CR1 (white squares). (c) Binding selectivity of CX₃CL1-FTP and CX₃CL1-based FTPs determined as fold improved affinity for US28 relative to CX₃CR1. (d) Cell killing of CX₃CL1-FTP (grey symbols) and CX₃CL1-based FTPs on tetracycline induced HEK-293 cells expressing US28 (black circles) and CX₃CR1 (white squares). (e) Selectivity of CX₃CL1-FTP and CX₃CL1-based FTPs determined as fold improved potency in killing US28- relative to CX₃CR1-expressing cells. Values present IC₅₀ values from 3–5 independent biological replicates (b) and (d).

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