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

Figure 4

Design, cell killing, and antiviral activity of FTPs without domain II and optional with as GS-linker and Ib domain. (a) F49A-FTP as template for F49A-FTP-5 without domain II between the chemokine domain of CX₃CL1 and domain III of PE or for F49A-FTP-6 with an additional amino-acid linker (GGS) and part of the Ib domain. (b-c) Inhibition of virus replication measured by luciferase activity of MRC-5 cells infected with (MOI 0,1) and treated once with F49A-FTP (pos. control; dotted line), F49A-FTP-5, and F49A-FTP-6 (black circles). (d-e) Selectivity of F49A-FTP and F49A-FTP-6 determined as fold improved potency in killing US28- relative to CX₃CR1-expressing cells. Error bars indicate SEM for 3–5 independent biological replicates.

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