Enhanced lysis by bispecific oncolytic measles viruses simultaneously using HER2/neu or EpCAM as target receptors.
To target oncolytic measles viruses (MV) to tumors, we exploit the binding specificity of designed ankyrin repeat proteins (DARPins). These DARPin-MVs have high tumor selectivity while maintaining excellent oncolytic potency. Stability, small size, and efficacy of DARPins allowed the generation of MVs simultaneously targeted to tumor marker HER2/neu and cancer stem cell (CSC) marker EpCAM. For optimization, the linker connecting both DARPins was varied in flexibility and length. Flexibility had no impact on fusion helper activity whereas length had. MVs with bispecific MV-H are genetically stable and revealed the desired double-target specificity. In vitro, the cytolytic activity of bispecific MVs was superior or comparable to mono-targeted viruses depending on the target cells. In vivo, therapeutic efficacy of the bispecific viruses was validated in an orthotopic ovarian carcinoma model revealing an effective reduction of tumor mass. Finally, the power of bispecific targeting was demonstrated on cocultures of different tumor cells thereby mimicking tumor heterogeneity in vitro, more closely reflecting real tumors. Here, bispecific excelled monospecific viruses in efficacy. DARPin-based targeting domains thus allow the generation of efficacious oncolytic viruses with double specificity, with the potential to handle intratumoral variation of antigen expression and to simultaneously target CSCs and the bulk tumor mass.
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Jan Rh
JR
Hanauer
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Lisa
L
Gottschlich
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Dennis
D
Riehl
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Tillmann
T
Rusch
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Vivian
V
Koch
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Katrin
K
Friedrich
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Stefan
S
Hutzler
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Steffen
S
Prüfer
Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut , Langen, Germany.
Thorsten
T
Friedel
Department of Biostatistics, Paul-Ehrlich-Institut , Langen, Germany.
Kay-Martin
KM
Hanschmann
Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut , Langen, Germany.
Robert C
RC
Münch
Institute of Biochemistry, University of Zurich , Zurich, Switzerland.
Christian
C
Jost
Institute of Biochemistry, University of Zurich , Zurich, Switzerland.
Andreas
A
Plückthun
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Klaus
K
Cichutek
Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut, Langen, Germany; German Cancer Consortium, Heidelberg, Germany.
Christian J
CJ
Buchholz
Oncolytic Measles Viruses and Vaccine Vectors, Paul-Ehrlich-Institut , Langen, Germany.
Michael D
MD
Mühlebach