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VOL. 76 (3), 327-342, 2010 ANTITUMORAL ACTIVITY OF ONCOLYTIC VACCINIA VIRUS...

Figure 2. VV-PKR shows reduced pathogenicity in comparison to VVLUC and
VV-K296R in C57/BL6 mice. A. Mice C57/BL6, four per group, were inoculated with
5x107 pfu per mouse of VVLUC or VV-PKR by intranasal route. Mice were weighed
daily. Virus was titrated in lungs at third day post-infection. B. Mice C57/BL6, four
per group, were inoculated with 5x107 pfu per mouse with VVLUC, VV-K296R, VV-
PKR or PBS by intraperitoneal route at days 0 and 3. Mice were weighed daily. Virus
was titrated in spleen at third and fifth days post-infection. Mean values titers are
shown.

3.3. Systemic inoculation of VV-PKR in mice with transplantable
prostate cancer cells reduces tumour burden

Next we wanted to define if VV-PKR could be used as an oncolyt-
ic vector. Thus, C57/BL6 mice were inoculated by subcutaneous route
with TRAMP-C1 prostate tumour cells and when the tumour median
volume reached 75 to 100 mm3, 10 mice per group were injected by
i.p. route with 5x107 pfu of different VACV vectors: VV-LUC, VV-PKR
and its mutant VV-PKR(K296R), or control PBS. Virus was inoculat-
ed twice with the same dose, three days apart. Tumour size was
recorded every 3-4 days using a digital caliper. As shown in Figure 4,
the tumour size was reduced in mice inoculated with the three viral

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