Stock DZ
05.06.2018 kl 11:05

Takk for svar Otard

in the patent publication they talk about about 3 distinct doses. photosensitiser TPCS2a dose, vaccine dose and illumination dose (time). based on the text below, I believe by low dose they mean TPCS2a dose, but in mice it seems that the response was getting higher with higher TPCS2a dosage ( 10, 25, 50, 100 and 250 μg), this sounds to be the opposite of what is reported in phase-1, it also says however that higher TPCS2a doses also caused more local inflammation (see below)

"Analysis of the Effect of the dose of Photosensitizer on the PCI-Mediated Generation of an Immune Response.

We then reduced the OVA immunisation dose in order to titrate out the effect of OVA and increasing doses of TPCS2a was titrated into the vaccine. Immunisation with 10 μg OVA alone produced no measurable effect on SIINFEKL-specific CD8 T cells in blood as compared to untreated animals (data not shown). Several experiments with TPCS2a at 10, 25, 50, 100 and 250 μg showed that increasing TPCS2a doses also increased the measured OVA-specific immune response (data not shown). Representatively, PCI with 25 μg TPCS2a caused 40% good responders, 40% week responders and 20% non-responders as measured for SIINFEKL-specific CD8 T cells in blood on day 8, while PCI with 250 μg TPCS2a produced 100% good responders (FIG. 8A). On day 11 the splenocytes were tested by flow cytometry for IFN-y production. Immunisation with OVA alone showed weak responders in all mice tested, whereas immunisation with OVA and PCI caused better responders in nine out of ten (90%) mice tested (FIG. 8B). Again, PCI with 250 μg TPCS2a showed 100% responders and the highest frequency of IFN-γ producing cells. Whereas intracellular staining and flow cytometry qualitatively measures whether cells can produce cytokines, ELISA measures how much cytokine the cell can produce. We therefore re-stimulated the day 11 splenocytes with SIINFEKL in vitro and analysed IL-2 (FIG. 8C) and IFN-γ (FIG. 8D) after 24 and 72 hours, respectively. Immunisation with OVA alone produced weak but clearly measurable IL-2, but not IFN-γ secretion. Immunisation with OVA and PCI at 25 μg TPCS2a did not cause an increase in IL-2, but a strong increase in IFN-γ secretion as compared to immunisation with OVA alone. At 250 μg TPCS2a, strong secretion of both IL-2 and IFN-γ was detected. Finally, while PCI with TPCS2a had a dose-dependent adjuvant effect with regards to the immune response measured, higher TPCS2a doses also caused more local inflammation with transient erythema on days 1-3 after illumination (data not shown)"