Mice are closely monitored to follow the response to an antibody treatment at the level of the organism, but also within different organs, depending on the expected mode of action of the mAb. Efficacy readouts performed at MI-mAbs include:
Survival: first readout that depends on the end-points defined for each study. Monitored for subcutaneously (SC) and intravenously (IV) grafted tumours.
Tumour load evaluation:
Direct tumour size measurement (SC grafted cells) with a digital caliper.
Tumour load assessment by in vivo bioluminescence using the IVIS Spectrum BL Imaging system and tumour cells engineered to express luciferase. Particularly of interest for IV grafted liquid tumours.
Tumour expansion (metastasis, secondary tumours) is monitored by bioluminescence using the IVIS Spectrum BL Imaging system
Tumour load. Mice were IV-engrafted with luciferase-expressing liquid tumour cells. Examples of dorsal (A) and ventral (B) imaging by in vivo bioluminescence are shown for 10 mice at day 14 post-injection. Bioluminescent signals were quantified across time (C, dorsal view).
Inflammatory response is measured by sampling blood to determine the levels of cytokines/chemokines released in the blood stream.
Immunohistochemistry (IHC). IHC analysis provides a picture of the tissue organization and can confirm the presence of given cell populations in response to a mAb treatment. This assay is performed as described in Target Expression Profiling.
Immune cell profiling.
Immune cell content in tumour, non-tumour tissue and blood - by FACS
Cytokine production/release - by FACS
Expression of immune cell markers on tissue sections – by IHC
Immunophenotyping (Cytometer park at CIPHE): presence, proportions and evolution of immune cell populations; extensive multiparametric FACS analysis panels (standard or customized). See illustration below.