Last call to take a place in our next in vivo shuttle session
02 / 11 / 2020
As a reminder, registration deadline is February 21, 2020.
Figure 1: Individual tumor growth profile of subcutaneously inoculated CT26 colon, EMT6 breast and MCA205 sarcoma tumor-bearing mouse models. Mice were subcutaneously implanted with respective tumor cells and tumor growth was monitored overtime via calipering.
Case study on subcutaneously-inoculated MCA205 sarcoma mouse tumor model
Figure 2: Subcutaneously-implanted MCA205 sarcoma tumor-bearing mouse model is responsive to PDL1 blockade. Mice were subcutaneously implanted with tumor cells and exposed to anti-PDL1 antibody. Tumor growth was monitored overtime via calipering. Tumor volume (A) and survival (B) were then determined.
Figure 3: A. Immunometabolic profiling of the MCA205 sarcoma model by intratumoral microdialysis. Mice were implanted with tumour cells and then processed for intratumoral microdialysis at the tumor volume average of ~200mm3, for the determination of glutamine, arginine, and adenosine levels by LC/MS. The tumour model displays differential levels for arginine and particularly for adenosine between tumor and non-tumor compartments – both pathways are known to be involved in the immune escape. While being essential for a proper immune system functioning, glutamine and levels were shown to be lower, while adenosine was shown to be higher, within the tumor microenvironment, thereby conferring a peculiar immunometabolic profile to this model. B. PDL1 blockade triggers a decrease of tumoral adenosine production. Mice were challenged with MCA205 tumors, treated or not with anti-PDL1, and then processed for intratumoral microdialysis. Adenosine levels were measured by LC/MS. Anti-PDL1 induced a limitation of the tumoral adenosine level thus arguing for an important role of the adenosine axis in the control of the anti-tumor immune response.
Figure 4: Analysis of PDL1 blockade mechanism of action on the MCA205 tumor-infiltrating leukocytes populations. Flow cytometry analysis of MCA205 tumours shows infiltration by both lymphocytic (CD4, CD8) and myeloid cells including the immunosuppressive MDSC population (CD11b/Gr1low-int) and macrophages (M1 and M2 subsets). Upon anti-PDL1 treatment, investigation of tumor-infiltrating leukocytic cell subsets showed an increase in CD8 cytotoxic lymphocyte proportion as well as decrease of MDSC cell infiltration. In addition, while vehicle tumours were shown to be infiltrated by M2 macrophages, which helps conferring an immunosuppressive microenvironment, PDL1 blockade was demonstrated to reprogram this macrophage profile by increasing the M1 and decreasing the M2 subset proportions, thereby suggesting an effect on macrophage polarization and proliferation.