Tumors induce a subset of inflammatory monocytes with immunosuppressive activity on CD8⁺ T cells
J. Clin. Invest. Giovanna Gallina, et al. 116:2777 doi:10.1172/JCI28828 [Go to this article.]

Figure 1
MSCs inhibit antigen-induced T lymphocyte proliferation but not IFN-γ release. (A) CFSE-labeled splenocytes derived from mice transferred with HA-specific CD8⁺ (CL4) T cells and primed with HA-encoding vaccinia virus were stimulated with the HA peptide in the absence (No CD11b) or in the presence of CD11b⁺ cells magnetically purified from either the spleen or the tumor infiltrate of tumor-bearing mice and admixed at a 1:10 ratio. The cultures were stimulated for 60 hours with the relevant peptide, and the clonotypic proliferation was evaluated as CFSE dilution by flow cytometry. (B) Data are presented as the mean percentage of CL4 cells in each cycle from triplicate wells (± SEM); 1 of 2 representative experiments is reported. (C) MSCs do not suppress IFN-γ production from naive or antigen-experienced (memory) CD8⁺ T cells. MSCs were isolated from the spleens of normal or tumor-bearing mice, and 6 × 10⁵ cells were admixed with 3 × 10⁶ splenocytes containing naive (2.4 × 10⁵) or in vivo antigen-experienced (2.1 × 10⁵) HA-specific CD8⁺ T cells stimulated with the relevant peptide in an ELISPOT assay. Data (mean ± SEM) are derived from triplicate wells of 1 representative experiment.