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Figure 3 | Journal of Translational Medicine

Figure 3

From: Indoleamine 2,3-dioxygenase 1 (IDO1) activity correlates with immune system abnormalities in multiple myeloma

Figure 3

IDO activity correlates with expanded Treg cells and with diminished NY-ESO-1-specific CD8+T cells. Panel A: The frequency of bona fide Treg cells in patients’ PB was estimated with flow cytometry, as already published [26]. Bars depict median values and inter-quartile ranges. Comparisons between MM patients and healthy controls were performed with Kruskal-Wallis test for unpaired determinations with Dunns correction for multiple comparisons. Panel B: Patients with MM were arbitrarily categorized into KYNhi or KYNlo if serum KYN were greater or lower than the median in healthy controls (1.8 μM), respectively. The frequency of Treg cells in MM patients and healthy controls was compared with the Kruskal-Wallis test for unpaired determinations. Bars illustrate median values and inter-quartile ranges. Panel C: The frequency of circulating Treg cells was correlated with IDO protein levels, as measured by Western blotting in purified PC from a subgroup of 17 patients with MM. r2=0.4332; p=0.0041. Panel D: The expression of HLA-A2 on PB leukocytes was preliminarily investigated by flow cytometry using an anti-HLA-A2 mAb in 22 MM patients whose malignant PC expressed NY-ESO-1 protein (Additional file 2A). Sixteen MM patients were HLA-A2+, whereas 6 were HLA-A2-. PBMC from the 16 HLA-A2+ MM patients were stained with NY-ESO-1 pentamers, as detailed in Materials and Methods. The frequency of influenza-specific CD8+ T cells was measured in each MM patient to rule out immune exhaustion. A representative experiment is shown. Panel E: The frequency of NY-ESO-1-specific CD8+ T cells was significantly lower in KYNhi compared with KYNlo MM patients. The very low percentage of NY-ESO-1-specific CD8+ T cells in the 6 HLA-A2- MM patients reflects the background signal for pentamer staining. Panel F: The frequency of Treg cells in the 16 HLA-A2+ MM patients is shown with respect to IDO1 status. Bars depict median values and inter-quartile ranges.

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