Figure 1. Quantification of MHC class I, Beta-2 microglobulin, and T-cell subsets.

A. Representative staining in triplicate of MHC class I (MHC-I) expression in 5 colorectal liver metastases, with calculated mean percent surface expression ±standard error. For the same tumors, example of Beta-2 microglobulin (β2m) staining of one of the triplicate core is shown. Correlation of MHC-I and β2m expression is shown. Solid and dotted lines represent median and terciles, respectively (MHC-I, 32%, 48%, and 65%; β2m, 13%, 21%, and 33%).

B. Quantification of intratumoral CD3 (n=154), CD4 (n=155), and CD8 (n=155) T cells. One dot represents one metastasis (cells/core, mean of replicates). Bars represent medians (109, 9, and 52 cells/core, respectively). One value is out of scale (CD8=502).

C. Within the 52 tumors found to express the highest level of MHC-I (upper tercile), 31 displayed high CD3 infiltration, 80.6% of which represented tumors detected to have high CD4 and/or CD8 infiltration (25 of 31, medians used as cut-off points).

D. Dot plot representing the absence of correlation between MHC-I expression and CD3 infiltration. Using the highest tercile as cut-off for high MHC-I expression (broken Y axis, 65%) and the median count for high CD3 infiltration (broken X axis, 109 cells/core), 4 groups are defined: MHC-I^hiCD3^hi (n=31, red); MHC-I^loCD3^hi (n=46, blue); MHC-I^hiCD3^lo (n=19, yellow); MHC-I^loCD3^lo (n=58, black).

Spearman r used for correlation analysis.