CD200 is induced by ERK and is a potential therapeutic target in melanoma
J. Clin. Invest. Kimberly B. Petermann, et al. 117:3922 doi:10.1172/JCI32163 [Go to this article.]

Figure 4
CD200 is required for T cell repression. (A) IL-2 production by T lymphocytes during MLRs with the addition of human melanoma cell lines with varying levels of CD200 expression. WM2664, SKMEL24, and SKMEL28 express high levels of CD200; PMWK, Mel505, and SKMEL187 express low levels of CD200. IL-2 production, as a marker of T cell activation, was determined by ELISA after 72 hours of incubation. Indicated statistical comparisons are between the indicated cell line versus T cells plus DCs only (**P < 0.005; ***P < 0.0001). Error bars are ± SEM. (B) MLRs in the presence of WM2664, SKMEL24, and SKMEL28 transduced with nonspecific hairpin (WMNS, SK24NS, SK28NS) and WM2664, SKMEL24, and SKMEL28 transduced with CD200 knockdown (WMKD, SK24KD, SK28KD). DCs and T cells were mixed with the indicated human melanoma cell lines with or without CD200 shRNA knockdown. IL-2 production was significantly higher in CD200-knockdown melanoma cell lines (WMKD, SK24KD, SK28KD) when compared with the parental melanoma cell lines transduced with a nonspecific shRNA (WMNS, SK24NS, and SK28NS). Error bars are ± SEM. (C) Quantification of T cell rosettes. WMKD and SK24KD show a significant increase in the formation of T cell rosettes when compared with their parental cell lines transduced with a nonspecific shRNA in MLRs. A mix of T cells and DCs was used as a positive control (far-left bar). Error bars are ± SEM. (D) WMKD and SK24KD show a significant increase in the formation of T cell rosettes when compared with their parental cell lines transduced with a nonspecific shRNA in MLRs. A mix of T cells and DCs was used as a positive control (far-left panel). Original magnification, ×100.