Total HLA Class I Antigen Loss with the Downregulation of Antigen-Processing Machinery Components in Two Newly Established Sarcomatoid Hepatocellular Carcinoma Cell Lines

Figure 3

Differential expression of surface HLA class I antigens and various cytoplasmic antigens including β₂-microgobulin (β₂m), heavy chains, and selected antigen-processing machinery (APM) components in three newly established sHCC cell lines. (a) Surface HLA class I (sHLA-ABC) using mAb W6/32 and cytoplasmic HLA class I (cHLA-ABC) using mAb TP25.99, β₂m, and heavy chains (cHC) of the three sHCC cell lines were determined cytofluormetrically, and the results of a representative experiment were presented by histograms. (b) Cytoplasmic expression of additional HLA-A, HLA-B, -C allospecificities and APM components TAP1, TAP2, LMP2, and LMP7 were determined cytofluormetrically. The data are representative of three independent experiments. Symbols “s” and “c” at the prefix of indicated antigen stand for surface and cytoplasmic antigens, respectively. The results of cytofluorometric analysis are expressed as % positive cells on the left frame and mean fluorescence intensity (MFI) on the right frame. (c) Percent expression relative to sHCC74 of HLA class I allospecificities, heavy chains, β₂m, and selected APM components in sHCC29 and sHCC63 are shown. Results are expressed as percent MFI ± SD of three independent experiments. TAP: transporter associated with antigen processing; LMP: low-molecular-weight protein.

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