Reduced expression of MHC class I antigen in human cancer cell lines with defective LMP-7.
The function of major histocompatibility complex (MHC) class I molecule is to sample peptides derived from intracellular proteins and to present these peptides to CD8+ T cells. We analyzed twenty-nine human cancer cell lines for expression of the TAP-1/2 and LMP-2/7 genes and identified whether defects in these genes were associated with the level of expression of MHC molecules in cancer cells. Expression of TAP-1 was positive in 86% (25/29) of the cell lines, TAP-2 expression was positive in 82% (24/29), LPM2 was positive in 86% (25/29), and LMP-7 was positive in 52% (15/29) at the cell lines. In fifteen cell lines that expressed LMP-7, the mean fluorescence intensity (MFI) was 825.1 +/- 123.2; however, in the cell lines that lacked LMP-7, the MFI was 314.7 +/- 77.2. These data suggest that the expression level of MHC class I molecules is associated, in most cases, with the loss of the LMP-7 gene but without the loss of the TAP-1, TAP-2 or LMP-2 genes.
Yoon
S J
SJ
Cancer Research Center, Seoul National University Medical College, Korea.
Kang
J O
JO
Park
J S
JS
Kim
N K
NK
Heo
D S
DS
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D003546:Cysteine Endopeptidases; D005260:Female; D005805:Genes, MHC Class I; D018922:HL-60 Cells; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D020014:K562 Cells; D008214:Lymphocytes / Q000276:immunology*; D008285:Major Histocompatibility Complex; D008297:Male; D009097:Multienzyme Complexes; D009369:Neoplasms / Q000235:genetics* / Q000276:immunology*; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D020298:U937 Cells
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D015395:Histocompatibility Antigens Class I; D009097:Multienzyme Complexes; D011506:Proteins; C071313:LMP-2 protein; C071692:TAP2 protein, human; D003546:Cysteine Endopeptidases; C077436:LMP7 protein; D046988:Proteasome Endopeptidase Complex