Expression of transporter associated with antigen processing 1 and 2 (TAP1/2) in malignant melanoma cell lines

✍ Scribed by Per Thor Straten; Alexei F. Kirkin; Tina Seremet; Jesper Zeuthen

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: French
• Weight: 108 KB
• Volume: 70
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19970304)70:5<582::aid-ijc15>3.0.co;2-f

✦ Synopsis

TAP1 and TAP2 molecules are involved in the transport of peptides prior to their association with class I molecules and are mandatory for efficient antigen presentation. To investigate whether loss of expression of TAP1 or TAP2 is a likely mechanism of immune escape in malignant melanoma, TAP1 and TAP2 mRNA was analyzed by RT-PCR in 39 melanoma cell lines expressing at least 2 of the known melanomaassociated antigens, tyrosinase, Melan-A/MART-1, gp100, MAGE-1 and MAGE-3. All 39 cell lines expressed both TAP1 and TAP2 at the mRNA level. To investigate other factors potentially involved in immune escape, the expression of LMP2, LMP7, HLA class I molecules, b 2 -microglobulin (b 2 m) and specific HLA-A alleles was evaluated by RT-PCR and FACS analyses. All 39 cell lines expressed LMP2, LMP7 and b 2 m. A single cell line (FM37) had lost the expression of class I molecules, and this same cell line showed loss of expression of the HLA-A2 heavy chain. No cell lines showed loss of expression of the HLA-A1 heavy chain. Based on our studies of in vitro established cell lines, loss of TAP1/2 or LMP2/7 expression does not appear to be a common mechanism of immune escape in malignant melanoma.