TY - JOUR
T1 - HLA-E surface expression is independent of the availability of HLA class I signal sequence-derived peptides in human tumor cell lines
AU - Palmisano, Giulio Lelio
AU - Contardi, Elisabetta
AU - Morabito, Anna
AU - Gargaglione, Vittoria
AU - Ferrara, Giovanni Battista
AU - Pistillo, Maria Pia
PY - 2005/1
Y1 - 2005/1
N2 - Human leukocyte antigen (HLA)-E is a nonclassic HLA class I molecule whose expression at the cell surface of tumor cells might allow them to escape T- and natural killer (NK)-cell immune surveillance. In this study, we analyzed HLA-E expression in a panel of human HLA-typed tumor cell lines of different histotypes by flow cytometry with anti-HLA-E monoclonal antibodies and by reverse transcriptase-polymerase chain reaction. Although specific HLA-E transcripts were detected in all cell lines, except in HELA, surface expression was detected at different intensities on seven (23%) of 30 cell lines with higher frequency and intensity among osteosarcoma cell lines. HLA-E-positive tumor cell lines mainly expressed the HLA-A*02 class I allele. Some tumor cell lines demonstrating HLA class I A* or Cw* alleles, which we expected to allow HLA-E surface expression on the basis of reported data on lymphoid cells, instead were HLA-E negative. All tumor cell lines were either tapasin and TAP-1 positive by flow cytometry, except two osteosarcoma cell lines, a finding that suggests an intact assembly machinery for peptide loading. We conclude that the concomitant presence of the appropriate HLA class I alleles with leader sequence-derived peptides and HLA-E heavy chain may not be sufficient to allow HLA-E surface expression in tumor cell lines as opposed to lymphoid cells.
AB - Human leukocyte antigen (HLA)-E is a nonclassic HLA class I molecule whose expression at the cell surface of tumor cells might allow them to escape T- and natural killer (NK)-cell immune surveillance. In this study, we analyzed HLA-E expression in a panel of human HLA-typed tumor cell lines of different histotypes by flow cytometry with anti-HLA-E monoclonal antibodies and by reverse transcriptase-polymerase chain reaction. Although specific HLA-E transcripts were detected in all cell lines, except in HELA, surface expression was detected at different intensities on seven (23%) of 30 cell lines with higher frequency and intensity among osteosarcoma cell lines. HLA-E-positive tumor cell lines mainly expressed the HLA-A*02 class I allele. Some tumor cell lines demonstrating HLA class I A* or Cw* alleles, which we expected to allow HLA-E surface expression on the basis of reported data on lymphoid cells, instead were HLA-E negative. All tumor cell lines were either tapasin and TAP-1 positive by flow cytometry, except two osteosarcoma cell lines, a finding that suggests an intact assembly machinery for peptide loading. We conclude that the concomitant presence of the appropriate HLA class I alleles with leader sequence-derived peptides and HLA-E heavy chain may not be sufficient to allow HLA-E surface expression in tumor cell lines as opposed to lymphoid cells.
KW - HLA typing
KW - HLA-E
KW - leader peptides
KW - tumors
UR - http://www.scopus.com/inward/record.url?scp=11144282643&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=11144282643&partnerID=8YFLogxK
U2 - 10.1016/j.humimm.2004.10.006
DO - 10.1016/j.humimm.2004.10.006
M3 - Article
C2 - 15620456
AN - SCOPUS:11144282643
VL - 66
SP - 1
EP - 12
JO - Human Immunology
JF - Human Immunology
SN - 0198-8859
IS - 1
ER -