Weiss EH, Cannich A, Sprinks M, Fernandez N, Ulbrecht M. Unique biochemical properties of human leukocyte antigen-E allow for a highly specific function in immune recognition.
Am J Reprod Immunol 1998;
40:177-82. [PMID:
9764362 DOI:
10.1111/j.1600-0897.1998.tb00410.x]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
PROBLEM
Does a correlation exist between the expression of human leukocyte antigen (HLA) class Ia and HLA-E and what is its biological significance?
METHOD OF STUDY
HLA-E transcripts were detected by reverse transcriptase-polymerase chain reaction. Metabolically labeled HLA-E heavy chains were immunoprecipited and analyzed by one-dimensional isoelectric focusing. Mouse RMA-S cells defective with regard to transporter associated with antigen processing (TAP) function were transfected with HLA-E and human beta 2-microglobulin to investigate TAP dependence of the cell-surface expression of HLA-E.
RESULTS
HLA-E is transcribed regardless of the down-regulation of polymorphic HLA class Ia expression. HLA-E is transported to the cell surface in the absence of TAP-controlled peptide loading. In human cells, the amount of HLA-E protein is very low regardless of the presence of correct peptide ligands.
CONCLUSIONS
HLA-E regulates immune functions in cells that have down-regulated the expression of polymorphic HLA-class Ia molecules, either by preventing harmful natural killer cells from attacking targets that have physiologically decreased HLA-class Ia expression or by activating effector cells against virus-infected and tumor cells with impaired HLA-class Ia expression.
Collapse