Open AccessIdentification of a novel splice variant of human PD‐L1 mRNA encoding an isoform‐lacking Igv‐like domain
Author(s) -
HE Xianhui,
XU Lihui,
LIU Yi
Publication year - 2005
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2005.00086.x
Subject(s) - splice , gene isoform , messenger rna , alternative splicing , identification (biology) , biology , computational biology , microbiology and biotechnology , genetics , rna splicing , gene , encoding (memory) , rna , neuroscience , botany
Aim : To investigate the expression and regulation of PD‐1 ligand 1 (PD‐L1) in peripheral blood mononuclear cells (PBMC). Methods : The cDNA encoding human PD‐L1 precursor was cloned from the total RNA extracted from the resting and phorbol dibutyrate plus ionomycin‐ or phytohemagglutinin‐activated PBMC, by reverse transcription polymerase chain reaction (RT‐PCR), and independent clones were sequenced and analyzed. The expression and subcellular localization were examined in transiently transfected cells. The PD‐L1 gene expression in different PBMC was also analyzed by RT‐PCR. Results : A novel human PD‐L1 splice variant was identified from the activated PBMC. It was generated by splicing out exon 2 encoding an immunoglobulin variable domain (Igv)‐like domain but retaining all other exons without a frame‐shift. Consequently, the putative translated protein contained all other domains including the transmembrane region except for the Igv‐like domain. Furthermore, the conventional isoform was expressed on the plasma surface whereas the novel isoform showed a pattern of intracellular membrane distribution in transiently transfected K562 cells. In addition, the expression pattern of the PD‐L1 splice variant was variable in different individuals and in different cellular status. Conclusion : PD‐L1 expression may be regulated at the posttranscriptional level through alternative splicing, and modulation of the PD‐L1 isoform expression may influence the outcome of specific immune responses in the peripheral tissues.