I have been working with the K562 cell line for a while.
But I never really found out why K562 do not express HLA molecules.
I have seen publications that IFN-g treatment can induce HLA class I expression by K562.
Does anybody here have some insights into what is the mechanism how K562 do not express HLA molecules on their surface at steady state?
Thanks a lot!
Hello Zc Liu
The K562 cell line expresses very low levels of class I antigens, and specific viral gene products suppress class I expression in K562 cells. This type of repressor effect in K562 demonstrates the site of action to be transcriptional.
Agents like IFN-g inhibits RNA synthesis that suppress class I transcription and favors the accumulation of positive regulatory factor thus allowing increased HLA class I transcription. This clearly demonstrates the post-transcriptional control mechanisms for HLA class I gene expression. This type of mechanism is seen not only in K562 cells but also in other tumor cells as well as in undifferentiated embryonic tissues.
So, it may be concluded that both positive and negative regulatory factors are involved in transcriptional regulation of major histocompatibility complex class I genes in K562 leukemia cells. For more information you may want to refer to the articles attached below.
Article Negative and positive regulation of human leukocyte antigen ...
Article Adenovirus type 12 early region 1A proteins repress class I ...
Best.