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Updated: Mar 21, 2026
In Vitro Differentiation of Human CD4+FOXP3+ Induced Regulatory T Cells (iTregs) from Naïve CD4+ T Cells Using a TGF-β-containing Protocol
Published on: December 30, 2016
In vitro Treg expansion favors the full-length splicing isoform of CTLA4
Tanja Kaartinen1,2, Heidi Harjunpää1, Jukka Partanen1
1Research & Development, Finnish Red Cross Blood Service, Kivihaantie 7, 00310 Helsinki, Finland.
Aim:
We compared fresh and in vitro expanded human Tregs for their CTLA4 splicing isoform expression.
Methods:
The CD4(+)CD25(+)CD127(low/-)phenotype was used for sorting Tregs and mRNA levels were measured with relative qRT-PCR.
Results:
In fresh Tregs the level of soluble CTLA4 (sCTLA4) was half of that of full-length CTLA4, whereas in expanded cells sCTLA4 level was tenfold lower. The most striking change took place early on: sCTLA4 expression decreased significantly when cells were simply kept in culture.
Conclusion:
In the in vitro expanded Tregs, the splicing of CTLA4 is affected. Our findings can be significant for clinical cell manufacturing. First, even minimal processing of cells may impact the functional molecules. Second, Treg expansion yields more potent CTLA4 receptor bearing cells.
