The effect of transforming growth factor-beta on the expression of CD8 in the CTLL-2 cell line

Park, Soo Young; Chang, Yoon Hae; Cho, Young Joo

Abstract

BACKGROUND: Transforming growth factor-beta(TGF-beta) has multiple regulatory effects on cells of the immune system, and it has been suggested that differentiation of lymphoid cells is influenced by low concentra tions of this cytokine.
OBJECTIVES
The aim or this study was to investigate the role of TGF-beta in regulation of T cell growth and differentiation, and to compare this effect with that of other cell signals known to be important in T cell ontogeny.
METHODS
We used the CTLL-2 cell line in the presence of IL-2. Surface phenotype expression was analysed to see whether these cells could be switched to the other subtype of cells. RESULT: Treatment of CTLL-2 cells with TGF-beta resulted in dose dependent growth inhibition and morphological changes. Curing routine passage, less than 5% of cells were CD8alpha positive, whereas 38% of cells expressed CD8alpha when treated with IL-2 plus TGF-beta. However, TPA plus calcium ionophore, IFN-gamma, or TNF-alpha caused no significant changes in the proportion of CD8 cells.
CONCLUSION
Our results show that this experiment can be a useful model for investigating CD8 precursor potentials in populations of CD4-CD8-(double negative) cells, and such a model may offer a way to study the molecular regulation of CD8 gene expression.