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

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.