Abstract
Transforming growth factor beta (TGF-β) has an important role in mediating T-cell suppression in B-cell non-Hodgkin lymphoma (NHL). However, the underlying mechanism responsible for TGF-β-mediated inhibition of effector memory T (T m) cells is largely unknown. As reported here, we show that exhaustion is a major mechanism by which TGF-β inhibits T m cells, and TGF-β mediated exhaustion is associated with upregulation of CD70. We found that TGF-β upregulates CD70 expression on effector T m cells while it preferentially induces Foxp3 expression in naive T cells. CD70 induction by TGF-β is Smad3-dependent and involves IL-2/Stat5 signaling. CD70 + T cells account for TGF-β-induced exhaustion of effector T m cells. Both TGF-β-induced and preexisting intratumoral CD70 + effector T m cells from B-cell NHL have an exhausted phenotype and express higher levels of PD-1 and TIM-3 compared with CD70 - T cells. Signaling transduction, proliferation and cytokine production are profoundly decreased in these cells, and they are highly susceptible to apoptosis. Clinically, intratumoral CD70-expressing T cells are prevalent in follicular B-cell lymphoma (FL) biopsy specimens, and increased numbers of intratumoral CD70 + T cells correlate with an inferior patient outcome. These findings confirm TGF-β-mediated effector T m cell exhaustion as an important mechanism of immune suppression in B-cell NHL.
Original language | English (US) |
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Pages (from-to) | 1872-1884 |
Number of pages | 13 |
Journal | Leukemia |
Volume | 28 |
Issue number | 9 |
DOIs | |
State | Published - 2014 |
ASJC Scopus subject areas
- Hematology
- Oncology
- Cancer Research