Up-regulated expression of indoleamine 2,3-dioxygenase 1 in non-Hodgkin lymphoma correlates with increased regulatory T-cell infiltration.

Indoleamine 2,3-dioxygenase 1 (IDO1), which is a key enzyme in tryptophan metabolism expressed in some subsets of normal and neoplastic cells, participates in tumor-induced tolerance. However, the mechanisms involved are not clearly understood. A hypothesis suggests that IDO1 may be involved in proliferation and conversion of regulatory T cells (Tregs).

IL-9 contributes to immunosuppression mediated by regulatory T cells and mast cells in B-cell non-hodgkin's lymphoma.

It has been known that regulatory T (Treg) cells and mast cells (MCs) are involved in tumor immunity regulation, but the exact roles and mechanisms of Treg cells and MCs in B-cell non-Hodgkin's lymphoma (NHL) are incompletely defined. In the present study, we found that the number of Foxp3(+) Treg cells and CD117(+) MCs increased in B-cell NHL patients. Concomitantly, a high level of interleukin (IL)-9 was observed in the sera from B-cell NHL patients.

[Clinical significance of Livin expression in non-Hodgkin's lymphoma].

This study was aimed to explore clinical significance of Livin mRNA and protein expressions in non-Hodgkin's lymphoma (NHL). The immunohistochemistry was used to determine the expression of Livin protein in lymph nodes of 30 patients with NHL and 11 patients with reactive hyperplasia of lymph node. The real-time PCR was performed to detect the expression levels of Livin mRNA in 20 patients with NHL, 10 patients with reactive hyperplasia of lymph node and 4 normal person lymph nodes.