The Foxp3 expression was similar in ATL and HAMSS, but significantly higher in HAM-SS than AC-SS (p<0.05). p65 was expressed in LSG MNC nuclei from all SS patients and co-expressed with Foxp3.
Tax-specific CTL correlated inversely with FoxP3, an increase in the ratio of CD163+ tumor-associated macrophages was associated with worse clinical prognosis, and ATLL cell lines proliferated significantly following direct co-culture with M2 macrophages.
"The combination of arsenic, interferon-alpha, and zidovudine restores an ""immunocompetent-like"" cytokine expression profile in patients with adult T-cell leukemia lymphoma."
We conclude that ATLL is not a tumor of FoxP3(+) regulatory T cells, and that a population of FoxP3(+) cells distinct from ATLL cells has regulatory functions and may impair the cell-mediated immune response to HTLV-1 in patients with ATLL.
We describe here different features in Foxp3 expression profile between normal and leukemic CD4(+)CD25(+) T cells, using peripheral blood samples from healthy controls (HCs), human T-cell leukemia virus type-1 (HTLV-1)-infected asymptomatic carriers (ACs), patients with adult T-cell leukemia (ATL), and various hematopoietic cell lines.
Recent studies demonstrated that FOXP3, which is a master control gene of naturally occurring regulatory T (Treg) cells, is expressed in the tumor cells from a subset of patients with ATLL.
These results indicate that Foxp3 expression is variable in ATL cases and that Foxp3-high ATL cells, which resemble Treg phenotypically as well as functionally, may be involved in immune suppression in ATL.
Real-time polymerase chain reaction and immunostaining detected FoxP3 expression in 10 ATLL cases, but was relatively down-regulated compared with Treg from normal subjects.
In addition, we also found a high expression of FoxP3 mRNA and protein, a hallmark of regulatory T cells, in ATLL cells, indicating the possibility that ATLL cells originated from regulatory T cells.