Our results, thus, demonstrate the presence of a common oncogenic cascade initiated by FRA2/JUND in CCR4-expressing mature T-cell malignancies such as ATLL and CTCLs.
Previously, we and others have shown that the majority of ATL cases are strongly positive for CCR4, which may explain the frequent skin invasion of ATL.
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.
The immunological abnormality of T lymphocytes in patients with adult T cell leukemia (ATL) is characterized by the abnormal enhanced expression of the 55 kDa chain of the receptor for interleukin 2 (IL-2R/p55) (Tac), and down-regulation of CD3 antigen.
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.
Recently, the FDA has approved four drugs for patients with relapsed/refractory PTCL over the past 5 years, and if one counts the recent Japanese approval of the anti-CCR4 monoclonal antibody for patients with adult T-cell leukemia/lymphoma, five drugs have been approved worldwide.
In addition, LBH589 caused a marked decrease in levels of factors involved in ATLL cell proliferation and invasion such as CCR4, IL-2R and HTLV-1 HBZ-SI, a spliced form of the HTLV-1 basic zipper factor HBZ.
The present study sought to elucidate the prognosis of adult T-cell leukemia-lymphoma (ATL) patients receiving mogamulizumab, a defucosylated anti-CCR4 monoclonal antibody.
Areas covered: Mogamulizumab is a humanized, defucosylated monoclonal antibody that acts by targeting the CC chemokine receptor 4 (CCR4) on malignant cells of ATL.
Furthermore, the anti-CCR4 monoclonal antibody mogamulizumab has been shown to have marked cytotoxic effects on ATL cells, especially in the leukemic type of ATL.
ATL cells often abnormally express interleukin 2 (IL-2) receptors, and ATL patients may show clinical evidence of hypercalcemia, osteolytic bone lesions, or increased bone turnover.
Transforming activity was further demonstrated by the ability of the FBXW7 D510E mutant to provide IL-2-independent growth of Tax-immortalized human T cells and increase the tumor formation in a xenograft mouse model of ATL.
This prospective, observational, postmarketing surveillance was conducted to evaluate the safety and effectiveness of mogamulizumab, an anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, in patients with CCR4-positive, relapsed or refractory (r/r) adult T-cell leukemia-lymphoma (ATL) in Japan.
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.
Adult T-cell leukemia (ATL) cells have been shown to express the receptor for IL-2 by studies using anti-CD25 monoclonal antibody, but these cells usually show no or only a weak proliferative response to IL-2.
This study suggests that frequencies of CCR4 expression and genomic CCR4 mutations and an association between the two may be considerably different between ATL cases and non-ATL T/NK-cell lymphomas.
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.
Mogamulizumab (Mog), a humanized anti-CC chemokine receptor 4 (CCR4) mAb that mediates antibody-dependent cellular cytotoxicity (ADCC) using FcγR IIIa (CD16)-expressing effector cells, has recently been approved for treatment of CCR4-positive adult T-cell leukemia (ATL) in Japan.