Abstract. We previously showed that a combination therapy
with tumor cell-pulsed monocyte-derived dendritic cells
(DCs) and activated lymphocytes was well tolerated in
accumulating evidence has indicated that regulatory T-cells
(Tregs), a unique population of CD4+T-cells, are increased
in patients with several advanced malignancies and prevent
cell-mediated immune responses against tumors. However,
reports analyzing the relationship between the Tregs
population and the effects of immunotherapy are extremely
rare. In the present study, 22 patients received an intravenous
injection of DC-activated lymphocytes (DAK) and/or a
subcutaneous injection of tumor-pulsed DCs (DC vaccine)
every 2 to 4 weeks. The Tregs were defined based on their
expression of CD4, CD25 and FOXP3, a transcription factor.
Most CD4+CD25highT-cells expressed FOXP3. Therefore,
CD4+CD25highT-cells were evaluated as Tregs in the present
study. As reported previously, the percentage of Tregs (%
Tregs) among total CD4+T-cells in peripheral blood
mononuclear cells (PBMCs) was significantly higher for
advanced cancer patients than for healthy volunteers. When
the patients were divided into three groups according to their
survival time, i.e. 12 short-survival patients, 4 medium-
survival patients and 6 long-survival patients, the % Tregs
of the long-survival patients before the therapy was
significantly lower than that of the short-survival patients
(p=0.026). The % Tregs decreased after the therapy,
although the difference did not reach statistical significance.
When the patients were divided into a high group (>4.99%:
7 patients) and a low group (<4.99%: 15 patients)
according to their % Tregs before the therapy, the survival
times of the two groups differed significantly (p=0.0034).
These data suggest that the % Tregs among the PBMCs
immunotherapy for patients with advanced cancer.
be usedas an effectprediction factorof
Recent accumulating evidence has indicated the existence of a
unique CD4+T-cell population, designated regulatory T-cells
(Tregs) (1-3). Tregs were originally identified as CD4+T-cells
that constitutively express the interleukin (IL)-2 receptor α-
chain (CD25) (4) and account for 5-10% of the total CD4+T-
cell population. More recent studies have shown that the
transcription factor forkhead box P3 (FOXP3) is not only a key
intracellular marker, but also a crucial developmental and
functional factor for CD4+CD25+Tregs (5-7). Therefore, it is
now generally considered that CD4+T-cells expressing both
CD25 and FOXP3 are Tregs.
The human immune system consists of an elegant balance
between immune surveillance and immune ignorance of self-
antigens. Tregs have been shown to contribute to the
prevention of autoimmune disorders by controlling the
activity of autoreactive T-cells (2, 8, 9). In other words, Tregs
are considered to act as players in immune tolerance against
self-antigens. Tregs are increased in the peripheral blood and
cancer tissues in several types of advanced cancer (10-14),
and these increases in Tregs have been proposed to play
critical roles in immune tolerance against malignancies (15),
since most tumor-associated antigens are self-antigens.
Importantly, it has been shown that increased numbers of
Tregs were associated with increasing tumor burden, and that
removal of the Tregs resulted in enhanced antitumor immune
responses (16). Based on these investigations, several
Abbreviations: Tregs, regulatory T-cells; Foxp3, forkhead box
protein P3; FACS, fluorescence-activated cell sorting; DC, dendritic
cells; DAK, dendritic cells-activated lymphocytes; PBMCs;
peripheral blood mononuclear cells.
Correspondence to: Mitsuo Katano, Department of Cancer Therapy
and Research, Graduate School of Medical Sciences, Kyushu
University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
+8192 6426941, Fax:+81 92 6426221, e-mail:
Key Words: Regulatory T-cells, human FOXP3, immunotherapy,
tumor immunity, dendritic cells, survival.
ANTICANCER RESEARCH 28: 2401-2408 (2008)
Regulatory T-Cells Are Possible Effect Prediction
Markers of Immunotherapy for Cancer Patients
JUNJI WADA1, AKIO YAMASAKI1, SHUNTARO NAGAI1, KOUSUKE YANAI1, KOUTA FUCHINO2,
CHIZU KAMEDA1, HARUO TANAKA1, KENICHIRO KOGA1, HIROSHI NAKASHIMA1,
MASAFUMI NAKAMURA1, MASAO TANAKA3, MITSUO KATANO1and TAKASHI MORISAKI2
Departments of1Cancer Therapy and Research, and
3Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka;
2Yakuin CA Clinic, Fukuoka, Japan
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Received February 2, 2008
Revised May 2, 2008
Acccepted May 9, 2008
ANTICANCER RESEARCH 28: 2401-2408 (2008)