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*
Mitsubishi Kagaku Institute of Life Sciences, Tokyo, Japan; and
Chemicals Assessment Center, Chemicals Evaluation and Research Institute, Fukuoka, Japan
| Abstract |
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| Introduction |
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Progesterone is known to be essential for the establishment and maintenance of pregnancy including ovulation, uterine, and mammary gland development (8). The major sources of progesterone during pregnancy are the corpus luteum of the ovary and, in many species including humans and rodents, the placenta (9). The serum progesterone concentration increases up to 0.3 µM during pregnancy in mice (10, 11, 12, 13). However, in the placenta where the fetal Ags are directly exposed to the mothers immune system, progesterone is synthesized in large quantities, and its concentration reaches much higher levels, e.g., 110 µM in humans (9). Progesterone binds to two progesterone receptors (PR),3 PRA and PRB, which are products of a single gene (14). However, the cellular and molecular mechanisms of progesterone effects on T cell differentiation are vastly unknown. Thus, we first examined whether progesterone directly affects T cell differentiation into Th1 or Th2. We used two experimental systems with isolated T cells in the absence of other cell types in vitro. In one system, we took advantage of our in vitro thymocyte differentiation system (15, 16). Differentiation and survival of isolated CD4+CD8+ thymocytes to Th1 and Th2 cells were induced by two pulse stimulations with proper combinations of the calcium ionophore ionomycin and the protein kinase C activator PMA, followed by cytokine treatment in the presence or absence of progesterone. In the second system, Th1 or Th2 was induced from isolated naive T cells of normal mice with Abs to CD3 and CD28 together with cytokines in the presence or absence of progesterone. We found that progesterone directly suppressed T cell differentiation into Th1 but enhanced differentiation into IL-10-producing Th2 cells in both systems. Furthermore, we found that glucocorticoids exerted similar effects.
| Materials and Methods |
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Male MHC class I and class II double knockout (DKO) mice
(C57BL/6 deficient in A
b and
2-microglobulin) were obtained from Taconic
Farms (Immuno-Biological Laboratories, Gunma, Japan). Male C57BL/6 mice
(46 wk of age) were obtained from Charles River Laboratories
(Yokohama, Japan). The mice were kept in our animal facility for at
least 1 wk before use. Progesterone, corticosterone, mifepristone
(RU-486), and PMA were obtained from Sigma-Aldrich (St. Louis, MO).
Dexamethasone was obtained from Wako (Osaka, Japan). Ionomycin and
SB203580 were obtained from Calbiochem (La Jolla, CA). U0126 was
obtained from Promega (Tokyo, Japan). Mouse rIL-2, mouse rIL-4, and
mouse rIL-12 were obtained from Genzyme (Cambridge, MA). To express
IL-2 and IL-4 activities, U was used by calculating as 1
U/ml = 1 ED50 according to the
manufacturers definition of ED50.
Thymocyte culture
For induction of in vitro differentiation of thymocytes into CD4
T cells and Th1/Th2 cells, DKO mouse thymocytes were used. T cell
differentiation is arrested at the
CD4+CD8+ stage in the
thymus of these mice, and most of the thymocytes are
CD4+CD8+ (17).
Thymocytes (3.754 x 106) were suspended
in 1 ml of DMEM supplemented with 10% heat-inactivated FCS (Intergen,
Purchase, NY), 3 mM L-glutamine, 1 mM sodium pyruvate, 1x
MEM nonessential amino acids, 50 µM 2-ME, 20 mM HEPES (pH
7.2), 20 U of penicillin, and 20 µg of streptomycin (complete DMEM)
and were cultured with 0.2 µg/ml ionomycin and 0.2 ng/ml PMA for
20 h at 37°C in 24-well tissue culture plates (25820; Corning
Glass, Corning, NY) (Fig. 1
, step A).
Each lot of FCS was selected by its low toxicity to
CD4+CD8+ thymocytes. After
culture, the stimulated cells were washed twice with fresh medium and
were further cultured in the same volume of complete DMEM without the
stimuli to induce
CD4+CD8low/- cells
committed to the CD4 T cell lineage (step B) (15). For the
secondary stimulation, the cells (5 x 106
cells per ml) were cultured with 0.2 µg/ml ionomycin and 3 ng/ml PMA
for 16 h (step C). After culture, the cells were washed twice and
further cultured at 1 x 106 cells/ml in
complete DMEM containing 40100 U/ml mouse rIL-2 in the presence of
the indicated concentrations of mouse rIL-4 and/or mouse rIL-12 for
35 days (step D) (16). For cultures longer than 4 days,
cells were expanded 2-fold on the fourth day after the start of
cytokine treatment in the continued presence of cytokines. To assess
the functional differentiation of the cells to Th1 or Th2,
intracellular cytokines or secreted cytokines upon stimulation were
detected.
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Splenic CD4 T cells were obtained from C57BL/6 mice by using Dynabeads Mouse CD4 and DetachaBead Mouse CD4 (Dynal Biotech, Oslo, Norway) and were stained with FITC-labeled anti-CD44 mAb (IM7) and PE-labeled anti-CD45RB (16A) (BD PharMingen, San Diego, CA). Naive CD4 T cells (CD44lowCD45RBhigh) were isolated by sorting with a FACStarPlus and Consort 30 software program (Nippon Becton Dickinson, Tokyo, Japan). Sorted naive CD4 T cells were plated at a density of 5 x 105 cells/ml in 24-well suspension culture plates (Sumitomo Bakelite, Tokyo, Japan) that had been coated with 3 µg/ml anti-CD3 mAb (145-2C11) (18) and 1 µg/ml anti-CD28 mAb (37.51; BD PharMingen). Cytokines and reagents were added to wells at the initiation of culture as indicated. After 58 days, cells were harvested and washed twice and were restimulated for measurement of cytokine production.
Measurement of cytokine production
To assess cytokine secretion into the medium, cells were suspended in fresh medium for 2 days in 24-well suspension culture plates that had been coated with 3 µg/ml anti-CD3 mAb and 3 µg/ml anti-CD28 mAb. The culture supernatants were assessed for cytokine concentrations with OptEIA mouse cytokine kits (BD PharMingen).
To assess intracellular cytokines, the cells were stimulated with 0.4
µg/ml ionomycin and 10 ng/ml PMA for 5 h, and monensin was added
for the last 2 h of the culture to inhibit intracellular transport
processes. After culture, cells were treated with anti-CD16/32
(FcgIII/IIR) mAb (2.4G2) to block FcR and then washed. The cells were
then fixed and permeabilized with a Cytofix/Cytoperm kit (BD
PharMingen) and stained with FITC-labeled anti-IFN-
mAb
(XMG1.2), PE-labeled anti-IL-4 mAb (11B11), PE-labeled
anti-IL-10 mAb (JES5-16E3), and/or FITC-labeled anti-IL-10 mAb
(BD PharMingen). The stained cells were analyzed for fluorescence
levels by FACS.
FACS analysis of surface markers
The cells were stained with labeled Abs to PE-conjugated mAb to CD4 (RM4-5) or CD45RB and/or FITC-labeled mAb to CD8 (53-6.7) or CD44 mAb (IM7) (BD PharMingen). Intact cells were gated by using forward and side scatters with a FACScan flow cytometer and FACScan Research Software (BD Biosciences, Lincoln Park, NJ) and were analyzed for marker expression. The gate for viable cells was determined using propidium iodide exclusion and Paint-a-Gate software (Nippon Becton Dickinson).
| Results |
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To examine the direct effect of progesterone on T cell
differentiation, we first used
CD4+CD8+ thymocytes from
DKO mice as starting cells. The in vitro differentiation of thymocytes
easily provided >108 T cells per mouse, ready
for differentiation into Th1 or Th2 (16). As shown in Fig. 1
, suspended thymocytes were transiently stimulated twice with
ionomycin/PMA followed by culture with IL-2 and IL-4 and/or IL-12 in
the presence of graded concentrations of progesterone (step D) for 35
days. IL-4 and IL-12 are required to induce Th2 and Th1 cells,
respectively, from naive T cells (19). The cultured cells
were washed and restimulated with plate-bound Abs to CD3 and CD28 to
assess their ability to produce IFN-
, IL-4, and IL-10. Progesterone
inhibited IFN-
production dose dependently in the presence or
absence of IL-4 (Fig. 2
, A
(
and
) and D), but its effect was not significant in
the presence of 0.1 ng/ml or higher concentrations of IL-12 (Fig. 2
A,
, and data not shown). Progesterone moderately
enhanced IL-4 production (Fig. 2
E), but progesterone at 10
µM in some experiments of 3 days or shorter of step D culture failed
to show enhancement (Fig. 2
B). IL-10 production was dose
dependently enhanced by progesterone in the presence of 0.011 ng/ml
IL-12 with or without IL-4 (80100 U/ml) (Fig. 2
, C (
)
and F; and data not shown). In the absence of both IL-4 and
IL-12, the development of IL-10-producing cells was not induced in the
presence or absence of progesterone. However, in the presence of IL-4
without IL-12, progesterone at only 10 µM moderately enhanced IL-10
production (Fig. 2
C,
).
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-expressing cells and an increase in IL-10-expressing cells.
Most of the IL-10-expressing cells induced in the presence of
progesterone also expressed IL-4 (Fig. 3
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Kinetic changes in cytokine productivity of the cultured
thymocytes were studied. After two pulse stimulations with
ionomycin/PMA, the cells were cultured for graded periods in the
presence of both IL-4 (100 U/ml) and IL-12 (0.01 ng/ml) to induce both
Th1 and Th2, and the effect of 10 µM progesterone was analyzed. In
the absence of progesterone, IFN-
production assessed by stimulation
with Abs to CD3 and CD28 quickly increased during 3 days of culture and
thereafter moderately decreased, whereas progesterone suppressed
IFN-
production throughout the culture period (Fig. 4
A). The IL-4 production
increased after 1 days of culture and peaked after 3 days. Thereafter,
IL-4 production decreased quickly, but progesterone moderated the
decrease (Fig. 4
B). IL-10 production increased and reached a
plateau after 2 days of culture in the absence of progesterone.
However, in the presence of progesterone, IL-10 production continued to
increase (Fig. 4
C). Intracellular cytokine staining
indicated that the majority of IL-10-expressing cells were also
expressing IL-4 after 5 days of culture with progesterone (data not
shown).
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-producing
cells and promoted their differentiation into IL-4-producing cells
(Fig. 6
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, IL-4, and IL-10 (data not shown).
We also examined the effect of progesterone on Th1 or Th2 development
in the skewed condition to induce either one of them in the presence of
IL-12 or IL-4. Progesterone significantly suppressed IFN-
production
at 0.3 and 10 µM in both culture conditions (Fig. 6
, G and
J; p < 0.02 or 0.001), although percent
inhibition in the presence of 0.1 ng/ml IL-12 was lower than that in
the absence of IL-12. Progesterone at 10 µM but not 0.3 µM enhanced
both IL-4 and IL-10 production when the cells were cultured with
IL-12 (p < 0.05) but not IL-4 (Fig. 6
, H, I, K, and L).
These results collectively suggest that progesterone directly suppresses T cell differentiation into Th1 and that it directly enhances T cell differentiation into IL-10/IL-4-producing Th2 at a relatively late stage. IL-10 productivity appears to be affected with the concentrations of IL-4 and IL-12.
Corticosterone exerts effects similar to those of progesterone on T cell differentiation
Because progesterone is known to cross-react significantly with
glucocorticoid receptors (GR) (22, 23), we examined
whether glucocorticoids might exert similar effects on T cell
differentiation. As shown in Fig. 7
, the
major glucocorticoid in mice, corticosterone, dose dependently
suppressed cultured thymocyte differentiation into IFN-
-producing
cells and enhanced their differentiation into IL-4- and IL-10-producing
cells. The induction of cells expressing IL-4 but not IL-10 was
suppressed, but that of the cells expressing both IL-4 and IL-10 was
significantly enhanced (Fig. 7
B). The proportion of the
cells expressing IL-10 but not IL-4 was small; however, induction of
these cells was also enhanced by corticosterone. Similar results were
obtained with the synthetic glucocorticoid dexamethasone at 0.01 µM
(data not shown). Corticosterone was 10100 times more effective than
progesterone (Fig. 7
and data not shown). IL-4 production was
significantly increased in the cells treated with 1 µM corticosterone
(Fig. 7
C), but the intracellular IL-4-expressing cells were
decreased (Fig. 7
A), indicating that the IL-4 production per
IL-4-expressing cell increased. In naive T cells, similar results were
obtained, although corticosterone at concentrations of 0.010.1 µM
somewhat suppressed IL-10 production (Fig. 7
D). Nonetheless,
the results collectively suggest that corticosterone exerts effects
similar to those of progesterone on T cell differentiation, but more
strongly.
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Involvement of mitogen-activated protein kinases (MAPKs) has been
suggested in Th1 and Th2 differentiation (24, 25, 26). Thus,
we compared the effects of MAPK inhibitors on T cell differentiation
with those of progesterone. The p38 MAPK inhibitor SB203580
(27) suppressed cell differentiation into
IFN-
-producing cells and enhanced differentiation into
IL-4-producing cells (Fig. 8
). In
contrast, the MAPK kinase (MEK) inhibitor U0126 (28)
suppressed the cell differentiation into IL-4-producing cells and
enhanced differentiation into IFN-
-producing cells (Fig. 8
). The
findings indicate that p38 MAPK and extracellular signal-regulated
kinase (ERK) pathways are indeed involved in Th1 and Th2 development,
respectively, and that the effects of SB203580 on the development of
IFN-
-producing cells and IL-4-producing cells resemble those of
progesterone. Progesterone synergized with SB203580 to suppress the
development of IFN-
-producing cells but suppressed the SB203580
enhancement of development of IL-4-producing cells (Fig. 8
).
Furthermore, SB203580 neither affected the development of
IL-10-producing cells by itself nor synergized with progesterone to
enhance the development of IL-10-producing cells (Fig. 8
C).
Thus, it is unlikely that the progesterone effects are simply due to
inhibition of p38 MAPK activity.
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| Discussion |
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The reagent RU-486 is known to be an antagonist of PR and GR
(34). However, RU-486 itself at 1 and 10 µM exerted
similar effects to progesterone and corticosterone in our experimental
systems (data not shown). Because RU-486 has predominantly
glucocorticoid agonist actions in several tissues (35, 36), RU-486 might exert an agonist effect on T cell
differentiation via GR or PR. PR expression appears to be low in T
cells (23, 37, 38) but increased upon exposure to
progesterone and probably with TCR-mediated stimulation
(39). Indirect effects of progesterone on T cells through
binding to PR in other cell types may also be possible, as reported in
other situations. The indirect mechanism is involved in the hormonally
controlled accumulation and survival of uterine mucosal NK cells,
because neither PR nor estrogen receptors were detected in these NK
cells (37). PR in thymus is localized in
reticuloepithelial cells (38) and is required for normal
fertility, probably through a PR-dependent paracrine mechanism that
blocks T cell lymphopoiesis during pregnancy (40).
Progesterone has one-third the affinity exhibited by corticosterone for
GR (22), whereas corticosterone has a very high affinity
for its own receptor (Kd
10-9 M) (22, 41). In
contrast, corticosterone has a relative affinity 25-fold lower than
progesterone for PR in rat placenta and in human mononuclear leukocytes
(23, 42). GR is expressed in immature and mature T cells
(43, 44). Thus, physiological concentrations of
progesterone during pregnancy are sufficient to bind to GR as well. We
have shown in this study that the glucocorticoid corticosterone can
directly affect T cells to give a skewed differentiation into Th2
cells. Progesterone may exert its effect on the functional
differentiation of T cells partly through GR. During the second half of
pregnancy in mice, plasma corticosterone levels reach a peak of 4 µM
on day 16,
60 times the nonpregnant resting level (45).
Most of the plasma corticosterone is of adrenal origin, and the
remaining portion of the corticosterone is feto-placental in origin
(45). It has been previously suggested that
glucocorticoids indirectly affect T cell differentiation and skew it
toward the Th2 type, because glucocorticoids reduce the secretion of
the Th1-promoting factor IL-12 in LPS-stimulated dendritic cells
(46) or because IL-4-producing
NK1.1+ T cells are more resistant to
glucocorticoid-induced apoptosis than conventional T cells in vivo
(47). These and present results collectively suggest that
both progesterone and glucocorticoids directly and indirectly
contribute to inducing a shift in differentiation of T cells into the
Th2 type during pregnancy, particularly at the maternal-fetal
interface. The placental levels of progesterone in mice may be lower
than in humans (13) but may be supplemented by
glucocorticoids in mice.
Induction of IL-10-producing T cells was also directly enhanced by
progesterone and glucocorticoids. IL-10 is known to inhibit the
production of IL-12 and the expression of MHC class II Ags or
costimulatory molecules by macrophages, monocytes, or various types of
dendritic cells (48). Furthermore, IL-10 treatment of
dendritic cells contributes to a state of anergy in
alloantigen-activated T cells (49, 50). Thus, progesterone
and glucocorticoids are likely to inhibit Th1 differentiation also
through up-regulating IL-10 production in vivo and may contribute to a
state of anergy in paternal Ag-activated T cells. Most of the
IL-10-expressing cells induced in the presence of progesterone or
corticosterone in vitro were also expressing IL-4 (Figs. 3
and 7
),
indicating that these cells were not Tr1, which produce high levels of
IL-10, normal levels of IL-5, and low levels of IL-2 and IL-4
(51), at least within the culture period in this study.
The enhanced induction of IL-10-producing cells from naive T cells
appeared to be influenced by several conditions. The progesterone
concentration was necessary to be 110 µM, and the presence of IL-12
(0.010.1 ng/ml) was required (Fig. 6
).
The molecular mechanism of the direct effect of progesterone and
glucocorticoids on T cell differentiation remains unclear. Inhibition
of IL-12-induced Stat4 phosphorylation may contribute to the effect of
glucocorticoids (52). In the presence of progesterone,
activated human lymphocytes, especially 
T cells, synthesize a
34-kDa molecule (progesterone-induced blocking factor) that inhibits NK
activity and exerts an antiabortive effect in vivo (53).
Progesterone-induced blocking factor may be responsible in part for the
progesterone effect on T cells (53). Progesterone also
plays a role in the induction of leukemia inhibitory factor, essential
for embryo implantation, in the presence of IL-4, and the production of
leukemia inhibitory factor and/or Th2 cytokines by decidual T cells
contributes to the maintenance of pregnancy (54).
Our findings indicate that progesterone and glucocorticoids directly suppress T cell differentiation into Th1 and enhance IL-10-producing Th2. However, in the presence of high concentrations of the Th1-promoting factor IL-12, progesterone cannot suppress or less efficiently suppresses the Th1 differentiation that may cause abortive responses, but can enhance the induction of IL-10-producing cells. IL-10 may then indirectly inhibit Th1 differentiation.
| Acknowledgments |
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| Footnotes |
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2 Address correspondence and reprint requests to Dr. Makoto Iwata, Mitsubishi Kagaku Institute of Life Sciences, 11 Minamiooya, Machida-shi, Tokyo 194-8511, Japan. E-mail address: iwata{at}libra.ls.m-kagaku.co.jp ![]()
3 Abbreviations used in this paper: PR, progesterone receptor; DKO, double knockout; GR, glucocorticoid receptor; MAPK, mitogen-activated protein kinase; ERK, extracellular signal-regulated kinase; MEK, MAPK kinase. ![]()
Received for publication July 26, 2001. Accepted for publication November 16, 2001.
| References |
|---|
|
|
|---|
response and increased production of Th2 cytokines. J. Immunol. 156:644.[Abstract]
-production by suppressing natural killer cell stimulatory factor/IL-12 synthesis in accessory cells. J. Exp. Med. 178:1041.
expression by Th1 effector T cells mediated by the p38 MAP kinase signaling pathway. EMBO J. 17:2817.[Medline]

T cells in progesterone-mediated immunomodulation during pregnancy: a review. Am. J. Reprod. Immunol. 42:44.
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