| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Roche Milano Ricerche, Milan, Italy; and
Department of Inflammation/Autoimmune Diseases, Hoffmann-La Roche, Inc., Nutley, NJ 07110
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
/ß), in addition to IL-12, have been shown to
play an important role in the differentiation of human, but not mouse,
Th cells. We show here that IFN-/ß act directly on human T cells
to drive Th1 development, bypassing the need for IL-12-induced
signaling, whereas IFN- cannot substitute IL-12 for mouse Th1
development. The molecular basis for this species specificity is that
IFN-/ß activate Stat4 in differentiating human, but not mouse, Th
cells. Unlike IL-12, which acts only on Th1 cells, IFN-/ß can
activate Stat4 not only in human Th1, but also in Th2 cells. However,
restimulation of human Th2 lines and clones in the presence of IFN-
does not induce the production of IFN-
. These results suggest that
activation of Stat4, which is necessary for the differentiation of
naive T cells into polarized Th1 cells, is not sufficient to induce
phenotype reversal of human Th2 cells. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
and TNF-ß and are the mediators of
phagocyte-dependent immune reactions, whereas Th2 cells that secrete
IL-4 and IL-5 are responsible for phagocyte-independent host defense
(2). Uncontrolled Th1 and Th2 responses can cause chronic inflammatory
autoimmune diseases and allergies, respectively (3). Th1 and Th2 cells develop from naive CD4+ T cells. The differentiation process is initiated by ligation of the TCR and directed by cytokines present during the initiation of a T cell response (4). IL-4 promotes Th2 development (5, 6, 7), whereas IL-12 is a potent inducer of Th1 cells (8, 9, 10, 11). IL-4 activates Stat6 in Th2 cells (12, 13), and IL-12 induces tyrosine phosphorylation of Stat4 in developing and differentiated Th1 cells (14, 15, 16, 17, 18, 19). The activation of these two STAT factors is essential for T cell subset development, since Stat6-deficient T lymphocytes fail to differentiate into Th2 cells in response to IL-4 (20, 21, 22), and the analysis of Stat4-/--deficient mice revealed that Stat4 is essential for Th1 cell differentiation (23, 24).
Regulation of the IL-12 signaling pathway is crucial for the development of Th cells. The IL-12Rß2 subunit, a ligand-binding and signal-transducing component of the IL-12R (25), is expressed on human Th1, but not Th2, cells (18, 19). Triggering of the Ag receptor on naive T cells is sufficient for the initial expression of functional IL-12Rs, which are quickly lost during differentiation of human and mouse cells along the Th2 pathway (18, 19). In addition to TCR-mediated regulation, the IL-12Rß2 subunit can be up-regulated by IL-12 (19).
IFNs have also been shown to play an important role in Th1 cell
development. Recently, we have shown that human cord blood leukocytes
primed in the presence of IFN-, but not IFN-, develop into
IFN--producing Th1 cells even when cultured in the presence of IL-4
and neutralizing anti-IL-12 Abs. The Th1 cells generated in this
manner express the IL-12Rß2 mRNA and are responsive to IL-12 (19). In
contrast to human cells, IFN-/ß are unable to induce Th1
development and prime mouse T cells to respond to IL-12 (26). In the
present study we investigated the molecular basis for the
species-specific effect of IFN-/ß on the selective induction of
Th1-type immune responses. Our results indicate that IFN-/ß, by
phosphorylating Stat4 in human, but not in mouse, T cells, promote
species-specific induction of Th1-type immune responses. Furthermore,
since T cell responsiveness to IFN- is not lost during Th2
differentiation, we explored the effect of IFN--induced Stat4
activation on the phenotype of fully differentiated Th2 cells.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Human neonatal leukocytes were isolated from freshly collected,
heparinized, neonatal blood by Ficoll-Paque (Pharmacia Biotech,
Uppsala, Sweden) density gradient centrifugation. Monocytes were
removed by one round of plastic adherence, and CD4+ T cells
were isolated by negative selection with an Ab mixture and magnetic
activated cell sorting, according to a protocol supplied by the
manufacturer (CD4+ T cell isolation kit, Miltenyi Biotec,
Bergisch Gladbach, Germany). Neonatal T cell preparations were >97%
CD45 RA+ and >99% CD4+. Th1 and Th2 cell
lines were generated by stimulating neonatal CD4+ T cells
with irradiated (6000 rad), autologous monocytes and 2 µg/ml PHA
(Wellcome, Beckenham, U.K.) in the presence of 2.5 ng/ml IL-12
(Hoffmann-La Roche, Nutley, NJ) and 200 ng/ml neutralizing
anti-IL-4 Abs (18500D, PharMingen, San Diego, CA) for Th1 cultures,
or 1 ng/ml IL-4 (PharMingen, San Diego, CA) and 2 µg/ml neutralizing
anti-IL-12 Abs 17F7 and 20C2 (provided by M. Gately, Hoffmann-La
Roche, Nutley, NJ) for Th2 cultures, respectively. To test the effect
of IFNs on Th cell development, 1000 U/ml of IFN- (Roferon A,
Hoffmann-La Roche, Basel, Switzerland), IFN- (Hoffmann-La Roche,
Basel, Switzerland), or IFN-ß (Frone, Ares Serono, Geneva,
Switzerland) was added at the time of priming to cultures containing
IL-4 and neutralizing anti-IL-12 Abs (Th2-inducing conditions).
Cells were washed on day 4 and expanded in complete RPMI 1640 medium
(Life Technologies, Milan, Italy) supplemented with 5% FetalClone I
(HyClone, Logan, UT), 2 mM L-glutamine, 1 mM sodium
pyruvate, and 100 U/ml penicillin-streptomycin containing 100 U/ml IL-2
(Hoffmann-La Roche, Nutley, NJ).
Purification and stimulation of CD45RA+ T cells
Human PBMC from healthy donors were isolated from buffy coats by
Ficoll-Paque density gradient centrifugation. Monocytes were depleted
by two rounds of plastic adherence, and B cells were depleted by
adherence to nylon wool as previously described (27).
CD45RA+ T cells were isolated by two rounds of
immunomagnetic negative selection with a mixture of mAbs as described
previously (28). The purity of the CD3/CD45RA+ T cells
using this procedure was typically >98% as determined by flow
cytometry. Purified CD45RA+ T cells were stimulated with
plate-bound anti-CD3 mAb (TR66) (29) in the presence of IL-12 (2.5
ng/ml) and neutralizing anti-IL-4 mAb (200 ng/ml), or IL-4 (1
ng/ml) for the generation of Th1 and Th2 lines, respectively. To test
whether IFNs exert their functional effects directly on T cells,
IFN-, IFN-ß, or IFN- (1000 U/ml) was added at the time of
stimulation to cultures containing IL-4 (1 ng/ml). Cells were washed on
day 3 and expanded in complete medium containing 100 U/ml IL-2.
T cell clones
T cell clones GL93 and D4.11 have been described previously (30, 31). Briefly, Lol p1-specific T cell clones were generated from PBMC of
two Lol p1 allergic subjects as previously described (32). The three
Lol p1-specific T cell clones that we selected for this study had a
polarized cytokine profile. Two (D4.11 and E4.1) produced IL-4 but not
IFN- and were categorized as Th2 clones, and one (ET3.22) that was
able to produce IFN- but not IL-4 was categorized as a Th1 clone.
Th1 clone GL93 is specific for the hepatitis virus 
Ag and has been
described previously (30). To analyze cytokine production,
105/0.2 ml T cells were stimulated with a combination of
anti-CD3 mAb (0.1 µg/ml; CLB-T3/4E, CLB, Amsterdam, The
Netherlands) and anti-CD28 mAb (1 µg/ml; PharMingen) in the
presence or the absence of IL-12 (2.5 ng/ml) or IFN- (1000 U/ml).
Cell-free supernatants were collected after 24 h, and IFN- was
measured by a specific sandwich ELISA following a protocol provided by
the manufacturer (Genzyme, Cambridge, MA).
Single cell analysis of intracellular IFN- and IL-4 production
Single cell analysis of IFN- and IL-4 production was
performed as described previously (33). Briefly, T cell lines were
collected 7 days after priming and washed, and 106 cells
were restimulated with PMA (50 ng/ml; Sigma, St. Louis, MO) and
ionomycin (1 µg/ml; Sigma) for 2 h at 37°C in complete medium.
Brefeldin A (10 µg/ml; Sigma) was added to the cultures, and the
cultures were incubated for an additional 2 h. Then the cells were
fixed with 4% paraformaldehyde and permeabilized with saponin. Fixed
cells were stained with anti-human IFN--FITC (PharMingen, San
Diego, CA) and anti-human IL-4-PE (PharMingen) following a protocol
provided by the manufacturer and analyzed with a FACScan flow cytometer
(Becton Dickinson, Mountain View, CA).
Generation of anti-human IL-12Rß2 mAbs
Lewis rats were immunized and boosted with purified recombinant huIL-12Rß2-IgG1 fusion protein consisting of the extracellular domain of human IL-12Rß2 and the Fc portion of human IgG1 (D. H. Presky et al., manuscript in preparation). Splenocytes from the immunized rat were isolated and fused to the SP2/0 mouse myeloma cell line, and Ab-producing hybridomas were produced by standard methods (34). Hybridoma supernatants were screened by flow cytometry using a human IL-12Rß2-expressing Ba/F3 cell line (25), and the mAb 2B6 bound to the human IL-12Rß2-expressing transfectants, but not the parental Ba/F3 cell line. Purified 2B6, a rat IgG2a, was prepared by sequential caprylic acid and ammonium sulfate precipitation as described previously (35).
Cell surface staining of IL-12R subunits
Cells were stained with 1 µg/ml of purified rat anti-human IL-12Rß1 mAb (2B10) (36), rat anti-human IL-12Rß2 mAb (2B6), and isotype-matched control Abs at 4°C for 45 min. After being washed with cold FACS-buffer (PBS, 2% FCS, and 0.1% sodium azide), the cells were incubated as before with 2 µg/ml of biotinylated polyclonal anti-mouse or anti-rat IgG Ab (Jackson ImmunoResearch Laboratories, West Grove, PA). Cells were washed in FACS buffer and incubated with streptavidin-phycoerythrin (1/100; Jackson ImmunoResearch Laboratories). After two additional washes, the cells were resuspended in 0.5 ml of FACS buffer and analyzed with a FACScan flow cytometer (Becton Dickinson).
Cell extracts, immunoprecipitations, and Western blot analysis
T cell lines generated from human cord blood leukocytes were
harvested on day 9 after priming, and mouse T cells were harvested 6
days after stimulation. Cells (107) were washed and
incubated 30 min at 37°C in 1 ml of complete medium with or without
IL-12 (2.5 ng/ml) or IFN-, IFN-ß, or IFN- (1,000 U/ml). Cells
were washed once in PBS before lysing the cell pellet in 250 µl of IP
buffer (10 mM Tris-HCl (pH 7.4); 150 mM NaCl; 1 mM EDTA (pH 8.0); 1 mM
EGTA (pH 8.0); 1% Nonidet P-40; 0.25% sodium deoxycholate, 10 µg/ml
aprotinin, leupeptin, and NaF; 1 mM 4-(2-aminoethyl)-benzene sulfonyl
fluoride hydrochloride (AEBSF), and sodium orthovanadate). The
lysate was incubated 30 min on a shaker at 4°C, and insoluble debris
was removed by centrifugation (13,000 rpm, 4°C, 30 min). Stat4 was
immunoprecipitated with rabbit polyclonal anti-Stat4 antisera
(Santa Cruz Biotechnology, Santa Cruz, CA) and resolved by SDS-PAGE.
Following transfer to nitrocellulose, blots were probed with
anti-phosphotyrosine Ab 4G10 (Upstate Biotechnology, Lake Placid,
NY), and immunoreactive bands were visualized using the ECL Western
blotting system (Amersham, Italy), according to the company’s
protocols. To control for equal protein loading, blots were stripped
and reprobed with anti-Stat4 antisera.
Generation of mouse Th1 and Th2 lines from DO.11.10-transgenic CD4+ T cell cultures
Mel-14high CD4+ T cells were purified
from spleen and lymph nodes of DO11.10 TCR-transgenic mice (37) by
positive selection using anti-CD4-FITC (PharMingen)
and an anti-FITC multisort kit (Miltenyi Biotec, Bergisch Gladbach,
Germany) followed by positive selection of Mel-14high cells
using anti-CD62L microbeads (Miltenyi Biotec). Naive
CD4+ T cells (2.5 x 105 cells/well) were
stimulated with 0.3 µM OVA peptide 323–339 and mitomycin C-treated
BALB/c splenocytes (5 x 106 cells/well) as APC in a
total volume of 2 ml in 24-well plates in the presence of 100 pg/ml
IL-12 (provided by M. Gately, Hoffmann-La Roche, Nutley, NJ) and 10
µg/ml anti-IL-4 mAb (11B11) to promote Th1 phenotype development
or in the presence of 20 ng/ml IL-4 and 10 µg/ml anti-IL-12 mAb
10F6 (provided by M. Gately, Hoffmann-La Roche, Nutley, NJ) to promote
Th2 phenotype development as described previously (16, 38). Cells were
expanded in complete medium supplemented with recombinant human IL-2
(10 ng/ml; provided by M. Gately, Hoffmann-La Roche, Nutley, NJ) and
harvested on day 5 or 7. The Th phenotype was determined by
intracellular staining for IFN- and IL-4 production after
restimulation with PMA/ionomycin as described previously (38).
Analysis of IL-12Rß2 transcripts in mouse Th cells
RNase protection assays to analyze IL-12Rß2 transcripts in mouse Th cells were performed as previously described (39). Briefly, a 332-bp SacI DNA fragment from the mouse IL-12Rß2 subunit (25) was subcloned into pSPUTK (Stratagene, La Jolla, CA). The construct was linearized with EcoRI, and radiolabeled antisense transcripts were synthesized with SP6 polymerase and a commercial kit, according to the manufacturer’s protocol (Promega, Madison, WI). RNA was extracted from cells using Ultraspec total RNA extraction reagent (Biotecx, Houston, TX) as previously described (40). The antisense RNA probes were hybridized to 10 µg of total RNA, and RNase protection assays were performed with a commercial kit (Ambion, Austin, TX), according to the company’s protocol. Products were resolved on 6% denaturing polyacrylamide gels, and the protected fragments were visualized by autoradiography. The radioactivity present in the protected fragments was also quantitated using a MolecularImager (Bio-Rad, Richmond, CA). An 18S RNA probe was used as a control for equal RNA loading.
Expression of MHC class I molecules in mouse Th1 and Th2 cells
Mouse Th1 and Th2 lines generated from DO.11.10-transgenic
CD4+ T cell cultures were harvested 5 days after
stimulation and incubated for 3 days with or without IFN- (1000
U/ml). Cells were stained with biotinylated anti-clonotypic mAb
KJ1-26 (41) followed by incubation with streptavidin-FITC (PharMingen)
and anti-H-2Kd-PE (PharMingen) or an isotype-matched
control mAb. Cells were analyzed with a FACScan flow cytometer (Becton
Dickinson).
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
/ß act directly on human T cells to promote Th1
development
To examine the roles of IFN-, IFN-ß, and IFN- in the
differentiation of human Th cell subsets, we generated T cell lines
from CD4+, CD45RA+ T cells isolated from cord
blood. Naive T cells were stimulated with irradiated allogeneic
monocytes and PHA in the presence of IL-12 and neutralizing
anti-IL-4 mAb or IL-4 and neutralizing anti-IL-12 mAb,
respectively. IFN-, IFN-ß, or IFN- were added at the time of
priming to cultures containing IL-4 and neutralizing anti-IL-12
mAbs (Th2-inducing conditions). The Th phenotype was determined 7 days
after stimulation. After restimulation with PMA and ionomycin, IFN-
and IL-4 productions were determined at the single cell level by
intracellular staining (Fig. 1
). Neonatal
T cells primed in the presence of IL-12 and neutralizing anti-IL-4
mAbs developed mostly into Th1 cells (55% IFN--producing cells vs
4% IL-4 producers and 8% double producers; Fig. 1A),
whereas priming in the presence of IL-4 and neutralizing anti-IL-12
mAbs induced development of a polarized Th2 population (0.5%
IFN--producing cells vs 23% IL-4 producers; Fig. 1B).
Addition of IFN- (Fig. 1C) or IFN-ß (Fig. 1D) at the time of priming under Th2-inducing conditions
(IL-4 and anti-IL-12 mAbs) resulted in a marked increase in cells
producing IFN- (11 and 20% compared with 0.5%) and a reduction
(two- to fourfold) in cells producing IL-4 (12 and 5% compared with
23%). IFN-, in contrast, was less effective in inducing Th1 cell
development (Fig. 1E): only a marginal increase in cells
producing IFN- (2.9% compared with 0.5%) and a minor decrease in
IL-4-producing cells (20% compared with 23%) were observed in
cultures that had been stimulated in the presence of IL-4, neutralizing
anti-IL-12 mAbs, and IFN-. Priming in the presence of IFN-,
neutralizing anti-IL-4 mAb, and anti-IL-12 mAb also resulted in
the development of Th1 cells, indicating that IFN- is directly
implicated in Th1 development rather than through the action of IL-4
(data not shown). These results confirm and extend our previous finding
that cord blood leukocytes primed with PHA in the presence of IL-4,
anti-IL-12 mAbs, and IFN- secrete predominantly IFN- upon
restimulation (19).
|
/ß promote Th1 development by acting
directly on naive T cells or whether the presence of APC is required.
Purified CD45RA+ T cells isolated from peripheral blood
were stimulated with plate-bound anti-CD3 mAb in the presence of
IL-12 and neutralizing anti-IL-4 mAb to induce Th1 development or
in the presence of IL-4 to promote Th2 development, respectively.
IFN-, IFN-ß, or IFN- was added at the time of CD3 stimulation
to cultures containing IL-4. After 3 days of culture, the cells were
washed and expanded for an additional 6 days in medium containing IL-2.
The IL-12 responsiveness of the cell lines was used as a readout to
determine the Th phenotype. As expected, IL-12 induced tyrosine
phosphorylation of Stat4 in cultures that have been stimulated in the
presence of IL-12 (Fig. 2A, lane 2),
whereas it was unable to activate this signaling pathway in cultures
that had been primed in the presence of IL-4 (lane
4). Moreover, addition of IFN- or IFN-ß at priming even in
the presence of the Th2-inducing cytokine IL-4 resulted in the
development of IL-12-responsive T cells (lanes 6 and
8), whereas IFN- did not significantly increase IL-12
responsiveness under these conditions (lane 10). In
addition, IL-12 induced tyrosine phosphorylation of Stat4 in cultures
that had been stimulated in the presence of IFN- and neutralizing
anti-IL-4 mAb (data not shown). The ability of cells primed in the
presence of IFN-/ß to signal in response to IL-12 correlates with
IL-12Rß2 expression. Surface IL-12R expression was monitored using
mAbs directed against the ß1 and ß2 subunits of the IL-12R. Fig. 2B shows that while IL-12Rß1 was expressed to the same
extent regardless of the cytokines present at priming, IL-12Rß2 was
selectively expressed by T cells primed in the presence of IL-12 or
IFN-/ß. In conclusion, these data indicate that in addition to
IL-12, IFN- and IFN-ß act directly on human T cells to promote the
development of Th1-type cells.
|
does not induce the development of mouse Th1 cells
Wenner et al. have shown that in contrast to human cells,
IFN-/ß could not induce Th1 development and IL-12 responsiveness
in mouse T cells (26). IFN-, however, induced IL-12-responsive mouse
T cells by up-regulating the IL-12Rß2 subunit (18). To address the
apparent differences in IFN action in the two species, we compared side
by side the functional effects of IFN-/ß on human and mouse Th
subset differentiation. Mouse OVA-specific Th1 and Th2 lines were
generated by stimulating purified naive CD4+ T cells from
DO11.10 TCR-transgenic mice specific for OVA peptide 323–339 with OVA
peptide presented by mitomycin C-treated BALB/c splenocytes in the
presence of IL-12 and neutralizing anti-IL-4 mAb or IL-4 and
neutralizing anti-IL-12 mAbs, respectively (16, 38). At priming,
IFN- or IFN- was added to cultures containing IL-4 and
neutralizing anti-IL-12 mAbs. The Th phenotype of these lines was
analyzed by staining for intracellular cytokines after stimulation with
PMA and ionomycin. As expected, priming in the presence of IL-12 and
neutralizing anti-IL-4 mAb induced Th1 phenotype development,
whereas priming in the presence of IL-4 and neutralizing anti-IL-12
mAbs promoted differentiation of Th2 cells (data not shown). Addition
of IFN- or IFN- at priming to cultures containing IL-4 and
neutralizing anti-IL-12 mAbs had no significant effect on the Th2
cytokine profile of the resulting population (data not shown).
We next analyzed expression of the IL-12Rß2 subunit and IL-12
responsiveness in these cells. As Abs against the mouse IL-12Rß1 and
-ß2 subunits are not yet available, transcripts encoding the
IL-12Rß1 and -ß2 subunits were analyzed by RNase protection assays.
Consistent with previous observations (18, 39), no significant
differences in IL-12Rß1 mRNA expression were detected in mouse Th
cell lines (data not shown). Since IL-12 up-regulates the expression of
IL-12Rß2 transcripts in activated human and mouse T cells (19, 39),
we used induction of IL-12Rß2 mRNA by IL-12 as a readout for IL-12
responsiveness. IL-12Rß2 is expressed in mouse Th1 cells (Fig. 3, lane 1) and culturing Th1
cells for 20 h in the presence of IL-12 strongly up-regulates the
expression of IL-12Rß2 (lane 2), indicating the
presence of a functional IL-12R. T cells primed under Th2-inducing
conditions in the absence (lane 3) or the presence
(lane 5) of IFN- did not express IL-12Rß2
transcripts, and IL-12 treatment did not induce IL-12Rß2 mRNA
expression (lanes 4 and 6). In contrast,
priming in the presence of IFN- resulted in the development of cells
that express IL-12Rß2 transcripts and are IL-12 responsive
(lanes 7 and 8). These cells, when
restimulated in the presence of IL-12, secreted IFN- (data not
shown).
|
/ß results in the development of IFN--producing cells that
express the IL-12Rß2 subunit (Figs. 1
and 2) (19).
IFN-/ß induces tyrosine phosphorylation of Stat4 in human, but
not in mouse, Th1 and Th2 cells
To determine whether the distinct functional effects of
IFN-/ß on human and mouse Th cell development originate from
different uses of signaling molecules, we analyzed tyrosine
phosphorylation of Stat4 in response to IFNs and IL-12 in
differentiating human and mouse Th1 and Th2 cells. In agreement with
our previous findings (19) and those of other laboratories (16, 17, 18),
IL-12 induces tyrosine phosphorylation of Stat4 in human Th1, but not
Th2, cells (Fig. 4A,lanes 2 and 7). Interestingly, IFN- and IFN-ß were
very efficient in activating Stat4 in human Th1 cells, and unlike
IL-12, they also induced tyrosine phosphorylation of Stat4 in Th2 lines
(lanes 3, 4, 8, and
9). IFN-, in contrast, did not induce activation of Stat4
in Th1 or Th2 cells (lanes 5 and 10).
|
induces tyrosine phosphorylation of
Stat4 in mouse Th1 and Th2 cells. DO11.10 Th1 and Th2 lines were
exposed to IL-12, IFN-, or IFN-. As shown in Fig. 4B,
Stat4 is activated by IL-12 in Th1 cells, but neither IFN- nor
IFN- induces Stat4 tyrosine phosphorylation in mouse Th1 or Th2
cells. Notably, both cell types respond to IFN- by up-regulating
class I molecules (Fig. 4C), thus indicating that mouse T
cells also express a functional IFN- receptor. These results provide
clear evidence for a species-specific difference in IFN--induced
activation of the Stat4 molecule. Functional effects of STAT activation on cytokine production by differentiated human T cells
The analysis of Stat4- and Stat6-deficient mice has
demonstrated the crucial role of STAT proteins in the initiation of
transcription programs leading to the differentiation of naive T cells
into polarized Th1 and Th2 subsets, respectively (20, 21, 22, 23, 24). An important
question is whether activation of a specific STAT protein in
differentiated Th1 and Th2 cells is sufficient to alter their cytokine
secretion pattern. Since IFN-, in contrast to IL-12, induces Stat4
phosphorylation in differentiating human Th1 and Th2 cells (Fig. 4A) as well as in established human Th1 and Th2 clones (data
not shown), we tested whether stimulation of Th2 lines and clones in
the presence of IFN- results in IFN- production. Restimulation of
Th2 lines (Fig. 5A) and clones
(Fig. 5B) in the presence of IFN- resulted in only a
modest increase in IFN- production. Consistent with a previous
report, we detected high amounts of IFN- in the culture supernatant
after restimulation of Th2 cells in the presence of IL-12 (42). Thus,
activation of Stat4 does not appear to be sufficient to induce IFN-
production by differentiated Th2 cells despite the fact that it has
been shown to bind to a tandem site present in the first intron of the
human IFN- gene and thus has been implicated in the regulation of
the IFN- gene (43).
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The functions of IFN-/ß and IFN- in inducing
differentiation of human and mouse naive T cells to Th1-type effector
cells have remained controversial. Stimulation of resting human T cells
in the presence of IFN- increases the frequency of IFN--secreting
CD4+ T cells (44), and allergen-specific T cell clones
generated in the presence of IFN- from the peripheral blood of
atopic patients demonstrate a shift toward the Th0/1 phenotype (45). In
addition, human cord blood leukocytes primed in the presence of IFN-
develop into IFN--producing Th1 cells, even when cultured in the
presence of the Th2-inducing cytokine IL-4 and neutralizing
anti-IL-12 mAbs. The Th1 cells generated in this manner express the
IL-12Rß2 mRNA and are responsive to IL-12 (19). In contrast, IFN-,
but not IFN-, has been shown to be an important cofactor for Th1
development in mice (26, 46, 47). IFN- can rescue IL-12Rß2 mRNA
expression even in the presence of IL-4 and restore IL-12
responsiveness in early developing mouse Th2 cells (18).
The data presented in this report provide a molecular basis for the
previously described effect of IFN-/ß in human Th1 development and
help to explain the divergent function of type I IFNs when comparing
human and mouse Th cell development. Consistent with our previous
observation (19), IFN-/ß induce Th1 development in human naive T
cells, even in the presence of the Th2-inducing cytokine IL-4 (Fig. 1).
Importantly, this is a direct effect on T cells, as it occurs in the
absence of APCs or exogenous factors other than IFN-/ß. Th1 cells
generated by IFN-/ß in the absence of IL-12 are comparable to
IL-12-generated Th1 cells in terms of cytokine production, IL-12
responsiveness, and cell surface expression of the IL-12Rß2 subunit.
Together, these findings provide clear evidence that human Th1-type
immune responses can develop in the absence of IL-12.
To analyze the functions of IFN-/ß and IFN- in mouse T
cell differentiation, we generated mouse OVA-specific Th1 and Th2 cell
lines from DO11.10 TCR-transgenic mice (16, 37). Neither IFN- nor
IFN-, when added at priming to cultures containing IL-4 and
neutralizing anti-IL-12 mAbs, had a significant effect on the
cytokine secretion profile of the resulting cell lines (data not
shown). These data are in agreement with previous findings (18, 26).
Importantly, priming of naive T cells in the presence of IFN-, but
not IFN-, results in the expression of IL-12Rß2 transcripts. These
cells are IL-12 responsive, as demonstrated by IL-12-induced
up-regulation of IL-12Rß2 transcripts (Fig. 3) and Stat4
phosphorylation (data not shown). Restimulation of these cultures in
the presence of IL-12 results in the production of IFN- (18) (data
not shown). These data suggest that IFN- contributes to Th1
development in mice, whereas IFN- has no effect, unlike previous
suggestions made from the analysis of transgenic mice expressing
IFN- under the control of the rat insulin promoter (48). In
conclusion, these data indicate that IFN-/ß act directly on human,
but not mouse, T cells to induce Th1 development, whereas IFN- acts
in both species in at least two ways; on the one hand, IFN- induces
Th1 development by enhancing IL-12-production by human and mouse
phagocytic cells (49), and on the other hand, it up-regulates the
expression of functional IL-12Rs on CD4+ T cells, rendering
the cells more responsive to IL-12 (18, 50). Our data indicate that the
effect of IFN- on the induction of IL-12 responsiveness is much
stronger in mouse than in human T cells, as the expression of
IL-12Rß2 is up-regulated in response to IFN- at much higher levels
in mouse rather than in human T cells. Together, these findings
indicate that in mice IFN- provides a signal for initiating Th1
development, the full progression of which requires IL-12-induced
signaling. On the contrary, IFN-/ß are able to induce Th1
development in the absence of IL-12 in human, but not in mouse, cells.
Species-specific activation of Stat4 by IFN-/ß
To explain the divergent effects of IFN-/ß and IFN- on Th1
development in human compared with mouse T cells, we analyzed their
ability to activate different signaling pathways. IFN- and IFN-ß
induced a strong and rapid tyrosine phosphorylation of Stat4 in human
Th1 and Th2 cells. Our findings are consistent with a recent report
showing that IFN- efficiently induces phosphorylation of Stat4 in
mitogen-activated PBMC (51). Thus, both IL-12 and IFN-/ß activate
Stat4, a protein critically involved in the generation of Th1 responses
(23, 24). In contrast, IFN- treatment does not induce tyrosine
phosphorylation of Stat4 in Th1 and Th2 cells generated from DO11.10
TCR transgenic mice, confirming that IFN- is unable to activate
Stat4 in a mouse Th1 clone (15). These data indicate a striking and to
date unparalleled species-specific activation of a STAT factor and
provide a molecular basis for the finding that IFN-/ß are powerful
inducers of Th1 development only in human cells. Given the importance
of Stat4 activation for Th1 phenotype development, it is conceivable
that activation of Stat4 in response to type I IFNs produced, for
example, in the course of a viral infection may induce Th1 development
in human T cells independently of IL-12.
Functional effects of STAT activation on differentiated Th2 cells
The analysis of Stat4- and Stat6-deficient mice has revealed
that activation of Stat4 and Stat6 is necessary for the development of
Th1 and Th2 responses, respectively (20, 21, 22, 23, 24), but is activation of
Stat4 and Stat6 sufficient to alter the cytokine secretion pattern
characteristic for differentiated Th1 and Th2 cells, respectively? Our
finding that IFN-/ß induce Stat4 tyrosine phosphorylation and DNA
binding to a similar extent in human Th1 and Th2 cells might suggest
that IFN-/ß, in addition to the induction of Th1 differentiation
of naive T cells, have similar functional effects on established Th2
cells. Alternatively, activation of Stat4 may only be required at
priming of T cells or at early stages of Th subset development to
induce differentiation toward the Th1 phenotype. We have analyzed
whether IFN- treatment of established Th2 lines and clones can, at
least transiently, restore IFN- production. Our finding that
restimulation of Th2 lines and clones in the presence of IFN- does
not significantly increase IFN- secretion indicates that activation
of Stat4, which is essential to initiate the genetic program leading to
the development of Th1 immune responses, is not sufficient to induce
IFN- production in differentiated Th2 cells. It will be interesting
to analyze whether activation of Stat4 in Th2 cells via IFN-/ß can
induce other Th1-specific functions. In conclusion, our findings
suggest that the loss of IL-12 responsiveness along Th2 differentiation
may be important to establish a hierarchy between the Th2- and
Th1-inducing signals of IL-4 and IL-12, respectively, but is not
required to maintain the polarized phenotype of Th2 cells. Once
effector T cells have reached their developmental end point, other
factors may be implicated in maintaining the polarized phenotype.
Recent reports have demonstrated the differential expression of
c-maf and GATA-3 transcription factors in Th1 and Th2 cells
and their contributions to the maintenance of Th phenotypes (52, 53).
|
Acknowledgments |
|---|
|
Footnotes |
|---|
Received for publication April 13, 1998. Accepted for publication August 24, 1998.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
ß T cell-receptor transgenic system. Proc. Natl. Acad. Sci. USA 89:6065. production and diminishes interleukin 4 inhibition of such priming. Proc. Natl. Acad. Sci. USA 90:10188. production and type I cytokine responses. Immunity 4:471.[Medline]
and IFN- in IL-12 induced T helper cell-1 development. J. Immunol. 1156:1442.
(IFN-) production during differentiation of human T helper (Th) and transient IFN- production in established Th2 cell clones. J. Exp. Med. 179:1273. increases the frequency of interferon -producing CD4+ T cells. J. Exp. Med. 178:1655. on cytokine profile, T cell receptor repertoire and peptide reactivity of human allergen-specific T cells. Eur. J. Immunol. 26:697.[Medline]
and is inhibited by transforming growth factor-ß. Eur. J. Immunol. 24:793.[Medline]
in regulation of Th1 cell development. J. Immunol. 157:1350.[Abstract]
induces autoimmune T cells through the induction of intracellular adhesion molecule-1 and B7.2. J. Immunol. 157:522.[Abstract]
: evidence for the involvement of ligand-induced tyrosine and serine phosphorylation. J. Immunol. 157:4781.[Abstract]
This article has been cited by other articles:
|
|
 |
|
  K. M. E. Gallagher, S. Lauder, I. W. Rees, A. M. Gallimore, and A. J. Godkin Type I Interferon (IFN{alpha}) Acts Directly on Human Memory CD4+ T Cells Altering Their Response to Antigen J. Immunol., September 1, 2009; 183(5): 2915 - 2920. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Penna, B. Fibbi, S. Amuchastegui, C. Cossetti, F. Aquilano, G. Laverny, M. Gacci, C. Crescioli, M. Maggi, and L. Adorini Human Benign Prostatic Hyperplasia Stromal Cells As Inducers and Targets of Chronic Immuno-Mediated Inflammation J. Immunol., April 1, 2009; 182(7): 4056 - 4064. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Davis, H. J. Ramos, L. S. Davis, and J. D. Farrar Cutting Edge: A T-bet-Independent Role for IFN-{alpha}/{beta} in Regulating IL-2 Secretion in Human CD4+ Central Memory T Cells J. Immunol., December 15, 2008; 181(12): 8204 - 8208. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Sachdeva, V. Asthana, T. H. Brewer, D. Garcia, and D. Asthana Impaired Restoration of Plasmacytoid Dendritic Cells in HIV-1-Infected Patients with Poor CD4 T Cell Reconstitution Is Associated with Decrease in Capacity to Produce IFN-{alpha} but Not Proinflammatory Cytokines J. Immunol., August 15, 2008; 181(4): 2887 - 2897. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M Krakauer, P Sorensen, M Khademi, T Olsson, and F Sellebjerg Increased IL-10 mRNA and IL-23 mRNA expression in multiple sclerosis: interferon-{beta} treatment increases IL-10 mRNA expression while reducing IL-23 mRNA expression Multiple Sclerosis, June 1, 2008; 14(5): 622 - 630. [Abstract] [PDF]
|
|
|
|
|
|
A. M. Davis, K. A. Hagan, L. A. Matthews, G. Bajwa, M. A. Gill, M. Gale Jr., and J. D. Farrar Blockade of Virus Infection by Human CD4+ T Cells via a Cytokine Relay Network J. Immunol., May 15, 2008; 180(10): 6923 - 6932. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. C. Lebre, S. L. Jongbloed, S. W. Tas, T. J.M. Smeets, I. B. McInnes, and P. P. Tak Rheumatoid Arthritis Synovium Contains Two Subsets of CD83-DC-LAMP- Dendritic Cells with Distinct Cytokine Profiles Am. J. Pathol., April 1, 2008; 172(4): 940 - 950. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. R. Sedaghat, J. German, T. M. Teslovich, J. Cofrancesco Jr., C. C. Jie, C. C. Talbot Jr., and R. F. Siliciano Chronic CD4+ T-Cell Activation and Depletion in Human Immunodeficiency Virus Type 1 Infection: Type I Interferon-Mediated Disruption of T-Cell Dynamics J. Virol., February 15, 2008; 82(4): 1870 - 1883. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Scheler, J. Wenzel, T. Tuting, O. Takikawa, T. Bieber, and D. von Bubnoff Indoleamine 2,3-Dioxygenase (IDO): The Antagonist of Type I Interferon-Driven Skin Inflammation? Am. J. Pathol., December 1, 2007; 171(6): 1936 - 1943. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Miyagi, M. P. Gil, X. Wang, J. Louten, W.-M. Chu, and C. A. Biron High basal STAT4 balanced by STAT1 induction to control type 1 interferon effects in natural killer cells J. Exp. Med., October 1, 2007; 204(10): 2383 - 2396. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Ramos, A. M. Davis, T. C. George, and J. D. Farrar IFN-{alpha} Is Not Sufficient to Drive Th1 Development Due to Lack of Stable T-bet Expression J. Immunol., September 15, 2007; 179(6): 3792 - 3803. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Fahey, R. A. Robins, and C. S. Constantinescu Reciprocal effects of IFN-{beta} and IL-12 on STAT4 activation and cytokine induction in T cells J. Leukoc. Biol., June 1, 2007; 81(6): 1562 - 1567. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. D. Brideau-Andersen, X. Huang, S.-C. C. Sun, T. T. Chen, D. Stark, I. J. Sas, L. Zadik, G. N. Dawes, D. R. Guptill, R. McCord, et al. Directed evolution of gene-shuffled IFN-{alpha} molecules with activity profiles tailored for treatment of chronic viral diseases PNAS, May 15, 2007; 104(20): 8269 - 8274. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. A. Byrnes, D.-Y. Li, K. Park, D. Thompson, C. Mocilnikar, P. Mohan, J. P. Molleston, M. Narkewicz, H. Zhou, S. F. Wolf, et al. Modulation of the IL-12/IFN-{gamma} axis by IFN-{alpha} therapy for hepatitis C J. Leukoc. Biol., March 1, 2007; 81(3): 825 - 834. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Penna, S. Amuchastegui, N. Giarratana, K. C. Daniel, M. Vulcano, S. Sozzani, and L. Adorini 1,25-Dihydroxyvitamin D3 Selectively Modulates Tolerogenic Properties in Myeloid but Not Plasmacytoid Dendritic Cells J. Immunol., January 1, 2007; 178(1): 145 - 153. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Loving, S. L. Brockmeier, W. Ma, J. A. Richt, and R. E. Sacco Innate Cytokine Responses in Porcine Macrophage Populations: Evidence for Differential Recognition of Double-Stranded RNA J. Immunol., December 15, 2006; 177(12): 8432 - 8439. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. S. Berenson, M. Gavrieli, J. D. Farrar, T. L. Murphy, and K. M. Murphy Distinct Characteristics of Murine STAT4 Activation in Response to IL-12 and IFN-{alpha} J. Immunol., October 15, 2006; 177(8): 5195 - 5203. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Miro, C. Nobile, N. Blanchard, M. Lind, O. Filipe-Santos, C. Fieschi, A. Chapgier, G. Vogt, L. de Beaucoudrey, D. S. Kumararatne, et al. T Cell-Dependent Activation of Dendritic Cells Requires IL-12 and IFN-{gamma} Signaling in T Cells J. Immunol., September 15, 2006; 177(6): 3625 - 3634. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Fahey, R. A. Robins, K. B. Kindle, D. M. Heery, and C. S. Constantinescu Effects of glucocorticoids on STAT4 activation in human T cells are stimulus-dependent J. Leukoc. Biol., July 1, 2006; 80(1): 133 - 144. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Penna, A. Roncari, S. Amuchastegui, K. C. Daniel, E. Berti, M. Colonna, and L. Adorini Expression of the inhibitory receptor ILT3 on dendritic cells is dispensable for induction of CD4+Foxp3+ regulatory T cells by 1,25-dihydroxyvitamin D3 Blood, November 15, 2005; 106(10): 3490 - 3497. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Wille-Reece, B. J. Flynn, K. Lore, R. A. Koup, R. M. Kedl, J. J. Mattapallil, W. R. Weiss, M. Roederer, and R. A. Seder HIV Gag protein conjugated to a Toll-like receptor 7/8 agonist improves the magnitude and quality of Th1 and CD8+ T cell responses in nonhuman primates PNAS, October 18, 2005; 102(42): 15190 - 15194. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Persky, K. M. Murphy, and J. D. Farrar IL-12, but Not IFN-{alpha}, Promotes STAT4 Activation and Th1 Development in Murine CD4+ T Cells Expressing a Chimeric Murine/Human Stat2 Gene J. Immunol., January 1, 2005; 174(1): 294 - 301. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. R. Foster, S. H. Masri, R. David, M. Jones, A. Datta, G. Lombardi, L. Runkell, C. de Dios, I. Sizing, M. J. James, et al. IFN-{alpha} Subtypes Differentially Affect Human T Cell Motility J. Immunol., August 1, 2004; 173(3): 1663 - 1670. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Di Stefano, G. Caramori, A. Capelli, I. Gnemmi, F.L. Ricciardolo, T. Oates, C.F. Donner, K.F. Chung, P.J. Barnes, and I.M. Adcock STAT4 activation in smokers and patients with chronic obstructive pulmonary disease Eur. Respir. J., July 1, 2004; 24(1): 78 - 85. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. W. Eriksen, V. H. Sommer, A. Woetmann, A. B. Rasmussen, C. Brender, A. Svejgaard, S. Skov, C. Geisler, and N. Odum Bi-phasic Effect of Interferon (IFN)-{alpha}: IFN-{alpha} UP- AND DOWN-REGULATES INTERLEUKIN-4 SIGNALING IN HUMAN T CELLS J. Biol. Chem., January 2, 2004; 279(1): 169 - 176. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Athie-Morales, H. H. Smits, D. A. Cantrell, and C. M. U. Hilkens Sustained IL-12 Signaling Is Required for Th1 Development J. Immunol., January 1, 2004; 172(1): 61 - 69. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Nagai, O. Devergne, T. F. Mueller, D. L. Perkins, J. M. van Seventer, and G. A. van Seventer Timing of IFN-{beta} Exposure during Human Dendritic Cell Maturation and Naive Th Cell Stimulation Has Contrasting Effects on Th1 Subset Generation: A Role for IFN-{beta}-Mediated Regulation of IL-12 Family Cytokines and IL-18 in Naive Th Cell Differentiation J. Immunol., November 15, 2003; 171(10): 5233 - 5243. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Freudenberg, C. Kalis, Y. Chvatchko, T. Merlin, M. Gumenscheimer, and C. Galanos Role of interferons in LPS hypersensitivity Innate Immunity, October 1, 2003; 9(5): 308 - 312. [Abstract] [PDF]
|
|
|
|
|
|
M. Mohty, A. Vialle-Castellano, J. A. Nunes, D. Isnardon, D. Olive, and B. Gaugler IFN-{alpha} Skews Monocyte Differentiation into Toll-Like Receptor 7-Expressing Dendritic Cells with Potent Functional Activities J. Immunol., October 1, 2003; 171(7): 3385 - 3393. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. B. Mailliard, Y.-I. Son, R. Redlinger, P. T. Coates, A. Giermasz, P. A. Morel, W. J. Storkus, and P. Kalinski Dendritic Cells Mediate NK Cell Help for Th1 and CTL Responses: Two-Signal Requirement for the Induction of NK Cell Helper Function J. Immunol., September 1, 2003; 171(5): 2366 - 2373. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Arora, B. Liu, H. He, J. Kim, T. L. Murphy, K. M. Murphy, R. L. Modlin, and K. Shuai PIASx Is a Transcriptional Co-repressor of Signal Transducer and Activator of Transcription 4 J. Biol. Chem., June 6, 2003; 278(24): 21327 - 21330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Raman, M. H. Kaplan, C. M. Hogaboam, A. Berlin, and N. W. Lukacs STAT4 Signal Pathways Regulate Inflammation and Airway Physiology Changes in Allergic Airway Inflammation Locally Via Alteration of Chemokines J. Immunol., April 1, 2003; 170(7): 3859 - 3865. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. R. Lankford and D. M. Frucht A unique role for IL-23 in promoting cellular immunity J. Leukoc. Biol., January 1, 2003; 73(1): 49 - 56. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. B. Nguyen, T. P. Salazar-Mather, M. Y. Dalod, J. B. Van Deusen, X.-q. Wei, F. Y. Liew, M. A. Caligiuri, J. E. Durbin, and C. A. Biron Coordinated and Distinct Roles for IFN-{alpha}{beta}, IL-12, and IL-15 Regulation of NK Cell Responses to Viral Infection J. Immunol., October 15, 2002; 169(8): 4279 - 4287. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. B. Nguyen, W. T. Watford, R. Salomon, S. R. Hofmann, G. C. Pien, A. Morinobu, M. Gadina, J. J. O'Shea, and C. A. Biron Critical Role for STAT4 Activation by Type 1 Interferons in the Interferon-gamma Response to Viral Infection Science, September 20, 2002; 297(5589): 2063 - 2066. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Freudenberg, T. Merlin, C. Kalis, Y. Chvatchko, H. Stubig, and C. Galanos Cutting Edge: A Murine, IL-12-Independent Pathway of IFN-{gamma} Induction by Gram-Negative Bacteria Based on STAT4 Activation by Type I IFN and IL-18 Signaling J. Immunol., August 15, 2002; 169(4): 1665 - 1668. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Luft, M. Jefford, P. Luetjens, T. Toy, H. Hochrein, K.-A. Masterman, C. Maliszewski, K. Shortman, J. Cebon, and E. Maraskovsky Functionally distinct dendritic cell (DC) populations induced by physiologic stimuli: prostaglandin E2 regulates the migratory capacity of specific DC subsets Blood, July 30, 2002; 100(4): 1362 - 1372. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Luft, P. Luetjens, H. Hochrein, T. Toy, K.-A. Masterman, M. Rizkalla, C. Maliszewski, K. Shortman, J. Cebon, and E. Maraskovsky IFN-{alpha} enhances CD40 ligand-mediated activation of immature monocyte-derived dendritic cells Int. Immunol., April 1, 2002; 14(4): 367 - 380. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Mohty, D. Jarrossay, M. Lafage-Pochitaloff, C. Zandotti, F. Briere, X.-N. de Lamballeri, D. Isnardon, D. Sainty, D. Olive, and B. Gaugler Circulating blood dendritic cells from myeloid leukemia patients display quantitative and cytogenetic abnormalities as well as functional impairment Blood, December 15, 2001; 98(13): 3750 - 3756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Dondi, E. Pattyn, G. Lutfalla, X. Van Ostade, G. Uze, S. Pellegrini, and J. Tavernier Down-modulation of Type 1 Interferon Responses by Receptor Cross-competition for a Shared Jak Kinase J. Biol. Chem., December 7, 2001; 276(50): 47004 - 47012. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Martin, D. J. Metzger, S. M. Michalek, T. D. Connell, and M. W. Russell Distinct Cytokine Regulation by Cholera Toxin and Type II Heat-Labile Toxins Involves Differential Regulation of CD40 Ligand on CD4+ T Cells Infect. Immun., July 1, 2001; 69(7): 4486 - 4492. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. K. Levings, R. Sangregorio, F. Galbiati, S. Squadrone, R. de Waal Malefyt, and M.-G. Roncarolo IFN-{{alpha}} and IL-10 Induce the Differentiation of Human Type 1 T Regulatory Cells J. Immunol., May 1, 2001; 166(9): 5530 - 5539. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Bauer, V. Redecke, J. W. Ellwart, B. Scherer, J.-P. Kremer, H. Wagner, and G. B. Lipford Bacterial CpG-DNA Triggers Activation and Maturation of Human CD11c-, CD123+ Dendritic Cells J. Immunol., April 15, 2001; 166(8): 5000 - 5007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E.-Y. So, H.-H. Park, and C.-E. Lee IFN-{gamma} and IFN-{alpha} Posttranscriptionally Down-Regulate the IL-4-Induced IL-4 Receptor Gene Expression J. Immunol., November 15, 2000; 165(10): 5472 - 5479. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Murphy, E. D. Geissal, J. D. Farrar, and K. M. Murphy Role of the Stat4 N Domain in Receptor Proximal Tyrosine Phosphorylation Mol. Cell. Biol., October 1, 2000; 20(19): 7121 - 7131. [Abstract] [Full Text]
|
|
|
|
 |
|
 F. SINIGAGLIA and D. D'AMBROSIO Regulation of Helper T Cell Differentiation and Recruitment in Airway Inflammation Am. J. Respir. Crit. Care Med., October 1, 2000; 162(4): S157 - 160. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Elhofy, I. Marriott, and K. L. Bost Salmonella Infection Does Not Increase Expression and Activity of the High Affinity IL-12 Receptor J. Immunol., September 15, 2000; 165(6): 3324 - 3332. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Bave, G. V. Alm, and L. Ronnblom The Combination of Apoptotic U937 Cells and Lupus IgG Is a Potent IFN-{alpha} Inducer J. Immunol., September 15, 2000; 165(6): 3519 - 3526. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. E. Verhagen, T. de Boer, H. H. Smits, F. A.W. Verreck, E. A. Wierenga, M. Kurimoto, D. A. Lammas, D. S. Kumararatne, O. Sanal, F. P. Kroon, et al. Residual Type 1 Immunity in Patients Genetically Deficient for Interleukin 12 Receptor {beta}1 (IL-12R{beta}1): Evidence for an IL-12R{beta}1-Independent Pathway of IL-12 Responsiveness in Human T Cells J. Exp. Med., August 21, 2000; 192(4): 517 - 528. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. H. Glimcher and K. M. Murphy Lineage commitment in the immune system: the T helper lymphocyte grows up Genes & Dev., July 15, 2000; 14(14): 1693 - 1711. [Full Text]
|
|
|
|
|
|
K. S. Wang, D. A. Frank, and J. Ritz Interleukin-2 enhances the response of natural killer cells to interleukin-12 through up-regulation of the interleukin-12 receptor and STAT4 Blood, May 15, 2000; 95(10): 3183 - 3190. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Frucht, M. Aringer, J. Galon, C. Danning, M. Brown, S. Fan, M. Centola, C.-Y. Wu, N. Yamada, H. El Gabalawy, et al. Stat4 Is Expressed in Activated Peripheral Blood Monocytes, Dendritic Cells, and Macrophages at Sites of Th1-Mediated Inflammation J. Immunol., May 1, 2000; 164(9): 4659 - 4664. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. L. Heath, L. Showe, C. Crain, F. J. Barrat, G. Trinchieri, and A. O'Garra Cutting Edge: Ectopic Expression of the IL-12 Receptor-{beta}2 in Developing and Committed Th2 Cells Does Not Affect the Production of IL-4 or Induce the Production of IFN-{gamma} J. Immunol., March 15, 2000; 164(6): 2861 - 2865. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Nishikomori, R. O. Ehrhardt, and W. Strober T Helper Type 2 Cell Differentiation Occurs in the Presence of Interleukin 12 Receptor {beta}2 Chain Expression and Signaling J. Exp. Med., March 6, 2000; 191(5): 847 - 858. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. D. Farrar, J. D. Smith, T. L. Murphy, and K. M. Murphy Recruitment of Stat4 to the Human Interferon-alpha /beta Receptor Requires Activated Stat2 J. Biol. Chem., January 28, 2000; 275(4): 2693 - 2697. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Vallin, A. Perers, G. V. Alm, and L. Ronnblom Anti-Double-Stranded DNA Antibodies and Immunostimulatory Plasmid DNA in Combination Mimic the Endogenous IFN-{alpha} Inducer in Systemic Lupus Erythematosus J. Immunol., December 1, 1999; 163(11): 6306 - 6313. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Colantonio, A. Iellem, B. Clissi, R. Pardi, L. Rogge, F. Sinigaglia, and D. D'Ambrosio Upregulation of Integrin alpha 6/beta 1 and Chemokine Receptor CCR1 by Interleukin-12 Promotes the Migration of Human Type 1 Helper T Cells Blood, November 1, 1999; 94(9): 2981 - 2989. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. v. Wely, P. C. L. Beverley, S. J. Brett, C. J. Britten, and J. P. Tite Expression of L-Selectin on Th1 Cells Is Regulated by IL-12 J. Immunol., August 1, 1999; 163(3): 1214 - 1221. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Rogge, A. Papi, D. H. Presky, M. Biffi, L. J. Minetti, D. Miotto, C. Agostini, G. Semenzato, L. M. Fabbri, and F. Sinigaglia Antibodies to the IL-12 Receptor {beta}2 Chain Mark Human Th1 But Not Th2 Cells In Vitro and In Vivo J. Immunol., April 1, 1999; 162(7): 3926 - 3932. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Coccia, N. Passini, A. Battistini, C. Pini, F. Sinigaglia, and L. Rogge Interleukin-12 Induces Expression of Interferon Regulatory Factor-1 via Signal Transducer and Activator of Transcription-4 in Human T Helper Type 1 Cells J. Biol. Chem., March 5, 1999; 274(10): 6698 - 6703. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Braun, J. He, C.-Y. Wu, and B. L. Kelsall Cholera Toxin Suppresses Interleukin (IL)-12 Production and IL-12 Receptor {beta}1 and {beta}2 Chain Expression J. Exp. Med., February 1, 1999; 189(3): 541 - 552. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
