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*
Department of Dermatology, Ludwig Boltzmann Institute for Cell Biology and Immunobiology of the Skin, University of Münster, Münster, Germany; and
Centre d’Immunologie, Institut National de la Santé et de la Recherche Médicale-Centre National de la Recherche Scientifique de Marseille Luminy, Marseille, France
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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by
cytotoxic T cell clones, suggesting a role for Thy-1 in cytolysis and
lymphokine production (5). Apart from these data, no significant information exists about the functional role of Thy-1 for peripheral T cells in vivo. Because of the high Thy-1 expression on thymic T cells, Hueber et al. recently investigated Thy-1-deficient mice to determine the role of Thy-1 for thymocyte differentiation and function; however, only subtle abnormalities were found (6).
This report addresses the functional role of Thy-1 for peripheral T
cells. We show that Thy-1-/- mice have a gradual but
definitive reduction of various T cell-mediated immune responses in
vivo, including contact hypersensitivity
(CHS)3, irritant dermatitis,
and delayed-type hypersensitivity (DTH). In contrast, the Ag-presenting
functions of epidermal cells and bone marrow-derived dendritic cells
(BmDCs) from Thy-1-/- donors were not altered. The
proliferation of Thy-1-/- T cells after stimulation with
immobilized anti-CD3 was impaired, but secretion of IL-2, IL-4, and
IFN- was not affected. Furthermore, peripheral T cells from
Thy-1-/- mice exhibited a markedly diminished
Ca2+ influx and reduced protein tyrosine phosphorylation
after CD3 stimulation. Taken together, these data indicate that T
cell-dependent immune responses are decreased in Thy-1-deficient mice,
and that impaired T cell activation after stimulation may contribute to
the decreased cutaneous immunity observed in these animals.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Thy-1-deficient (Thy-1-/-) mice were established in a 129/Sv x C57BL/6 background as described previously (7). F2 littermates from the intercross of F1 Thy+/- mice were used for comparative studies between Thy-1-/- and Thy-1+/+ mice.
CHS, DTH, irritant dermatitis, and immunohistochemistry
CHS and DTH experiments were performed as described previously (8, 9). Briefly, mice (n = 5) were sensitized by painting 100 µl of 0.15% trinitrochlorobenzene (TNCB) or 50 µl of 2% oxazolone in acetone/corn oil (4:1) onto the shaved back. For elicitation of CHS responses, 10 µl of 0.8% TNCB or 0.5% oxazolone was painted on both sides of each ear. CHS was determined by the degree of ear swelling of the hapten-exposed ear compared with the ear thickness before challenge and was measured with a micrometer (Mitutoyo, Tokyo, Japan) at 24 and 48 h postchallenge. Mice that were ear challenged without prior sensitization served as negative controls.
For assessment of DTH responses, nucleated spleen cells from naive BALB/c (H-2d) mice were used. For sensitization, 1 x 108 spleen cells were injected s.c. at two sites at the dorsum of naive Thy-1-/- and Thy+/+ mice (n = 5; H-2b). Control groups received equivalent injections of PBS. For elicitation of DTH, mice were challenged by a s.c. injection of 1 x 107 spleen cells (suspended in 30 µl of PBS) into one hind footpad. Control groups that had not been sensitized received identical footpad injections. DTH was determined by the degree of footpad swelling of the injected site compared with the untreated contralateral footpad and was measured with a micrometer at 24 h postchallenge.
To assess irritant dermatitis, groups of mice (n = 5) were painted with 10 µl of 1% croton oil in acetone/corn oil (4:1) on both sides of each ear. Ear swelling was measured 24 h later as described above and compared with the ear thickness before painting. Mice painted only with acetone/corn oil served as a negative control.
For immunohistochemical analyses, deparaffinized embedded sections were mounted on Tissue-Tek (Mikrom, Walldorf, Germany), washed in 1% methanolic hydrogen peroxide, rinsed with PBS, preincubated with 2% BSA for 30 min, and incubated with the primary Abs rat anti-mouse CD4 (clone H 129.19; PharMingen, San Diego, CA) and rat anti-mouse CD8a (clone 53-6.7; PharMingen) diluted 1/10 in 1% BSA for 2 h at room temperature. Sections were developed by an indirect immunoperoxidase technique using the following reagents: PBS (0.01 M, pH 7.4), peroxidase-conjugated goat anti-rat IgG (dilution 1/100, Dianova, Hamburg, Germany), 0.01% hydrogen peroxide, and 3-amino-9-ethylcarbazole (Sigma, St. Louis, MO). Incubation of sections of mouse skin with anti-mouse CD4 and anti-mouse CD8 (for negative controls the unconjugated Ab was used) was followed by a peroxidase-conjugated goat anti-rat IgG Ab (dilution 1/100, Dianova). Counterstaining was performed with Meyer’s hemalaun solution (Merck, Darmstadt, Germany).
Generation and culture of BmDCs
BmDCs were generated by the culture of bone marrow cells in the presence of granulocyte-macrophage CSF (GM-CSF) and IL-4, as described by Inaba et al. (10). Briefly, bone marrow was collected from tibias and femurs of Thy-1-/- and Thy-1+/+ mice, using PBS and a syringe with a 25-gauge needle, and suspended by vigorous pipetting. E were lysed by incubating cells in lysing buffer (Ortho, Neckargmünd, Germany) for 2 min. The remaining cells were passed through nylon mesh to remove small pieces of bone and debris. The cells were washed twice with cold PBS, resuspended in BM medium (RPMI 1640 medium supplemented with 5% FCS, 2 mM L-glutamine, 0.1 mM essential and nonessential amino acids, 50 µM 2-ME, and 20 µg/ml gentamicin), and cultured in petri dishes (Becton Dickinson, Heidelberg, Germany) at a density of 0.5 x 106 cells/cm2 for 4 h. Nonadherent cells were collected; 1 x 106 cells were placed in 24-well plates (Becton Dickinson), adjusted to 1 ml with BM medium, and supplemented with 150 U/ml GM-CSF (R&D Systems, Wiesbaden, Germany) and 75 U/ml IL-4 (PharMingen) (11). After 2 days of incubation (37°C, 5% CO2), 600 µl of medium was removed and replaced with the same volume of fresh BM medium containing 150 U/ml GM-CSF and 75 U/ml IL-4. Cells were incubated for an additional 3 days, and nonadherent cells were harvested by pipetting and subsequently subcultured in 6-well plates in medium containing 150 U/ml GM-CSF and 75 U/ml IL-4. After 2 days of incubation, >70% of the nonadherent cells in culture had acquired typical dendritic morphology. These cells were harvested and used as source of BmDCs in subsequent experiments.
Flow cytometry of BmDCs
BmDCs were harvested and washed three times with ice-cold PBS. Thereafter, aliquots of 1 x 105 cells were incubated with mAb against CD80 (clone 1G10; Dianova), Ia (clone M5/114; Boehringer Mannheim, Mannheim, Germany), F4/80 and nonlymphoid dendritic cell 145 (both from BMA, Augst, Switzerland), CD40 (clone 3/23, PharMingen), ICAM-1 (clone 3E2, PharMingen), CD86 (clone GL/1, PharMingen), or rat IgG as isotype control (Dianova) for 45 min on ice (1 µg/ml diluted in PBS/1% BSA (v/w)). Cells were washed twice with PBS/0.1% BSA (v/w) and incubated with FITC-conjugated goat anti-rat IgG (Dianova, diluted 1/50 in PBS/1% mouse serum (v/v)) for 45 min on ice. Propidium iodide (100 µM; Sigma) was added after incubation, and cells were washed twice and subsequently analyzed in an EPICS-XL flow cytometer (Coulter, Krefeld, Germany). Dead cells, as determined by their propidium iodide fluorescence, were gated out.
BmDC-lymphocyte alloreaction
BmDCs were incubated in RPMI 1640 medium supplemented with 10% heat-inactivated FCS (Life Technologies, Grand Island, NY), 100 U/ml penicillin, 100 mg/ml streptomycin, 0.1 mM essential and nonessential amino acids, 2 mM L-glutamine, 1 mM sodium pyruvate, and 0.01 M HEPES buffer ("complete medium") containing 50 µg/ml mitomycin C (Sigma) for 30 min (37°C, 5% CO2); washed six times with cold PBS; and applied in serial dilutions to 2 x 105 allogeneic T cells in 96-well round-bottom plates. T cells were obtained from the spleen cells of BALB/c mice by nylon wool purification. After 4 days, T cell proliferation was measured by adding 1 µCi of [3H]thymidine per well followed by quantification of incorporated [3H]thymidine.
Mixed epidermal cell-lymphocyte reaction (MELR)
Primary MELR was performed as described previously (9, 12). T cells were prepared by passing RBC-depleted spleen cells over a nylon wool column followed by the removal of the remaining contaminants using mAbs M5/114, Mac-1, and B220 with immunomagnetic microbeads (MiniMACS, Miltenyi Biotech, Bergisch Gladbach, Germany). The resulting cell preparation contained <0.1% IA+ cells. T cells were then cocultured with freshly prepared epidermal cells from Thy-1-/- and Thy-1+/+ mice in complete medium without essential amino acids and FCS and supplemented with 1.5% mouse serum and 5 mg/ml indomethacin ("MELR medium"). Serial dilutions of triplicate samples of epidermal cells were mixed with a constant amount (2 x 105) of allogeneic T cells in round-bottom 96-well plates. Cells were cultured for 6 days and pulsed with 1 µCi of [3H]thymidine per well for 18 h. Subsequently, cells were harvested for the evaluation of [3H]thymidine incorporation.
Lymphocyte proliferation and cytokine quantification
Nylon wool-enriched splenic T cells were used for proliferation
experiments. The stimulation of T cells was performed with either Con A
(3 µg/ml) or PMA (3 ng/ml) plus ionomycin (300 ng/ml) (all from
Sigma) for 48 h. For anti-CD3 stimulation, 100 µl
supernatant from the clone 145-2C11 (American Type Culture Collection,
Manassas, VA) was used to coat each well of a 96-well plate at 4°C
overnight. T cells were subsequently incubated in these precoated
plates for 48 h. T cell proliferation was measured by adding 1
µCi of [3H]thymidine per well followed by
quantification of incorporated [3H]thymidine at 16–18 h
after pulsing. IL-2 concentrations were measured using a CTLL-assay,
and IL-4 concentrations were measured using the CT.4S cell line as
described previously (13, 14). IFN- was quantitated using a
commercially available ELISA (Biosource, Ratingen, Germany).
Western blotting
Freshly collected lymph node cells (1 x 107) were stimulated with anti-CD3 mAb (145-2C-11, 20 mg/ml) at 37°C for various periods of time. Cells were immediately diluted with 15 ml ice-cold PBS, pelleted, and lysed in lysis buffer (10 mM Tris-HCl (pH 7.5); 150 mM NaCl; 1 mM EDTA; 1 mM sodium pyrophosphate; 1 mM NaF; 1 mM Na3VaO4; 5 mg/ml each of leupeptin, aprotinin, and pepstatin; and 0.5% Triton X-100). Lysates were centrifuged (12,000 x g, 10 min, 4°C) to remove insoluble material. The proteins were resolved on 12.5% SDS-PAGE and transferred to a polyvinylidene difluoride membrane that was then incubated with an anti-phosphotyrosine mAb (4G10, Santa Cruz Biotechnology, Santa Cruz, CA). Equal loading of each lane was determined using an anti-Lck mAb (2102, Santa Cruz Biotechnology). Staining of the anti-phosphotyrosine mAb and anti-Lck mAb was performed using anti-mouse Ig coupled to a horseradish peroxidase enhanced chemiluminescence system (Amersham, Freiburg, Germany).
Calcium analysis
Lymph node cells were initially loaded with Indo-1 (Sigma) before labeling with NaN3-free anti-CD4 and anti-CD8 mAb. After prewarming to 37°C, purified anti-CD3 mAb (40 mg/ml) was added to the cell samples (at 2 min of recording); Ca2+ influx in T lymphocytes was measured on a FACStar Plus (Becton Dickinson). Data were analyzed using MTIME software (Phoenix Flow Systems, San Diego, CA).
Statistics
A total of five mice were used per group in each CHS or DTH experiment. All experiments were performed at least three times. The data presented show the values obtained from one representative experiment. Data were analyzed using the Student t test for independent samples.
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Results |
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To study the effects of Thy-1 deficiency in CHS responses to
contact allergens, age-matched Thy-1-/- and
Thy-1+/+ control mice were sensitized to oxazolone. At 5
days after sensitization, these groups and their nonsensitized controls
were challenged on the ears; CHS responses were assessed 24 h
later. The data depicted in Fig. 1
A demonstrate a significantly
decreased swelling response of Thy-1-/- mice compared
with Thy-1+/+ controls. An additional experiment was also
performed using TNCB as a contact allergen. Again, a significantly
suppressed CHS response was seen after TNCB challenge in sensitized
Thy-1-/- mice compared with sensitized
Thy-1+/+ controls (data not shown). In addition, histologic
evaluation of the CHS reactions revealed a significant reduction in the
inflammatory cellular infiltrate and edematous tissue swelling in
Thy-1-/- mice as opposed to Thy-1+/+ controls
(Fig. 1, B and C), which suggests a role for
Thy-1 in murine CHS reactions. Immunohistochemical analyses were
performed to evaluate the CD4/CD8 ratio of the lymphocyte
infiltrate in these lesions. No differences in the subset ratio in
Thy-1-/- mice compared with Thy-1+/+ controls
were detected (data not shown).
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D. To exclude the possibility that altered numbers of Langerhans cells and dendritic epidermal T cells (DETCs) were responsible for this effect, we determined the number of Langerhans cells and DETCs present in the epidermal sheets of Thy-1-/- and Thy-1+/+ mice. Thy-1-deficient mice were found to have normal numbers of DETCs and Langerhans cells as determined by the staining of epidermal sheets with a fluorescence-labeled anti-CD3 mAb or anti-I-Ab mAb (data not shown).
Decreased DTH to alloantigens in Thy-1-deficient mice
To address the question of whether Thy-1 plays a role in DTH
reactions to alloantigens, Thy-1-/- and
Thy-1+/+ control mice (both H-2b) were
immunized to alloantigens by s.c. injection of nucleated spleen cells
from H-2d donors (BALB/c). After 5 days, challenge was
performed by injecting 1 x 107 BALB/c-derived spleen
cells into one hind footpad. Footpad swelling of the injected vs
noninjected site was assessed 24 h later as a measure of DTH
responses. The data shown in Fig. 2
indicate a significantly reduced DTH response to alloantigens in
Thy-1-/- mice compared with Thy-1+/+ control
mice. Groups of mice that were vehicle (PBS)-treated or only challenged
displayed no swelling.
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To test whether an impaired ability to present Ag could
account for the reduced CHS and DTH reactions in Thy-1-deficient mice,
BmDCs were prepared from Thy-1-/- and
Thy-1+/+ controls and used to stimulate allogeneic T cells
in the mixed BmDC-lymphocyte reaction. The data in Fig. 3A demonstrate a similar
stimulation of allogeneic T cells by various concentrations of BmDCs
from Thy-1-/- mice compared with Thy-1+/+
control mice. Furthermore, a portion of these BmDCs was evaluated for
various cell surface markers by flow cytometry. Neither
I-Ab, CD40, nonlymphoid dendritic cell 145, nor CD80
or CD86 surface marker expression was markedly altered in
Thy-1-/- mice compared with Thy-1+/+ control
mice (data not shown). In addition, epidermal cells from
Thy-1-/- mice (and Thy-1+/+ controls) were
prepared and used to stimulate allogeneic T cells in the MELR.
Epidermal cells from Thy-1-/- mice were able to stimulate
allogeneic T cells to a magnitude similar to that of
Thy-1+/+ control cells (Fig. 3B). This finding
suggests that BmDCs as well as epidermal cells from
Thy-1-/- mice are able to stimulate alloantigeneic T
cells equally as well as Thy-1+/+ controls, indicating that
the ability to present Ags is not impaired in Thy-1-deficient mice.
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As Thy-1 has been shown to regulate TCR signaling in thymocytes,
we analyzed early TCR-mediated signaling events in peripheral T
lymphocytes from Thy-1+/+ and Thy-1-/- mice.
The earliest detectable effects that follow TCR engagement are a series
of tyrosine phosphorylation events initiated by activated protein
tyrosine kinases (PTKs), which are essential in coupling the TCR to the
downstream signaling pathways. These initial events include
hydrolysis of inositol-containing phospholipids, Ca2+
mobilization, and activation of the Ras/mitogen-activated protein
kinase cascade. The data presented in Fig. 4 show the kinetics of tyrosine
phosphorylation of substrates in Thy-1+/+ and
Thy-1-/- lymphocytes after TCR/CD3 cross-linking. T cells
were stimulated at various timepoints with an anti-CD3 mAb and
lysed immediately. Tyrosine-phosphorylated proteins were analyzed by
immunoblotting with an Ab directed against phosphotyrosine. Increases
of tyrosine phosphoproteins in Thy-1+/+ mice were maximally
detected following a 2–5-min stimulation. Although a similar kinetic
of tyrosine phosphorylation of substrates following anti-CD3 mAb
cross-linking was observed in T cells from Thy-1-/- mice,
there was a significant decrease in the overall intensity of tyrosine
phosphoproteins. This finding suggests an impairment in
Thy-1-/- peripheral T lymphocytes in the TCR-triggered
activation of PTKs. This impairment is consistent with an alteration in
the downstream signaling event. The data in Fig. 5 demonstrate that the calcium
mobilization in Thy-1-/- T cells by anti-CD3 mAb
cross-linking was significantly reduced compared with their
Thy-1+/+ counterparts. In another experiment,
Thy-1-/- and Thy-1+/+ T cells demonstrated
identically increased intracellular Ca2+ in the presence of
thapsicargine, which is known to release internal
Ca2+ stores by blocking the endoplasmic reticulum
ATPase/Ca2+ pump (data not shown).
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Taking into account the impaired Ca2+ influx and the
reduced tyrosine phosphorylation in Thy-1-deficient T cells, we were
interested in investigating the proliferative response and cytokine
expression of Thy-1-/- peripheral T cells after various
stimuli. Thy-1-deficient mice had similar numbers and subsets of
peripheral T lymphocytes as Thy-1+/+ mice. Nylon
wool-enriched splenic T cells were stimulated with either immobilized
anti-CD3, Con A, or PMA plus ionomycin. Subsequently, proliferation
was measured by assessing the radio-labeled thymidine uptake. The data
in Table I show that treatment with
immobilized anti-CD3, but not stimulation of Thy-1-/-
T cells with Con A or PMA plus ionomycin, resulted in altered
proliferative responses in Thy-1-/- T cells compared with
Thy-1+/+ control T cells. Subsequently, culture
supernatants were harvested and assayed for the presence of IL-2, IL-4,
and IFN-. The data in Table II
indicate that the production of IL-2, IL-4, and IFN- after various
stimuli is similar in Thy-1-/- T cells and
Thy-1+/+ control T cells. These data suggest that Thy-1
expression may play a role during proliferative T cell responses after
TCR/CD3 stimulation, and that Thy-1 deficiency might not be able to
perturb the cytokine secretion pattern of these cells.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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and CD3
chains, as
mediated by the Lck src kinase. This alteration in early TCR
signaling seems to be responsible for enhanced downstream signaling
events such as Ca2+ mobilization and cell proliferation.
Consistent with enhanced negative selection, a recent report using
Thy-1-/- mice containing a TCR transgene specific for a
MHC class II-restricted Ag indicated that normal self-tolerance
occurs in the absence of Thy-1 (15). In the present study, Thy-1-/- mice demonstrated reduced cutaneous immune responses compared with Thy-1+/+ mice but were not completely unable to develop CHS or DTH reactions. After CD3/TCR stimulation, Thy-1-/- peripheral T cells showed decreased proliferative responses and less influx of free Ca2+ into the cytoplasm. In addition, CD3/TCR activation led to less protein tyrosine phosphorylation in Thy-1-/- T cells than in Thy-1+/+ controls, suggesting that Thy-1 is one modulator of T cell function. Our findings indicate that Thy-1 is not essentially required for the complex signaling events that orchestrate cutaneous immune responses but appears to be involved in the fine-tuning of T cell function. Since Thy-1 is absent on all lymphocytes of these deficient mice, both Ag-specific and Ag-nonspecific cutaneous inflammation models are involved. Thus, impaired T cell activation could be an explanation for decreased T cell-mediated immune responses in Thy-1-deficient mice.
There is also evidence for a role of Thy-1 in the activation of
peripheral T cells. The physiologic ligand of Thy-1 is still unknown,
but ligation of Thy-1 by several anti-Thy-1 mAbs reacting with
different epitopes on the molecule results in the proliferation of
various T cell clones and T cell hybridomas (2, 16, 17). This
proliferative response occurs in parallel with a rise in free
intracellular Ca2+. Our own data support these findings,
since peripheral T cells from Thy-1-deficient mice demonstrated less
proliferative responses and less free intracellular Ca2+
after CD3/TCR activation. Other reports indicated that in
Thy-1- and CD3/TCR- variants of T cell
clones, the cotransfection of Thy-1 and CD3/TCR complexes was needed to
observe IL-2 secretion as a measure of proliferation after Thy-1
stimulation by anti-Thy-1 Ab (1). Moreover, T cell activation
induced by glycophosphatidylinositol-linked proteins is closely linked
to the production of IL-2 as a late event of stimulation that favors
autocrine growth (3). Our findings demonstrate that Thy-1-deficient
lymphocytes are able to produce similar amounts of IL-2, IL-4, or
IFN- after CD3/TCR activation, indicating that Thy-1 may not be
involved in the production of IL-2.
Signal transduction through the TCR or through
glycophosphatidylinositol-linked cell surface molecules such as Thy-1
appears to activate cytoplasmic PTKs, although no clear intrinsic PTK
activity has been demonstrated by the TCR or Thy-1. Lck and Fyn, which
are members of the Src family of PTKs, seem to be critically involved
in TCR- and Thy-1-induced signaling (18). In particular, cellular Fyn
has been shown to be associated with Thy-1 as detected by
coimmunoprecipitation. Accordingly, mice that underwent gene-targeted
disruption of the lymphocytic form of Fyn showed profound functional
defects in mature thymocytes after Thy-1 activation in terms of
intracellular Ca2+ elevation, IL-2 production, and
proliferation (19). Our findings further support a role for Thy-1 in
protein tyrosine phosphorylation, because T lymphocytes from
Thy-1-deficient mice demonstrated less tyrosine phosphorylation after
TCR/CD3 stimulation. This decrease in tyrosine phosphorylation in
Thy-1-/- lymphocytes was found to be particularly
associated with bands of 21, 36, 50, and 68 kDa. The p21 and p36 could
represent the phosphorylated TCR and LAT,
respectively, as they are known to be the major tyrosine-phosphorylated
bands in this molecular mass range (20). Moreover, their
phosphorylation is known to link the TCR to downstream signaling events
such as calcium mobilization.
Alternatively, the impaired peripheral T lymphocyte activation in Thy-1-/- mice could be a consequence of the thymic developmental defects found in these animals. In fact, it is possible that, in the absence of the negative regulation of TCR signaling in thymocytes by Thy-1, an inappropriate negative selection process leads to the accumulation of thymocytes that normally display a reduced signaling capability via TCR. Once they have emigrated to the periphery, these T cells will suboptimally respond to TCR signaling.
In addition to being involved in lymphocyte activation, murine Thy-1
has also been shown to be involved in cell to cell adhesion, notably in
the binding of murine thymocytes to mouse thymic epithelial cells (4).
In this system, thymoepithelial interactions involved the binding of
Thy-1 to sulfated glycans such as pentosan sulfate, dextran sulfate,
and fucoidan, which were inhibited by 
40% by soluble Thy-1 molecules
and did not require Ca2+ (21). Therefore, it is possible
that cell to cell interactions between lymphocytes and epithelial cells
or APCs could be altered in Thy-1-/- mice. Such a
putative, defective interaction could consequently be an alternative
explanation for the decreased CHS and DTH responses in Thy-1-deficient
mice. However, we do not have any evidence for such a mechanism at this
time, although current studies are underway to further test this
hypothesis.
Finally, one could speculate that Thy-1+ DETCs may also be
involved in differences in cutaneous immune responses between
Thy-1+/+ and Thy-1-/- mice. Murine skin also
contains a population of DETCs, which have been identified by their
expression of Thy-1 (22, 23). DETCs are bone marrow-derived T cells
that express the TCR - and 
-chains (24). Apart from being a
marker for these cells, there is no evidence that Thy-1 expression is
of particular functional relevance in these cells. Studies with a
recently generated murine Thy-1+-DETC line indicate that
these cells may participate in the modulation of the skin immune system
by secretion of a distinct pattern of cytokines (25). However,
Thy-1-deficient mice were found to have normal numbers of DETCs, as
visualized by staining for CD3. Thus, it is unlikely that differences
in the number of DETCs account for the impaired immunity in vivo.
Taken together, our data show that Thy-1 deficiency leads to an impairment of in vivo T cell-mediated immune responses. This impairment might be due to a defective fine-tuning of T cell effector functions in the absence of Thy-1.
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Acknowledgments |
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Footnotes |
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2 Address correspondence and reprint requests to Dr. Stefan Beissert, Department of Dermatology, University of Münster, von Esmarch Strasse 56, D-48149 Münster, Germany. E-mail address:
3 Abbreviations used in this paper: CHS, contact hypersensitivity; DTH, delayed-type hypersensitivity; BmDC, bone marrow-derived dendritic cell; GM-CSF, granulocyte-macrophage CSF; MELR, mixed epidermal cell-lymphocyte reaction; DETC, dendritic epidermal T cell; PTK, protein tyrosine kinase; TNCB, trinitrochlorobenzene.
Received for publication April 3, 1998. Accepted for publication July 14, 1998.
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T cell receptor on Thy-1+ dendritic epidermal cell lines. Science 236:834.This article has been cited by other articles:
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  K. Loser, J. Apelt, M. Voskort, M. Mohaupt, S. Balkow, T. Schwarz, S. Grabbe, and S. Beissert IL-10 Controls Ultraviolet-Induced Carcinogenesis in Mice J. Immunol., July 1, 2007; 179(1): 365 - 371. [Abstract] [Full Text] [PDF]
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 T. A. Rege and J. S. Hagood Thy-1 as a regulator of cell-cell and cell-matrix interactions in axon regeneration, apoptosis, adhesion, migration, cancer, and fibrosis FASEB J, June 1, 2006; 20(8): 1045 - 1054. [Abstract] [Full Text] [PDF]
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 J. S. Hagood, P. Prabhakaran, P. Kumbla, L. Salazar, M. W. MacEwen, T. H. Barker, L. A. Ortiz, T. Schoeb, G. P. Siegal, C. B. Alexander, et al. Loss of Fibroblast Thy-1 Expression Correlates with Lung Fibrogenesis Am. J. Pathol., August 1, 2005; 167(2): 365 - 379. [Abstract] [Full Text] [PDF]
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W. L. W. Hazenbos, Y. Murakami, J.-i. Nishimura, J. Takeda, and T. Kinoshita Enhanced Responses of Glycosylphosphatidylinositol Anchor-Deficient T Lymphocytes J. Immunol., September 15, 2004; 173(6): 3810 - 3815. [Abstract] [Full Text] [PDF]
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 A. Jain, A. Lam, I. Vivanco, M. F. Carey, and R. E. Reiter Identification of an Androgen-Dependent Enhancer within the Prostate Stem Cell Antigen Gene Mol. Endocrinol., October 1, 2002; 16(10): 2323 - 2337. [Abstract] [Full Text] [PDF]
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S. Beissert, D. Ruhlemann, T. Mohammad, S. Grabbe, A. El-Ghorr, M. Norval, H. Morrison, R. D. Granstein, and T. Schwarz IL-12 Prevents the Inhibitory Effects of cis-Urocanic Acid on Tumor Antigen Presentation by Langerhans Cells: Implications for Photocarcinogenesis J. Immunol., December 1, 2001; 167(11): 6232 - 6238. [Abstract] [Full Text] [PDF]
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