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Functional Genomics Unit, Gene Targeting Facility, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892;
Developmental and Metabolic Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892;
Veterinary and Tumor Pathology Section, Office of Laboratory Animal Science, National Cancer Institute, National Institutes of Health, Frederick, MD 21702;
§
Laboratory of Cell Regulation and Carcinogenesis,
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Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; and
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Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.
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Abstract |
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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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We have previously identified some of the molecular mechanisms underlying the immune dysregulation in this complex phenotype (9, 10). The >50% embryonic lethality observed in TGF-ß1-/- mice is associated with defects in early hematopoiesis and vasculature in the embryonic yolk sac (11). Live born TGF-ß1-/- mice exhibit the onset of inflammation as early as postnatal day 7 coincident with enhanced expression of both classes of MHC molecules (12) and increased adhesion of leukocytes to vascular endothelium (12, 13, 14, 15, 16, 17, 18). These mice exhibit autoimmune manifestations including elevated levels of Abs to nuclear Ags and kidney deposits of immune complexes (19, 20, 21). These studies also support earlier observations indicating the involvement of endogenous TGF-ß1 in autoimmune responses (22, 23, 24) and the effects of exogenous TGF-ß1 in suppressing progressive inflammation in animal models of autoimmune diseases (25, 26, 27, 28). TGF-ß1-/- mice also show increased numbers of circulating immature granulocytes, monocytes, and platelets, suggesting enhanced myelopoiesis in these mice (7, 29).
Enhanced expression of MHC class I and class II Ags in TGF-ß1-/- mice before the onset of inflammatory infiltrates implicates both molecules in the development of the inflammation and autoimmunity associated with TGF-ß1 deficiency. Mice homozygous for both the TGF-ß1 null allele and the MHC class II null allele lack inflammatory infiltrates, circulating autoantibodies, and glomerular immune complex deposits, suggesting an important role of MHC class II Ags in the pathogenesis of TGF-ß1-/- mice (30, 31). However, the significance of MHC class I Ags during this autoimmune response is not well characterized.
To identify the contribution of the MHC class I molecule in the pathogenesis of autoimmunity and inflammation in TGF-ß1-/- mice, we have generated TGF-ß1-/- mice in the genetic background of MHC class I/ß2-microglobulin (ß2M)2 deficiency by cross-breeding TGF-ß1+/- mice with ß2M-/- mice. ß2M-/- mice lack expression of MHC class I Ag and peripheral CD8+ T cells (32, 33) because ß2M is essential for the proper assembly, transport, and cell surface expression of the MHC class I heterodimers of heavy and light chains (34). These events are required for normal development of CD8+ T cells. In this paper we report on the phenotypic analysis of TGF-ß1-/-;ß2M-/- mice. Mice mutant for both loci exhibit an increased life span that was associated with a reduction in tissue inflammation and in the severity of the autoimmune response. Myelopoiesis was increased in TGF-ß1-/-;ß2M-/- mice as evident from the increased numbers of GR-1+ myeloid cells. Moreover, selective depletion of CD8+ cells in TGF-ß1-/-; ß2M+/+ mice also reduced the severity of the clinical manifestations and increased their life span, implicating the involvement of CD8+ T cells in the etiology of the inflammation associated with TGF-ß1 deficiency. These data support the hypothesis that ß2M, and specifically class MHC-I and CD8+ T cell interactions, play an important role in the evolution of immune dysregulation in the TGF-ß1-/- mouse.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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TGF-ß1+/- mice were generated by gene targeting (8). ß2M-/- mice (33) were obtained from The Jackson Laboratory (Bar Harbor, ME). Both mutations were generated in the same genetic background of the 129/SvJ strain (33). These mice were crossbred to generate the founder (TGF-ß1+/-;ß2M-/-) mice, which were then intercrossed to generate TGF-ß1;ß2M double null (TGF-ß1-/-;ß2M-/-) mice. These mice were genotyped for the TGF-ß1 gene by PCR (8) and for the ß2M gene by Southern blot analysis (33). All mice were maintained in a pathogen-free, double-barrier facility and were provided with autoclaved food and water (8).
Pathological and immunohistochemical analysis
Tissues were harvested from moribund TGF-ß1-/-;ß2M-/- mice euthanized by CO2 narcosis or immediately after death (from 21 to 123 days of age). Tissues were fixed either in 10% buffered formalin or Bouin’s fixative or frozen in OCT compound (Miles Scientific, Naperville, IL). Fixed tissues were embedded in paraffin and sectioned at 4–6 µm. Selected frozen or Bouin’s-fixed tissues were used to analyze specific surface Ags of infiltrating inflammatory cells. The following Abs and kits were used: goat biotinylated anti-mouse IgG (Vector Laboratories, Burlingame, CA), rat anti-mouse Mac-2 (American Type Culture Collection, Manassas, VA), biotinylated anti-mouse B220 (Boehringer Mannheim, Indianapolis, IN), rabbit anti-human CD3 (DAKO, Carpinteria, CA), and Vectastain Elite ABC kits (Vector Laboratories).
Northern blot analysis
Total RNA was extracted from various organs of three animals
using RNA STAT-60 (Tel-Test, Friendswood, TX). Total RNA (15 µg) was
electrophoresed on a 1% agarose/6.8% formaldehyde gel and then
blotted onto a nylon membrane (Schleicher & Schuell, Keene, NH) as
previously described (35). The A
-, Aß-, and
Eß-chain class II probes (12) were used at the same time
for detection of MHC class II transcripts. Prehybridization and
hybridization were conducted as described (35). After
washing, the filters were exposed to Kodak X-AR film (Rochester, NY) at
-70°C with intensifying screens.
Flow cytometric analysis
Single cell suspensions of bone marrow, spleen, and thymus from five of each of TGF-ß1-/-;ß2M-/- and TGF-ß1+/+;ß2M-/- mice were prepared, and 1.5 x 106 cells were stained for expression of the designated lineage markers with the following Abs from PharMingen (San Diego, CA): anti-GR-1 and anti-CD11b for myeloid lineages and anti-CD4, -CD5, and -CD8 for T cells. Flow cytometric analysis was performed after the incubation of the cells with primary Abs (17).
Treatment of TGF-ß1-/- mice with mAb to CD8
To examine the contribution of CD8+ cells to the phenotype of TGF-ß1-/- mice, TGF-ß1-/- mice were treated with anti-CD8 Ab. The rat IgG2b mAb to CD8 (Ab 2.43) and the control, nonimmune rat IgG (Ab 49) were kindly provided by Dr. Crystal Mackall and Dr. Ron Gress (National Cancer Institute, National Institutes of Health) (36). A minimum of 10 TGF-ß1-/- mice received i.p. injections of anti-CD8 mAb, starting with 1 mg on the first day of injections and continuing with 0.5 mg (in 0.2 ml) on an alternating day schedule, 3 days/wk. Control groups included five TGF-ß1+/+ mice injected with Ab 2.43 and five TGF-ß1-/- mice that received Ab 49. Animals were weighed on each injection day. At sacrifice, tissues were submitted for evaluation by immunohistochemical studies (as above).
ELISA and glomerular Ig deposition
For the detection of anti-ssDNA Abs, ssDNA was obtained by heating calf thymus DNA (Sigma, St. Louis, MO) for 10 min, followed by immediate cooling on ice. Plates were first blocked with PBS and 5% fetal bovine serum. For determination of 16/6 Id binding Abs, plates were coated with the human anti-DNA 16/6 Id bearing mAb (19, 37, 38). Subsequently, serial dilutions of mouse sera were incubated in the wells for 90 min, washed, and then incubated for 75 min with goat anti-mouse IgG (Sigma) conjugated to peroxidase (Jackson ImmunoResearch, West Grove, PA). Plates were then washed and incubated with the substrate 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS, Sigma) and read using an ELISA reader at 414 nm.
For detection of Ig deposits, frozen kidney sections (5 µm thick) were fixed in cold acetone for 10 min and stained with FITC-conjugated goat Abs to mouse IgG as described previously (19, 38).
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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By intercrossing the founder
(TGF-ß1+/-;ß2M-/-)
mice, we obtained 139 live born mice. Genotyping of these mice revealed
that 45 mice (32.4%) were normal for the TGF-ß1 gene
(TGF-ß1+/+;ß2M-/-),
75 (53.9%) were heterozygous
(TGF-ß1+/-;ß2M-/-),
and 19 (13.7%) were TGF-ß1 null
(TGF-ß1-/-;ß2M-/-).
These results suggest that 
45% of
TGF-ß1-/-;ß2M-/-
mice died in utero, consistent with the known embryonic lethality of
the TGF-ß1-/- genotype, suggesting
ß2M deficiency did not influence the causes of
embryonic lethality seen in TGF-ß1-/-
mice. Kaplan-Meier survival analysis shows a significant improvement of
survival (p = 4 x
10-5) in
TGF-ß1-/-;ß2M-/-
mice (Fig. 1
A). Despite this
increase in viability,
TGF-ß1-/-;ß2M-/-
mice continue to show significant reductions in body weight profiles
relative to
TGF-ß1+/+;ß2M-/-
littermates (Fig. 1B). The severity of wasting syndrome and
degree of longevity is variable in mice that survive beyond 4 wk, with
a single mouse surviving to 18 wk of age (Table I, mouse 45-2).
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To identify factors contributing to the increased survival of
TGF-ß1-/-;ß2M-/-
mice, we analyzed various tissues to examine whether the multifocal
inflammatory process seen in TGF-ß1-/-
mice was reduced in
TGF-ß1-/-;ß2M-/-
mice. In TGF-ß1-/- mice, lungs and
heart were always severely affected (8, 17) and other
frequently affected organs include liver, salivary glands, spleen,
colon, and pancreas (8, 17, 21). A total of 14
TGF-ß1-/-;ß2M-/-
mice of different ages were processed for histopathological examination
(Table I
). Although the tissue distribution of inflammatory lesions was
similar to that found in TGF-ß1-/-
mice, the severity of inflammation was significantly reduced in
TGF-ß1-/-;ß2M-/-
mice, especially in the heart (Fig. 2,
A and B). Only 6 of 14
TGF-ß1-/-;ß2M-/-
mice had cardiac lesions and these demonstrated a minimal grade of
inflammation (Table I). Infiltration of Mac-2 immunoreactive
macrophages in the heart was also less severe in
TGF-ß1-/-;ß2M-/-
mice (Fig. 2D) than in
TGF-ß1-/- mice (Fig. 2C).
Five of 13
TGF-ß1-/-;ß2M-/-
mice showed perivascular cuffing of inflammatory cells in the brain,
although they did not exhibit apparent neurological manifestations.
Furthermore, the perivascular cuffing was apparent only in mice older
than 4 wk of age (Table I), indicating the slower progression of the
inflammatory process in
TGF-ß1-/-;ß2M-/-
mice. Some of these changes were accompanied by demyelination, with
infiltration of Mac-2 reactive macrophages in the demyelinating lesions
(Fig. 3, A and B).
Lung lesions, which mainly consisted of perivascular cuffing of
lymphocytes, were present in all 14
TGF-ß1-/-;ß2M-/-
mice, although the grade of inflammation was substantially lower than
in TGF-ß1-/- mice (Table I).
Bronchopneumonia was observed in two younger mice. Liver cholangitis
was present in 9 of 13
TGF-ß1-/-;ß2M-/-
mice. In
TGF-ß1-/-;ß2M-/-
mice, CD3+ lymphocytes were most prevalent
in the inflammatory lesions of the liver, lungs (Fig. 3, C and E), and some other tissues, with fewer
B220+ cells (Fig. 3, D and
F). Lymph node enlargement also was less common in
TGF-ß1-/-;ß2M-/-
mice than in TGF-ß1-/- mice, and the
immunoblastic lesions of the spleen and lymph nodes in
TGF-ß1-/-;ß2M-/-
mice were less severe.
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MHC class II mRNA levels in the heart, lungs (Fig. 4), and other tissues, including brain,
spleen, and liver (data not shown) of
TGF-ß1-/-;ß2M-/-
mice were significantly lower than those seen in
TGF-ß1-/- mice (Fig. 4), a finding
consistent with the reduction in inflammation present in these mice.
However, expression levels remained higher than those in wild-type
mice.
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As shown in Table II, flow
cytometric analysis revealed the expected deficiency of mature
CD8+ T cells in the spleen and bone marrow. The
corresponding reduction in CD8+ T cells in thymi
of
TGF-ß1-/-;ß2M-/-
mice reflects a decrease in
CD4+/CD8+ double positive
thymic precursors (22.4% in
TGF-ß1-/-;ß2M-/-
mice vs 69.2% in
TGF-ß1+/+;ß2M-/-
mice), which is consistent with the thymic phenotype of TGF-ß1 null
mice previously reported (16).
TGF-ß1-/-;ß2M-/-
mice exhibited a relative increase in myelopoiesis, as evidenced by the
higher percentage of GR-1+ cells in the bone
marrow, spleen, and thymus (55.2% vs 33.3%, 13.4% vs 6.57%, and
16.7% vs 0.6%, respectively) when compared with
TGF-ß1+/+;ß2M-/-
littermates. We also observed a consistent reduction in the relative
number of B cells in the marrow of
TGF-ß1-/-;ß2M-/-
mice (16.6% vs 32.6% in controls), and a relative increase in
CD4+ T cells in bone marrow (4.3% vs 0.7%) was
also observed in all
TGF-ß1-/-;ß2M-/-
mice. These findings were previously considered secondary to the
chronic proinflammatory stimuli; however, they are clearly present even
in the absence of extensive inflammation, supporting the conclusion
that these findings represent a primary phenotype associated with the
TGF-ß1 null mutation.
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As described above,
TGF-ß1-/-;ß2M-/-
mice lack CD8+ T cells. To determine the
contribution of CD8+ T cell subset to the
pathogenesis of the TGF-ß1-/-
phenotype, we performed a depletion study in
TGF-ß1-/- mice. It has been reported
that CD8+ T cell depletion caused the enhanced
autoimmune reaction in mice in which experimental systemic lupus
erythematosus (SLE) was induced (39). It might therefore
be possible that CD8+ T cell depletion in
TGF-ß1-/- mice would increase the
severity of the observed autoimmunity and inflammation. However,
treatment of TGF-ß1-/- mice with
anti-CD8 Ab 2.43 improved their survival (average age at sacrifice
65 ± 5 days, vs 25 days for untreated TGF-ß1 null mice) and
normalized their body weight profile. Growth curves of CD8-depleted
TGF-ß1 null mice appear similar to those of
TGF-ß1-/-;ß2M-/-
mice exhibiting a reduction in symptoms.
TGF-ß1-/- mice began to lose weight at
the age of 2 wk (Fig. 5A).
CD8+ T cell depletion with Ab 2.43 started at day
18–19 delayed the progression of this wasting syndrome (Fig. 5, C and D), whereas treatment with control Ab had
no effect on the phenotype of TGF-ß1-/-
mice (Fig. 5B). A reduction in the number of infiltrating
inflammatory cells was observed in all tissue examined (data not
shown), suggesting CD8+ T cell involvement in the
development of autoimmune-related inflammation and systemic wasting
syndrome observed in TGF-ß1-/-
mice.
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We have reported earlier the elevated levels of serum Abs to nuclear Ags and immune complex deposition in the kidneys of TGF-ß1-/- mice as early as 11 days of age (19, 20). This autoimmune response overlaps with the initiation of the inflammatory processes, suggesting an etiological role in multifocal inflammation in these mice (17).
To determine whether such a response occurs in the absence of
ß2M expression, we measured the titers of
anti-ssDNA and 16/6 Id Abs in seven
TGF-ß1-/-;ß2M-/-
mice (from 21 to 72 days of age). As shown in Fig. 6A, sera from
TGF-ß1-/-;ß2M-/-
mice showed the elevated titers of autoantibodies even without MHC
class I Ags compared with sera from
TGF-ß1+/+;ß2M-/-
mice. However, only one of seven
TGF-ß1-/-;ß2M-/-
mice (14.2%) showed an elevated titer to 16/6 Id (Fig. 6A)
as compared with the previously reported frequency in
TGF-ß1-/- mice (50.0%)
(19). Elevation in serum Ab titers to ssDNA was detected
in two
TGF-ß1-/-;ß2M-/-
mice (28.6%; Fig. 6A), compared with our previously
reported frequency of three of eight in
TGF-ß1-/- mice (37.5%)
(19). Of the remaining seven
TGF-ß1-/-;ß2M-/-
mice (3–11 wk of age), four were negative for both autoantibodies. We
also examined the immune complex deposits in the kidneys because the
immune complexes are pathogenic and cause damage to the kidneys and
they are the hallmarks of the prognosis of SLE. The frequency of renal
deposition of immune complexes was significantly reduced in
TGF-ß1-/-;ß2M-/-
mice, occurring in only one of six, as compared with six of nine
TGF-ß1-/- mice (16.7% vs 66.7%) (Fig. 6B). Only the oldest
TGF-ß1-/-;ß2M-/-
mouse (72 days old) showed a mild degree of immune complex deposition
in the kidneys, and serum from this mouse was also positive for 16/6
Id Ab.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Involvement of CD8+ T cells in the pathogenesis of TGF-ß1-/- mice is not clearly defined. Given the role of MHC class I molecules in CD8+ T cell selection (40), MHC class I deficiency precludes the normal development of CD8+ cells (32, 33). Although a role of CD8+ T cells in certain autoimmune diseases may be suppressive (39, 41), CD8+ T cells are known to play an important role in the initiation and development of autoimmune diseases and autoimmune-related inflammation. For example, it has been shown that CD8+ T cells initiate autoimmune disease in nonobese diabetic mice (42, 43, 44) and that the thyroid-infiltrating CD8+ T cells found in autoimmune thyroid disease have been shown to express perforin and cause organ damage (45). CD8+ cells have been also implicated in the cardiomyocytic damage in an in vitro model for inflammatory heart disease (46). It seems reasonable that absence of CD8+ T cells may underlie the reduction of inflammation in TGF-ß1-/-;ß2M-/- mice, a result that might be observed whether this inflammation is autoimmune-driven or not. This conclusion is supported by our demonstration that depletion of CD8+ T cells in TGF-ß1-/- mice improved viability by decreasing the inflammatory response in these mice.
There have been several reports showing that CD8+ T cytotoxic cells can develop even in the absence of ß2M expression and have been demonstrated to mediate allograft or tumor cell rejection in ß2M-/- mice (47, 48). We have not detected development of mature, single positive CD8+ T cells in our TGF-ß1-/-;ß2M-/- mice, and there is no evidence that they are responsible for the symptoms that eventually develop in some of these mice. Such a difference might be explained by the lack of TGF-ß in TGF-ß1-/-;ß2M-/- mice. It is known that TGF-ß can modify CD8 Ag expression on the surface of T cells, regulate the rate at which CD4+CD8+ thymocytes are generated from CD4-CD8low precursor cells, and affect T cell differentiation (49, 50). Indeed, a reduction in CD4+CD8+ thymocytes is consistently observed in TGF-ß1-/- mice (8). FACS analysis revealed decreased CD8+ T cells in thymus of TGF-ß1-/-;ß2M-/- mice compared with ß2M-/- mice. It has been reported that single positive CD8+ T cells in thymus of ß2M-/- mice are deficient although double positive CD4+CD8+ T cells remain unaltered (32, 33). The reduction in CD8+ T cells observed results from a reduction in the double positive CD4+CD8+ T cells, again suggesting that endogenous TGF-ß1 expression in the thymus plays an important role in T cell development.
Another factor that may contribute to the enhanced survival of TGF-ß1-/-;ß2M-/- mice is the lower frequency of autoantibody-associated immune complex deposition. As mentioned above, immune complex deposition in kidneys is the major factor that affects the prognosis of autoimmune diseases. Anti-ssDNA or 16/6 Id Abs, which are detected in TGF-ß1-/- mice (19) and are also associated with active SLE (37, 51), were reduced in TGF-ß1-/-;ß2M-/- mice as compared with that in TGF-ß1-/- mice. The 16/6 Id Ab is detectable in 54% of active SLE patients, and concordance is found between Id levels and clinical activity (37). Furthermore, experimental SLE can be induced in mouse by immunization with either human or murine 16/6 Id Ab, and these mice exhibit leukopenia, increased erythrocyte sedimentation rates, and proteinuria (37, 52). Examination of the kidneys of the mice discloses immune complex deposits, thickening of Bowman’s capsule, and glomerular necrosis (52). Thus 16/6 Id Ab has been considered to be associated with the induction and progression of SLE.
It has been reported that MHC class I-deficient mice exhibit a resistance to experimental SLE (38), a finding that is consistent with the decreased autoantibody production observed in TGF-ß1-/-;ß2M-/- mice. It has been also reported that the lupus-like autoimmune syndrome of MRL-lpr mice is dependent on ß2M expression (53).
Although survival of TGF-ß1-/- mice is much improved in the absence of ß2M expression, these mice still have a significant reduction in their survival. A factor that may contribute to the death of TGF-ß1 null mice might be the hematopoietic abnormality previously described in a class II MHC null background (30), as suggested by the relative increase in the GR-1+ population observed in lymphoid organs and bone marrow of TGF-ß1-/-;ß2M-/- mice. This result suggests that MHC class I deficiency may not reverse the myeloproliferative syndrome observed in TGF-ß1-/- mice and provides a possible explanation for the only modestly enhanced survival and limited or partial rescue of the TGF-ß1 null phenotype.
The variation in clinical severity and life span in TGF-ß1-/-;ß2M-/- mice may be also linked to the genetic polymorphism in modifier genes. Strain-specific phenotypic differences have been reported in TGF-ß1-/- mice (54) and many other gene knockout mice (55, 56, 57). The most likely candidates for modifier genes may be those involved in the initiation and suppression of autoimmune response and inflammation regulated by either TGF-ß1 or MHC class I molecules or both.
In summary, our results demonstrate that TGF-ß1-/- mice in a genetic background of ß2M deficiency have an improved prognosis, associated with the diminished tissue inflammation and autoimmune manifestations. This partial rescue of phenotype results from loss of CD8+ T cell-driven inflammation and the lower frequency of immune complex deposits due to MHC class I deficiency. TGF-ß1-/-;ß2M-/- mice will be a valuable animal model to examine the role of this cytokine in relation to ß2M and MHC Ag function in immune dysregulation and inflammation.
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Acknowledgments |
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Footnotes |
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2 Abbreviations used in this paper: ß2M: ß2-microglobulin; SLE, systemic lupus erythematosus.
Received for publication March 1, 1999. Accepted for publication July 26, 1999.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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ß T-cell receptor cytotoxic T cells with major histocompatibility complex (MHC) class I antigen-directed cytotoxicity in ß2-microglobulin, MHC class I-deficient mice. Proc. Natl. Acad. Sci. USA 90:2837.This article has been cited by other articles:
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  M. J. Gros, P. Naquet, and R. R. Guinamard Cell Intrinsic TGF-{beta}1 Regulation of B Cells J. Immunol., June 15, 2008; 180(12): 8153 - 8158. [Abstract] [Full Text] [PDF]
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 M. Shimizu, S. Kondo, M. Urushihara, M. Takamatsu, K. Kanemoto, M. Nagata, and S. Kagami Role of integrin-linked kinase in epithelial-mesenchymal transition in crescent formation of experimental glomerulonephritis Nephrol. Dial. Transplant., September 1, 2006; 21(9): 2380 - 2390. [Abstract] [Full Text] [PDF]
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W. V. Ingman, R. L. Robker, K. Woittiez, and S. A. Robertson Null Mutation in Transforming Growth Factor {beta}1 Disrupts Ovarian Function and Causes Oocyte Incompetence and Early Embryo Arrest Endocrinology, February 1, 2006; 147(2): 835 - 845. [Abstract] [Full Text] [PDF]
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 W. Z. Mehal, S. Z. Sheikh, L. Gorelik, and R. A. Flavell TGF-{beta} signaling regulates CD8+ T cell responses to high- and low-affinity TCR interactions Int. Immunol., May 1, 2005; 17(5): 531 - 538. [Abstract] [Full Text] [PDF]
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S. C. McKarns and R. H. Schwartz Distinct Effects of TGF-{beta}1 on CD4+ and CD8+ T Cell Survival, Division, and IL-2 Production: A Role for T Cell Intrinsic Smad3 J. Immunol., February 15, 2005; 174(4): 2071 - 2083. [Abstract] [Full Text] [PDF]
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 M. Mamura, W. Lee, T. J. Sullivan, A. Felici, A. L. Sowers, J. P. Allison, and J. J. Letterio CD28 disruption exacerbates inflammation in Tgf-{beta}1-/- mice: in vivo suppression by CD4+CD25+ regulatory T cells independent of autocrine TGF-{beta}1 Blood, June 15, 2004; 103(12): 4594 - 4601. [Abstract] [Full Text] [PDF]
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V. V. Parekh, D. V. R. Prasad, P. P. Banerjee, B. N. Joshi, A. Kumar, and G. C. Mishra B Cells Activated by Lipopolysaccharide, But Not By Anti-Ig and Anti-CD40 Antibody, Induce Anergy in CD8+ T Cells: Role of TGF-{beta}1 J. Immunol., June 15, 2003; 170(12): 5897 - 5911. [Abstract] [Full Text] [PDF]
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R. Bommireddy, V. Saxena, I. Ormsby, M. Yin, G. P. Boivin, G. F. Babcock, R. R. Singh, and T. Doetschman TGF-{beta}1 Regulates Lymphocyte Homeostasis by Preventing Activation and Subsequent Apoptosis of Peripheral Lymphocytes J. Immunol., May 1, 2003; 170(9): 4612 - 4622. [Abstract] [Full Text] [PDF]
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R. Bommireddy, I. Ormsby, M. Yin, G. P. Boivin, G. F. Babcock, and T. Doetschman TGF{beta}1 Inhibits Ca2+-Calcineurin-Mediated Activation in Thymocytes J. Immunol., April 1, 2003; 170(7): 3645 - 3652. [Abstract] [Full Text] [PDF]
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 J. Cheng and J. P. Grande Transforming Growth Factor-{beta} Signal Transduction and Progressive Renal Disease Experimental Biology and Medicine, December 1, 2002; 227(11): 943 - 956. [Abstract] [Full Text]
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 M. Mori, Y. Terui, M. Tanaka, H. Tomizuka, Y. Mishima, M. Ikeda, T. Kasahara, M. Uwai, M. Ueda, R. Inoue, et al. Antitumor Effect of {beta}2-Microglobulin in Leukemic Cell-bearing Mice via Apoptosis-inducing Activity: Activation of Caspase-3 and Nuclear Factor-{{kappa}}B Cancer Res., June 1, 2001; 61(11): 4414 - 4417. [Abstract] [Full Text] [PDF]
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),
TGF-ß1+/+;ß2M-/-
(
), and
TGF-ß1-/-;ß2M-/-
(•) mice. The standard symbols indicate the mean of the each group
(each group consists of at least four animals at any week of age), and
vertical bars refer to the SD of the mean.
, n = 5) and
TGF-ß1-/-;ß2M-/-
(•, n = 7) mice. Each symbol represents the OD at
414 nm resulting from a 1:10 serum dilution of an individual mouse. The
mean for each mouse group is indicated by a solid line. The data
between
TGF-ß1+/+;ß2M-/-
and
TGF-ß1-/-;ß2M-/-
mice were statistically compared using the two-tailed Student’s
t test. B, Immune complex deposits in the
kidneys. Relative staining intensity ranges from none (0), minimal
(+1), and mild (+2) to intense (+3) according to the previous report
(