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IMMUNOBIOLOGY
From the Department of Immunology, Mayo Graduate and
Medical Schools, Mayo Clinic, Rochester, MN.
B7-H1 is a recently described B7-like molecule that costimulates
T-cell growth and cytokine secretion without binding to CD28, cytotoxic
T-lymphocyte antigen-4 (CTLA-4), and inducible costimulator (ICOS). In this report, a mouse homologue of human B7-H1 is
identified, and its immunologic functions are studied in vitro and in
vivo. Mouse B7-H1 shares 69% amino acid homology to the human
counterpart. Similar to human B7-H1, mouse B7-H1 can be induced
to express on macrophages, T cells, and B cells and to enhance
T-cell proliferation and secretion of interleukin-10 (IL-10),
interferon- The antigen-specific induction of
proliferation and differentiation of lymphocytes requires a first
signal delivered through T-cell or B-cell receptor together with a
second, costimulatory signal. Stimulation of T cells by antigen in the
absence of costimulation can result in unproductive T-cell responses or
T-cell anergy. Engagement of CD28 by its natural ligand B7-1 or B7-2
promotes T-cell activation, proliferation, and the differentiation of
effector functions for both CD4+ and CD8+ T
cells.1-3 CD28 triggering augments both Th1 and Th2
cytokine secretion including interleukin-2 (IL-2), interferon- We have recently identified a new member of human B7 family
designated B7-H1.19 B7-H1 gene encodes a putative type I
transmembrane protein of 290 amino acids and consists of an
immunoglobulin (Ig)V-like domain and an IgC-like domain in its
extracellular portion. Although homology between B7-H1, B7h/B7RP-1,
B7-1, and B7-2 is limited, the putative secondary and tertiary
structures of these molecules are very similar (Chen et al, unpublished
data, 2001). B7-H1 messenger RNA (mRNA) is found in various
tissues, including lung, heart, skeletal muscle, and placenta, as well
as several lymphoid organs, including spleen, thymus, and liver. B7-H1
can be detected on macrophages but not on T and B cells. Activation by
various stimuli, however, can up-regulate the expression of B7-H1 on
these cells. Stimulation of purified T cells by immobilized B7-H1Ig
fusion protein in the presence of anti-CD3 antibodies induces a
profound proliferative response and secretion of cytokines. Examination of cytokines on costimulation by B7-H1 ligation reveals a unique pattern: B7-H1 selectively costimulates the production of IL-10 and
IFN- By cloning mouse B7-H1, immunologic functions of B7-H1 are evaluated
both in vitro and in vivo. We demonstrate that, in contrast to a more
broad immunomodulatory functions of B7-1 and B7-2, B7-H1 appears to
selectively enhance antigen-specific helper T-cell responses but has
minimal effect on the generation and differentiation of cytolytic T cells.
Mice and cell lines
Cloning and identification of mouse B7-H1 complementary
DNA
RNA analysis Tissue distribution of mB7-H1 was carried out, using mouse RNA dot blot (Clontech) according to the manufacture's instructions. The random-primed cDNA probe containing the full-length of mB7-H1 cDNA (895 base pairs) was labeled, using 32P-dCTP. The hybridization was performed for 16 hours at 65°C. After a 4-time wash with 2× SSC-sodium dodecyl sulfate, the membrane was exposed at 80°C to
x-ray films.
Antibodies and fusion proteins Rabbit antibodies against mB7-H1 protein were prepared by the Cocalico Biologicals (Reamstown, PA) by immunization with keyhole limpet hemocyanin (KLH)-conjugated hydrophilic peptides, spanning mB7-H1 amino acid sequence 95-119 (GNAALQITDVKLQDAGVYCCIISYG). The antibodies were purified from rabbit serum by using peptide-conjugated affinity columns. Both enzyme-linked immunosorbent assay (ELISA) and flow-activated cell sorter (FACS) staining of mB7-H1 transfected COS cells demonstrated that the antibodies bound specifically to mB7-H1. Purified monoclonal antibody (mAb) against CD3, CD4 (GK1.5), and CD28; fluorescein isothiocyanate (FITC)-conjugated mAb against CD3, CD4, CD8, and CD40L; phycoerythrin (PE)-conjugated CD3; B220; and Mac-1 were purchased from Pharmingen (San Diego, CA). FITC- and PE-conjugated goat antibody against rabbit IgG was purchased from Southern Biotechnology Associates (Birmingham, AL). Purified rabbit IgG and hamster IgG (Rockland, Gilbertsville, PA) and rat IgG (Sigma, St Louis, MO) were used as controls. To prepare the mB7-H1Ig fusion protein, cDNA encoding mouse B7-H1 extracellular domain was generated by reverse transcriptase-polymerase chain reaction (RT-PCR), using the sense primer 5'-CAGGAATTCACCATGAGGATATTTGCTG-3' and the antisense primer 5'-CATCAGATCTATGTGAGTCCTGTTCTGTG-3' from mouse T-cell mRNA. After digestion with EcoRI and BglII, the PCR products were fused to CH2-CH3 domain of mouse IgG2a in the expression plasmid pmIgV.19 The resulting plasmid, pmB7-H1Ig, was transfected into Chinese hamster ovary (CHO) cells and cultured by using serum-free CHO media (Life Technologies). The mB7-H1Ig in the supernatants was purified by a protein G-Sepharose column (Pierce, Rockford, IL) and dialyzed in lipopolysaccharide (LPS)-free phosphate-buffered saline (PBS). The endotoxin concentration was less than 1 pg/mg of purified protein according to limulus amebocyte lysate assays (Cape Cod, Woods Hole, MA). The mB7-1 immunoglobulin fusion protein (mB7-1Ig) was prepared by the same methods.Flow cytometric analysis The method for FACS analysis of surface molecules by antibodies has been previously described.6,20 For indirect immunofluorescence, the cells were incubated with the antibodies at 4°C for 30 minutes in the presence of blocking mAb to CD16/32 (Pharmingen). The cells were washed and further incubated with FITC- or PE-conjugated antirabbit IgG. For activation of T cells, nylon-wool (NW)-purified T cells (> 75% CD3+ cells) at 2 × 106/mL were cultured with Con A (3 µg/mL), anti-CD3 (5 µg/mL), or a combination of anti-CD3 and anti-CD28 (5 µg/mL). For preparation of activated B cells, splenocytes were cultured with 10 µg/mL LPS for 24 to 48 hours (Sigma). Monocytes were obtained from the peritoneal cavity of mice, which had been injected with thioglycollate 7 days before, and these cells were cultured with IFN- at 10 U/mL and LPS at 100 ng/mL. All cultures were collected
and analyzed at 48 hours. To detect CD40L expression, CD4+
T cells were purified by magnetic sorting (see the followings) and
further incubated with FITC-conjugated mAb to CD40L. Fluorescence was
analyzed by a FACS Calibur flow cytometry and analyzed with Cell Quest
software (Becton Dickinson, Mountain View, CA).
T-cell costimulation and cytokine assay NW column-purified T cells were further positively selected by magnetic sorting, using FITC-conjugated mAb against CD4 or CD8 and anti-FITC microbeads according to the manufacture's instructions (Miltenyi Biotec, Auburn, CA). The purity of isolated CD4+ and CD8+ T cells was more than 95% by FACS analysis, using mAb to CD4 and CD8, respectively. Purified T cells at 2 × 106/mL from mouse spleens were cultured in 96-well plates that were precoated with anti-CD3 in the presence of 10 µg/mL mB7-H1Ig or control mouse IgG2a. mAb against CD28 (2.5 µg/mL) was used in soluble form as a positive control. Proliferation of T cells was determined by incorporation of 1 µCi/well of 3H-TdR during the last 15 hours of the 3-day culture. 3H-TdR incorporation was counted by a MicroBeta TriLux liquid scintillation counter (Wallac, Turku, Finland). To detect cytokines, supernatants were collected at 18 to 72 hours of cultures, and the concentrations of IFN-, IL-2, IL-10, IL-4, and GM-CSF were measured by sandwich ELISA
following the manufacture's instructions (Pharmingen). Assay for
proliferative responses of CD4+ T cells in mixed lymphocyte
responses to allogeneic antigens has been described.19
Generation of mB7-H1-expressing P815 cells and induction of cytotoxic lymphocyte P815 cells were transfected with mB7-H1.pcDNA3 plasmid by Fugene (Roche, Mannheim, Germany) according to manufacture's instructions. The transfected cells were selected in complete medium containing 1 mg/mL G418 (Life Technologies) and were subsequently cloned by limiting dilution. mB7-H1+ P815 cells were identified by FACS analysis, using anti-B7-H1 antibody. A representative clone, mB7-H1+ P815, was selected for further study. P815 clones transfected with pcDNA vector (mock.P815) and mB7-1.pcDNA (mB7-1+ P815) were also generated as described previously.6To induce alloantigen-specific CTL activity in vitro, NW-purified T cells (2.5 × 106/mL) from B6 splenocytes were stimulated with irradiated (10 000 rad) mock.P815, mB7-1+ P815, or mB7-H1+ P815 cells (2.5 × 105/mL). After the 5-day stimulation, CTL activities against P815 (H-2d) and EL4 (H-2b) were measured by a standard 51Cr release assay.6,20 Alternatively, NW-purified T cells from BALB/c splenocytes at 3 × 106/mL were stimulated with irradiated B6 splenocytes at 1 × 106/mL in the presence of immobilized B7-H1Ig for 5 days, and CTL activity against allogeneic (EL4) or syngeneic target cells (P815) was measured by 51Cr release assay. To induce tumor-specific CTL activity in vivo, DBA/2 mice were inoculated subcutaneously with 1 × 106 lived cells from mock.P815, mB7-1+ P815, or mB7-H1+ P815. The draining lymph nodes were removed 7 to 10 days after tumor injection, and the suspended lymph node cells (3 × 106/mL) were restimulated with P815 cells (3 × 105/mL) for 5 days. The CTL activity was measured in a standard 51Cr release assay.6,20 In vivo induction and assay of 2,4,6-trinitrophenyl- specific antibody 2,4,6-trinitrophenyl (TNP)-KLH (Biosearch Technologies, Novato, CA) at 100 µg/mouse in PBS was injected intraperitoneally into B6 mice on day 0. On days 1 and 4, the mice were injected intraperitoneally with 100 µg of control mIg, mB7-1Ig, or mB7-H1Ig. Sera were collected on days 7 and 14. To examine TNP-specific antibodies in sera, 0.3 mg/mL TNP-BSA (Biosearch Technologies) was bound to 96-well ELISA plates overnight at 4°C. Nonspecific binding was blocked with 10% FBS in PBS for 90 minutes at room temperature. After extensive washing, samples, diluted by 1/200 to 1/2000 with PBS, were added and incubated for 2 hours. The plates were then washed, and biotinylated rat antimouse IgM, IgG1, IgG2a, or IgG3 (Pharmingen) was added to the wells. The plates were further incubated for 1 hour at room temperature. Bound biotinylated rat antibodies were detected by incubation with horseradish peroxidase-conjugated streptavidin (Caltag Laboratories, Burlingame, CA) for 1 hour at room temperature. Color reactions were developed by 3,3',5,5'-tetramethyl-benzidine substrate (Sigma) and the optical density (OD) reading at 450 nm was evaluated.T-cell proliferation to KLH B6 mice were immunized with 100 µg TNP-KLH in incomplete Freund's adjuvant (IFA) subcutaneously or in PBS intraperitoneally on day 0 and were subsequently treated with fusion protein or control immunoglobulin intraperitoneally on days 1 and 4. To detect T-cell responses to KLH, draining lymph nodes and spleens were removed from immunized mice on days 7 and 14, respectively. Suspended cells were cultured with KLH at 1.56 to 100 µg/mL as indicated. Proliferation of T cells to KLH was determined by addition of 1 µCi/well 3H-TdR during the last 15 hours of the 3-day culture. 3H-TdR incorporation was counted by a Microbeta Trilux liquid scintillation counter (Wallac).
Characterization of mouse B7-H1 gene The mB7-H1 gene encodes a putative type I transmembrane protein of 290 amino acids and has 69% overall amino acid homology to human B7-H1 (Figure 1A). Similar to other members of B7 family, mB7-H1 consists of an IgV-like domain, an IgC-like domain, a hydrophobic transmembrane domain, and a cytoplasmic tail. B7-H1 shares 20% homology to mB7-1, 14% to mB7-2, and 19% to mB7h/B7RP-1, based on analysis using McVector 6.5 software (Figure 1B). Four structural cysteines are well conserved, the same as other B7 members.
RNA analysis revealed that mB7-H1 mRNA was abundant in heart, spleen,
lung, skeletal muscle, and liver, less abundant but positive in kidney,
liver, thymus, and thyroid (Figure 2A).
Therefore, the expression pattern is similar to human B7-H1
mRNA.19 Negligible expression of the B7-H1 mRNA was
observed in pancreas and testis.
FACS analysis using the antibody against mB7-H1 showed that freshly
isolated as well as Con A-stimulated CD3+ T cells express
negligible amounts of B7-H1. However, stimulation by anti-CD3 or a
combination of anti-CD3/CD28 mAb moderately increased the expression of
B7-H1 (Figure 2B). A small fraction of B220+ B cells and
Mac-1+ macrophages expressed a low level of B7-H1 (Figure
2C, upper panel). Activation of B cells with LPS and macrophages with
LPS plus IFN- B7-H1 costimulation is CD28 independent and preferential for CD4+ T cells To investigate the costimulatory effect of B7-H1, we stimulated NW-purified T cells with B7-H1Ig and suboptimal doses of anti-CD3 mAb. B7-H1 can enhance T-cell growth up to 5-fold compared to that of the control immunoglobulin (Figure 3A). The costimulatory effect of the B7-H1 is dose dependent and is dependent on anti-CD3 mAb because, in the absence of anti-CD3 mAb, B7-H1Ig up to 10 µg/mL did not stimulate the proliferation of T cells (Figure 3B, left panel). When purified T cells were cultured with 293 cells transfected with mB7-H1.pcDNA3 or control vector in the presence of suboptimal doses of anti-CD3 mAb, B7-H1-transfected 293 cells also enhanced T-cell proliferation substantially compared with that of the control vector-transfected 293 cells (data not shown). We conclude that, similar to human B7-H1, mB7-H1 costimulates T-cell proliferation.
The role of CD28 in B7-H1 costimulation was evaluated by comparing the
effects of mB7-H1Ig costimulation on T cells isolated from
CD28 We next examined the preference of B7-H1 costimulation on CD4+ and CD8+ T cells. Purified CD4+ and CD8+ T cells were stimulated with the same concentration of mB7-H1Ig and anti-CD3. Proliferation of CD4+ T cells was up to 10-fold, and the proliferation of CD8+ T cells was only enhanced 2- to 3-fold (Figure 3C). Thus, costimulatory effect of B7-H1 is more favorable for CD4+ T cells. Effects of B7-H1 costimulation on cytokine secretion We have previously shown that human B7-H1 preferentially stimulated secretion of IL-10 and IFN- but not IL-2 and
IL-4.19 To examine whether mB7-H1 functions similarly, we
measured the levels of these cytokines as well as GM-CSF from T cells
after stimulation with mB7-H1Ig or anti-CD28 mAb in the presence of anti-CD3 mAb. Figure 4A shows that
mB7-H1, similar to anti-CD28 mAb, can induce high levels of IL-10
production in the 72-hour culture supernatants. IL-10 was not
detectable at the same time point when T cells were treated with
control immunoglobulin and anti-CD3. mB7-H1 also promotes the secretion
of IFN- and GM-CSF, which are also induced by anti-CD28 mAb. In
sharp contrast to anti-CD28 mAb, which induces high levels of IL-2 and
IL-4, mB7-H1Ig induces low or negligible levels of IL-2 and IL-4 up to
3 days (Figure 4A). We conclude that mouse B7-H1 and human B7-H1 have similar selectivity for cytokine production.
Because IL-2 is undetectable in the presence of B7-H1 costimulation, it is thus possible that B7-H1 ligation inhibits IL-2 secretion. To test this possibility, we examined the effect of B7-H1 costimulation in IL-2 secretion from T cells stimulated by anti-CD3/28 mAb. Figure 4B shows that inclusion of immobilized mB7-H1Ig up to 10 µg/mL in the culture results in a small but not significant decrease in IL-2 production during 18 to 48 hours. Similarly, mB7-H1Ig did not inhibit IL-2 production from the culture, in which T cells were stimulated with anti-CD3 alone (Figure 4B). Our results thus indicate that mB7-H1 ligation does not inhibit the production of IL-2. Effect of B7-H1 costimulation on antigen-specific T-cell responses To examine the effect of B7-H1 costimulation on the generation of CTL, we transfected mouse P815 tumor cells with mB7-H1.pcDNA3 plasmid. Clones that stably express mB7-H1 on their surface were selected for further experiments. A representative clone, B7-H1+ P815, expresses high levels of mB7-H1 as indicated by FACS staining, using the anti-mB7-H1 antibodies (Figure 5A). The binding of the antibody is specific because mock.P815 cells (Figure 5A, left panel) and mB7-1+ P815 cells (data not shown) are negative for the staining. Furthermore, inclusion of the peptide of B7-H1, which was used for immunization, completely blocks the binding of anti-B7-H1 antibodies to mB7-H1+ P815 (Figure 5A, right panel).
We showed previously that inclusion of B7-H1Ig fusion protein enhances mixed lymphocyte responses to allogeneic antigen in human T-cell culture.19 Similar to this observation, stimulation of purified T cells from B6 mice with allogeneic mB7-H1+ P815 cells induces proliferative responses superior to that stimulated with mock.P815 cells. As a control, stimulation with mB7-1+ P815 cells also induces high-level proliferative responses (Figure 5B). The proliferative responses enhanced by both mB7-H1+ P815 as well as mB7-1+ P815 cells can be completely inhibited by anti-CD4 mAb (data not shown). However, mB7-H1+ P815 cells as well as mock.P815 are poor stimulators of P815-specific CTL activity, whereas mB7-1+ P815 elicited a strong P815-specific CTL activity as assayed in standard 51Cr release assay (Figure 5C). The CTL induced by mB7-1 was allogeneic antigen specific because it did not lyse H-2b EL4 cells. Similar results were also obtained in a different system in which purified T cells from BALB/c mice were stimulated with irradiated B6 spleen cells as allogeneic antigen-presenting cells. As shown in Figure 5D, proliferative responses are enhanced by inclusion of B7-H1Ig fusion protein, and the response can be completely blocked by an anti-CD4 antibody. CTL activity against allogeneic antigens in this system is not affected (Figure 5E). Therefore, B7-H1 costimulation does not facilitate the generation of allogeneic CTL in vitro. We also examined the ability of mB7-H1+ P815 cells to stimulate P815-specific CTL in vivo. DBA/2 mice were injected subcutaneously with lived cells from mock.P815, mB7-1+ P815, or mB7-H1+ P815 lines. T cells from tumor-draining lymph nodes were removed 7 to 10 days later and cocultivated with wild-type (wt).P815 cells for 5 days. In mice injected with mB7-H1+ P815, a small, but not significant increase in CTL activity against P815 cells was detected compared to CTL from the mock.P815-injected mice. In contrast, mB7-1+ P815 elicited a strong CTL activity in vivo. CTL activity is P815 specific since syngeneic but antigenically irrelevant L1210 cells were not lysed (Figure 5F). We conclude that expression of B7-H1 in P815 cells does not enhance the induction of CTL activity against P815 tumor antigens. B7-H1 costimulation amplifies antigen-specific T-helper cell responses and T-cell-dependent humoral responses in vivo To investigate the effect of B7-H1 costimulation on T-helper cell function, we immunized B6 mice with TNP-conjugated KLH and subsequently injected the mice with mB7-H1Ig at day 1 and day 4. The proliferation of T cells obtained from both lymph nodes and spleens of the immunized mice (control mice) was examined by exposure to KLH in vitro. As shown in Figure 6, T cells from both spleens and lymph nodes of TNP-KLH-immunized mice proliferated to KLH in a dose-dependent fashion. Administration of mB7-H1Ig to TNP-KLH-immunized mice amplified the proliferative responses up to 2- to 3-fold. Our result indicates that B7-H1 costimulation can enhance T-helper cell responses in vivo.
We next examined the effect of B7-H1 costimulation in the generation of
antigen-specific antibodies to TNP. This is a well-established system
in which antibody production against TNP is dependent on helper T-cell
response to KLH.21,22 The production of antibodies against
TNP in the sera from TNP-KLH-immunized mice was measured after
treatment with control immunoglobulin, mB7-1Ig, or mB7-H1Ig. In
preliminary experiments, we have found a significant increase of total
IgG levels in mice treated with mB7-H1Ig compared to those treated with
control mIg (data not shown). The subclasses of IgG, including IgG1,
IgG2a, IgG2b, and IgG3 were further examined. As shown in Figure
7, TNP-specific IgG2a antibody was
increased significantly in mice treated with mB7-H1Ig, and there were
no significant changes on other immunoglobulin subtypes. This effect is
different from mice treated with mB7-1Ig since other IgG components, including IgG1 and IgG2b, were also increased significantly (Figure 7).
Therefore, B7-H1 costimulation enhances T-helper cell proliferation and
T-helper-dependent humoral immune responses.
CD40-CD40L interaction is critical for T-helper cell-B-cell
interaction for the generation of antibody responses and for
immunoglobulin class switching.23 We examined whether
B7-H1 costimulation up-regulates CD40L on T cells. Purified
CD4+ T cells from B6 mice were stimulated with suboptimal
anti-CD3 mAb in the presence of mB7-H1Ig. Anti-CD28 mAb was also
included as a control. Expression of CD40L on T cells was detected by a specific mAb to CD40L by flow cytometry analysis. B7-H1Ig up-regulated CD40L rapidly (25.3% in 4-hour incubation) compared with that of the
control IgG (6.6%) or anti-CD28 (10.5%). The expression of CD40L was
further increased on 24-hour stimulation (Figure 8A). Similar results were also obtained
with CD4+ T cells, using optimal dose of anti-CD3
stimulation (Figure 8B). Our results suggest that triggering of
B7-H1 counter-receptor on T cells rapidly up-regulates the expression
of CD40L that may contribute to enhanced antibody production.
In this study, we have identified the mouse homologue of human
B7-H1 and shown its characteristic functions in vitro and in vivo.
Similar to its human counterpart, mouse B7-H1 can markedly costimulate
T-cell proliferation in the presence of suboptimal doses of anti-CD3
and stimulate secretion of a unique pattern of cytokines. Both
CD28 Costimulation mediated by B7-1 and B7-2 plays a crucial role in the induction of CTLs. The expression of B7-1 and B7-2 on tumor cells, including P815 cells, has been shown to enhance MHC class I-restricted CTL responses specific for allogeneic or syngeneic tumor antigens in vitro and in vivo.7,8 Augmentation of MHC class II-restricted responses by B7-1 costimulation has also been demonstrated.24 Several studies indicate that priming of T cells by B7-transfected tumor cells requires cross presentation by host professional antigen-presenting cells, direct presentation by tumor cells, or both.7,25-27 One of the hypotheses for enhanced cross presentation of tumor antigens after transfection of B7-1 is increased sensitivity of tumor cells to natural killer (NK) cells.28 We have found that both B7-1+ and B7-H1+ P815 cells express high levels of MHC class I antigens and are resistant to NK-cell lysis in vitro (Tamura et al, unpublished data, 2001). In addition, the expression of B7-H1 by P815 cells appears to have a marginal effect on the stimulation of CTL both in vitro and in vivo, whereas the growth of CD4+ T cells in the presence of B7-H1 costimulation are augmented in the same cultures (Figure 5). The failure of B7-H1-transfected P815 cells to costimulate CTL response may be partially due to less responsiveness of CD8+ T cells to B7-H1 costimulation than that of CD4+ T cells (Figure 3C). It is not known whether this difference is caused by differential expression of the counter-receptor of B7-H1 on CD4+ versus CD8+ T cells. Human CD28 receptor has been found to express on the majority of CD4+ T cells, but only 50% of CD8+ T cells are CD28 positive.2 CD28 engagement has been shown to enhance the production of various
cytokines, including IL-2, IL-4, IFN- During the review process of this paper, Freeman et al29 reported the sequence of mouse PD-1L that is identical to mB7-H1. They have found that PD-1LIg inhibits the proliferation of mouse T cells in vitro in the presence of a high dose (10 µg/mL) of anti-CD3 mAb. In our system, anti-CD3 mAb in suboptimal doses (0.125 to 0.25 µg/mL) costimulates the growth of mouse T cells (Figure 3). Therefore, the effect of B7-H1 on T-cell growth or inhibition may depend on antigen strength. It is also possible there is additional counter-receptor of B7-H1 than PD-1 on T cells. It has been reported that the production of IgG1 and IgG2b was
decreased in CD28
We thank Dr Moses Rodrigues for providing CD28-deficient mice and Kathy Jensen for editing the manuscript.
Submitted July 26, 2000; accepted November 17, 2000.
Supported in part by the Mayo Foundation. G.Z. is supported by NIH postdoctoral fellow training grant CA09127, and K.T. is a US Army Breast Cancer Research Program postdoctoral fellow.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Lieping Chen, Department of Immunology, Mayo Clinic, 200 First St SW, Rochester, MN 55905; e-mail: chen.lieping{at}mayo.edu.
1. Chambers CA, Allison JP. Co-stimulation in T cell responses. Curr Opin Immunol. 1997;9:396-404[CrossRef][Medline] [Order article via Infotrieve]. 2. Lenschow DJ, Walunas TL, Bluestone JA. CD28/B7 system of T cell costimulation. Annu Rev Immunol. 1996;14:233-258[CrossRef][Medline] [Order article via Infotrieve]. 3. Chen L, Linsley PS, Hellstrom KE. Costimulation of T cells for tumor immunity. Immunol Today. 1993;14:483-486[CrossRef][Medline] [Order article via Infotrieve]. 4. Linsley PS, Ledbetter JA. The role of the CD28 receptor during T cell responses to antigen. Annu Rev Immunol. 1993;11:191-212[Medline] [Order article via Infotrieve]. 5. Boise LH, Minn AJ, Noel PJ, et al. CD28 costimulation can promote T cell survival by enhancing the expression of Bcl-XL. Immunity. 1995;3:87-98[CrossRef][Medline] [Order article via Infotrieve].
6.
Chen L, McGowan P, Ashe S, et al.
Tumor immunogenicity determines the effect of B7 costimulation on T cell-mediated tumor immunity.
J Exp Med.
1994;179:523-532
7.
Harding FA, Allison JP.
CD28-B7 interactions allow the induction of CD8+ cytotoxic T lymphocytes in the absence of exogenous help.
J Exp Med.
1993;177:1791-1796 8. Chen L, Ashe S, Brady WA, et al. Costimulation of antitumor immunity by the B7 counterreceptor for the T lymphocyte molecules CD28 and CTLA-4. Cell. 1992;71:1093-1102[CrossRef][Medline] [Order article via Infotrieve].
9.
Townsend SE, Allison JP.
Tumor rejection after direct costimulation of CD8+ T cells by B7-transfected melanoma cells.
Science.
1993;259:368-370 10. Yang G, Hellstrom KE, Hellstrom I, Chen L. Antitumor immunity elicited by tumor cells transfected with B7-2, a second ligand for CD28/CTLA-4 costimulatory molecules. J Immunol. 1995;154:2794-2800[Abstract].
11.
Allison JP, Krummel MF.
The Yin and Yang of T cell costimulation.
Science.
1995;270:932-933
12.
Swallow MM, Wallin JJ, Sha WC.
B7h, a novel costimulatory homolog of B7.1 and B7.2, is induced by TNF 13. Yoshinaga SK, Whoriskey JS, Khare SD, et al. T-cell co-stimulation through B7RP-1 and ICOS. Nature. 1999;402:827-832[CrossRef][Medline] [Order article via Infotrieve].
14.
Ling V, Wu PW, Finnerty HF, et al.
Identification of GL50, a novel B7-like protein that functionally binds to ICOS receptor.
J Immunol.
2000;164:1653-1657 15. Brodie D, Collins AV, Laboni A, et al. LICOS, a primordial costimulatory ligand? Curr Biol. 2000;10:333-336[CrossRef][Medline] [Order article via Infotrieve]. 16. Mages HW, Hutloff A, Heuck C, et al. Molecular cloning and characterization of murine ICOS and identification of B7h as ICOS ligand. Eur J Immunol. 2000;30:1040-1047[CrossRef][Medline] [Order article via Infotrieve].
17.
Wang S, Zhu G, Chapoval AI, et al.
Costimulation of T cells by B7-H2, a B7-like molecule that binds ICOS.
Blood.
2000;96:2808-2813 18. Yoshinaga SK, Zhang M, Pistillo J, et al. Characterization of a new human B7-related protein: B7RP-1 is the ligand to the co-stimulatory protein ICOS. Int J Immunol. 2000;12:1439-1447. 19. Dong H, Zhu G, Tamada K, Chen L. B7-H1, a third member of the B7 family, co-stimulates T-cell proliferation and interleukin-10 secretion. Nat Med. 1999;5:1365-1369[CrossRef][Medline] [Order article via Infotrieve].
20.
Li Y, Hellstrom KE, Newby SA, Chen L.
Costimulation by CD48 and B7-1 induces immunity against poorly immunogenic tumors.
J Exp Med.
1996;183:639-644
21.
Marrack PC, Kappler JW.
Antigen-specific and nonspecific mediators of T cell/B cell cooperation. I. Evidence for their production by different T cells.
J Immunol.
1975;114:1116-1125
22.
Romano TJ, Lerman SP, Bangasser S, Thorbecke GJ, Nisonoff A.
Induction of an immune response through interaction of helper cells with an immune complex bound to the surface of B cells.
Proc Natl Acad Sci U S A.
1975;72:4555-4558 23. Calderhead DM, Kosaka Y, Manning EM, Noelle RJ. CD40-CD154 interactions in B-cell signaling. Curr Top Microbiol Immunol. 2000;245:73-99[Medline] [Order article via Infotrieve]. 24. Ostrand-Rosenberg S. Tumor immunotherapy: the tumor cell as an antigen-presenting cell. Curr Opin Immunol. 1994;6:722-727[CrossRef][Medline] [Order article via Infotrieve].
25.
Huang AY, Bruce AT, Pardoll DM, Levitsky HI.
Does B7-1 expression confer antigen-presenting cell capacity to tumors in vivo?
J Exp Med.
1996;183:769-776 26. Cayeux S, Richter G, Noffz G, Dorken B, Blankenstein T. Influence of gene-modified (IL-7, IL-4, and B7) tumor cell vaccines on tumor antigen presentation. J Immunol. 1997;158:2834-2841[Abstract]. 27. Amstrong TD, Clements VK, Ostrand-Rosenberg S. Class II-transfected tumor cells directly present endogenous antigen to CD4+ T cells in vitro and are APCs for tumor-encoded antigens in vivo. J Immunother. 1998;21:218-224.
28.
Wu TC, Huang AY, Jaffee EM, Levitsky HI, Pardoll DM.
A reassessment of the role of B7-1 expression in tumor rejection.
J Exp Med.
1995;182:1415-1421
29.
Freeman GJ, Long AJ, Iwai Y, et al.
Engagement of the PD-1 immunoinhibitory receptor by a novel B7 family member leads to negative regulation of lymphocyte activation.
J Exp Med.
2000;192:1027-1034
30.
Shahinian A, Pfeffer K, Lee KP, et al.
Differential T cell costimulatory requirements in CD28-deficient mice.
Science.
1993;261:609-612
31.
McAdam AJ, Farkash EA, Gewurz BE, Sharpe AH.
B7 costimulation is critical for antibody class switching and CD8(+) cytotoxic T-lymphocyte generation in the host response to vesicular stomatitis virus.
J Virol.
2000;74:203-208
32.
Rousset F, Garcia E, Defrance T, et al.
Interleukin 10 is a potent growth and differentiation factor for activated human B lymphocytes.
Proc Natl Acad Sci U S A.
1992;89:1890-1893 33. Moore KW, O'Garra A, de Waal Malefyt R, Vieira P, Mosmann TR. Interleukin-10. Annu Rev Immunol. 1993;11:165-190[CrossRef][Medline] [Order article via Infotrieve]. 34. Finkelman FD, Katona IM, Mosmann TR, Coffman RL. IFN-gamma regulates the isotypes of Ig secreted during in vivo humoral immune responses. J Immunol. 1988;140:1022-1027[Abstract]. 35. Snapper CM, Peschel C, Paul WE. IFN-gamma stimulates IgG2a secretion by murine B cells stimulated with bacterial lipopolysaccharide. J Immunol. 1988;140:2121-2127[Abstract].
36.
Briere F, Servet-Delprat C, Bridon JM, Saint-Remy JM, Banchereau J.
Human interleukin 10 induces naive surface immunoglobulin D+ (sIgD+) B cells to secrete IgG1 and IgG3.
J Exp Med.
1994;179:757-762
37.
Malisan F, Briere F, Bridon JM, et al.
Interleukin-10 induces immunoglobulin G isotype switch recombination in human CD40-activated naive B lymphocytes.
J Exp Med.
1996;183:937-947
© 2001 by The American Society of Hematology.
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  S. Yao, S. Wang, Y. Zhu, L. Luo, G. Zhu, S. Flies, H. Xu, W. Ruff, M. Broadwater, I.-H. Choi, et al. PD-1 on dendritic cells impedes innate immunity against bacterial infection Blood, June 4, 2009; 113(23): 5811 - 5818. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Zhu, M. M. Augustine, T. Azuma, L. Luo, S. Yao, S. Anand, A. C. Rietz, J. Huang, H. Xu, A. S. Flies, et al. B7-H4-deficient mice display augmented neutrophil-mediated innate immunity Blood, February 19, 2009; 113(8): 1759 - 1767. [Abstract] [Full Text] [PDF]
|
|
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 |
|
 S. Wei, A. B. Shreiner, N. Takeshita, L. Chen, W. Zou, and A. E. Chang Tumor-Induced Immune Suppression of In vivo Effector T-Cell Priming Is Mediated by the B7-H1/PD-1 Axis and Transforming Growth Factor {beta} Cancer Res., July 1, 2008; 68(13): 5432 - 5438. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Berger, R. Rotem-Yehudar, G. Slama, S. Landes, A. Kneller, M. Leiba, M. Koren-Michowitz, A. Shimoni, and A. Nagler Phase I Safety and Pharmacokinetic Study of CT-011, a Humanized Antibody Interacting with PD-1, in Patients with Advanced Hematologic Malignancies Clin. Cancer Res., May 15, 2008; 14(10): 3044 - 3051. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Green, T. Okazaki, T. Honjo, W. J. Cook, and W. R. Green The Programmed Death-1 and Interleukin-10 Pathways Play a Down-Modulatory Role in LP-BM5 Retrovirus-Induced Murine Immunodeficiency Syndrome J. Virol., March 1, 2008; 82(5): 2456 - 2469. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Okazaki and T. Honjo PD-1 and PD-1 ligands: from discovery to clinical application Int. Immunol., July 2, 2007; (2007) dxm057v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Hori, M. Wang, M. Miyashita, K. Tanemoto, H. Takahashi, T. Takemori, K. Okumura, H. Yagita, and M. Azuma B7-H1-Induced Apoptosis as a Mechanism of Immune Privilege of Corneal Allografts J. Immunol., November 1, 2006; 177(9): 5928 - 5935. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Ding, L. Lu, B. Wang, Y. Zhou, Y. Jiang, X. Zhou, L. Xin, Z. Jiao, and K.-Y. Chou B7H1-Ig Fusion Protein Activates the CD4+ IFN-{gamma} Receptor+ Type 1 T Regulatory Subset through IFN-{gamma}-Secreting Th1 Cells J. Immunol., September 15, 2006; 177(6): 3606 - 3614. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. K. Kim, H. Guan, G. Zu, H. Li, L. Wu, X. Feng, C. Elmets, Y. Fu, and H. Xu High-level expression of B7-H1 molecules by dendritic cells suppresses the function of activated T cells and desensitizes allergen-primed animals J. Leukoc. Biol., April 1, 2006; 79(4): 686 - 695. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Geng, G.-M. Zhang, D. Li, H. Zhang, Y. Yuan, H.-G. Zhu, H. Xiao, L.-F. Han, and Z.-H. Feng Soluble Form of T Cell Ig Mucin 3 Is an Inhibitory Molecule in T Cell-Mediated Immune Response J. Immunol., February 1, 2006; 176(3): 1411 - 1420. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. R Blazar and W. J Murphy Bone marrow transplantation and approaches to avoid graft-versus-host disease (GVHD) Phil Trans R Soc B, September 29, 2005; 360(1461): 1747 - 1767. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Tamura, K. Dan, K. Tamada, K. Nakamura, Y. Shioi, H. Hyodo, S.-D. Wang, H. Dong, L. Chen, and K. Ogata Expression of Functional B7-H2 and B7.2 Costimulatory Molecules and Their Prognostic Implications in De novo Acute Myeloid Leukemia Clin. Cancer Res., August 15, 2005; 11(16): 5708 - 5717. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Yamazaki, H. Akiba, A. Koyanagi, M. Azuma, H. Yagita, and K. Okumura Blockade of B7-H1 on Macrophages Suppresses CD4+ T Cell Proliferation by Augmenting IFN-{gamma}-Induced Nitric Oxide Production J. Immunol., August 1, 2005; 175(3): 1586 - 1592. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Guleria, A. Khosroshahi, M. J. Ansari, A. Habicht, M. Azuma, H. Yagita, R. J. Noelle, A. Coyle, A. L. Mellor, S. J. Khoury, et al. A critical role for the programmed death ligand 1 in fetomaternal tolerance J. Exp. Med., July 18, 2005; 202(2): 231 - 237. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. E. Sandner, M. R. Clarkson, A. D. Salama, A. Sanchez-Fueyo, C. Domenig, A. Habicht, N. Najafian, H. Yagita, M. Azuma, L. A. Turka, et al. Role of the Programmed Death-1 Pathway in Regulation of Alloimmune Responses In Vivo J. Immunol., March 15, 2005; 174(6): 3408 - 3415. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Hirano, K. Kaneko, H. Tamura, H. Dong, S. Wang, M. Ichikawa, C. Rietz, D. B. Flies, J. S. Lau, G. Zhu, et al. Blockade of B7-H1 and PD-1 by Monoclonal Antibodies Potentiates Cancer Therapeutic Immunity Cancer Res., February 1, 2005; 65(3): 1089 - 1096. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Koga, J.-i. Suzuki, H. Kosuge, G. Haraguchi, Y. Onai, H. Futamatsu, Y. Maejima, R. Gotoh, H. Saiki, F. Tsushima, et al. Blockade of the Interaction Between PD-1 and PD-L1 Accelerates Graft Arterial Disease in Cardiac Allografts Arterioscler Thromb Vasc Biol, November 1, 2004; 24(11): 2057 - 2062. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-F. He, G.-M. Zhang, X.-H. Wang, H. Zhang, Y. Yuan, D. Li, and Z.-H. Feng Blocking Programmed Death-1 Ligand-PD-1 Interactions by Local Gene Therapy Results in Enhancement of Antitumor Effect of Secondary Lymphoid Tissue Chemokine J. Immunol., October 15, 2004; 173(8): 4919 - 4928. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Saudemont and B. Quesnel In a model of tumor dormancy, long-term persistent leukemic cells have increased B7-H1 and B7.1 expression and resist CTL-mediated lysis Blood, October 1, 2004; 104(7): 2124 - 2133. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Chemnitz, R. V. Parry, K. E. Nichols, C. H. June, and J. L. Riley SHP-1 and SHP-2 Associate with Immunoreceptor Tyrosine-Based Switch Motif of Programmed Death 1 upon Primary Human T Cell Stimulation, but Only Receptor Ligation Prevents T Cell Activation J. Immunol., July 15, 2004; 173(2): 945 - 954. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Smith, C. M. Walsh, N. E. Mangan, R. E. Fallon, J. R. Sayers, A. N. J. McKenzie, and P. G. Fallon Schistosoma mansoni Worms Induce Anergy of T Cells via Selective Up-Regulation of Programmed Death Ligand 1 on Macrophages J. Immunol., July 15, 2004; 173(2): 1240 - 1248. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kezuka, M. Takeuchi, H. Keino, Y. Usui, A. Takeuchi, N. Yamakawa, and M. Usui Peritoneal Exudate Cells Treated with Calcitonin Gene-Related Peptide Suppress Murine Experimental Autoimmune Uveoretinitis via IL-10 J. Immunol., July 15, 2004; 173(2): 1454 - 1462. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Saatian, X.-Y. Yu, A. P. Lane, T. Doyle, V. Casolaro, and E. Wm. Spannhake Expression of genes for B7-H3 and other T cell ligands by nasal epithelial cells during differentiation and activation Am J Physiol Lung Cell Mol Physiol, July 1, 2004; 287(1): L217 - L225. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Steinberger, O. Majdic, S. V. Derdak, K. Pfistershammer, S. Kirchberger, C. Klauser, G. Zlabinger, W. F. Pickl, J. Stockl, and W. Knapp Molecular Characterization of Human 4Ig-B7-H3, a Member of the B7 Family with Four Ig-Like Domains J. Immunol., February 15, 2004; 172(4): 2352 - 2359. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Matsumoto, H. Inoue, T. Nakano, M. Tsuda, Y. Yoshiura, S. Fukuyama, F. Tsushima, T. Hoshino, H. Aizawa, H. Akiba, et al. B7-DC Regulates Asthmatic Response by an IFN-{gamma}-Dependent Mechanism J. Immunol., February 15, 2004; 172(4): 2530 - 2541. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Wintterle, B. Schreiner, M. Mitsdoerffer, D. Schneider, L. Chen, R. Meyermann, M. Weller, and H. Wiendl Expression of the B7-Related Molecule B7-H1 by Glioma Cells: A Potential Mechanism of Immune Paralysis Cancer Res., November 1, 2003; 63(21): 7462 - 7467. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kanai, T. Totsuka, K. Uraushihara, S. Makita, T. Nakamura, K. Koganei, T. Fukushima, H. Akiba, H. Yagita, K. Okumura, et al. Blockade of B7-H1 Suppresses the Development of Chronic Intestinal Inflammation J. Immunol., October 15, 2003; 171(8): 4156 - 4163. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. E. Strome, H. Dong, H. Tamura, S. G. Voss, D. B. Flies, K. Tamada, D. Salomao, J. Cheville, F. Hirano, W. Lin, et al. B7-H1 Blockade Augments Adoptive T-Cell Immunotherapy for Squamous Cell Carcinoma Cancer Res., October 1, 2003; 63(19): 6501 - 6505. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. E. Wiley, S. Goncharova, T. Shea, J. R. Johnson, A. J. Coyle, and M. Jordana Evaluation of Inducible Costimulator/B7-Related Protein-1 as a Therapeutic Target in a Murine Model of Allergic Airway Inflammation Am. J. Respir. Cell Mol. Biol., June 1, 2003; 28(6): 722 - 730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Wang, J. Bajorath, D. B. Flies, H. Dong, T. Honjo, and L. Chen Molecular Modeling and Functional Mapping of B7-H1 and B7-DC Uncouple Costimulatory Function from PD-1 Interaction J. Exp. Med., May 5, 2003; 197(9): 1083 - 1091. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. E. Annenkov, G. M. Daly, T. Brocker, and Y. Chernajovsky Clustering of immunoreceptor tyrosine-based activation motif-containing signalling subunits in CD4+ T cells is an optimal signal for IFN-{gamma} production, but not for the production of IL-4 Int. Immunol., May 1, 2003; 15(5): 665 - 677. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. G. Petroff, L. Chen, T. A. Phillips, D. Azzola, P. Sedlmayr, and J. S. Hunt B7 Family Molecules Are Favorably Positioned at the Human Maternal-Fetal Interface Biol Reprod, May 1, 2003; 68(5): 1496 - 1504. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Selenko-Gebauer, O. Majdic, A. Szekeres, G. Hofler, E. Guthann, U. Korthauer, G. Zlabinger, P. Steinberger, W. F. Pickl, H. Stockinger, et al. B7-H1 (Programmed Death-1 Ligand) on Dendritic Cells Is Involved in the Induction and Maintenance of T Cell Anergy J. Immunol., April 1, 2003; 170(7): 3637 - 3644. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Radhakrishnan, L. T. Nguyen, B. Ciric, D. R. Ure, B. Zhou, K. Tamada, H. Dong, S.-Y. Tseng, T. Shin, D. M. Pardoll, et al. Naturally Occurring Human IgM Antibody That Binds B7-DC and Potentiates T Cell Stimulation by Dendritic Cells J. Immunol., February 15, 2003; 170(4): 1830 - 1838. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Brown, D. M. Dorfman, F.-R. Ma, E. L. Sullivan, O. Munoz, C. R. Wood, E. A. Greenfield, and G. J. Freeman Blockade of Programmed Death-1 Ligands on Dendritic Cells Enhances T Cell Activation and Cytokine Production J. Immunol., February 1, 2003; 170(3): 1257 - 1266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Gardby, J. Wrammert, K. Schon, L. Ekman, T. Leanderson, and N. Lycke Strong Differential Regulation of Serum and Mucosal IgA Responses as Revealed in CD28-Deficient Mice Using Cholera Toxin Adjuvant J. Immunol., January 1, 2003; 170(1): 55 - 63. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Yamazaki, H. Akiba, H. Iwai, H. Matsuda, M. Aoki, Y. Tanno, T. Shin, H. Tsuchiya, D. M. Pardoll, K. Okumura, et al. Expression of Programmed Death 1 Ligands by Murine T Cells and APC J. Immunol., November 15, 2002; 169(10): 5538 - 5545. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Rajagopalan, M. K. Smart, E. V. Marietta, and C. S. David Staphylococcal enterotoxin B-induced activation and concomitant resistance to cell death in CD28-deficient HLA-DQ8 transgenic mice Int. Immunol., July 1, 2002; 14(7): 801 - 812. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. P. Gray, P. Arosio, and P. Hersey Heavy chain ferritin activates regulatory T cells by induction of changes in dendritic cells Blood, May 1, 2002; 99(9): 3326 - 3334. [Abstract] [Full Text] [PDF]
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 |
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 T. Okazaki, A. Maeda, H. Nishimura, T. Kurosaki, and T. Honjo PD-1 immunoreceptor inhibits B cell receptor-mediated signaling by recruiting src homology 2-domain-containing tyrosine phosphatase 2 to phosphotyrosine PNAS, October 31, 2001; (2001) 231486598. [Abstract] [Full Text] [PDF]
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|
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T. Okazaki, A. Maeda, H. Nishimura, T. Kurosaki, and T. Honjo PD-1 immunoreceptor inhibits B cell receptor-mediated signaling by recruiting src homology 2-domain-containing tyrosine phosphatase 2 to phosphotyrosine PNAS, November 20, 2001; 98(24): 13866 - 13871. [Abstract] [Full Text] [PDF]
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Top
Abstract
Introduction
(TNF-
/
) or control immunoglobulin (
) in the
presence of a suboptimal dose (200 ng/mL) of precoated anti-CD3 mAb.
The proliferation of T cells was determined by 3H-thymidine
incorporation assay. (B) B7-H1 costimulation is CD28 independent.
NW-purified T cells obtained from spleens of wild-type (wt, left panel)
and CD28
), or mB7-H1Ig (
; B7-H1Ig, 
) in the precoated plate with immobilized anti-CD3 (1 µg/mL). Supernatants were collected at 18, 24, 36, and 48 hours, and
IL-2 concentrations in the supernatants were determined by sandwich
ELISA. Data present one experiment of 3. Error bars represent the SD of
the mean of triplicate T-cell culture wells.
,
mB7-1Ig. Serum from individual mice was collected on days 7 and 14. The
concentrations of anti-TNP-specific IgG of all subclasses and IgM were
determined by specific sandwich ELISA as described in "Materials and
methods." The results of the OD450 reading are expressed
as the mean ± SD.
