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* Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720;
Howard Hughes Medical Institute and Departments of Physiology and Biochemistry, University of California, San Francisco, CA 94143; and
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511
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Introduction |
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T cell development (3). This block is associated with an impairment of V to DJ rearrangement at the TCR locus in DN3 stage thymocytes. Given the importance of Notch in cell fate decisions during T cell development, it is important to address how Notch activity may be regulated during this process. One of the proteins that has been implicated as a regulator of Notch is Numb (14, 15). Numb is an adapter protein that contains an N-terminal phosphotyrosine binding (PTB)4 domain and a C-terminal proline-rich region containing several putative Src homology 3 binding domains. Numb was first identified as a gene controlling cell fate specification in development of the Drosophila peripheral nervous system. Further studies of Drosophila neural development showed that Numb acts by antagonizing Notch signals. Recent reports suggest that Numb may regulate Notch activity by promoting the down-regulation and/or degradation of Notch receptor (16, 17). In mammals, two homologues of Numb, Numb and Numblike, have been described (18, 19, 20). Because Numb is expressed in the thymus (21), it is a good candidate for regulation of Notch activity during T cell development.
Notch receptors and ligands are also expressed on cells of the peripheral immune system (22, 23, 24) and appear to have a role in T cell responses. Some studies suggest that Notch may have a role in inducing regulatory T cells (22, 25, 26, 27). Other studies suggest a role for Notch in modulating T cell responses (28, 29, 30) and affecting Th1/Th2 differentiation (31, 32). Thus, it appears that Notch also plays a role in peripheral T cell responses, although the exact mechanism and effects of Notch are still unclear.
In this study we provide evidence for the physical association of TCR, Notch, and Numb in both immature and mature T cells. We also explored the role of Numb in T cell development by generating mice in which Numb is deleted specifically in T cells, and we found that there is no appreciable effect of Numb deficiency on T cell development, perhaps due to redundancy with the homologous protein Numblike. Our results provide a basis for future examination of the roles of Notch and Numb in modulating TCR signaling.
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Materials and Methods |
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Lck-Cre and CD4-Cre transgenic mice (33) were provided by C. Wilson (University of Washington). Numbflox/flox and Numb+/– mice have been previously described (34). AND TCR transgenic (H-2b) mice were purchased from The Jackson Laboratory. AND TCR transgenic RAG–/– (H-2d) mice were purchased from Taconic Farms. All animals were housed in accordance with the guidelines established by the animal care and use committee at University of California, Berkeley.
Colocalization assay
DCEK.ICAM cells (I-EK) (35) were cultured on four-well, poly-L-lysine-coated slides at 105 cells/well in complete RPMI 1640 and incubated overnight at 37°C. Twelve to 16 h before the addition of T cells, DCEK.ICAM cells were either pulsed with 10 µM pigeon cytochrome c (PCC) peptide or left untreated. Thymocytes (106) from AND TCR transgenic (H-2d) mice or 106 lymph node cells (LNC) from AND TCR transgenic (H-2b) mice were then added with or without freshly added peptide and cultured for 20 min. After incubation, slides were spun down at 700 rpm for 5 min. Cells were then fixed with 4% paraformaldehyde for 15 min at 4°C, permeabilized, and stained with Abs against Numb, Notch, and CD3. The Abs used are affinity-purified rabbit antisera generated against the C terminus of murine Numb (aa 489–524) as previously described (19), goat anti-rabbit Alexa-546, goat anti-rabbit Alexa-488, goat anti-hamster Alexa-546 (Molecular Probes), anti-CD3-allophycocyanin, anti-CD4 (BD Biosciences; which we conjugated in-house to Alexa-546 according to the manufacturer’s protocol (Molecular Probes)), and anti-Notch (clone 8G10; see below). T cell/APC conjugates were visualized on a Nikon E800 fluorescence microscope retrofit for three-dimensional capture. Images were deconvolved using SlideBook software (Intelligent Imaging Innovations).
Isolation of mAb reactive with mouse Notch1
A hamster mAb against mouse Notch1 (clone 8G10) was generated by immunizing a Syrian hamster with a bacterial fusion protein consisting of the region from epidermal growth factor repeat 33 through LIN-12, Notch, GLP-1 repeat 1 (nucleotides 3898–4476) of mouse Notch1 fused to GST. Spleen cells were fused with a hamster hybridoma partner, and the clones were screened by ELISA for reactivity with the fusion protein. Positive clones were then recloned and screened for reactivity against full-length mouse Notch1 by immunoblotting. Anti-Notch1 Ab was generated from hybridoma culture supernatant and was either purified on a protein G column or used as a concentrated culture supernatant. The 8G10 Ab reacts with mouse and rat Notch1, but not with other Notch family members (data not shown). The Ab has been licensed to Upstate Biotechnology.
Immunoprecipitation and immunoblotting
For immunoprecipitations, 108 thymocytes from either C57BL/6 or AND-TCR transgenic (H-2d) mice were lysed in lysis buffer (20 mM Tris-HCl (pH 8.0), 138 mM NaCl, 9.5% glycerol, 1 mM sodium orthovanadate, 2 mM EDTA, 10 mM NaF containing either 1% Brij 58 detergent (Pierce), or 1% Nonidet P-40 (Sigma-Aldrich)) supplemented with mini complete EDTA-free protease inhibitor mixture (Roche). Cell lysates were precleared with protein G agarose beads (Sigma-Aldrich) bound with rabbit anti-GST for 2 h at 4°C. Samples were then briefly centrifuged, and the supernatant was added to protein G agarose beads bound with Numb antisera and incubated overnight at 4°C. Samples were separated on a 10% SDS-PAGE gel, transferred onto nitrocellulose (Hybond ECL; Amersham Pharmacia), and immunoblotted. For kinetic analysis of Numb associations after TCR stimulation, DCEK.ICAM cells were plated at 105 cells/ml in complete RPMI 1640 and incubated overnight at 37°C. Four hours before the addition of T cells, DCEK.ICAM cells were either pulsed with 10 µM PCC peptide or left untreated. Thymocytes (1.5 x 108) were then added with or without freshly added peptide and cultured for 5, 15, or 20 min at 37°C. Thymocytes were then washed off and immediately lysed as described above. Cells (106) were removed from the samples for the lysate control. The remaining cells were immunoprecipitated with Numb as described above. For the analysis of Numb deletion, cell lysates were prepared by resuspending 106 cells in lysis buffer (1% Nonidet P-40, 150 mM NaCl, 50 mM Tris (pH 7.4), and 0.02% NaN3) supplemented with mini complete protease inhibitor mixture (Roche). Cell lysates were separated as described above, transferred onto nitrocellulose, and immunoblotted using Numb antisera. Where indicated, CD3+ T cells were purified using T cell enrichment columns (R&D Systems). Abs used for immunoblotting are as follows: affinity-purified rabbit antisera generated against the C terminus of murine Numb (aa 489–524), anti-phosphotyrosine (4G10), anti-Lck (clone 3A2), anti-Vav, anti-GST (Z-5), anti-c-Cbl (A-9; Santa Cruz Biotechnology), and anti-CD4 (L3T4; BD Biosciences). Bound Abs were detected with goat anti-rabbit HRP-conjugated secondary Ab (Southern Biotechnology Associates) and goat anti-mouse IgG-HRP (Jackson ImmunoResearch Laboratories) and visualized using ECL (Amersham Pharmacia).
Flow cytometry
Single-cell suspensions from thymus, lymph node, and spleen were prepared and stained with the following Abs: anti- TCR, anti-CD3 labeled with FITC (BD Biosciences/eBiosciences), anti-CD19, labeled with PE (BD Biosciences/eBiosciences), anti-CD4 labeled with PE-Texas Red (Caltag Laboratories), and anti-CD8 labeled with PE-Cy5 (eBiosciences). All data was collected on a Coulter EPICS-XL cytometer (Beckman Coulter) and analyzed with FlowJo software (TreeStar).
Assays for T lymphocyte function
Activation with anti-CD3. CD3+ T cells were purified from lymph nodes using CD3 enrichment columns (R&D Systems) CD3+ T cells (1 x 104–5 x 104/well) were then cultured in triplicate in flat-bottom 96-well plates that had been coated with anti-CD3 (BD Biosciences). Cells were cultured 48 h and pulsed with 1 µCi/well [3H]thymidine for the last 16 h. Cells were then harvested, and [3H]thymidine incorporation was determined in a rack beta scintillation counter (Beckman Coulter).
LNC proliferation. Mice were immunized s.c. at five sites with 100 µg of OVA (Sigma-Aldrich) emulsified in CFA (Difco). Draining lymph nodes were harvested 10 days later. LNCs (4 x 105/well) were cultured in triplicate in 96-well, round-bottom plates in the presence of various concentrations of Ag for 48 h and pulsed with 1 µCi/well [3H]thymidine for the last 16 h. [3H]thymidine incorporation was determined as described above.
Homeostatic proliferation. CD3+ lymph node T cells were purified from Numb–/– mice and littermate controls (Ly5.2) using T cell enrichment columns (R&D Systems). Cells were then labeled with 2 µM CFSE (Molecular Probes) and transferred i.v. (106/mouse) to B65.1 (Ly5.1) that had been irradiated with 400 rad 24 h earlier. On day 6 post-transfer, spleen cells were harvested and stained with Abs to CD4, CD8, and Ly5.1. Data were collected on a Coulter EPICS XL cytometer (Beckman Coulter) and analyzed as described above.
RT-PCR
Total RNA was extracted from either thymocytes or purified CD3+ LNC using TRIzol (Invitrogen Life Technologies). RNA was treated with DNase I to eliminate contaminating genomic DNA before cDNA synthesis using SuperScript (Invitrogen Life Technologies). First-strand cDNA was then used in PCR. The following primers were used: -actin: forward, 5'-tggaatctgtggcatccatgaaa c-3'; reverse, 5'-taaaacgcagctcagtaacagtccg-3'; and Numblike: forward, 5'-ctgaaaccttcaggacggag-3'; reverse, 5'-cacaggacagacttcacgga-3'. PCR products were visualized by agarose gel electrophoresis.
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Given the likely involvement of the Notch and TCR signaling pathways in both immature and mature T cell responses, we hypothesized that these pathways may be physically linked in T cells. To test this hypothesis, we examined the localization of Notch and CD3 in lymph node T cells from AND TCR transgenic (H-2b) mice after exposure to peptide-pulsed APCs by fluorescence microscopy. We found that Notch is recruited to the T cell/APC interface and coclusters with CD3 after Ag exposure (Fig. 1A). Because Numb has been reported to associate with the intracellular region of Notch (15, 19), we examined whether Numb also coclusters with CD3 after Ag exposure. As shown in Fig. 1B, Numb is also recruited to the T cell/APC interface and coclusters with CD3 after Ag exposure.
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30% of conjugates had CD3 plus Notch clustered at the interface. No clustering of CD3, Notch, or CD3 plus Notch was observed in the absence of Ag (Fig. 2A). For the experiments examining the clustering of CD3 and Numb, some clustering of CD3 or Numb alone to the interface was observed in the presence and the absence of Ag. However, coclustering of CD3 plus Numb was only observed in the presence of Ag (Fig. 2A). Second, we chose representative examples of thymocyte/APC conjugates and determined the pixel intensity of the CD3, CD8, and Numb signals at the T cell/APC interface relative to the pixel intensity over the whole cell. The percentage of CD3 and Numb signals that localized at the T cell/APC interface in thymocytes increased in the presence of Ag, whereas the amount of CD8 signal at the interface remained the same in the presence or the absence of Ag (Fig. 2B). Thus, it appears that both Notch and Numb are recruited to the T cell/APC interface and cocluster with the TCR complex upon Ag exposure in immature and mature T cells, suggesting a physical association between the Notch and TCR signaling pathways in these cells. Given that Numb has the structural features of an adapter protein, we hypothesized that it may provide a link between the TCR and Notch signaling pathways. To investigate this, we examined what proteins interact with Numb in thymocytes. Because Numb contains a PTB domain, we first looked for associated proteins containing phosphorylated tyrosines by immunoprecipitation with Numb antisera, followed by immunoblotting with an anti-phosphotyrosine Ab. We observed several prominent tyrosine-phosphorylated proteins in the Numb immunoprecipitates that were not present in control immunoprecipitations using species-matched antisera of irrelevant specificity (preclear lane, Fig. 3A). Upon reprobing the blot with specific Abs, we found that Lck (Fig. 3B), c-Cbl (Fig. 3C), and Vav (Fig. 3D), coprecipitated with Numb in thymocytes. Similar results were obtained in peripheral T cells (data not shown). The comigration of these bands with prominent phosphotyrosine-containing proteins together with previous reports that these proteins are tyrosine phosphorylated in T cells suggest that the indicated bands in the anti-phosphotyrosine blot correspond to phospho-c Cbl, phospho-Lck, and phospho-Vav (Fig. 3A). We also probed the blot with anti-CD4 and found CD4 in the immunoprecipitate (Fig. 3E) as expected, because Lck is known to associate strongly with CD4 (36). Thus, Numb appears to exist in a preformed complex with TCR signaling proteins, and this complex gets recruited to the T cell/APC interface in an Ag-dependent manner.
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Given our data implicating Numb as a link between the TCR and Notch signaling pathways, we chose to address the role of Numb at different stages of T cell development. Because germline deletion of Numb leads to lethality on embryonic day 11.5 (34, 37), we used Cre/lox technology to target deletion of the Numb gene specifically to developing T cells. To achieve this we crossed Numbflox/floxmice (34) with mice expressing the Cre recombinase under the control of the Lck proximal and CD4 promoters. These promoters have been shown to effect deletion at the DN2/3 and DN3/4 stages of thymic development, respectively (3, 33, 38). We generated mice in which one allele of Numb was already deleted by first crossing Numb+/– (34) mice to Cre transgenic mice and subsequently crossing progeny from this cross to Numbflox/flox mice. To assess the extent of deletion of Numb, we extracted total genomic DNA from unfractionated thymocytes and examined the Numb locus by PCR using primers that distinguish wild-type (WT), floxed, and deleted Numb alleles (34). Fig. 5A shows a representative example of the deletion of Numb. In thymocytes from Lck Cre– Numbfl/+ mice, both the WT and floxed alleles are detected; however, in the Lck-Cre+ Numbfl/– (Numb-deficient) littermate, the deleted allele is the predominant product with a very low level of floxed allele detected. This residual Numb could be due to the presence of DN cells that have not yet deleted Numb, or it could be the result of incomplete deletion of Numb. We next examined Numb protein expression in both unfractionated thymocytes and purified peripheral T cells by immunoblotting (Fig. 5B). We estimate that the deletion of Numb protein in thymocytes and mature T cells from Numb-deficient mice is >95%, with deletion occurring to a similar extent in Numb-deficient mice generated under the Lck-proximal and CD4 promoters. We also observed the presence of a lower m.w. band in lysates from Numb+/– and Numb-deficient mice that was not present in lysates from Numb+/+ or floxed mice (Fig. 5B and data not shown). Sequence analysis of RT-PCR products from these mice indicates that this minor band corresponds to a splice around the targeted exons of Numb (data not shown). This mutant Numb protein is unlikely to be functional given that it lacks a significant portion of the PTB domain and an independently generated Numb-deficient mouse displays a similar embryonic phenotype (34, 37).
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We examined T cell development in mice in which Numb deletion was driven by CRE expressed under the control of the Lck proximal and CD4 promoters. In Lck-Cre+ Numbfl/ –mice, we observed a modest block between DN3 and DN4 that could be attributed to the presence of the Lck Cre transgene because it was also observed in Lck-Cre+ Numb+/+ controls (data not shown). Similarly, a reduction in the number of peripheral T cells and a skew in the ratio of CD4/CD8 T cells in Lck-Cre+ Numbfl/ –mice could also be attributed to the presence of the Lck Cre transgene alone (Fig. 6, A and B). In addition, we did not observe any defects in thymic development or in the periphery of Numb-deficient mice generated under the CD4 promoter (Fig. 6, C and D, and data not shown). Taken together these data suggest that T cell development can proceed normally in the absence of Numb.
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Given our data implicating Numb in TCR signaling, we examined next the ability of Numb-deficient T cells to respond to signals through the TCR. As shown in Fig. 7A, Numb-deficient T cells proliferate equally well in response to plate-bound anti-CD3 as do Numb WT T cells. To examine the ability of Numb-deficient T cells to respond to a more physiologic stimulus, we assessed the in vitro recall response to OVA after immunization with OVA in CFA. As shown in Fig. 7B, there is no significant difference in the ability of Numb-deficient T cells to proliferate in response to Ag stimulation relative to Numb WT littermate controls. We also found no significant differences in the production of IFN-
by Numb-deficient T cells relative to littermate controls (data not shown). Finally, we examined the ability of Numb-deficient T cells to respond to homeostatic signals that regulate T cell survival and drive proliferation in response to lymphopenia (reviewed in Refs. 39 and 40). We transferred CFSE-labeled peripheral T cells isolated from Numb WT or Numb-deficient mice to irradiated recipients and analyzed the ability of T cells to undergo homeostatic proliferation by comparing CFSE dilution profiles. We found that Numb-deficient T cells and Numb WT T cells undergo homeostatic division to a similar degree (Fig. 8). We also examined the phosphorylation of TCR-
, which is constitutively phosphorylated in normal T cells in response to environmental survival signals (41), and found that its phosphorylation is similar in Numb-deficient T cells compared with T cells from littermate controls (data not shown). Taken together, these data suggest that Numb deficiency does not affect peripheral T cell function and homeostasis.
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The lack of an appreciable effect of Numb deficiency on thymocyte development and peripheral T cell responses despite evidence for functional associations between Numb and the TCR signaling apparatus raises the possibility of functional redundancy by a related protein. Numblike is highly homologous to Numb (20), and low levels of Numblike have been shown to functionally compensate for Numb deficiency (42). We examined the expression of Numblike in both thymocytes and peripheral T cells and found that Numblike is expressed in both thymocytes and peripheral T cells (Fig. 9 and data not shown), providing a possible explanation for the normal T cell development and functional responses we observe in Numb-deficient mice.
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Discussion |
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A number of recent studies point to a role for Notch in modulating TCR signaling. In some studies, Notch activity was found to enhance TCR-induced proliferation by potentiating IL-2R expression (28) and NF-
B activity (29), whereas another study found an inhibitory effect of Notch on TCR signaling (30). Notch has also been implicated in regulating the balance of Th1/Th2 cell development (31, 32). For thymocytes, we have found that Notch synergizes with TCR signals to regulate gene expression in thymocytes (44), whereas others have reported that Notch activity dampens TCR signals (45). Together, these studies point to a complex functional interplay between the TCR and Notch signaling pathways. Our data showing physical associations among TCR, Notch, and Numb provide a framework for further examination of how Notch and TCR signals could be influencing one another.
In addition to its role in regulating Notch, Numb has been implicated in the cellular processes of endocytosis and ubiquitination (16, 17, 46). Two recent reports suggest that these functions of Numb may be related to its ability to regulate Notch. First, Numb was found to associate with the ubiquitin ligase Itch, thereby promoting the ubiquitination and degradation of membrane-associated Notch receptor (16). Second, Numb was found to associate with -adaptin, a protein involved in receptor-mediated endocytosis, and this interaction was found to be important in down-regulating Notch expression (17). Given these considerations and our data suggesting Numb as a link between the TCR and Notch signaling pathways, several nonmutually exclusive models of how these pathways operate in T cells emerge. In the first model, Numb regulates Notch activity in T cells, and Notch acts directly to modulate T cell fate. Although this model fits well with classic studies of Numb and Notch in other systems, it does not take into account our data showing the interaction of Numb with components of the T cell signaling apparatus or the recent studies suggesting regulation of TCR signaling by Notch (discussed above). In a second model, Numb functions as an adapter protein in T cells and regulates T cell signaling as a part of the TCR signalosome. This model fits with the idea of Numb as an adapter protein and our interaction data, but does not incorporate the well-established role of Numb in regulating Notch. In a third model, Numb regulates Notch signaling, and Notch then regulates signals through the TCR. In considering these last two models, Numb could regulate TCR, Notch, or both by targeting them for ubiquitination and degradation (16, 17). Our observation that the ubiquitin ligase c-Cbl is part of the complex containing Numb fits with this idea. Although we did not observe any difference in the levels of cell surface TCR or Notch expression in Numb-deficient T cells (data not shown), it is still possible that Numb targets a subset of activated TCR or Notch receptors for endocytosis and degradation, in line with previous suggestions (16, 17). The extent to which any of these models may operate in T cells will be the subject of future experiments.
Despite these indications for a connection between Notch signaling and TCR signaling, we did not see an appreciable effect of Numb deficiency on peripheral T cell responses. One possible explanation for this is that Numblike compensates for lack of Numb. Numblike is highly homologous to Numb, and low level expression of Numblike has been shown to be functionally redundant with Numb during neural development (42) (Y.-N. Jan and W. Zhong, unpublished observations). Because, Numblike is expressed in thymocytes (data not shown) and peripheral T cells, it is likely that Numblike compensates for the absence of Numb in Numb-deficient T cells. This may explain the lack of a thymic defect in Numb-deficient mice. Another possibility is that the T cells that are seeded to the periphery in Numb-deficient mice represent those that have best adapted to function normally in the absence of Numb. One way to resolve these issues is to examine development and function in T cells deficient for both Numb and Numblike.
In summary, we have shown that the TCR and Notch signaling pathways may be connected in T cells via the adapter protein Numb. Given the indications that Notch signaling affects multiple steps in T cell development and the possibility of complex interplay between the Notch and TCR signaling pathways, it is not surprising that many different effects have been attributed to Notch in T cells. Clarification of the role of Notch in T cell development and peripheral T cell function may come from a better understanding of which effects of Notch are direct consequences of Notch target gene expression vs modulation of TCR signals. Our data provide a framework for future work in deciphering how Notch mediates its effects in both immature and mature T cells.
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Acknowledgments |
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Footnotes |
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1 This work was supported by National Institutes of Heath Grant AI32985 (to E.R.). A.C.A. is supported by National Institutes of Heath Postdoctoral Fellowship F132AI50415-01. 
2 A.C.A. and E.A.K. contributed equally to this work.
3 Address correspondence and reprint requests to Dr. Ana C. Anderson, Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, HIM, 77 Avenue Louis Pasteur, Room 784, Boston, MA 02115. E-mail address: aanderson{at}rics.bwh.harvard.edu
4 Abbreviations used in this paper: PTB, phosphotyrosine binding; DN, double negative; LNC, lymph node cell; PCC, pigeon cytochrome c; WT, wild type.
Received for publication May 11, 2004. Accepted for publication November 3, 2004.
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- T cell receptors. Curr. Opin. Immunol. 9:250.[Medline]
rearrangement and allows pre-TCR-independent survival of early lineage thymocytes. Immunity 16:869.[Medline]
vs. 
T cell lineage decision. Cell 88:833.[Medline]
-like-1 in vitro. Immunity 17:749.[Medline]
-adaptin is required for Numb-mediated asymmetric cell division in Drosophila. Dev. Cell 3:221.[Medline]
production in peripheral T cells. J. Immunol. 171:3019. subunit: regulation of TRC-associated protein tyrosine kinase activity by TCR. Mol. Cell. Biol. 13:5771.This article has been cited by other articles:
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  M. Stahl, K. Uemura, C. Ge, S. Shi, Y. Tashima, and P. Stanley Roles of Pofut1 and O-Fucose in Mammalian Notch Signaling J. Biol. Chem., May 16, 2008; 283(20): 13638 - 13651. [Abstract] [Full Text] [PDF]
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 C. Ge and P. Stanley The O-fucose glycan in the ligand-binding domain of Notch1 regulates embryogenesis and T cell development PNAS, February 5, 2008; 105(5): 1539 - 1544. [Abstract] [Full Text] [PDF]
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 K. Laky and B.J. Fowlkes Presenilins regulate {alpha}{beta} T cell development by modulating TCR signaling J. Exp. Med., September 3, 2007; 204(9): 2115 - 2129. [Abstract] [Full Text] [PDF]
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 W. H. Luty, D. Rodeberg, J. Parness, and Y. M. Vyas Antiparallel Segregation of Notch Components in the Immunological Synapse Directs Reciprocal Signaling in Allogeneic Th:DC Conjugates J. Immunol., July 15, 2007; 179(2): 819 - 829. [Abstract] [Full Text] [PDF]
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A. Wilson, D.-L. Ardiet, C. Saner, N. Vilain, F. Beermann, M. Aguet, H. R. MacDonald, and O. Zilian Normal Hemopoiesis and Lymphopoiesis in the Combined Absence of Numb and Numblike J. Immunol., June 1, 2007; 178(11): 6746 - 6751. [Abstract] [Full Text] [PDF]
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A. M. Kostianovsky, L. M. Maier, C. Baecher-Allan, A. C. Anderson, and D. E. Anderson Up-Regulation of Gene Related to Anergy in Lymphocytes Is Associated with Notch-Mediated Human T Cell Suppression J. Immunol., May 15, 2007; 178(10): 6158 - 6163. [Abstract] [Full Text] [PDF]
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 J. T. Chang, V. R. Palanivel, I. Kinjyo, F. Schambach, A. M. Intlekofer, A. Banerjee, S. A. Longworth, K. E. Vinup, P. Mrass, J. Oliaro, et al. Asymmetric T Lymphocyte Division in the Initiation of Adaptive Immune Responses Science, March 23, 2007; 315(5819): 1687 - 1691. [Abstract] [Full Text] [PDF]
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 L. E. Matesic, D. C. Haines, N. G. Copeland, and N. A. Jenkins Itch genetically interacts with Notch1 in a mouse autoimmune disease model Hum. Mol. Genet., December 15, 2006; 15(24): 3485 - 3497. [Abstract] [Full Text] [PDF]
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C. J. Guidos Synergy between the pre-T cell receptor and Notch: cementing the {alpha}{beta} lineage choice J. Exp. Med., October 2, 2006; 203(10): 2233 - 2237. [Abstract] [Full Text] [PDF]
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cpm of triplicate wells, where 
