1
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Perica K, Bieler JG, Edidin M, Schneck J. Modulation of MHC binding by lateral association of TCR and coreceptor. Biophys J 2013. [PMID: 23199917 DOI: 10.1016/j.bpj.2012.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The structure of a T cell receptor (TCR) and its affinity for cognate antigen are fixed, but T cells regulate binding sensitivity through changes in lateral membrane organization. TCR microclusters formed upon antigen engagement participate in downstream signaling. Microclusters are also found 3-4 days after activation, leading to enhanced antigen binding upon rechallenge. However, others have found an almost complete loss of antigen binding four days after T cell activation, when TCR clusters are present. To resolve these contradictory results, we compared binding of soluble MHC-Ig dimers by transgenic T cells stimulated with a high (100 μM) or low (100 fM) dose of cognate antigen. Cells activated by a high dose of peptide bound sixfold lower amounts of CD8-dependent ligand K(b)-SIY than cells activated by a low dose of MHC/peptide. In contrast, both cell populations bound a CD8-independent ligand L(d)-QL9 equally well. Consistent with the differences between binding of CD8-dependent and CD8-independent peptide/MHC, Förster resonance energy transfer (FRET) measurements of molecular proximity reported little nanoscale association of TCR with CD8 (16 FRET units) compared to their association on cells stimulated by low antigen dose (62 FRET units). Loss of binding induced by changes in lateral organization of TCR and CD8 may serve as a regulatory mechanism to avoid excessive inflammation and immunopathology in response to aggressive infection.
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Affiliation(s)
- Karlo Perica
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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2
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Huang J, Meyer C, Zhu C. T cell antigen recognition at the cell membrane. Mol Immunol 2012; 52:155-64. [PMID: 22683645 DOI: 10.1016/j.molimm.2012.05.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 04/27/2012] [Accepted: 05/01/2012] [Indexed: 11/16/2022]
Abstract
T cell antigen receptors (TCRs) on the surface of T cells bind specifically to particular peptide bound major histocompatibility complexes (pMHCs) presented on the surface of antigen presenting cells (APCs). This interaction is a key event in T cell antigen recognition and activation. Most studies have used surface plasmon resonance (SPR) to measure the in vitro binding kinetics of TCR-pMHC interactions in solution using purified proteins. However, these measurements are not physiologically precise, as both TCRs and pMHCs are membrane-associated molecules which are regulated by their cellular environments. Recently, single-molecule förster resonance energy transfer (FRET) and single-molecule mechanical assays were used to measure the in situ binding kinetics of TCR-pMHC interactions on the surface of live T cells. These studies have provided exciting insights into the biochemical basis of T cell antigen recognition and suggest that TCRs serially engage with a small number of antigens with very fast kinetics in order to maximize TCR signaling and sensitivity.
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Affiliation(s)
- Jun Huang
- Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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3
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Clement M, Ladell K, Ekeruche-Makinde J, Miles JJ, Edwards ESJ, Dolton G, Williams T, Schauenburg AJA, Cole DK, Lauder SN, Gallimore AM, Godkin AJ, Burrows SR, Price DA, Sewell AK, Wooldridge L. Anti-CD8 antibodies can trigger CD8+ T cell effector function in the absence of TCR engagement and improve peptide-MHCI tetramer staining. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 187:654-63. [PMID: 21677135 PMCID: PMC3145095 DOI: 10.4049/jimmunol.1003941] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) T cells recognize immunogenic peptides presented at the cell surface bound to MHCI molecules. Ag recognition involves the binding of both TCR and CD8 coreceptor to the same peptide-MHCI (pMHCI) ligand. Specificity is determined by the TCR, whereas CD8 mediates effects on Ag sensitivity. Anti-CD8 Abs have been used extensively to examine the role of CD8 in CD8(+) T cell activation. However, as previous studies have yielded conflicting results, it is unclear from the literature whether anti-CD8 Abs per se are capable of inducing effector function. In this article, we report on the ability of seven monoclonal anti-human CD8 Abs to activate six human CD8(+) T cell clones with a total of five different specificities. Six of seven anti-human CD8 Abs tested did not activate CD8(+) T cells. In contrast, one anti-human CD8 Ab, OKT8, induced effector function in all CD8(+) T cells examined. Moreover, OKT8 was found to enhance TCR/pMHCI on-rates and, as a consequence, could be used to improve pMHCI tetramer staining and the visualization of Ag-specific CD8(+) T cells. The anti-mouse CD8 Abs, CT-CD8a and CT-CD8b, also activated CD8(+) T cells despite opposing effects on pMHCI tetramer staining. The observed heterogeneity in the ability of anti-CD8 Abs to trigger T cell effector function provides an explanation for the apparent incongruity observed in previous studies and should be taken into consideration when interpreting results generated with these reagents. Furthermore, the ability of Ab-mediated CD8 engagement to deliver an activation signal underscores the importance of CD8 in CD8(+) T cell signaling.
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Affiliation(s)
- Mathew Clement
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Kristin Ladell
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Julia Ekeruche-Makinde
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - John J. Miles
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Emily S. J. Edwards
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Garry Dolton
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Tamsin Williams
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Andrea J. A. Schauenburg
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - David K. Cole
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Sarah N. Lauder
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Awen M. Gallimore
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Andrew J. Godkin
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Scott R. Burrows
- Cellular Immunology Laboratory, Department of Infectious Disease and Immunology, Queensland Institute of Medical Research, Brisbane 4029, Australia
| | - David A. Price
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Andrew K. Sewell
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Linda Wooldridge
- Department of Infection, Immunity and Biochemisty, Henry Wellcome Building, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
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4
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Abstract
Ligand binding to cell membrane receptors sets off a series of protein interactions that convey the nuances of ligand identity to the cell interior. The information may be encoded in conformational changes, the interaction kinetics and, in the case of multichain immunoreceptors, by chain rearrangements. The signals may be modulated by dynamic compartmentalization of the cell membrane, cellular architecture, motility, and activation-all of which are difficult to reconstitute for studies of receptor signaling in vitro. In this paper, we will discuss how protein interactions in general and receptor signaling in particular can be studied in living cells by different fluorescence imaging techniques. Particularly versatile are methods that exploit Förster resonance energy transfer (FRET), which is exquisitely sensitive to the nanometer-range proximity and orientation between fluorophores. Fluorescence correlation microscopy (FCM) can provide complementary information about the stoichiometry and diffusion kinetics of large complexes, while bimolecular fluorescence complementation (BiFC) and other complementation techniques can capture transient interactions. A continuing challenge is extracting from the imaging data the quantitative information that is necessary to verify different models of signal transduction.
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Affiliation(s)
- Tomasz Zal
- Department of Immunology, University of Texas, MD Anderson Cancer Center, Houston TX, USA
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5
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Stone JD, Aggen DH, Chervin AS, Narayanan S, Schmitt TM, Greenberg PD, Kranz DM. Opposite effects of endogenous peptide-MHC class I on T cell activity in the presence and absence of CD8. THE JOURNAL OF IMMUNOLOGY 2011; 186:5193-200. [PMID: 21451107 DOI: 10.4049/jimmunol.1003755] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Nonstimulatory or endogenous peptide-MHC (pepMHC) presented on the surfaces of APCs, either alone or alongside agonist pepMHC, plays various roles in T cell selection and activation. To examine these properties in more detail, we explored several model systems of TCR and pepMHC ligands with sufficient affinity to be activated in the absence of CD8. The TCRs had a range of affinities for agonist and nonstimulatory ligands and were restricted by MHC class I alleles with different properties. We observed CD8-independent antagonism from TCR-pepMHC interactions with very low affinities (e.g., K(D) = 300 μM). In addition, endogenous peptide-L(d) complexes on APCs antagonized activation of coreceptor (CD8)-negative 2C T cells even by the strong agonist QL9-L(d). In contrast, TCRs m33 and 3D-PYY, restricted by K(b) and D(b), respectively, did not show signs of antagonism by endogenous pepMHC in the absence of CD8. This did not appear to be an inherent difference in the ability of the TCRs to be antagonized, as altered peptide ligands could antagonize each TCR. In the presence of CD8, endogenous pepMHC ligands acted in some cases as coagonists. These results show that endogenous pepMHC molecules exhibit complex behavior in T cells, leading to either reduced activity (e.g., in cases of low coreceptor levels) or enhanced activity (e.g., in presence of coreceptor). The behavior may be influenced by the ability of different TCRs to recognize endogenous pepMHC but also perhaps by the inherent properties of the presenting MHC allele.
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Affiliation(s)
- Jennifer D Stone
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
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6
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Zhong L, Zeng G, Lu X, Wang RC, Gong G, Yan L, Huang D, Chen ZW. NSOM/QD-based direct visualization of CD3-induced and CD28-enhanced nanospatial coclustering of TCR and coreceptor in nanodomains in T cell activation. PLoS One 2009; 4:e5945. [PMID: 19536289 PMCID: PMC2693923 DOI: 10.1371/journal.pone.0005945] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Accepted: 05/21/2009] [Indexed: 12/04/2022] Open
Abstract
Direct molecular imaging of nano-spatial relationship between T cell receptor (TCR)/CD3 and CD4 or CD8 co-receptor before and after activation of a primary T cell has not been reported. We have recently innovated application of near-field scanning optical microscopy (NSOM) and immune-labeling quantum dots (QD) to image Ag-specific TCR response during in vivo clonal expansion, and now up-graded the NSOM/QD-based nanotechnology through dipole-polarization and dual-color imaging. Using this imaging system scanning cell-membrane molecules at a best-optical lateral resolution, we demonstrated that CD3, CD4 or CD8 molecules were distinctly distributed as single QD-bound molecules or nano-clusters equivalent to 2–4 QD fluorescence-intensity/size on cell-membrane of un-stimulated primary T cells, and ∼6–10% of CD3 were co-clustering with CD4 or CD8 as 70–110 nm nano-clusters without forming nano-domains. The ligation of TCR/CD3 on CD4 or CD8 T cells led to CD3 nanoscale co-clustering or interaction with CD4 or CD8 co-receptors forming 200–500 nm nano-domains or >500 nm micro-domains. Such nano-spatial co-clustering of CD3 and CD4 or CD3 and CD8 appeared to be an intrinsic event of TCR/CD3 ligation, not purely limited to MHC engagement, and be driven by Lck phosphorylation. Importantly, CD28 co-stimulation remarkably enhanced TCR/CD3 nanoscale co-clustering or interaction with CD4 co-receptor within nano- or micro-domains on the membrane. In contrast, CD28 co-stimulation did not enhance CD8 clustering or CD3–CD8 co-clustering in nano-domains although it increased molecular number and density of CD3 clustering in the enlarged nano-domains. These nanoscale findings provide new insights into TCR/CD3 interaction with CD4 or CD8 co-receptor in T-cell activation.
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Affiliation(s)
- Liyun Zhong
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Gucheng Zeng
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Xiaoxu Lu
- School for Information and Optoelectronic Engineering, South China Normal University, Guangzhou, Guangdong, China
| | - Richard C. Wang
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Guangming Gong
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Lin Yan
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Dan Huang
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Zheng W. Chen
- Department of Microbiology and Immunology, Center for Primate Biomedical Research, University of Illinois College of Medicine, Chicago, Illinois, United States of America
- * E-mail:
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7
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Indirect recruitment of a CD40 signaling pathway in dendritic cells by B7-DC cross-linking antibody modulates T cell functions. PLoS One 2009; 4:e5373. [PMID: 19399172 PMCID: PMC2670496 DOI: 10.1371/journal.pone.0005373] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 04/01/2009] [Indexed: 01/22/2023] Open
Abstract
The human IgM B7-DC XAb protects mice from tumors in both therapeutic and prophylactic settings. Its mechanism of action is mediated by its binding to B7-DC/PD-L2 molecules on the surface of dendritic cells (DCs) to induce a multimolecular cap and subsequent activation of signaling cascades that determine a unique combination of DC phenotypes. One such phenotype, the B7-DC XAb-induced antigen accumulation in mTLR-matured DCs, has been linked to signaling through TREM-2, but the signals required for other DC phenotypes critical for the therapeutic effects in animal models remain unclear. Here, FRET and co-immunoprecipitation studies show that CD40 is recruited to the multi-molecular complex by B7-DC XAb. Signals emanating from CD40 are important, as CD40−/− DCs treated with B7-DC XAb (DCXAb) activated DAP12, but failed to activate NFκB, and were not protected from cell death upon cytokine withdrawal or treatment with Vitamin D3. CD40−/− DCXAb also failed to secrete IL-6 and were unable to support the conversion of T regulatory cells into IL-17+ effector T cells in vitro. Importantly, the expression of CD40 was required for the overall ability of B7-DC XAb to induce anti-tumor CTL, to provide protection from a number of tumor types, and for DCXAb to be effective anti-tumor vaccines in vivo. These results indicate that B7-DC XAb modulation of DC phenotypes is through its ability to indirectly recruit common signaling molecules and elements of their endogenous signaling pathways through targeted binding to a cell-specific surface determinant.
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8
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Gascoigne NRJ, Ampudia J, Clamme JP, Fu G, Lotz C, Mallaun M, Niederberger N, Palmer E, Rybakin V, Yachi PP, Zal T. Visualizing intermolecular interactions in T cells. Curr Top Microbiol Immunol 2009; 334:31-46. [PMID: 19521680 PMCID: PMC3079427 DOI: 10.1007/978-3-540-93864-4_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The use of appropriate fluorescent proteins has allowed the use of FRET microscopy for investigation of intermolecular interactions in living cells. This method has the advantage of both being dynamic and of working at the subcellular level, so that the time and place where proteins interact can be visualized. We have used FRET microscopy to analyze the interactions between the T cell antigen receptor and the coreceptors CD4 and CD8. This chapter reviews data on how these coreceptors are recruited to the immunological synapse, and how they interact when the T cell is stimulated by different ligands.
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Affiliation(s)
- Nicholas R J Gascoigne
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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9
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Radhakrishnan S, Arneson LN, Upshaw JL, Howe CL, Felts SJ, Colonna M, Leibson PJ, Rodriguez M, Pease LR. TREM-2 mediated signaling induces antigen uptake and retention in mature myeloid dendritic cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:7863-72. [PMID: 19017976 DOI: 10.4049/jimmunol.181.11.7863] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Myeloid dendritic cells (mDC) activated with a B7-DC-specific cross-linking IgM Ab (B7-DC XAb) take up and retain Ag and interact with T cell compartments to affect a number of biologic changes that together cause strong antitumor responses and blockade of inflammatory airway disease in animal models. The molecular events mediating the initial responses in mDC remain unclear. In this study we show that B7-DC XAb caused rapid phosphorylation of the adaptor protein DAP12 and intracellular kinases Syk and phospholipase C-gamma1. Pretreatment of mDC with the Syk inhibitor piceatannol blocked B7-DC XAb-induced Ag uptake with a concomitant loss of tumor protection in mice. Vaccination with tumor lysate-pulsed wild-type B7-DC XAb-activated mDC, but not TREM-2 knockout XAb-activated mDC, protected mice from lethal melanoma challenge. Multimolecular caps appeared within minutes of B7-DC XAb binding to either human or mouse mDC, and FRET analysis showed that class II, CD80, CD86, and TREM-2 are recruited in tight association on the cell surface. When TREM-2 expression was reduced in wild-type mDC using short hairpin RNA or by using mDC from TREM-2 knockout mice, in vitro DC failed to take up Ag after B7-DC XAb stimulation. These results directly link TREM-2 signaling with one change in the mDC phenotype that occurs in response to this unique Ab. The parallel signaling events observed in both human and mouse mDC support the hypothesis that B7-DC cross-linking may be useful as a therapeutic immune modulator in human patients.
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Affiliation(s)
- Suresh Radhakrishnan
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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10
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Zal T. Visualization of protein interactions in living cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 640:183-97. [PMID: 19065792 PMCID: PMC5788009 DOI: 10.1007/978-0-387-09789-3_14] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Ligand binding to cell membrane receptors sets off a series of protein interactions that convey the nuances ofligand identity to the cell interior. The information may be encoded in conformational changes, the interaction kinetics and, in the case of multichain immunoreceptors, by chain rearrangements. The signals may be modulated by dynamic compartmentalization of the cell membrane, cellular architecture, motility, and activation--all of which are difficult to reconstitute for studies of receptor signaling in vitro. In this chapter, we will discuss how protein interactions in general and receptor signaling in particular can be studied in living cells by different fluorescence imaging techniques. Particularly versatile are methods that exploit Förster resonance energy transfer (FRET), which is exquisitely sensitive to the nanometer-range proximity and orientation between fluorophores. Fluorescence correlation microscopy (FCM) can provide complementary information about the stoichiometry and diffusion kinetics of large complexes, while bimolecular fluorescence complementation (BiFC) and other complementation techniques can capture transient interactions. A continuing challenge is extracting from the imaging data the quantitative information that is necessary to verify different models of signal transduction.
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Affiliation(s)
- Tomasz Zal
- Department of Immunology, University of Texas, MD Anderson Cancer Center, Unit 902, 7455 Fannin, Houston TX, USA.
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11
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Schrum AG, Gil D, Dopfer EP, Wiest DL, Turka LA, Schamel WWA, Palmer E. High-sensitivity detection and quantitative analysis of native protein-protein interactions and multiprotein complexes by flow cytometry. ACTA ACUST UNITED AC 2007; 2007:pl2. [PMID: 17551170 PMCID: PMC3913565 DOI: 10.1126/stke.3892007pl2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Most mechanisms of cell development, physiology, and signal transduction are controlled by protein-protein interactions. Immunoprecipitation of multiprotein complexes detected by flow cytometry (IP-FCM) is a means to quantitatively measure these interactions. The high sensitivity of this method makes it useful even when very little biomaterial is available for analysis, as in the case of rare primary cell subsets or patient samples. Detection of the T cell antigen receptor associated with the CD3 multiprotein complex from as few as 300 primary murine T cells is presented as an example. The method is compatible with quantitative flow cytometry techniques, making it possible to estimate the number of coimmunoprecipitated molecules. Both constitutive and inducible protein-protein interactions can be analyzed, as illustrated in related methodology using glutathione S-transferase-fusion protein pull-down experiments. IP-FCM represents a robust, quantitative, biochemical technique to assess native protein-protein interactions, without requiring genetic engineering or large sample sizes.
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Affiliation(s)
- Adam G Schrum
- Department of Research, University Hospital-Basel, Basel, Switzerland.
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12
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Wooldridge L, Scriba TJ, Milicic A, Laugel B, Gostick E, Price DA, Phillips RE, Sewell AK. Anti-coreceptor antibodies profoundly affect staining with peptide-MHC class I and class II tetramers. Eur J Immunol 2006; 36:1847-55. [PMID: 16783852 DOI: 10.1002/eji.200635886] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The T cell coreceptors CD8 and CD4 bind to invariable regions of peptide-MHC class I (pMHCI) and class II (pMHCII) molecules, respectively, and facilitate antigen recognition by a number of mechanisms. It is established that some antibodies (Ab) specific for the CD8 molecule, which stabilizes TCR/pMHCI interactions, can alter the binding of pMHCI tetramers to cell surface TCR. In contrast, the extremely weak pMHCII/CD4 interaction does not stabilize TCR/pMHCII interactions or contribute to cognate tetramer binding; consequently, it is assumed that anti-CD4 Ab do not affect pMHCII binding. Here, we used a panel of point-mutated HLA A2 molecules with a range of affinities for CD8 spanning over three orders of magnitude to demonstrate that anti-CD8 Ab-mediated inhibition of pMHCI tetramer binding and cognate T cell activation correlates directly with the strength of the pMHCI/CD8 interaction. Further, some anti-CD4 Ab were found to block pMHCII tetramer binding; these effects were also paralleled in T cell activation assays. In sum, these data challenge the assertion that anti-coreceptor Ab exert their effects on T cell activation and pMHC binding solely by blocking pMHC/coreceptor interactions.
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Affiliation(s)
- Linda Wooldridge
- T-cell Modulation Group, The Peter Medawar Building for Pathogen Research, Oxford, UK
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13
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Kao C, Daniels MA, Jameson SC. Loss of CD8 and TCR binding to Class I MHC ligands following T cell activation. Int Immunol 2005; 17:1607-17. [PMID: 16263755 DOI: 10.1093/intimm/dxh340] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The capacity of T cells to bind peptide/MHC ligands changes with T cell development and differentiation. Here we study changes in peptide/MHC multimer binding following T cell activation. Surprisingly, T cell activation caused a marked reduction in specific peptide/MHC Class I multimer binding, which was distinct from transient TCR down-regulation, and was especially dramatic for engagement with low-affinity peptide/MHC ligands. Direct CD8-Class I interactions were also profoundly and rapidly impaired following T cell stimulation, even though surface CD8alpha and CD8beta levels were unchanged after activation, suggesting that decreased CD8 co-receptor binding contributes to this effect. Finally, we show that enzymatic desialylation restores much of the multimer binding on activated T cells, suggesting that altered glycosylation may inhibit TCR/CD8 binding to peptide/MHC ligands. These radical changes in activated T cells' ability to perceive peptide/MHC ligands may contribute to selective outgrowth of clones with high affinity for the stimulatory ligand.
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Affiliation(s)
- Charlly Kao
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota, MMC 334, 420 Delaware Street SE, Minneapolis, MN 55455, USA
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14
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Yachi PP, Ampudia J, Gascoigne NR, Zal T. Nonstimulatory peptides contribute to antigen-induced CD8-T cell receptor interaction at the immunological synapse. Nat Immunol 2005; 6:785-92. [PMID: 15980863 PMCID: PMC1352171 DOI: 10.1038/ni1220] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Accepted: 05/19/2005] [Indexed: 11/09/2022]
Abstract
It is unclear if the interaction between CD8 and the T cell receptor (TCR)-CD3 complex is constitutive or antigen induced. Here, fluorescence resonance energy transfer microscopy between fluorescent chimeras of CD3zeta and CD8beta showed that this interaction was induced by antigen recognition in the immunological synapse. Nonstimulatory endogenous or exogenous peptides presented simultaneously with antigenic peptides increased the CD8-TCR interaction. This finding indicates that the interaction between the intracellular regions of a TCR-CD3 complex recognizing its cognate peptide-major histocompatibility complex (MHC) antigen, and CD8 (plus the kinase Lck), is enhanced by a noncognate CD8-MHC interaction. Thus, the interaction of CD8 with a nonstimulatory peptide-MHC complex helps mediate T cell recognition of antigen, improving the coreceptor function of CD8.
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Affiliation(s)
- Pia P. Yachi
- Department of Immunology, IMM1, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Jeanette Ampudia
- Department of Immunology, IMM1, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Nicholas R.J. Gascoigne
- Department of Immunology, IMM1, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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15
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Holman PO, Walsh ER, Jameson SC. Characterizing the impact of CD8 antibodies on class I MHC multimer binding. THE JOURNAL OF IMMUNOLOGY 2005; 174:3986-91. [PMID: 15778355 DOI: 10.4049/jimmunol.174.7.3986] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many studies have suggested that CD8 Abs affect the binding of class I MHC tetramers/multimers to CD8(+) T cells, which has led to the interpretation that CD8 participates directly in multimer binding. In contrast, a recent publication has argued that CD8 Abs instead cause reorganization of TCR distribution and hence have an indirect effect on multimer binding to the TCR alone. We address these issues by testing the role of CD8 and the impact of CD8 Abs on the binding of normal and mutant multimers to Ag-specific mouse T cells. Our data suggest that, in this system, CD8 Abs act directly on CD8 and only mediate their effects on multimer binding when CD8 is capable of binding to the multimer. These data reinforce the paradigm that CD8 plays an active and direct role in binding of class I MHC multimers.
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Affiliation(s)
- Philmore O Holman
- Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
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16
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Using live FRET imaging to reveal early protein–protein interactions during T cell activation. Curr Opin Immunol 2004. [DOI: 10.1016/j.coi.2004.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Zal T, Gascoigne NRJ. Using live FRET imaging to reveal early protein–protein interactions during T cell activation. Curr Opin Immunol 2004; 16:418-27. [PMID: 15245734 DOI: 10.1016/j.coi.2004.05.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The emerging challenge for proteomics in general and lymphocyte biology in particular is to understand protein-protein interactions in the dynamic context of the living cell. Particularly interesting are the molecular dynamics of the T cell receptor-CD3 complex and other immunoreceptors in immune synapses. Fluorescence (or Förster) resonance energy transfer (FRET) is one of the few techniques that are capable of giving dynamic information about the nanometer-range proximity between molecules, as opposed to simply the subcellular co-localization that is provided by fluorescence microscopy. Spectral changes in fluorescence intensity and down modulation of donor lifetime are the basis for rapidly developing approaches to real-time FRET imaging. With two-photon excitation, FRET can now be extended to in vivo imaging.
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Affiliation(s)
- Tomasz Zal
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
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18
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Stanic AK, Shashidharamurthy R, Bezbradica JS, Matsuki N, Yoshimura Y, Miyake S, Choi EY, Schell TD, Van Kaer L, Tevethia SS, Roopenian DC, Yamamura T, Joyce S. Another View of T Cell Antigen Recognition: Cooperative Engagement of Glycolipid Antigens by Va14Ja18 Natural TCR. THE JOURNAL OF IMMUNOLOGY 2003; 171:4539-51. [PMID: 14568927 DOI: 10.4049/jimmunol.171.9.4539] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Va14Ja18 natural T (iNKT) cells rapidly elicit a robust effector response to different glycolipid Ags, with distinct functional outcomes. Biochemical parameters controlling iNKT cell function are partly defined. However, the impact of iNKT cell receptor beta-chain repertoire and how alpha-galactosylceramide (alpha-GalCer) analogues induce distinct functional responses have remained elusive. Using altered glycolipid ligands, we discovered that the Vb repertoire of iNKT cells impacts recognition and Ag avidity, and that stimulation with suboptimal avidity Ag results in preferential expansion of high-affinity iNKT cells. iNKT cell proliferation and cytokine secretion, which correlate with iNKT cell receptor down-regulation, are induced within narrow biochemical thresholds. Multimers of CD1d1-alphaGalCer- and alphaGalCer analogue-loaded complexes demonstrate cooperative engagement of the Va14Ja18 iNKT cell receptor whose structure and/or organization appear distinct from conventional alphabeta TCR. Our findings demonstrate that iNKT cell functions are controlled by affinity thresholds for glycolipid Ags and reveal a novel property of their Ag receptor apparatus that may have an important role in iNKT cell activation.
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MESH Headings
- Animals
- Antigens/metabolism
- Antigens, CD1/metabolism
- Antigens, CD1d
- Cell Line
- Clone Cells
- Cytotoxicity Tests, Immunologic
- Galactosylceramides/immunology
- Galactosylceramides/metabolism
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Kinetics
- Lymphocyte Activation
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Sensitivity and Specificity
- Sphingosine/immunology
- Sphingosine/metabolism
- Structure-Activity Relationship
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
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Affiliation(s)
- Aleksandar K Stanic
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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19
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Doucey MA, Legler DF, Faroudi M, Boucheron N, Baumgaertner P, Naeher D, Cebecauer M, Hudrisier D, Rüegg C, Palmer E, Valitutti S, Bron C, Luescher IF. The beta1 and beta3 integrins promote T cell receptor-mediated cytotoxic T lymphocyte activation. J Biol Chem 2003; 278:26983-91. [PMID: 12690105 DOI: 10.1074/jbc.m302709200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recognition by CD8+ cytotoxic T lymphocytes (CTLs) of antigenic peptides bound to major histocompatibility class (MHC) I molecules on target cells leads to sustained calcium mobilization and CTL degranulation resulting in perforin-dependent killing. We report that beta1 and beta3 integrin-mediated adhesion to extracellular matrix proteins on target cells and/or surfaces dramatically promotes CTL degranulation. CTLs, when adhered to fibronectin but not CTL in suspension, efficiently degranulate upon exposure to soluble MHC.peptide complexes, even monomeric ones. This adhesion induces recruitment and activation of the focal adhesion kinase Pyk2, the cytoskeleton linker paxillin, and the Src kinases Lck and Fyn in the contact site. The T cell receptor, by association with Pyk2, becomes part of this adhesion-induced activation cluster, which greatly increases its signaling.
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Affiliation(s)
- Marie-Agnès Doucey
- Institute for Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland.
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20
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Radhakrishnan S, Nguyen LT, Ciric B, Ure DR, Zhou B, Tamada K, Dong H, Tseng SY, Shin T, Pardoll DM, Chen L, Kyle RA, Rodriguez M, Pease LR. Naturally occurring human IgM antibody that binds B7-DC and potentiates T cell stimulation by dendritic cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1830-8. [PMID: 12574348 DOI: 10.4049/jimmunol.170.4.1830] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A human IgM Ab, serum-derived human IgM 12 (sHIgM12), is identified that binds mouse and human dendritic cells (DC), inducing dramatic immunopotentiation following treatment of the mouse DC in vitro. Competition, transfection, and knockout studies identified the ligand on mouse DC as the costimulatory molecule family member B7-DC. Potent T cell responses are stimulated by Ag-pulsed DC treated with the sHIgM12 Ab in vitro and upon adoptive transfer of Ab-treated Ag-pulsed DC into animals. The multivalent structure of pentameric IgM provides the potential for cross-linking cell surface targets, endowing the soluble Abs with biological potential not normally associated with immune function. The ability of the sHIgM12 Ab to potentiate the immune response is dependent on the multimeric structure of IgM, as bivalent monomers do not retain this property. Furthermore, pretreatment of DC with IgM monomers blocks subsequent potentiation by intact IgM pentamers, an indication that cross-linking of B7-DC on the cell surface is critical for potentiation of Ag presentation. These findings imply that, in addition to known costimulatory roles, B7-DC can function as a receptor for signals delivered by cells expressing B7-DC ligands.
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MESH Headings
- Adjuvants, Immunologic/chemistry
- Adjuvants, Immunologic/metabolism
- Adjuvants, Immunologic/physiology
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/metabolism
- Antibodies, Monoclonal/physiology
- Antigen Presentation/immunology
- B7-1 Antigen/metabolism
- Binding Sites, Antibody/physiology
- Cell Line
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Cells, Cultured
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Humans
- Immunity, Innate
- Immunoglobulin M/blood
- Immunoglobulin M/chemistry
- Immunoglobulin M/physiology
- Lymphocyte Activation/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Programmed Cell Death 1 Ligand 2 Protein
- Receptors, Fc/metabolism
- Receptors, IgG/metabolism
- Species Specificity
- Structure-Activity Relationship
- T-Lymphocytes/immunology
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Affiliation(s)
- Suresh Radhakrishnan
- Department of Immunology, Mayo Medical and Graduate Schools, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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21
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Doucey MA, Goffin L, Naeher D, Michielin O, Baumgärtner P, Guillaume P, Palmer E, Luescher IF. CD3 delta establishes a functional link between the T cell receptor and CD8. J Biol Chem 2003; 278:3257-64. [PMID: 12215456 DOI: 10.1074/jbc.m208119200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
T cells expressing T cell receptor (TCR) complexes that lack CD3 delta, either due to deletion of the CD3 delta gene, or by replacement of the connecting peptide of the TCR alpha chain, exhibit severely impaired positive selection and TCR-mediated activation of CD8 single-positive T cells. Because the same defects have been observed in mice expressing no CD8 beta or tailless CD8 beta, we examined whether CD3 delta serves to couple TCR.CD3 with CD8. To this end we used T cell hybridomas and transgenic mice expressing the T1 TCR, which recognizes a photoreactive derivative of the PbCS 252-260 peptide in the context of H-2K(d). We report that, in thymocytes and hybridomas expressing the T1 TCR.CD3 complex, CD8 alpha beta associates with the TCR. This association was not observed on T1 hybridomas expressing only CD8 alpha alpha or a CD3 delta(-) variant of the T1 TCR. CD3 delta was selectively co-immunoprecipitated with anti-CD8 antibodies, indicating an avid association of CD8 with CD3 delta. Because CD8 alpha beta is a raft constituent, due to this association a fraction of TCR.CD3 is raft-associated. Cross-linking of these TCR-CD8 adducts results in extensive TCR aggregate formation and intracellular calcium mobilization. Thus, CD3 delta couples TCR.CD3 with raft-associated CD8, which is required for effective activation and positive selection of CD8(+) T cells.
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Affiliation(s)
- Marie-Agnès Doucey
- Institute for Biochemistry, University of Lausanne, Epalinges 1066, Switzerland
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22
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Abstract
Many different signaling pathways are involved in deregulation of cell proliferation leading to cancer. Although genomic approaches successfully identified a great variety of molecules associated with cancerogenesis, other strategies must be applied to elucidate complex interactions between these molecules. One promising approach is fluorescence resonance energy transfer, a proximity-dependent fluorescence phenomenon. With the development of spectrally different fluorescent proteins and improved technologies for fluorescence measurements, this approach gains an enormous potential for future research. The fluorescence resonance energy transfer principle can be applied for studying all kinds of interactions or conformational changes, and it can also be used for microscopic visualization and subcellular localization of biochemical reactions, thereby promoting the progress of cancer research. Moreover, it can be exploited to develop sensitive and efficient drug screening systems and to design valuable diagnostic tools.
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Affiliation(s)
- Johannes A Schmid
- Department of Vascular Biology and Thrombosis Research, University of Vienna, Austria.
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23
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Buslepp J, Kerry SE, Loftus D, Frelinger JA, Appella E, Collins EJ. High affinity xenoreactive TCR:MHC interaction recruits CD8 in absence of binding to MHC. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:373-83. [PMID: 12496422 DOI: 10.4049/jimmunol.170.1.373] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The TCR from a xenoreactive murine cytotoxic T lymphocyte clone, AHIII 12.2, recognizes murine H-2D(b) complexed with peptide p1058 (FAPGFFPYL) as well as human HLA-A2.1 complexed with human self-peptide p1049 (ALWGFFPVL). To understand more about T cell biology and cross-reactivity, the ectodomains of the AHIII 12.2 TCR have been produced in E. coli as inclusion bodies and the protein folded to its native conformation. Flow cytometric and surface plasmon resonance analyses indicate that human p1049/A2 has a significantly greater affinity for the murine AHIII 12.2 TCR than does murine p1058/D(b). Yet, T cell binding and cytolytic activity are independent of CD8 when stimulated with human p1049/A2 as demonstrated with anti-CD8 Abs that block CD8 association with MHC. Even in the absence of direct CD8 binding, stimulation of AHIII 12.2 T cells with "CD8-independent" p1049/A2 produces p56(lck) activation and calcium flux. Confocal fluorescence microscopy and fluorescence resonance energy transfer flow cytometry demonstrate CD8 is recruited to the site of TCR:peptide MHC binding. Taken together, these results indicate that there exists another mechanism for recruitment of CD8 during high affinity TCR:peptide MHC engagement.
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MESH Headings
- Animals
- Antigen Presentation/genetics
- Antigens, Heterophile/metabolism
- CD8 Antigens/metabolism
- CD8 Antigens/physiology
- CHO Cells
- Cell Line
- Clone Cells
- Cricetinae
- Cytotoxicity, Immunologic/genetics
- H-2 Antigens/genetics
- H-2 Antigens/metabolism
- HLA-A2 Antigen/genetics
- HLA-A2 Antigen/metabolism
- Histocompatibility Antigen H-2D
- Humans
- Lymphocyte Activation/genetics
- Mice
- Mice, Inbred C57BL
- Oligopeptides/immunology
- Oligopeptides/metabolism
- Protein Binding/genetics
- Protein Binding/immunology
- Receptors, Antigen, T-Cell/biosynthesis
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- Surface Plasmon Resonance
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
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Affiliation(s)
- Jennifer Buslepp
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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24
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Lee PUY, Kranz DM. Allogeneic and syngeneic class I MHC complexes drive the association of CD8 and TCR on 2C T cells. Mol Immunol 2003; 39:687-95. [PMID: 12531280 DOI: 10.1016/s0161-5890(02)00259-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In most cases, cytotoxic T cell activation is dependent on the interaction of the T cell receptor (TCR) and CD8 with MHC class I molecules. In the CD8(+) T cell system based on the mouse cytotoxic T cell clone 2C, recognition of the allogeneic MHC L(d) exhibits a less significant role for CD8 than recognition of the syngeneic MHC K(b). Here, we examined whether this difference is related to the relative abilities of the two pepMHC complexes to drive the association of CD8 and TCR on the T cell surface. We show that both the syngeneic and allogeneic pepMHC induced association of CD8 and TCR, as revealed by fluorescence resonance energy transfer (FRET). Thus, the orientation of the syngeneic and allogeneic ligands when bound to the same TCR both allow CD8 to be recruited to the TCR complex. The conserved diagonal orientation of TCRs on different pepMHC ligands may facilitate such associations. The FRET results are consistent with the known binding properties and the CD8 involvement of the two different TCR:pepMHC interactions.
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Affiliation(s)
- Peter U Y Lee
- Department of Biochemistry, University of Illinois, 600 S. Mathews Ave., Urbana, IL 61801, USA
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25
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Schott E, Bertho N, Ge Q, Maurice MM, Ploegh HL. Class I negative CD8 T cells reveal the confounding role of peptide-transfer onto CD8 T cells stimulated with soluble H2-Kb molecules. Proc Natl Acad Sci U S A 2002; 99:13735-40. [PMID: 12374858 PMCID: PMC129760 DOI: 10.1073/pnas.212515399] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2002] [Accepted: 08/26/2002] [Indexed: 11/18/2022] Open
Abstract
Crosslinking of the T cell receptor has been proposed to be a prerequisite for T cell activation. Although the evidence supports this notion for CD4 T cells, the situation for CD8 T cells is less clear. Soluble class I monomers have been used to determine activation requirements in vitro with contradictory results. The possibility of transfer of peptide from soluble class I molecules onto class I molecules present on the surface of CD8 T cells, with ensuing presentation to other CD8 T cells, has been widely ignored. We show that monomeric and tetrameric class I molecules as well as free peptide can stimulate naive CD8 T cells in vitro. We generate and characterize CD8 T cells that express the OT-I T cell receptor (for K(b)/SIINFEKL) yet lack K(b) and D(b) molecules, and show that their activation requirements differ from their class I positive counterparts when stimulated with soluble K(b) molecules. By eliminating the confounding effect of peptide transfer, we unmask the true activation requirements for naive CD8 T cells and show that multivalent engagement of T cell receptors, as well as costimulation, is required for optimal stimulation.
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Affiliation(s)
- Eckart Schott
- Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
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26
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Werlen G, Palmer E. The T-cell receptor signalosome: a dynamic structure with expanding complexity. Curr Opin Immunol 2002; 14:299-305. [PMID: 11973126 DOI: 10.1016/s0952-7915(02)00339-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Signal transduction in T cells is a dynamic process involving a large number of membrane and cytosolic proteins. The TCR macromolecular complex (signalosome) is initiated by receptor occupancy and becomes more elaborate over time. This review describes how 'vertical' displacement mechanisms and lateral coalescence of lipid-raft-associated scaffold proteins combine to form distinct signalosomes, which control signal specificity.
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Affiliation(s)
- Guy Werlen
- Laboratory of Transplantation Immunology and Nephrology, Department of Research, University Hospital-Basel, Hebelstrasse 20, CH-4031, Basel, Switzerland.
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27
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Batard P, Szollosi J, Luescher I, Cerottini JC, MacDonald R, Romero P. Use of phycoerythrin and allophycocyanin for fluorescence resonance energy transfer analyzed by flow cytometry: advantages and limitations. CYTOMETRY 2002; 48:97-105. [PMID: 12116371 DOI: 10.1002/cyto.10106] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND This study validates the use of phycoerythrin (PE) and allophycocyanin (APC) for fluorescence energy transfer (FRET) analyzed by flow cytometry. METHODS FRET was detected when a pair of antibody conjugates directed against two noncompetitive epitopes on the same CD8alpha chain was used. FRET was also detected between antibody conjugate pairs specific for the two chains of the heterodimeric alpha (4)beta(1) integrin. Similarly, the association of T-cell receptor (TCR) with a soluble antigen ligand was detected by FRET when anti-TCR antibody and MHC class I/peptide complexes (<<tetramers>>) were used. RESULTS FRET efficiency was always less than 10%, probably because of steric effects associated with the size and structure of PE and APC. Some suggestions are given to take into account this and other effects (e.g., donor and acceptor concentrations) for a better interpretation of FRET results obtained with this pair of fluorochromes. CONCLUSIONS We conclude that FRET assays can be carried out easily with commercially available antibodies and flow cytometers to study arrays of multimolecular complexes.
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Affiliation(s)
- Pascal Batard
- Division of Clinical Onco-Immunology, Ludwig Institute for Cancer Research, Lausanne Branch, University Hospital (CHUV), Niveau 5, Avenue Pierre Decker 4, 1005 Lausanne, Switzerland.
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28
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Holdorf AD, Lee KH, Burack WR, Allen PM, Shaw AS. Regulation of Lck activity by CD4 and CD28 in the immunological synapse. Nat Immunol 2002; 3:259-64. [PMID: 11828322 DOI: 10.1038/ni761] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although the Src family tyrosine kinase Lck is essential for T cell receptor (TCR) signaling, whether or how Lck is activated is unknown. Using a phosphospecific antiserum to Lck, we show here that Lck becomes autophosphorylated when T cells are stimulated by antigen-presenting cells (APCs). We found that TCR cross-linking alone could not stimulate Lck autophosphorylation and CD45 was not required for this process. Instead, the T cell accessory molecules CD4 and CD28 cooperated to induce autophosphorylation of Lck. CD4 recruited Lck to the T cell--APC interface, whereas CD28 sustained Lck activation. These data show how the multiple interactions afforded by the immunological synapse drive efficient and highly specific signaling.
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Affiliation(s)
- Amy D Holdorf
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S. Euclid, Campus Box 8118, St. Louis, MO 63110, USA
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29
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Daniels MA, Devine L, Miller JD, Moser JM, Lukacher AE, Altman JD, Kavathas P, Hogquist KA, Jameson SC. CD8 binding to MHC class I molecules is influenced by T cell maturation and glycosylation. Immunity 2001; 15:1051-61. [PMID: 11754824 DOI: 10.1016/s1074-7613(01)00252-7] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
CD8 serves both as an adhesion molecule for class I MHC molecules and as a coreceptor with the TCR for T cell activation. Here we study the developmental regulation of CD8-mediated binding to noncognate peptide/MHC ligands (i.e., those not bound by the TCR). We show that CD8's ability to bind soluble class I MHC tetramers and to mediate T cell adhesion under shear flow conditions diminishes as double-positive thymocytes mature into CD8(+) T cells. Furthermore, we provide evidence that this decreased CD8 binding results from increased T cell sialylation upon T cell maturation. These data suggest that CD8's ability to interact with class I MHC is not fixed and is developmentally regulated through the T cell's glycosylation state.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 2
- ATP-Binding Cassette Transporters/genetics
- Animals
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD8 Antigens/immunology
- CD8 Antigens/metabolism
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- Cell Adhesion
- Cell Differentiation
- Cellular Senescence
- Glycosylation
- H-2 Antigens/immunology
- H-2 Antigens/metabolism
- Histocompatibility Antigen H-2D
- Ligands
- Macromolecular Substances
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- N-Acetylneuraminic Acid/metabolism
- Neuraminidase/pharmacology
- Ovalbumin/immunology
- Peptide Fragments/immunology
- Protein Binding
- Protein Processing, Post-Translational
- Receptors, Antigen, T-Cell, alpha-beta/deficiency
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Rheology
- Solubility
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Thymus Gland/cytology
- Thymus Gland/growth & development
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Affiliation(s)
- M A Daniels
- Center for Immunology, Department of Lab Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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