1
|
Adjou Moumouni PF, Naomasa S, Tuvshintulga B, Sato N, Okado K, Zheng W, Lee SH, Mosqueda J, Suzuki H, Xuan X, Umemiya-Shirafuji R. Identification and Characterization of Rhipicephalus microplus ATAQ Homolog from Haemaphysalis longicornis Ticks and Its Immunogenic Potential as an Anti-Tick Vaccine Candidate Molecule. Microorganisms 2023; 11:microorganisms11040822. [PMID: 37110244 PMCID: PMC10145298 DOI: 10.3390/microorganisms11040822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
Although vaccines are one of the environmentally friendly means to prevent the spread of ticks, there is currently no commercial vaccine effective against Haemaphysalis longicornis ticks. In this study, we identified, characterized, localized, and evaluated the expression patterns, and tested the immunogenic potential of a homologue of Rhipicephalus microplus ATAQ in H. longicornis (HlATAQ). HlATAQ was identified as a 654 amino acid-long protein present throughout the midgut and in Malpighian tubule cells and containing six full and one partial EGF-like domains. HlATAQ was genetically distant (homology < 50%) from previously reported ATAQ proteins and was expressed throughout tick life stages. Its expression steadily increased (p < 0.001) during feeding, reached a peak, and then decreased slightly with engorgement. Silencing of HlATAQ did not result in a phenotype that was significantly different from the control ticks. However, H. longicornis female ticks fed on a rabbit immunized with recombinant HlATAQ showed significantly longer blood-feeding periods, higher body weight at engorgement, higher egg mass, and longer pre-oviposition and egg hatching periods than control ticks. These findings indicate that the ATAQ protein plays a role in the blood-feeding-related physiological processes in the midgut and Malpighian tubules and antibodies directed against it may affect these tissues and disrupt tick engorgement and oviposition.
Collapse
Affiliation(s)
- Paul Franck Adjou Moumouni
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Souichirou Naomasa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Bumduuren Tuvshintulga
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Nariko Sato
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Kiyoshi Okado
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Weiqing Zheng
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Seung-Hun Lee
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Juan Mosqueda
- Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Carretera a Chichimequillas, Queretaro 76140, Mexico
| | - Hiroshi Suzuki
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Xuenan Xuan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| | - Rika Umemiya-Shirafuji
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Hokkaido, Japan
| |
Collapse
|
2
|
Bretz NP, Salnikov AV, Doberstein K, Garbi N, Kloess V, Joumaa S, Naumov I, Boon L, Moldenhauer G, Arber N, Altevogt P. Lack of CD24 expression in mice reduces the number of leukocytes in the colon. Immunol Lett 2014; 161:140-8. [DOI: 10.1016/j.imlet.2014.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/30/2014] [Accepted: 06/12/2014] [Indexed: 01/09/2023]
|
3
|
Peshavariya H, Dusting GJ, Di Bartolo B, Rye KA, Barter PJ, Jiang F. Reconstituted high-density lipoprotein suppresses leukocyte NADPH oxidase activation by disrupting lipid rafts. Free Radic Res 2010; 43:772-82. [DOI: 10.1080/10715760903045304] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
4
|
Glycosphingolipid composition of human immunodeficiency virus type 1 (HIV-1) particles is a crucial determinant for dendritic cell-mediated HIV-1 trans-infection. J Virol 2009; 83:3496-506. [PMID: 19193785 DOI: 10.1128/jvi.02249-08] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interactions of human immunodeficiency virus type 1 (HIV-1) with dendritic cells (DCs) are multifactorial and presumably require nonredundant interactions between the HIV-1 envelope glycoprotein gp120 and molecules expressed on the DC surface that define the cellular fate of the virus particle. Surprisingly, neutralization of HIV-1 gp120-dependent binding interactions with DCs was insufficient to prevent HIV-1 attachment. Besides gp120, HIV-1 particles also incorporate host cell-derived proteins and lipids in their particle membrane. In this study, we demonstrate a crucial role for host cell-derived glycosphingolipids (GSLs) for the initial interactions of HIV-1 particles with both immature and mature DCs. Production of HIV-1 particles from virus producer cells treated with ceramide synthase inhibitor fumonisin B1 or glucosylceramide synthase inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) resulted in the production of virus particles that, although capable of binding previously defined HIV-1 gp120-specific attachment factors CD4, DC-SIGN, and syndecans, were attenuated in their ability to be captured by both immature and mature DCs. Furthermore, GSL-deficient HIV-1 particles were inhibited in their ability to establish productive infections in DC-T-cell cocultures. These studies provide initial evidence for the role of HIV-1 particle membrane-associated GSLs in virus invasion of DCs and also provide additional novel cellular targets, GSL biosynthetic pathways and GSL-dependent HIV-1 interactions with DCs, for development of antiviral therapy.
Collapse
|
5
|
Lee M, Kistler C, Hartmann TB, Li F, Dummer R, Dippel E, Booken N, Klemke CD, Schadendorf D, Eichmüller SB. Immunoscreening of a cutaneous T-cell lymphoma library for plasma membrane proteins. Cancer Immunol Immunother 2007; 56:783-95. [PMID: 17089123 PMCID: PMC11030727 DOI: 10.1007/s00262-006-0239-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 10/11/2006] [Indexed: 10/24/2022]
Abstract
Cutaneous T-cell lymphomas (CTCL) belong to non-Hodgkin lymphomas, which are primarily manifested in the skin and mostly exhibit a T-helper memory phenotype. Mycosis fungoides (MF) and the leukemic variant Sézary syndrome (SzS) are the most common forms of CTCL. The aim of this study was to identify CTCL surface proteins with a tumor specific expression profile. A plasma membrane enriched fraction of the CTCL cell line HuT78 was used for immunization of two rabbits. Subsequently, a CTCL cDNA phage library was screened by a new variant of the SEREX method (serological identification of antigens by recombinant expression cloning) using the polyspecific rabbit antisera instead of patients' sera. Isolated reactive transfectants were sequenced and 42 different genes identified including four known plasma membrane proteins: Ligatin, HLA-A, integrin alpha4 and MT5-MMP. The level of transcripts of the matrix metalloproteinase MT5-MMP was diminished in MF tumor specimens. MT5-MMP normally occurs in several different protein variants. Western blot analysis revealed that activated MT5-MMPs were reduced in tumor specimens, whereas the amounts of most of the inactivated variants were unchanged. The amount of mRNA coding for the adhesion protein integrin alpha4 was not altered in tumor specimens in comparison to controls when analyzed by quantitative real-time PCR analysis. Ku86, known to be predominantly located in the nucleus and cytosol, was frequently detected during the SEREX screening. Western blot analysis revealed higher protein amounts of Ku86 in HuT78 than in control cells. In addition, we could show, that Ku86 can also be detected in lipid rafts of CTCL cells as it has been described for other tumor types. Thus, Ku86 might be involved in homo- and heterotypic adhesion steps of CTCL tumor cells and might protect these cells against apoptosis triggered by irradiation as it was suggested for multiple myeloma cells. The design of this study enabled screening for all proteins on the plasma membrane, irrespectively of whether these are directly anchored within the membrane or associated with other membrane proteins. Further analysis will unravel whether the list of identified proteins harbors candidates, which might be accessible for antibodies from outside the cell.
Collapse
Affiliation(s)
- Mieun Lee
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Claudia Kistler
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Tanja B. Hartmann
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Fang Li
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Reinhard Dummer
- Department of Dermatology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Edgar Dippel
- Department of Dermatology, Medical Centre Lippe-Lemgo, 32657 Lemgo, Germany
| | - Nina Booken
- Department of Dermatology, Mannheim University Clinics, University of Heidelberg, 68135 Mannheim, Germany
| | - Claus D. Klemke
- Department of Dermatology, Mannheim University Clinics, University of Heidelberg, 68135 Mannheim, Germany
| | - Dirk Schadendorf
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Department of Dermatology, Mannheim University Clinics, University of Heidelberg, 68135 Mannheim, Germany
| | - Stefan B. Eichmüller
- Skin Cancer Unit (D070), German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Department of Dermatology, Mannheim University Clinics, University of Heidelberg, 68135 Mannheim, Germany
| |
Collapse
|
6
|
Salgado FJ, Piñeiro A, Canda-Sánchez A, Lojo J, Nogueira M. Prothymosin alpha-receptor associates with lipid rafts in PHA-stimulated lymphocytes. Mol Membr Biol 2005; 22:163-76. [PMID: 16096260 DOI: 10.1080/09687860500063506] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lipid rafts are specialized plasma membrane microdomains in which glycosphingolipids and cholesterol are major structural components. Their relative insolubility to nonionic detergents is the most widely used method to purify these structures. Several signalling proteins are associated with these microdomains in T lymphocytes, including receptors for growth factors and cytokines. ProTalpha is a highly conserved and widely distributed protein whose physiological functions remain elusive. In previous works we identified, by means of affinity cross-linking, affinity chromatography and fluorescence microscopy, a set of binding proteins for ProTalpha in human lymphoblasts. Now, this work goes deeply in that ProTalpha receptor description revealing, by different experimental approaches, its presence in lipid rafts. Moreover, our results fit a model in which a tyrosine phosphorylation signalling cascade confined to rafts is initiated upon ProTalpha receptor recognition, which represents an important and promising finding in the research for elucidating the molecular mechanisms underlying the immunomodulatory functions of ProTalpha.
Collapse
Affiliation(s)
- Francisco J Salgado
- Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, Campus Sur s/n, 15782 Santiago de Compostela, A Coruña, Spain
| | | | | | | | | |
Collapse
|
7
|
Wang TY, Leventis R, Silvius JR. Artificially lipid-anchored proteins can elicit clustering-induced intracellular signaling events in Jurkat T-lymphocytes independent of lipid raft association. J Biol Chem 2005; 280:22839-46. [PMID: 15817446 DOI: 10.1074/jbc.m502920200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have incorporated artificial lipid-anchored streptavidin conjugates with fully saturated or polyunsaturated lipid anchors into the plasma membranes of Jurkat T-lymphocytes to assess previous conclusions that the activation of signaling processes induced in these cells by clustering of endogenous glycosylphosphatidylinositol-anchored proteins or ganglioside GM1 depends specifically on the association of these membrane components with lipid rafts. Lipid-anchored streptavidin conjugates could be incorporated into Jurkat or other mammalian cell surfaces by inserting biotinylated phosphatidylethanolamine-polyethyleneglycols (PE-PEGs) and subsequently binding streptavidin to the cell-incorporated PE-PEGs. Saturated dipalmitoyl-PE-PEG-streptavidin conjugates prepared in this manner partitioned substantially into the detergent-insoluble membrane fraction isolated from Jurkat or fibroblast cells, whereas polyunsaturated dilinoleoyl-PE-PEG-anchored conjugates were wholly excluded from this fraction, consistent with the differences in the affinities of the two types of lipid anchors for liquid-ordered membrane domains. Remarkably, however, antibody-mediated cross-linking of either dipalmitoyl- or dilinoleoyl-PE-PEG-anchored streptavidin conjugates in Jurkat cells induced elevation of cytoplasmic calcium levels and tyrosine phosphorylation of the scaf-folding protein linker of T-cell activation in a manner similar to that observed upon cross-linking of endogenous CD59 or ganglioside GM1. The amplitude of the cross-linking-stimulated elevation of cytoplasmic calcium moreover showed an essentially identical dependence on the level of incorporated streptavidin conjugate for either type of lipid anchor. Confocal fluorescence microscopy revealed that PE-PEG-streptavidin conjugates with saturated versus polyunsaturated anchors showed very similar surface distributions vis à vis GM1 or CD59 under conditions where one or both species were cross-linked. These results indicate that cross-linking of diverse proteins anchored only to the outer leaflet of the plasma membrane can induce activation of Jurkat T-cell-signaling responses, but they appear to contradict previous suggestions that this phenomenon rests specifically on the association of such species with lipid rafts.
Collapse
Affiliation(s)
- Tian-yun Wang
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | | | | |
Collapse
|
8
|
Marasas WFO, Riley RT, Hendricks KA, Stevens VL, Sadler TW, Gelineau-van Waes J, Missmer SA, Cabrera J, Torres O, Gelderblom WCA, Allegood J, Martínez C, Maddox J, Miller JD, Starr L, Sullards MC, Roman AV, Voss KA, Wang E, Merrill AH. Fumonisins disrupt sphingolipid metabolism, folate transport, and neural tube development in embryo culture and in vivo: a potential risk factor for human neural tube defects among populations consuming fumonisin-contaminated maize. J Nutr 2004; 134:711-6. [PMID: 15051815 DOI: 10.1093/jn/134.4.711] [Citation(s) in RCA: 380] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Fumonisins are a family of toxic and carcinogenic mycotoxins produced by Fusarium verticillioides (formerly Fusarium moniliforme), a common fungal contaminant of maize. Fumonisins inhibit ceramide synthase, causing accumulation of bioactive intermediates of sphingolipid metabolism (sphinganine and other sphingoid bases and derivatives) as well as depletion of complex sphingolipids, which interferes with the function of some membrane proteins, including the folate-binding protein (human folate receptor alpha). Fumonisin causes neural tube and craniofacial defects in mouse embryos in culture. Many of these effects are prevented by supplemental folic acid. Recent studies in LMBc mice found that fumonisin exposure in utero increases the frequency of developmental defects and administration of folate or a complex sphingolipid is preventive. High incidences of neural tube defects (NTD) occur in some regions of the world where substantial consumption of fumonisins has been documented or plausibly suggested (Guatemala, South Africa, and China); furthermore, a recent study of NTD in border counties of Texas found a significant association between NTD and consumption of tortillas during the first trimester. Hence, we propose that fumonisins are potential risk factors for NTD, craniofacial anomalies, and other birth defects arising from neural crest cells because of their apparent interference with folate utilization.
Collapse
|
9
|
Salgado FJ, Lojo J, Alonso-Lebrero JL, Lluis C, Franco R, Cordero OJ, Nogueira M. A role for interleukin-12 in the regulation of T cell plasma membrane compartmentation. J Biol Chem 2003; 278:24849-57. [PMID: 12676959 DOI: 10.1074/jbc.m212978200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The immunological synapse initiates the clustering and stabilization of the T cell receptor by the formation of a large lipid microdomain that accumulates (e.g. CD4/CD8) and segregates (e.g. CD45 and LFA-1) some proteins of the T cell plasma membrane. This work shows that a fraction of transmembrane glycoproteins CD26 and CD45 (the R0 isoform in particular) is present in the rafts of fresh and activated human T lymphocytes. CD26 is proposed as the costimulator of TCR-dependent activation, and CD45 is essential to the T cell activation process because it dephosphorylates at least the inhibitory site of Src kinases. These findings support a more complex model of compartmentation, depending on the stage of T cell maturation and post-transcriptional and post-translational regulation. In addition, interleukin 12 (IL-12; inducer of TH1 responses) drives CD26 and CD45R0 to particular microdomains, thereby involving interleukins in the rules governing raft inclusion or exclusion. The physical association of CD26 and CD45R0 has long been reported. The results presented in this work fit a model in which IL-12 up-regulates a certain type of CD26 expression that interacts on the cell surface with CD45R0, near but outside of the raft core. The use of antisense oligonucleotides for the CD26 mRNAs demonstrated that both events (enhanced by IL-12), CD26-CD45R0 association and membrane compartment redistribution, are related. Thus, CD26 could be part of a shuttling mechanism for CD45 that regulates membrane tyrosine-phosphatase activities, e.g. to control IL-12 receptor-dependent signal transduction.
Collapse
Affiliation(s)
- Francisco J Salgado
- Department of Biochemistry and Molecular Biology, Universidade de Santiago de Compostela, Spain
| | | | | | | | | | | | | |
Collapse
|
10
|
Pereira DA, Gomes L, El-Cheikh MC, Borojevic R. Dipeptidyl peptidase IV (CD26) activity in the hematopoietic system: differences between the membrane-anchored and the released enzyme activity. Braz J Med Biol Res 2003; 36:567-78. [PMID: 12715075 DOI: 10.1590/s0100-879x2003000500003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dipeptidyl peptidase IV (DPP-IV; CD26) (EC 3.4.14.5) is a membrane-anchored ectoenzyme with N-terminal exopeptidase activity that preferentially cleaves X-Pro-dipeptides. It can also be spontaneously released to act in the extracellular environment or associated with the extracellular matrix. Many hematopoietic cytokines and chemokines contain DPP-IV-susceptible N-terminal sequences. We monitored DPP-IV expression and activity in murine bone marrow and liver stroma cells which sustain hematopoiesis, myeloid precursors, skin fibroblasts, and myoblasts. RT-PCR analysis showed that all these cells produced mRNA for DPP-IV. Partially purified protein reacted with a commercial antibody to CD26. The K M values for Gly-Pro-p-nitroanilide ranged from 0.43 to 0.98 mM for the membrane-associated enzyme of connective tissue stromas, and from 6.76 to 8.86 mM for the enzyme released from the membrane, corresponding to a ten-fold difference, but only a two-fold difference in K M was found in myoblasts. K M of the released soluble enzyme decreased in the presence of glycosaminoglycans, nonsulfated polysaccharide polymers (0.8-10 micro g/ml) or simple sugars (320-350 micro g/ml). Purified membrane lipid rafts contained nearly 3/4 of the total cell enzyme activity, whose K M was three-fold decreased as compared to the total cell membrane pool, indicating that, in the hematopoietic environment, DPP-IV activity is essentially located in the lipid rafts. This is compatible with membrane-associated events and direct cell-cell interactions, whilst the long-range activity depending upon soluble enzyme is less probable in view of the low affinity of this form.
Collapse
Affiliation(s)
- D A Pereira
- Divisão de Farmacologia, Coordenação de Pesquisa, Instituto Nacional do Câncer, Rio de Janeiro, RJ, Brasil
| | | | | | | |
Collapse
|
11
|
Kimmel J, Ogun SA, de Macedo CS, Gerold P, Vivas L, Holder AA, Schwarz RT, Azzouz N. Glycosylphosphatidyl-inositols in murine malaria: Plasmodium yoelii yoelii. Biochimie 2003; 85:473-81. [PMID: 12770786 DOI: 10.1016/s0300-9084(03)00019-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycosylphosphatidyl-inositols (GPIs) are vital major glycoconjugates in intraerythrocytic stages of Plasmodium. Here, we report on the biosynthesis and the characterization of GPIs synthesized by the murine malarial parasite P. yoelii yoelii YM. Parasitized erythrocytes were labeled in vivo and in vitro with either radioactive nucleotide sugar precursors, ethanolamine or glucosamine. The pathway leading to the formation of GPI precursors was found to resemble that described for P. falciparum; however, in P. yoelii, the formation of an additional hydrophilic precursor containing an acid-labile modification was detected. The data suggest that this modification is linked to the fourth mannose attached to the trimannosyl backbone in an alpha1-2 linkage. The modification was susceptible to hydrofluoric acid (HF), but not to nitrous acid (HNO(2)). Data obtained from size-exclusion chromatography on Bio-Gel P4, and Mono Q analysis of the fragments generated by HNO(2) deamination suggest that the modification is due to the presence of an additional ethanolamine linked to the fourth mannose via a phosphodiester bond.
Collapse
Affiliation(s)
- Jürgen Kimmel
- Institut für Virologie, Zentrum für Hygiene und Med. Mikrobiologie, Philipps-Universität Marburg, 35037 Marburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Percherancier Y, Lagane B, Planchenault T, Staropoli I, Altmeyer R, Virelizier JL, Arenzana-Seisdedos F, Hoessli DC, Bachelerie F. HIV-1 entry into T-cells is not dependent on CD4 and CCR5 localization to sphingolipid-enriched, detergent-resistant, raft membrane domains. J Biol Chem 2003; 278:3153-61. [PMID: 12431990 DOI: 10.1074/jbc.m207371200] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The contribution of raft domains to human immunodeficiency virus (HIV) 1 entry was assessed. In particular, we asked whether the CD4 and CCR5 HIV-1 receptors need to associate with sphingolipid-enriched, detergent-resistant membrane domains (rafts) to allow viral entry into primary and T-cell lines. Based on Triton X-100 solubilization and confocal microscopy, CD4 was shown to distribute partially to rafts. In contrast, CCR5 did not associate with rafts and localized in nonraft plasma membrane domains. HIV-1-receptor partitioning remained unchanged upon viral adsorption, suggesting that viral entry probably takes place outside rafts. To directly investigate this possibility, we targeted CD4 to nonraft domains of the membrane by preventing CD4 palmitoylation and interaction with p56(lck). Directed mutagenesis of both targeting signals significantly prevented association of CD4 with rafts, but did not suppress the HIV-1 receptor function of CD4. Collectively, these results strongly suggest that the presence of HIV-1 receptors in rafts is not required for viral infection. We show, however, that depleting plasma membrane cholesterol inhibits HIV-1 entry. We therefore propose that cholesterol modulates the HIV-1 entry process independently of its ability to promote raft formation.
Collapse
|
13
|
Hoessli DC, Poincelet M, Gupta R, Ilangumaran S. Plasmodium falciparum merozoite surface protein 1. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:366-75. [PMID: 12605687 DOI: 10.1046/j.1432-1033.2003.03397.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In addition to the major carbohydrate moieties of the glycosylphosphatidylinositol (GPI) anchor, we report that Plasmodium falciparum merozoite surface protein 1 (MSP-1) bears O-GlcNAc modifications predominantly in beta-anomeric configuration, in both the C- and N-terminal portions of the protein. Subcellular fractionation of parasitized erythrocytes in the late trophozoite/schizont stage reveals that GPI-anchored C-terminal fragments of MSP-1 are recovered in Triton X-100 resistant, low-density membrane fractions. Our results suggest that O-GlcNAc-modified MSP-1 N-terminal fragments tend to localize within the parasitophorous vacuolar membrane while GPI-anchored MSP-1 C-terminal fragments associate with low-density, Triton X-100 resistant membrane domains (rafts), redistribute in the parasitized erythrocyte and are eventually shed as membrane vesicles that also contain the endogenous, GPI-linked CD59.
Collapse
Affiliation(s)
- Daniel C Hoessli
- Department of Pathology, Centre médical universitaire, Geneva, Switzerland.
| | | | | | | |
Collapse
|
14
|
Wonerow P, Obergfell A, Wilde JI, Bobe R, Asazuma N, Brdicka T, Leo A, Schraven B, Horejsí V, Shattil SJ, Watson SP. Differential role of glycolipid-enriched membrane domains in glycoprotein VI- and integrin-mediated phospholipase Cgamma2 regulation in platelets. Biochem J 2002; 364:755-65. [PMID: 12049640 PMCID: PMC1222625 DOI: 10.1042/bj20020128] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The platelet collagen receptor glycoprotein VI (GPVI) and the fibrinogen receptor integrin alphaIIbbeta3 trigger intracellular signalling cascades involving the tyrosine kinase Syk, the adapter SLP-76 and phospholipase Cgamma2 (PLCgamma2). Similar pathways are activated downstream of immune receptors in lymphocytes, where they have been localized in part to glycolipid-enriched membrane domains (GEMs). Here we provide several lines of evidence that GPVI-mediated tyrosine phosphorylation of PLCgamma2 in platelets is dependent on GEM-organized signalling and utilizes the GEM resident adapter protein LAT (linker for activation of T cells). In sharp contrast, although fibrinogen binding to platelets stimulates alphaIIbbeta3-dependent activation of Syk and tyrosine phosphorylation of SLP-76 and PLCgamma2, it does not utilize GEMs to promote these responses or to support platelet aggregation. These results establish that GPVI and alphaIIbbeta3 trigger distinct patterns of receptor signalling in platelets, leading to tyrosine phosphorylation of PLCgamma2, and they highlight the role of GEMs in compartmentalizing signalling reactions involved in haemostasis.
Collapse
Affiliation(s)
- Peter Wonerow
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Hoessli DC, Ilangumaran S, Soltermann A, Robinson PJ, Borisch B. Signaling through sphingolipid microdomains of the plasma membrane: the concept of signaling platform. Glycoconj J 2000; 17:191-7. [PMID: 11201790 DOI: 10.1023/a:1026585006064] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Transmembrane signaling requires modular interactions between signaling proteins, phosphorylation or dephosphorylation of the interacting protein partners and temporary elaboration of supramolecular structures, to convey the molecular information from the cell surface to the nucleus. Such signaling complexes at the plasma membrane are instrumental in translating the extracellular cues into intracellular signals for gene activation. In the most straightforward case, ligand binding promotes homodimerization of the transmembrane receptor which facilitates modular interactions between the receptor's cytoplasmic domains and intracellular signaling and adaptor proteins. For example, most growth factor receptors contain a cytoplasmic protein tyrosine kinase (PTK) domain and ligand-mediated receptor dimerization leads to cross phosphorylation of tyrosines in the receptor's cytoplasmic domains, an event that initiates the signaling cascade. In other signaling pathways where the receptors have no intrinsic kinase activity, intracellular nonreceptor PTKs (i.e. Src family PTKs, JAKs) are recruited to the cytoplasmic domain of the engaged receptor. Execution of these initial phosphorylations and their translation into efficient cellular stimulation requires concomitant activation of diverse signaling pathways. Availability of stable, preassembled matrices at the plasma membrane would facilitate scaffolding of a large array of receptors, coreceptors, tyrosine kinases and other signaling and adapter proteins, as it is the case in signaling via the T cell antigen receptor. The concept of the signaling platform has gained usage to characterize the membrane structure where many different membrane-bound components need to be assembled in a coordinated manner to carry out signaling. The structural basis of the signaling platform lies in preferential assembly of certain classes of lipids into distinct physical and functional compartments within the plasma membrane. These membrane microdomains or rafts (Figure 1) serve as privileged sites where receptors and proximal signaling molecules optimally interact. In this review, we shall discuss first how signaling platforms are assembled and how receptors and their signaling machinery could be functionally linked in such structures. The second part of our review will deal with selected examples of raft-based signaling pathways in T lymphocytes and NK cells to illustrate the ways in which rafts may facilitate signaling.
Collapse
Affiliation(s)
- D C Hoessli
- Department of Pathology, University of Geneva, Switzerland
| | | | | | | | | |
Collapse
|
16
|
Pesanová Z, Novotný J, Cerný J, Milligan G, Svoboda P. Thyrotropin-releasing hormone-induced depletion of G(q)alpha/G(11)alpha proteins from detergent-insensitive membrane domains. FEBS Lett 1999; 464:35-40. [PMID: 10611479 DOI: 10.1016/s0014-5793(99)01666-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The role of detergent-insensitive membrane domains (DIMs) in desensitisation of the G protein-coupled receptor-mediated hormone response was studied in clone E2M11 of HEK293 cells which stably express high levels of both thyrotropin-releasing hormone (TRH) receptors and G(11)alpha G protein. DIMs were prepared by flotation in equilibrium sucrose density gradients and characterised by a panel of membrane markers representing peripheral, glycosylphosphatidylinositol-bound as well as integral membrane proteins (caveolin, CD29, CD55, CD59, CD147, the alpha subunit of Na, K-ATPase) and enzyme activities (alkaline phosphatase, adenylyl cyclase). Caveolin-containing DIMs represented only a small fraction of the overall pool of G(q)alpha/G(11)alpha-rich domains. Prolonged stimulation of E2M11 cells with TRH resulted in dramatic depletion of G(q)alpha/G(11)alpha from all DIMs, which was paralleled by a concomitant G(q)alpha/G(11)alpha increase in the high-density gradient fractions containing the bulk-phase membrane constituents soluble in 1% Triton X-100. Distribution of membrane markers was unchanged under these conditions. Membrane domains thus represent a substantial structural determinant of the G protein pool relevant to desensitisation of hormone action.
Collapse
Affiliation(s)
- Z Pesanová
- Institute of Physiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20, Prague, Czech Republic
| | | | | | | | | |
Collapse
|
17
|
Ilangumaran S, Borisch B, Hoessli DC. Signal transduction via CD44: role of plasma membrane microdomains. Leuk Lymphoma 1999; 35:455-69. [PMID: 10609783 DOI: 10.1080/10428199909169610] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
CD44 is the principal cell surface receptor for extracellular matrix glycosaminoglycan hyaluronan. CD44-hyaluronan mediated cell adhesion is important in several pathophysiological processes such as inflammation and metastatic spread of cancer cells. It has been recently recognized that CD44 also functions as a signaling receptor in a variety of cell types. Cell stimulation by monoclonal anti-CD44 antibody or natural CD44 ligands activate several signaling pathways that culminate in cell proliferation, cytokine secretion, chemokine gene expression and cytolytic effector functions. One of the earliest signaling events following stimulation via CD44 is tyrosine phosphorylation of intracellular proteins substrates, and CD44 mediated cellular activation could be abolished by protein tyrosine kinase (PTK) inhibitors. The Src-family non-receptor PTKs such as Lck, Fyn, Lyn and Hck were shown to be coupled to CD44 via sphingolipid-rich microdomains (lipid rafts) of the plasma membrane. Studies on T cell receptor and IgE receptor mediated signaling in lymphocytes and mast cells have consolidated the notion that microdomains consist of signaling platforms where components of multiple signaling pathways are assembled. Co-isolation of CD44 with microdomains strongly suggests that CD44 generates cellular activation signals utilizing the signaling machinery of the plasma membrane microdomains.
Collapse
Affiliation(s)
- S Ilangumaran
- Department of Experirmental Therapeutics, Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Canada
| | | | | |
Collapse
|
18
|
Horejsí V, Drbal K, Cebecauer M, Cerný J, Brdicka T, Angelisová P, Stockinger H. GPI-microdomains: a role in signalling via immunoreceptors. IMMUNOLOGY TODAY 1999; 20:356-61. [PMID: 10431155 DOI: 10.1016/s0167-5699(99)01489-9] [Citation(s) in RCA: 206] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins and glycosphingolipids are assembled on the leukocyte surface within membrane microdomains, which also accommodate a set of cytoplasmic signalling molecules (Src family kinases, G-proteins, linker proteins). Recent results suggest that these membrane specializations mediate not only signal transduction via GPI-proteins and glycolipids but also play important roles in initiation of signalling via immunoreceptors.
Collapse
Affiliation(s)
- V Horejsí
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague 4, V denská 1083, Czech Republic.
| | | | | | | | | | | | | |
Collapse
|
19
|
Ilangumaran S, Arni S, van Echten-Deckert G, Borisch B, Hoessli DC. Microdomain-dependent regulation of Lck and Fyn protein-tyrosine kinases in T lymphocyte plasma membranes. Mol Biol Cell 1999; 10:891-905. [PMID: 10198045 PMCID: PMC25210 DOI: 10.1091/mbc.10.4.891] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Src family protein-tyrosine kinases are implicated in signaling via glycosylphosphatidylinositol (GPI)-anchored receptors. Both kinds of molecules reside in opposite leaflets of the same sphingolipid-enriched microdomains in the lymphocyte plasma membrane without making direct contact. Under detergent-free conditions, we isolated a GPI-enriched plasma membrane fraction, also containing transmembrane proteins, selectively associated with sphingolipid microdomains. Nonionic detergents released the transmembrane proteins, yielding core sphingolipid microdomains, limited amounts of which could also be obtained by detergent-free subcellular fractionation. Protein-tyrosine kinase activity in membranes containing both GPI-anchored and transmembrane proteins was much lower than in core sphingolipid microdomains but was strongly reactivated by nonionic detergents. The inhibitory mechanism acting on Lck and Fyn kinases in these membranes was independent of the protein-tyrosine phosphatase CD45 and was characterized as a mixed, noncompetitive one. We propose that in lymphocyte plasma membranes, Lck and Fyn kinases exhibit optimal activity when juxtaposed to the GPI- and sphingolipid-enriched core microdomains but encounter inhibitory conditions in surrounding membrane areas that are rich in glycerophospholipids and contain additional transmembrane proteins.
Collapse
Affiliation(s)
- S Ilangumaran
- Department of Pathology, Centre Médical Universitaire, CH-1211 Geneva 4, Switzerland
| | | | | | | | | |
Collapse
|
20
|
Millán J, Cerny J, Horejsi V, Alonso MA. CD4 segregates into specific detergent-resistant T-cell membrane microdomains. TISSUE ANTIGENS 1999; 53:33-40. [PMID: 10082429 DOI: 10.1034/j.1399-0039.1999.530104.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In T cells, glycolipids, glycoproteins attached to the membrane via a glycosylphosphatidylinositol (GPI) anchor, and Src-like tyrosine kinases are highly enriched in a membrane fraction resistant to solubilization by nonionic detergents. We have investigated the distribution of CD4 in T-cell membranes and found that approximately 10% of the CD4 co-receptor is associated with detergent-insoluble membrane microdomains, whilst the remaining 90% is in soluble membranes. Moreover, approximately 60% of the "insoluble CD4" is present in membrane microdomains containing GPI-anchored proteins and high glycolipid-dependent kinase activity, whereas the remaining 40% displays no association with GPI-anchored proteins and lacks glycolipid-associated kinase activity These results indicate that CD4 segregates at least into three different membrane microenvironments: 1) soluble membranes; 2) insoluble membrane microdomains containing GPI-anchored proteins; and 3) insoluble membrane microdomains devoid of GPI-anchored proteins. The level of CD4 in insoluble membranes was not modified upon triggering activation by T-cell receptor-crosslinking but detectable amounts of CD3 subunits were recruited into these specialized membranes under those conditions. The physical separation of CD4 into different membrane microenvironments raises the possibility of that some of the multiple functions of CD4 might segregate into distinct types of lipid microenvironment. The fact that components of T-cell receptor/CD3 complex were recruited into insoluble membranes upon stimulation is consistent with the CD4 present in this membrane fraction might participate in T-cell receptor-triggered activation events.
Collapse
Affiliation(s)
- J Millán
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Spain
| | | | | | | |
Collapse
|
21
|
Ilangumaran S, Hoessli DC. Effects of cholesterol depletion by cyclodextrin on the sphingolipid microdomains of the plasma membrane. Biochem J 1998; 335 ( Pt 2):433-40. [PMID: 9761744 PMCID: PMC1219799 DOI: 10.1042/bj3350433] [Citation(s) in RCA: 379] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sphingolipid microdomains are thought to result from the organization of plasma membrane sphingolipids and cholesterol into a liquid ordered phase, wherein the glycosylphosphatidylinositol (GPI)-anchored proteins are enriched. These domains, resistant to extraction by cold Triton X-100, can be isolated as buoyant membrane complexes (detergent-resistant membranes) in isopycnic density gradients. Here the effects of methyl-beta-cyclodextrin (MBCD), a specific cholesterol-binding agent that neither binds nor inserts into the plasma membrane, were investigated on the sphingolipid microdomains of lymphocytes. MBCD released substantial quantities of GPI-anchored Thy-1 and glycosphingolipid GM1, and also other surface proteins including CD45, and intracellular Lck and Fyn kinases. From endothelial cells, MBCD released GPI-anchored CD59, and CD44, but only a negligible amount of caveolin. Most MBCD-released Thy-1 and CD59 were not sedimentable and thus differed from Thy-1 released by membrane-active cholesterol-binding agents such as saponin and streptolysin O, or Triton X-100. Unlike that released by Triton X-100, only part of the Thy-1 molecules released by MBCD was buoyant in density gradients and co-isolated with GM1. Finally, treatment of Triton X-100-isolated detergent-resistant membranes with MBCD extracted most of the cholesterol without affecting the buoyant properties of Thy-1 or GM1. We suggest that (1) MBCD preferentially extracts cholesterol from outside, rather than within the sphingolipid microdomains and (2) this partly solubilizes GPI-anchored and transmembrane proteins from the glycerophospholipid-rich membrane and releases sphingolipid microdomains in both vesicular and non-vesicular form.
Collapse
Affiliation(s)
- S Ilangumaran
- Department of Pathology, Centre Médical Universitaire, 1 rue Michel Servet, 1211 Geneva 4, Switzerland
| | | |
Collapse
|
22
|
Montixi C, Langlet C, Bernard AM, Thimonier J, Dubois C, Wurbel MA, Chauvin JP, Pierres M, He HT. Engagement of T cell receptor triggers its recruitment to low-density detergent-insoluble membrane domains. EMBO J 1998; 17:5334-48. [PMID: 9736612 PMCID: PMC1170860 DOI: 10.1093/emboj/17.18.5334] [Citation(s) in RCA: 518] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
T-cell receptors (TCRs) upon binding to peptide-MHC ligands transduce signals in T lymphocytes. Tyrosine phosphorylations in the cytoplasmic domains of the CD3 (gammadeltaepsilon) and zeta subunits of the TCR complex by Src family kinases initiate the signaling cascades via docking and activation of ZAP-70 kinase and other signaling components. We examined the role of the low-density detergent-insoluble membranes (DIMs) in TCR signaling. Using mouse thymocytes as a model, we characterized the structural organization of DIMs in detail. We then demonstrated that TCR engagement triggered an immediate increase in the amount of TCR/CD3 present in DIMs, which directly involves the engaged receptor complexes. TCR/CD3 recruitment is accompanied by the accumulation of a series of prominent tyrosine-phosphorylated substrates and by an increase of the Lck activity in DIMs. Upon TCR stimulation, the DIM-associated receptor complexes are highly enriched in the hyperphosphorylated p23 zeta chains, contain most of the TCR/CD3-associated, phosphorylation-activated ZAP-70 kinases and seem to integrate into higher order, multiple tyrosine-phosphorylated substrate-containing protein complexes. The TCR/CD3 recruitment was found to depend on the activity of Src family kinases. We thus provide the first demonstration of recuitment of TCR/CD3 to DIMs upon receptor stimulation and propose it as a mechanism whereby TCR engagement is coupled to downstream signaling cascades.
Collapse
Affiliation(s)
- C Montixi
- Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Case 906, Cedex, France
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Jenski LJ, Scherer JM, Caldwell LD, Ney VA, Stillwell W. The triggering signal dictates the effect of docosahexaenoic acid on lymphocyte function in vitro. Lipids 1998; 33:869-78. [PMID: 9778134 DOI: 10.1007/s11745-998-0283-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Docosahexaenoic acid (DHA) is an n-3 fatty acid beneficial to several human conditions including inflammation and autoimmune disease. To better understand the effect of DHA on immunity, we monitored the rise in cytosolic free calcium, interleukin 2 receptor (IL2R) expression, and proliferation of splenic lymphocytes triggered with three different stimuli in the presence or absence of DHA. We found that 10 microg DHA/mL suppressed concanavalin A-induced mitogenesis and the mixed lymphocyte reaction while concurrently enhancing proliferation stimulated with anti-Thy-1 antibodies. Proliferation, as measured by [3H]thymidine incorporation after 2 to 5 d of culture, was affected by DHA, but earlier activation effects such as elevation of cytosolic free calcium and IL2R expression were not altered. These results imply that DHA incorporated into membrane phospholipids differentially affects the activity of distinct membrane-bound receptors and signaling molecules. This result suggests that DHA may be used to modulate immune responses selectively, e.g., to suppress undesired autoimmunity while maintaining protective immunity.
Collapse
Affiliation(s)
- L J Jenski
- Department of Biology, Indiana University-Purdue University at Indianapolis 46202-5132, USA.
| | | | | | | | | |
Collapse
|
24
|
Horejsí V, Cebecauer M, Cerný J, Brdicka T, Angelisová P, Drbal K. Signal transduction in leucocytes via GPI-anchored proteins: an experimental artefact or an aspect of immunoreceptor function? Immunol Lett 1998; 63:63-73. [PMID: 9761367 DOI: 10.1016/s0165-2478(98)00054-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane proteins anchored in the membrane via a glycolipid glycosylphosphatidylinositol (GPI) as well as some glycolipids are able to transduce signals and induce diverse functional responses in cells upon their cross-linking via antibodies or natural ligands. In some cases this signaling capacity seems to be due to associations of these molecules with specific transmembrane proteins. GPI-anchored proteins are components of membrane microdomains enriched in glycosphingolipids and cholesterol and devoid of most transmembrane proteins. These membrane specializations are relatively resistant to solubilization in solutions of some mild detergents at low temperatures. These 'GPI-microdomains' contain also cytoplasmic signaling molecules such as Src-family protein tyrosine kinases and trimeric G-proteins. Thus, at least some signaling elicited upon cross-linking of GPI-anchored proteins and glycolipids may be due to perturbation of the signaling molecules associated with these microdomains. It is suggested that these specialized areas of the membrane rich in signaling molecules interact with immunoreceptors (TCR, BCR, Fc receptors) cross-linked upon their interactions with ligands and importantly contribute to initiation of proximal phases of their signaling pathways.
Collapse
Affiliation(s)
- V Horejsí
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague.
| | | | | | | | | | | |
Collapse
|
25
|
CD44 Selectively Associates With Active Src Family Protein Tyrosine Kinases Lck and Fyn in Glycosphingolipid-Rich Plasma Membrane Domains of Human Peripheral Blood Lymphocytes. Blood 1998. [DOI: 10.1182/blood.v91.10.3901.3901_3901_3908] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CD44 is the major cell surface receptor for the extracellular matrix glycosaminoglycan hyaluronan and is implicated in a variety of biological events that include embryonic morphogenesis, lymphocyte recirculation, inflammation, and tumor metastasis. CD44 delivers activation signals to T lymphocytes, B lymphocytes, natural killer cells, polymorphonuclear leukocytes, and macrophages by stimulating protein tyrosine phosphorylation and calcium influx. The mechanism of signal transduction via CD44 remains undefined, although CD44 was shown to physically associate with intracellular protein tyrosine kinase Lck in T lymphocytes. In the present report, we show that a significant proportion of CD44 in human peripheral blood T lymphocytes and endothelial cells is associated with low-density plasma membrane fractions that represent specialized plasma membrane domains enriched in glycosphingolipids and glycosylphosphatidylinositol (GPI)-anchored proteins. CD44 and the GPI-anchored CD59 do not appear to directly interact in the low-density membrane fractions. In human peripheral blood T lymphocytes, 20% to 30% of the Src family protein tyrosine kinases, Lck and Fyn, are recovered from these fractions. CD44-associated protein kinase activity was selectively recovered from the low-density membrane fractions, corresponding to glycosphingolipid-rich plasma membrane microdomains. Reprecipitation of the in vitro phosphorylated proteins showed that CD44 associates not only with Lck but also with Fyn kinase in these membrane domains. Our results suggest that cellular stimulation via CD44 may proceed through the signaling machinery of glycosphingolipid-enriched plasma membrane microdomains and, hence, depend on the functional integrity of such domains.
Collapse
|
26
|
CD44 Selectively Associates With Active Src Family Protein Tyrosine Kinases Lck and Fyn in Glycosphingolipid-Rich Plasma Membrane Domains of Human Peripheral Blood Lymphocytes. Blood 1998. [DOI: 10.1182/blood.v91.10.3901] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
CD44 is the major cell surface receptor for the extracellular matrix glycosaminoglycan hyaluronan and is implicated in a variety of biological events that include embryonic morphogenesis, lymphocyte recirculation, inflammation, and tumor metastasis. CD44 delivers activation signals to T lymphocytes, B lymphocytes, natural killer cells, polymorphonuclear leukocytes, and macrophages by stimulating protein tyrosine phosphorylation and calcium influx. The mechanism of signal transduction via CD44 remains undefined, although CD44 was shown to physically associate with intracellular protein tyrosine kinase Lck in T lymphocytes. In the present report, we show that a significant proportion of CD44 in human peripheral blood T lymphocytes and endothelial cells is associated with low-density plasma membrane fractions that represent specialized plasma membrane domains enriched in glycosphingolipids and glycosylphosphatidylinositol (GPI)-anchored proteins. CD44 and the GPI-anchored CD59 do not appear to directly interact in the low-density membrane fractions. In human peripheral blood T lymphocytes, 20% to 30% of the Src family protein tyrosine kinases, Lck and Fyn, are recovered from these fractions. CD44-associated protein kinase activity was selectively recovered from the low-density membrane fractions, corresponding to glycosphingolipid-rich plasma membrane microdomains. Reprecipitation of the in vitro phosphorylated proteins showed that CD44 associates not only with Lck but also with Fyn kinase in these membrane domains. Our results suggest that cellular stimulation via CD44 may proceed through the signaling machinery of glycosphingolipid-enriched plasma membrane microdomains and, hence, depend on the functional integrity of such domains.
Collapse
|