title: Modulating p56Lck in T-Cells by a Chimeric Peptide Comprising Two Functionally Different Motifs of Tip from Herpesvirus saimiri.
abstract: The Lck interacting protein Tip of Herpesvirus saimiri is responsible for T-cell transformation both in vitro and in vivo. Here we designed the chimeric peptide hTip-CSKH, comprising the Lck specific interacting motif CSKH of Tip and its hydrophobic transmembrane sequence (hTip), the latter as a vector targeting lipid rafts. We found that hTip-CSKH can induce a fivefold increase in proliferation of human and Aotus sp. T-cells. Costimulation with PMA did not enhance this proliferation rate, suggesting that hTip-CSKH is sufficient and independent of further PKC stimulation. We also found that human Lck phosphorylation was increased earlier after stimulation when T-cells were incubated previously with hTip-CSKH, supporting a strong signalling and proliferative effect of the chimeric peptide. Additionally, Lck downstream signalling was evident with hTip-CSKH but not with control peptides. Importantly, hTip-CSKH could be identified in heavy lipid rafts membrane fractions, a compartment where important T-cell signalling molecules (LAT, Ras, and Lck) are present during T-cell activation. Interestingly, hTip-CSKH was inhibitory to Jurkat cells, in total agreement with the different signalling pathways and activation requirements of this leukemic cell line. These results provide the basis for the development of new compounds capable of modulating therapeutic targets present in lipid rafts.
authors.affiliation: Fisiología Celular y Molecular, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá 11001, Colombia ; Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá 11001, Colombia.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Vernot
authors.affiliation: Fisiología Celular y Molecular, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá 11001, Colombia.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Perdomo-Arciniegas
authors.affiliation: Fisiología Celular y Molecular, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá 11001, Colombia.
authors.forename: Luis Alberto
authors.initials: LA
authors.lastname: Pérez-Quintero
authors.affiliation: Fisiología Celular y Molecular, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá 11001, Colombia.
authors.forename: Diego Fernando
authors.initials: DF
authors.lastname: Martínez
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D016645:Aotidae; D006567:Herpesvirus 2, Saimiriine / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000235:genetics / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000235:genetics*; D010750:Phosphoproteins / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D010766:Phosphorylation; D010835:Phytohemagglutinins / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*
chemical_list: D010455:Peptides; D010750:Phosphoproteins; D010835:Phytohemagglutinins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; C092384:tyrosine kinase interacting protein, Saimiriine herpesvirus 2; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck)