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DESCRIPTION
Peptide labelling with fluor-19 and fluor-18 : OVA 323-339 and OVA 257-264 for the study of dendritic cells migration by PET Scan. Laïque Salma [1] , Lazarova Elena [2] , Monclus Michel [1] , Jacquemotte Françoise [3] , Communi David [4] , Flamand Véronique [2] , Goldman Serge [1] - PowerPoint PPT PresentationTRANSCRIPT
Peptide labelling with fluor-19 and fluor-18 : Peptide labelling with fluor-19 and fluor-18 : OVA 323-339 and OVA 257-264 for theOVA 323-339 and OVA 257-264 for the
study of dendritic cells migration by PET Scanstudy of dendritic cells migration by PET Scan
Laïque Salma [1], Lazarova Elena [2], Monclus Michel [1], Jacquemotte Françoise [3], Communi David [4], Flamand Véronique [2], Goldman Serge [1]
[1] PET/Biomedical Cyclotron Unit, ULB, Hopital Erasme, Route de Lennik 808, 1070 Anderlecht, BELGIUM[2] Institute for Medical Immunology, ULB, Rue A. Bolland, B 6041 Gosselies, BELGIUM[3] Département des Substances Naturelles, Institut Meurice, 50 Avenue Emile Gryzon, 1070 Anderlecht, BELGIUM[4] I.R.I.B.H.M. , Bldg. C, ULB, Route de Lennik 808, 1070 Anderlecht, BELGIUM
OVA 323-339 : NH2– Ile – Ser – Gln – Ala – Val – His – Ala – Ala – His – Ala – Glu – Ile – Asn – Glu – Ala – Gly – Arg – OH
Introduction
OVA 257-264 : NH2 – Ser – Ile – Ile – Asn – Phe – Glu – Lys – Leu – OH
Dendritic cells (DC) migration is important to evaluate in immunotherapy protocoles. Ovalbumin323-339 and Ovalbumin257-264 are known to be recognised by MHC II complex of DC and to induce T lymphocytes proliferation (1).We propose to radiolabel these fragment with [18F]fluoroethyl moiety to image by PET pulsed DC injected into mice. We here present the biological results of the non radioactive tracer, N-[19F]fluoro-ethyl-OVA323-339 (FEthOVA323-339) and our preliminary tests of radiolabelling on OVA257-264.
0.0 0.2 0.4 0.6 0.8
0.0
2.0e+4
4.0e+4
6.0e+4
8.0e+4
1.0e+5
1.2e+5
1.4e+5
DC-Wild TypeDC-LPS activatedWT-OVA-F19 loadedWT-OVA loadedLPS act.-OVA-F19 loadedLPS act.-OVA loaded
Biology
Non radioactive peptides
Peptide synthesis : on solid phase
Principle of SPPS In vitro comparaison between OVA323-339
and FEtOVA323-339, measured by 3H-thymidin incorporation after 48h MLR
FEtOTs synthesis (2)
Coupling reaction
Conclusions: FEthOVA323-339 holds antigenic properties of OVA323-339. The F-18-labeled form of this peptide should therefore be evaluated for PET imaging of pulsed-DC migration.
Radioactive peptides
1,2-ditosyloxyethane
protected OVA257-264NH-CH2-CH2-18F (+ 18FEtOTs)
OVA257-264NH-CH2-CH2-18F
18FEtOTs protected OVA257-264+
basic
conditions
TFA/TIS/thioanisole
18FEtOTs (+18F- + 1,2-ditosyloxyethane)18F-/K2.2.2./K2CO3
purification
18FEtOTs
QMA
Protected peptide :
OVA 257-264 : NH2 – Ser – Ile – Ile – Asn (Ttr) – Phe – Glu (OtBu) – Lys (Boc) – Leu – OH X : protecting groups
Validation byanalyitical HPLCLC-MS
OVA257-264NH-CH2-CH2-18F
scavengers suppression
preparative HPLC
purification
protected OVA257-264NH-CH2-CH2-18F
(1) Wilson AA, Dasilva JN, Houle S. Synthesis of two radiofluorinated cocaine analogues using distilled 2-[18F]fluoroethylbromide. Appl. Radiat. Isot. 46(8):765-770,1995(2) Roberston JM, Jensen PE, Evavold BD. DO11.10 and OT.II T cells recognise a C-terminal Ovalbumin 323-339 epitope. J. Immunol. 164:4706-4712, 2000
References : [email protected] : 0032-2-555.47.11
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