SELF-POTENTIATION OF LIGAND-TOXIN CONJUGATES CONTAINING RICIN-A CHAIN FUSED WITH VIRAL STRUCTURES

被引:28
作者
CHIGNOLA, R
ANSELMI, C
SERRA, MD
FRANCESCHI, A
FRACASSO, G
PASTI, M
CHIESA, E
LORD, JM
TRIDENTE, G
COLOMBATTI, M
机构
[1] UNIV VERONA,POLICLIN BORGO ROMA,IST IMMUNOL & MALATTIE INFETTIVE,I-37134 VERONA,ITALY
[2] CNR,CTR FIS STATI AGGREGATI,I-38050 TRENT,ITALY
[3] UNIV WARWICK,DEPT BIOL SCI,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND
关键词
D O I
10.1074/jbc.270.40.23345
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
A chimeric protein was obtained by fusing together the ricin toxin A chain (RTA) gene and a DNA fragment encoding the N terminus of protein G of the vesicular stomatitis virus. Chimeric RTA (cRTA) retained full enzymic activity in a cell-free assay, but was 10-fold less toxic against human leukemic cells than either native RTA (nRTA) or unmodified recombinant RTA (rRTA). However, conjugates made with cRTA and human transferrin (Tfn) showed 10-20 fold greater cell killing efficacy than Tfn-nRTA or Tfn-rRTA conjugates despite equivalent binding of the three conjugates to target tumor cells. As a consequence, by fusion of the KFT25 peptide to the RTA sequence, the specificity factor (i.e. the ratio between nonspecific and specific cytotoxicity) of Tfn-cRTA was increased 90-240 times with respect to those of Tfn-nRTA and Tfn-rRTA. cRTA interacted with phospholipid vesicles with 15-fold faster kinetics than nRTA at acidic pH. Taken together, our results suggest that the ability of vesicular stomatitis virus protein G to interact with cell membranes can be transferred to RTA to facilitate its translocation to the cell cytosol. Our strategy may serve as a general approach for potentiating the cytotoxic efficacy of antitumor immunotoxins.
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页码:23345 / 23351
页数:7
相关论文
共 42 条
  • [1] IMMUNOTOXINS AGAINST CANCER
    BRINKMANN, U
    PASTAN, I
    [J]. BIOCHIMICA ET BIOPHYSICA ACTA-REVIEWS ON CANCER, 1994, 1198 (01): : 27 - 45
  • [2] DIPHTHERIA-TOXIN INDUCES FUSION OF SMALL UNILAMELLAR VESICLES AT LOW PH
    CABIAUX, V
    VANDENBRANDEN, M
    FALMAGNE, P
    RUYSSCHAERT, JM
    [J]. BIOCHIMICA ET BIOPHYSICA ACTA, 1984, 775 (01) : 31 - 36
  • [3] CANDIANI C, 1992, CANCER RES, V52, P623
  • [4] CYTOREDUCTIVE EFFECTS OF ANTITRANSFERRIN RECEPTORS IMMUNOTOXINS IN A MULTICELLULAR TUMOR SPHEROID MODEL
    CHIGNOLA, R
    FORONI, R
    CANDIANI, C
    FRANCESCHI, A
    PASTI, M
    STEVANONI, G
    ANSELMI, C
    TRIDENTE, G
    COLOMBATTI, M
    [J]. INTERNATIONAL JOURNAL OF CANCER, 1994, 57 (02) : 268 - 274
  • [5] DISTRIBUTION OF ENDOCYTOSED MOLECULES TO INTRACELLULAR ACIDIC ENVIRONMENTS CORRELATES WITH IMMUNOTOXIN ACTIVITY
    CHIGNOLA, R
    COLOMBATTI, M
    DELLARCIPRETE, L
    CANDIANI, C
    TRIDENTE, G
    [J]. INTERNATIONAL JOURNAL OF CANCER, 1990, 46 (06) : 1117 - 1123
  • [6] CHIGNOLA R, 1994, J IMMUNOL, V152, P2333
  • [7] COBB PW, 1992, SEMIN HEMATOL, V29, P6
  • [8] POSITIVELY CHARGED RESIDUES ARE IMPORTANT DETERMINANTS OF MEMBRANE-PROTEIN TOPOLOGY
    DALBEY, RE
    [J]. TRENDS IN BIOCHEMICAL SCIENCES, 1990, 15 (07) : 253 - 257
  • [9] DALLASERRA M, 1993, LIFE SCI ADV BIOPHYS, V12, P109
  • [10] PH AND THE RECYCLING OF TRANSFERRIN DURING RECEPTOR-MEDIATED ENDOCYTOSIS
    DAUTRYVARSAT, A
    CIECHANOVER, A
    LODISH, HF
    [J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1983, 80 (08): : 2258 - 2262