TY - JOUR
T1 - Therapeutic levels of human Factor VIII in mice implanted with encapsulated cells
T2 - Potential for gene therapy of haemophilia A
AU - García-Martín, Carmen
AU - Chuah, Marinee K.L.
AU - Van Damme, An
AU - Robinson, Kelly E.
AU - Vanzieleghem, Beatrijs
AU - Saint-Remy, Jean Marie
AU - Gallardo, Dominique
AU - Ofosu, Frederick A.
AU - Vandendriessche, Thierry
AU - Hortelano, Gonzalo
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/3
Y1 - 2002/3
N2 - Background: A gene therapy delivery system based on microcapsules enclosing recombinant cells engineered to secrete a therapeutic protein has been evaluated. The microcapsules are implanted intraperitoneally. In order to prevent cell immune rejection, cells are enclosed in non-antigenic biocompatible alginate microcapsules prior to their implantation into mice. It has been shown that encapsulated myoblasts can deliver therapeutic levels of Factor IX (FIX) in mice. The delivery of human Factor VIII (hFVIII) in mice using microcapsules was evaluated in this study. Methods: Mouse C2C12 myoblasts and canine MDCK epithelial kidney cells were transduced with MFG-FVIII (B-domain deleted) vector. Selected recombinant clones were enclosed in alginate microcapsules. Encapsulated recombinant clones were subsequently implanted intraperitoneally into C57BL/6 and immunodeficient SCID mice. Results: Plasma of mice receiving C2C12 and encapsulated MDCK cells had transient therapeutic levels of FVIII in immunocompetent C57BL/6 mice (up to 20% and 7% of physiological levels, respectively). In addition, FVIII delivery in SCID mice was also transient, suggesting that a non-immune mechanism must have contributed to the decline of hFVIII in plasma. Quantitative RT-PCR analysis confirmed directly that the decline of hFVIII is due to a reduction in steady-state hFVIII mRNA, consistent with transcriptional repression. Furthermore, encapsulated cells retrieved from implanted mice were viable, but secreted FVIII ex vivo at three-fold lower levels than the pre-implantation levels. In addition, antibodies to hFVIII were detected in immunocompetent C57BL/6 mice. Conclusions: Implantable microcapsules can deliver therapeutic levels of FVIII in mice, suggesting the potential of this gene therapy approach for haemophilia A. The findings suggest vector down-regulation in vivo.
AB - Background: A gene therapy delivery system based on microcapsules enclosing recombinant cells engineered to secrete a therapeutic protein has been evaluated. The microcapsules are implanted intraperitoneally. In order to prevent cell immune rejection, cells are enclosed in non-antigenic biocompatible alginate microcapsules prior to their implantation into mice. It has been shown that encapsulated myoblasts can deliver therapeutic levels of Factor IX (FIX) in mice. The delivery of human Factor VIII (hFVIII) in mice using microcapsules was evaluated in this study. Methods: Mouse C2C12 myoblasts and canine MDCK epithelial kidney cells were transduced with MFG-FVIII (B-domain deleted) vector. Selected recombinant clones were enclosed in alginate microcapsules. Encapsulated recombinant clones were subsequently implanted intraperitoneally into C57BL/6 and immunodeficient SCID mice. Results: Plasma of mice receiving C2C12 and encapsulated MDCK cells had transient therapeutic levels of FVIII in immunocompetent C57BL/6 mice (up to 20% and 7% of physiological levels, respectively). In addition, FVIII delivery in SCID mice was also transient, suggesting that a non-immune mechanism must have contributed to the decline of hFVIII in plasma. Quantitative RT-PCR analysis confirmed directly that the decline of hFVIII is due to a reduction in steady-state hFVIII mRNA, consistent with transcriptional repression. Furthermore, encapsulated cells retrieved from implanted mice were viable, but secreted FVIII ex vivo at three-fold lower levels than the pre-implantation levels. In addition, antibodies to hFVIII were detected in immunocompetent C57BL/6 mice. Conclusions: Implantable microcapsules can deliver therapeutic levels of FVIII in mice, suggesting the potential of this gene therapy approach for haemophilia A. The findings suggest vector down-regulation in vivo.
KW - Alginate
KW - Factor VIII
KW - Haemophilia A
KW - Microcapsules
KW - Myoblasts
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U2 - 10.1002/jgm.248
DO - 10.1002/jgm.248
M3 - Article
C2 - 11933222
AN - SCOPUS:14044279364
VL - 4
SP - 215
EP - 223
JO - Journal of Gene Medicine
JF - Journal of Gene Medicine
SN - 1099-498X
IS - 2
ER -