Reviewer's report
Title:Hepatitis B Virus Inhibition in Mice by Lentiviral Vector Mediated Small
Interference RNA
Version: 1Date:13 May 2009
Reviewer: Patrick Arbuthnot
Reviewer's report:
The authors describe an assessment of the efficacy of lentiviral vectors encoding
RNAi activators that target 2 sites within the HBV genome and demonstrate
silencing of markers of viral replication in a hydrodynamic model of HBV
infection. The investigation of the usefulness of lentiviral vectors for silencing of
HBV infection is important as the ideal vector for RNAi-based treatment of HBV is
yet to be established. Utilising lentiviral vectors may well have some advantages.
There are however points about the reported investigation that need to be
addressed before a clear understanding of lentiviral vector utility can be
established.
Major Compulsory Revisions
1 In the introduction, mention is made that RNAi is a surveillance mechanism.
Although this may be true RNAi is most important for the processing of primary
miRs, which have important functions for regulation of gene expression.
2 Exclusion of non specific effects to account for the observations is important.
This includes providing evidence that the vectors generate generate exogenous
antiHBV activators of RNAi.
3 The method employed to deliver the lentiviral vectors, hydrodynamic injection,
is an unconventional way of administering a vector. Low pressure injection would
give a clearer insight into the efficiency of lentiviruses as vectors for HBV
treatment.
4 It is assumed that there is integration of the vector provirus into the mouse
genome, but the evidence for this (e.g. using Southern blot hybridisation) is not
provided.
5 The discussion of the drawbacks of using lentiviral vectors that express U6
shRNA cassettes for therapeutic application needs expansion. For example,
overexpression of hairpins from a U6 promoter within AAV vectors has been
shown to be toxic. Stable integration of similar cassettes, such as are used in this
study, potentially has profound undesirable effects.
6 Surely the lenti vectors deliver an expression cassette that produce shRNAs
and not siRNA. siRNAs are a product of Dicer processing of the hairpins.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests.
Reviewer's report
Title:Hepatitis B Virus Inhibition in Mice by Lentiviral Vector Mediated Small
Interference RNA
Version: 1Date:13 May 2009
Reviewer: Patrick Arbuthnot
Reviewer's report:
The authors describe an assessment of the efficacy of lentiviral vectors encoding
RNAi activators that target 2 sites within the HBV genome and demonstrate
silencing of markers of viral replication in a hydrodynamic model of HBV
infection. The investigation of the usefulness of lentiviral vectors for silencing of
HBV infection is important as the ideal vector for RNAi-based treatment of HBV is
yet to be established. Utilising lentiviral vectors may well have some advantages.
There are however points about the reported investigation that need to be
addressed before a clear understanding of lentiviral vector utility can be
established.
Major Compulsory Revisions
1 In the introduction, mention is made that RNAi is a surveillance mechanism.
Although this may be true RNAi is most important for the processing of primary
miRs, which have important functions for regulation of gene expression.
2 Exclusion of non specific effects to account for the observations is important.
This includes providing evidence that the vectors generate generate exogenous
antiHBV activators of RNAi.
3 The method employed to deliver the lentiviral vectors, hydrodynamic injection,
is an unconventional way of administering a vector. Low pressure injection would
give a clearer insight into the efficiency of lentiviruses as vectors for HBV
treatment.
4 It is assumed that there is integration of the vector provirus into the mouse
genome, but the evidence for this (e.g. using Southern blot hybridisation) is not
provided.
5 The discussion of the drawbacks of using lentiviral vectors that express U6
shRNA cassettes for therapeutic application needs expansion. For example,
overexpression of hairpins from a U6 promoter within AAV vectors has been
shown to be toxic. Stable integration of similar cassettes, such as are used in this
study, potentially has profound undesirable effects.
6 Surely the lenti vectors deliver an expression cassette that produce shRNAs
and not siRNA. siRNAs are a product of Dicer processing of the hairpins.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests.
Please review this paper.
user
Reviewer's report
Title:Hepatitis B Virus Inhibition in Mice by Lentiviral Vector Mediated Small
Interference RNA
Version: 1Date:13 May 2009
Reviewer: Patrick Arbuthnot
Reviewer's report:
The authors describe an assessment of the efficacy of lentiviral vectors encoding
RNAi activators that target 2 sites within the HBV genome and demonstrate
silencing of markers of viral replication in a hydrodynamic model of HBV
infection. The investigation of the usefulness of lentiviral vectors for silencing of
HBV infection is important as the ideal vector for RNAi-based treatment of HBV is
yet to be established. Utilising lentiviral vectors may well have some advantages.
There are however points about the reported investigation that need to be
addressed before a clear understanding of lentiviral vector utility can be
established.
Major Compulsory Revisions
1 In the introduction, mention is made that RNAi is a surveillance mechanism.
Although this may be true RNAi is most important for the processing of primary
miRs, which have important functions for regulation of gene expression.
2 Exclusion of non specific effects to account for the observations is important.
This includes providing evidence that the vectors generate generate exogenous
antiHBV activators of RNAi.
3 The method employed to deliver the lentiviral vectors, hydrodynamic injection,
is an unconventional way of administering a vector. Low pressure injection would
give a clearer insight into the efficiency of lentiviruses as vectors for HBV
treatment.
4 It is assumed that there is integration of the vector provirus into the mouse
genome, but the evidence for this (e.g. using Southern blot hybridisation) is not
provided.
5 The discussion of the drawbacks of using lentiviral vectors that express U6
shRNA cassettes for therapeutic application needs expansion. For example,
overexpression of hairpins from a U6 promoter within AAV vectors has been
shown to be toxic. Stable integration of similar cassettes, such as are used in this
study, potentially has profound undesirable effects.
6 Surely the lenti vectors deliver an expression cassette that produce shRNAs
and not siRNA. siRNAs are a product of Dicer processing of the hairpins.
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests.
assistant