Review for 10.1186/s12876-017-0600-2 (2017)

Reviewer ’s report  
 
Title: Impaired Liver Regeneration is associated with Reduced Cyclin B1 in Natural Killer T 
cell-deficient mice  
 
Version: 0 Date: 21 Dec 2016  
 
Reviewer: Stefano Di Biase  
 
Reviewer's report:  
 
Overall the study is interesting but there are some in congruences of crucial importance that need 
to be corrected. In the introduction and throughout the article, the authors refer to the importance 
of type I NKT cells (aka iNKT) in liver regeneration in the animal model used. However, they 
fail to induce a s pecific type I NKT cells depletion in both the in vivo models used. After 
suggesting the involvement of type I NKT cells in the "results" section, the authors do not 
mention this population at all in the Discussion. Moreover, in the "discussion" section, t he 
authors relate their results to the ones of others obtained by depleting the NK1.1 population 
which is definitely not a type I NKT cell marker. Type I and II NKT cells are populations with 
very different properties, the authors should be careful when at tributing a specific function to one 
of the two without having enough evidence. Maybe the authors could focus the paper more on 
NKT rather than narrowing dawn to type I NKTs? Without the use of a more type I NKT -
specific mouse model, the only conclusion of  this study is NKT cells could be involved in 
impaired liver regeneration.  
 
Specific points:  
1) CD1d -/- mice have an overall NKT cell depletion. In order to test the role of type I NKT 
cells, the authors should use a more appropriate mouse model deficien t in V14 NKT cells.   
2) As described in point 1, CD1d antibody will deplete both NKT type I and type II 
populations (two populations with very different properties). The authors are encouraged to 
use a more specific model of depletion or to tone down the statements regarding the role of 
type I NKT cells. Moreover, the efficacy of the depletion should be demonstrated with 
FACS.  
3) In the discussion section (page 11 lines 35 -56) the authors mention the importance of time -
dependent depletion and repopulation of the liver with NKT cells. It is crucial to show 
FACS analysis to demonstrate depletion, activation, and repopulation of the liver with NKT 
cells.   
4) In the graphs in figures 1, 4, and 5, it is hard to see which groups are being compared. I 
would sugge st to place the compared groups next to each other or to use a statistical 
bracket/bar connecting the groups that are being compared.  
5) In formal writing, "cannot" should always be used as opposed to the more colloquial 
contracted form "Can't" (page 12 l ines 23 and 24).  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required  in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five yea rs received reimbursements, fees, funding, or salary from an  
organisation that may in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, fundin g, or salary from an organization that 
holds  or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If yo u can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
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