Review Reports

Round 1

Reviewer 1 Report

The authors of this article investigated the expression of  G protein receptor15(GPR15) and of its natural ligand GPR15L  in immune cells of patients with Graves'disease. They found an increased expression in peripheral blood and in thyroid tissue of these patients with respect to healthy controls. Moreover, flow cytometry analysis revealed that GPR15 were over-expressed in  a variety  of cells known to be  able in triggering  inflammatory/immune processes, being also positively correlate toTfh-specific cytokines of IL 21 and IL4. They conclude  affirming that  their results indicate that GPR15-GPR15L  complex is associated with the activation and infiltration of proinflammatory immune cells in thyroid tissue of Graves' patients; thus blocking  this effect could be a potential treatment of this disease.

COMMENT

 GPR15 and its natural ligand GPR15L have been previously demonstrated in tissues of several organs, especially when affected by autoimmune/inflammatory diseases, but, their role in autoimmune thyroid diseases had not been explored to date.                                                                 This is an interesting paper which contributes at clarifying the possible physiopathological role of GPR15-GPR15L in favoring the development of Graves' disease,   However I have some concerns:                                           - It should be better clarified whether the overexpression of GPR15-GPR15L complex at thyroid level may be specific to Graves diseases or it  is also involved  in the other autoimmune/inflammatory thyroid disesaes. To clarify these aspects it should be useful to investigate the expression of this complex in patients with Hashimoto thyroiditis or with subacute thyroiditis .        - A recent paper demonstrated that GPR15L is a  pruritogen factor          ( Tseng and Horn. GPR15L is an epithelial inflammatio-derived pruritogen. Sci Adv 2022).  It should be interesting to ascertain whether the  patients enrolled in this study  showed overexpression of GPR15L also in their  localized dermopathy lesions and if they suffered from itching.                                              - References 4 and 23 in Bibliography. It is not necessary to add to the title of the Journal(Thyroid), the sentence; official journal of the American Thyroid Association. Please delete.

 

 

 

 

 

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Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript about the elevated expression of GPR15 in immune cells in GD is interesting and offers some new insights towards the relation of GPR15 to GD.

However, I strongly suggest, that findings need to be confirmed within an independent set of samples before publication. This is even more important, because authors stated, that no other study has identified this type of association. 

Besides that, I would like to recommend to adjust the statistical analysis. In addition to simple comparisons between GD patients and controls, authors should apply a linear model, that also considers co-variables such as age, gender and other parameters measure in GD patients and controls.

 

Minor points:

1. line 52: GPR15+T cells ? Shouldn't it be GPR15+ Tcells?

2. line 57: the term AITD has not been explained.

3. line 135: subsets - how did the authors define subsets or create subsets? 

4. in general: the numbering/order of the figures is somehow confusing, i.e. Figure 1D is names before Figure 1C.

5. The method and detection of differences for flow cytometry experimental data have to be explained in more detail. It is not clear to the reader, how differences in Figures i.e. 1D and 2A have been detected and statistically evaluated.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I believe that the paper has been improved following the lines suggested by the reviewers and may now be reconsidered for publication on Biomolecules

Author Response

We would sincerely like to thank the reviewer for the encouraging comments on our manuscript.

Reviewer 2 Report

The figures have not reordered in a proper way. An it is still not clear, how different groups can be distinguished in the flow cytometric plots (i.e. Figure 1 C). 

The statistical analysis has also not been changed. It is only a simple comparison of groups without multivariate model application.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf