Abstract
We thank you for the opportunity to respond to the letter regarding our manuscript entitled “CD204-Expressing Tumor-Associated Macrophages Are Associated with Malignant, High-Grade and Hormone Receptor-Negative Canine Mammary Gland Tumors” received from Dr. Sara Belluco.
Based on a recent article, 2 which studied different properties of macrophage polarization between canines and humans, the author suggests providing evidence to support CD204 as a marker of M2 macrophage in dog. Therefore, we would like to introduce the recent article 1 “Combined Administration of ASCs and BMP-12 Promotes an M2 Macrophage Phenotype and Enhances Tendon Healing.” In this article, the authors performed an in vivo study of the effect of promoting M2 macrophages on subsequent healing of tendon in dogs. In this study, CD204 was used as a marker in confirming the increase of M2 macrophages in response to adipose-derived mesenchymal stromal cell (ASC) application in dogs, and an anti-inflammatory response was also confirmed by assessment of gene and protein expression. 1 Although this research did not investigate the process of canine macrophage polarization in vitro, we thought that the above research could serve as a basis for our inference.
There is a still considerable lack of knowledge of macrophage polarization in dogs. Although the above-mentioned study 2 shows the evidence that M1 and M2 macrophages are considered to exist in dogs, the authors said that further validating experiments are needed to be verified on the protein levels and in vitro data on macrophage polarization cannot be simply adapted to in vivo situations. 2 Therefore, we agree that further studies should be conducted to investigate the polarization of canine macrophage, and we hope that our study provides some impetus for research in this area.