IGF1 Receptor Expression by Canine Immune Cells

Michelangella working in lab


Engineering and Applied Sciences


Project Summary

There has been importance of companion dogs  in studies of the immune system and cancer treatments has grown over the years. They have a similar immune system to humans and are susceptible to similar diseases humans experience. These similarities enable dogs to serve as a model for understanding humans as well. Dogs are a genetically diverse species that display an incredibly large and unique intra-species size variation. These size differences in breeds have been linked to their different levels of IGF1 expression. IGF1 stands for insulin like growth factor and it is a protein that plays a role in the growth of an organism. It is believed that the larger the dog, the more expression of IGF1. Interestingly IGF1 may affect immune activity and could be one of the reasons that large dogs are more susceptible to cancer. The goal of this project was to begin to test the hypothesis that IGF1 enhances the suppressive activities of particular myeloid and lymphoid cell subsets. We first needed to determine which dog white blood cells (if any) expressed the receptor for IGF1.

Using flow cytometry my colleagues and I discovered that several cell types express the receptor. Myeloid cells seem to have the highest percentages of IGFR1+ cell. Further research completed by my colleagues found that, intriguingly, almost all PMN-MDSCs (a suppressor population) express IGF1R, supporting our hypothesis that they may be regulated by IGF.

Looking forward we would like to test what IGF1 does to the identified cell types. We would like to determine if the addition of IGF1 will induce the activity of suppressor cells in the immune system. Hence, inhibiting the ability of large dogs to defend themselves against cancer.

Through my research experience, I learned about immunology and signaling biology. I also became aware of many nuances within the canine immune system as well as the different types and functions of white blood cells. Furthermore, I learned how to use the FACSCalibur machine, a flow cytometer that aids with cell counting and sorting. Finally, I was able to learn and use the FlowJo software to analyze and interpret the data that we collected.

This research has been beneficial to my educational experience because I expanded my knowledge within immunology. Prior to this research, I had minimal exposure to this subject and only knew the basics. It also enabled me to critically think about designing detailed  laboratory procedures that involved leukocyte isolations, red blood cell lysis, and antibody staining.