Targeting mast cells and carboxypeptidase A in asthma

This collaboration project brings together the PI Sara Wernersson at SLU with the postdoctoral researcher Srinivas Akula from UU, in studying a potential target for new treatments and diagnosis methods for asthma in humans and horses.

Asthma is a chronic disease in both people and horses, leading to reduced health and affecting the quality of life and animal welfare. Uncontrolled asthma is a major concern and there is a need for new treatment strategies. In addition, there are different kinds of asthma and it would be very valuable to develop diagnosis methods that can distinguish the different types.

Mast cells originate from the bone marrow and are involved in allergic reactions where they release histamine and other substances that result in a local inflammation. Mast cells also store and release a group of enzymes called proteases but their role in allergies and asthma has not been fully clarified. However, new findings suggest that the proteases are involved in disease development in asthma.

“In my group we have studied the three types of mast cell proteases that might contribute to asthma. In this project we will focus on one of them, carboxypeptidase A3, or CPA3 in short. We know that it is expressed in mast cells in airways and our aim is to determine its function and role in asthma. This new knowledge could lead to the development of new or improved therapies,” says Sara Wernersson.

Microscope image of mast cells
  Mast cells                                                                                                              Photo: Sara Wernersson

Determining the function of CPA3

To perform functional analyses of CPA3 the researchers need enough quantities of the pure protein. This will be achieved by producing recombinant proteins of both human, mouse and horse versions of CPA3. This is one of Srinivas Akula task’s in the project.

“To have a functionally active protein it has to be produced in mammalian cells,” he explains. “During my PhD studies I used a human cell line to produce another type of protease. CPA3 is more difficult to produce and I hope my previous experience from gene cloning and protein production will become useful.”

“This is actually one of the main benefits of this collaboration,” Sara says, “Srinivas is an expert on both proteases and gene cloning and we didn’t have this kind of cloning experience in my group before. Without his involvement we would not have been able to do these experiments.”

The function of the recombinant proteins will be studied in lung tissues related to asthma. By adding active CPA3 or CPA inhibitors to the tissues response during airway contraction can be studied.

The role of mast cells in horse asthma

Photo of a horse
                        Photo: Lena Holm

In the other main part of the project the researchers will explore how mast cells are involved in equine asthma. To this end they will characterize the phenotype of mast cells in horses by a transcriptome analysis.

“We will obtain mast cells from horse lung lavages, purify RNA from the cells and send the RNA for sequencing. The analysis will give a good picture of which genes are active in horse mast cells and if there are differences in gene activity between normal and asthma conditions. For instance, it will be very interesting to see if CPA3 expression is linked to clinical features of horse asthma, as it is in humans,” Srinivas says.

Valuable possibility to collaborate

Sara and Srinivas agree on that their collaboration has been made possible by the U-Share funding. They knew of each other’s work before, through journal clubs within a research consortium focusing on mast cells, but hadn’t had any previous collaboration.

“The funding possibility was very valuable and came in at the right time. Now my group can take advantage of Srinivas’s experience in comparative immunology and biochemical tools, and the links with his previous lab at Uppsala University,” Sara says.

“For my part, I will learn new technologies and become familiar with models of asthma and clinical samples from human and equine patients. The project is also an opportunity to be part of a larger network of mast cell and asthma researchers, which will be positive for my future career,” Srinivas adds.

They also believe that the collaboration will be beneficial for the universities and that the possibility to combine animal and human studies in collaboration projects is very good.

“Several people I know have asked me how we did to apply. So it seems like more researchers will be engaged in this kind of collaboration following the new call,” Srinivas concludes.