Most mucosal surfaces that interface with the outside world, such as the surface of the eyes, lungs, and GI tract are “wet.” The liquids that line these outward-facing organs are critical for innate defense and overall organ health. These liquids typically contain thousands of proteins including antimicrobial proteins/peptides, mucins, protease inhibitors, and antioxidants. For example, short palate and nasal epithelial clone 1 (SPLUNC1) is a secreted protein that is highly abundant in the lung lining fluid that can regulate fluid homeostasis and inflammation. Abnormal surface liquids are associated with several diseases. For example, in cystic fibrosis, the lung’s lining fluid becomes dehydrated and its protein composition dramatically changes. While the function of some proteins in the lung is well-known, many have not been studied. Moreover, most biological fluids also contain a significant number of peptides, which may be formed from the breakdown of proteins or by direct synthesis.

Eldec’s approach is to look for naturally occurring peptides and then screen them for biological activity against targets of interest. For example, we have identified the lung’s peptidome and have used this as the initial basis of our drug discovery efforts. As shown below, we have identified a number of peptides in the lung that can affect inflammation or cell growth. Using this approach, we have also discovered novel antiviral peptides. The advantage of using naturally occurring peptides as our scaffolds is that they are more likely to be well-tolerated in humans and non-immunogenic.