New Antibody Reaches Kidney Cysts and Slows Polycystic Disease, UCSB Study Finds
Scientists at UC Santa Barbara have designed a new antibody that can enter kidney cysts and block the signals that drive polycystic kidney disease (PKD). The condition causes painful, fluid-filled cysts that grow over time. As a result, many people eventually need dialysis.
Current treatments offer limited benefits. Some drugs slow cyst growth but often cause side effects. In addition, most antibodies are too large to pass through the cell layers that form the cyst walls.
Why Traditional Antibodies Fall Short
PKD cysts grow because their lining cells release growth factors into the cyst. These signals bounce back onto the same cells and encourage constant expansion. However, standard IgG antibodies cannot reach the cyst interior. Therefore, they cannot block these signals where it matters most.
UC Santa Barbara researchers focused on dimeric immunoglobulin A (dIgA). This antibody naturally crosses epithelial layers in the body. It also appears in mucus, saliva, and tears. The team believed dIgA could cross into kidney cysts and reach the receptors that fuel cyst growth.
How the New Antibody Works
The scientists engineered an IgG antibody into a dIgA form by altering its DNA sequence. This created a smaller, more flexible structure. Tests in mouse models showed that the new antibody moved through the cyst wall and stayed inside.
The treatment blocked the cMET receptor, a major driver of cyst expansion. As a result, cyst-lining cells began to die off, while healthy kidney tissue remained untouched. Researchers reported no harmful side effects.
This work remains in the preclinical stage. However, the team plans to test additional growth factors and compare different targets. Future therapies may even combine several antibodies to achieve stronger results.
