Water Channel Blockers Impair Immune Cell Movement, Revealing New Inflammation Targets

This study reveals how water channels in immune cells could become new targets for treating inflammatory diseases. Aquaporins (AQPs) are membrane proteins that allow rapid water movement across cell membranes, enabling the shape changes necessary for cell migration.

Researchers examined AQP3 and AQP9 expression in human white blood cells and tested how blocking these channels affects immune function. Using specific inhibitors, they studied bacterial phagocytosis and cell migration in response to lipopolysaccharide (LPS), a bacterial toxin that triggers inflammation.

The key finding was that blocking these water channels significantly impaired immune cell migration without affecting their ability to engulf and kill bacteria. AQP9 inhibition reduced migration in both neutrophils and peripheral blood mononuclear cells, while AQP3 blocking only affected mononuclear cell movement during LPS-induced inflammation. Interestingly, bacterial killing remained intact even when both channels were blocked simultaneously.

These results suggest that AQP3 and AQP9 play distinct but critical roles in immune cell motility. Since excessive immune cell migration contributes to tissue damage in sepsis and other inflammatory conditions, selectively blocking these channels could provide therapeutic benefits by reducing harmful inflammation while preserving essential antimicrobial functions.

The findings build on previous research showing that AQP deletion or blocking improves survival in animal models of sepsis, supporting the potential for developing AQP-targeted therapies for inflammatory diseases.