Interleukin-13 secreting macrophages improve functional recovery after spinal cord injury by exerting M2 effects and secreting interleukin-13

Abstract

Spinal cord injury (SCI) is a severe condition that has an enormous impact on society. In Europe, approximately 250 people per million inhabitants suffer from SCI. No effective therapy is available for these patients and current treatment options merely focus on symptom relieve. One of the main hallmarks of SCI is the chronic neuroinflammation, contributing to immune-related neural damage and limiting spinal cord repair. The key players involved in this inflammatory event are macrophages, being extensively present within the lesion epicenter. These macrophages are mainly present in a pro-inflammatory state. This will consequently aggravate neuroinflammation and prevent initial repair processes. Multiple studies show that shifting these macrophages towards an anti-inflammatory state, ameliorates the condition. Moreover, interleukin-13 (IL-13), an M2 macrophage-related cytokine, protects neurons and stimulates neural repair. Within this research, we combine the positive effects of both M2 macrophages and IL-13 by creating IL-13 secreting macrophages. Accordingly, it was hypothesized that IL-13 secreting macrophages improve functional recovery after SCI by locally exerting M2 functions and secreting IL-13.