A Spatial Examination of Cytokines Along the Gastrointestinal Tract

Abstract

We have come to know that the gut microbiome influences the education of the innate immune system; however, how this education occurs at the molecular level is poorly understood. Previous work by the Brooks Lab has elucidated the role of cytokines in the regulation of key AMPs in the mammalian gut. Here I seek to delineate a spatial profile for several cytokines, IL-4, IL-13, IL-22, and IL-23 and their patterning with respect to the expression profiles of the AMPs they have been shown to regulate. My findings reveal that IL-13 and Retnlb expression are paired across the murine gut and demonstrate elevated levels in colon. Interestingly, IL-4 does not exhibit any patterning with IL-13 or Retnlb. I also showed that IL-23 and IL-22 levels were paired across the length of the gut. Despite previous works demonstrating that the IL-23/IL-22 axis responsible for inducing REG3G, I demonstrate that in healthy mice the IL-22 spatial patterning is decoupled from that of REG3G because baseline levels of IL-22 are not sufficient. However, further work is required to fully determine if these findings are real.