%0 Journal Article
%T Interleukin-7 receptor blockade suppresses adaptive and innate inflammatory responses in experimental colitis
%A Willis Cynthia R
%A Seamons Audrey
%A Maxwell Joe
%A Treuting Piper M
%J Journal of Inflammation
%D 2012
%I BioMed Central
%R 10.1186/1476-9255-9-39
%X Background Interleukin-7 (IL-7) acts primarily on T cells to promote their differentiation, survival, and homeostasis. Under disease conditions, IL-7 mediates inflammation through several mechanisms and cell types. In humans, IL-7 and its receptor (IL-7R) are increased in diseases characterized by inflammation such as atherosclerosis, rheumatoid arthritis, psoriasis, multiple sclerosis, and inflammatory bowel disease. In mice, overexpression of IL-7 results in chronic colitis, and T-cell adoptive transfer studies suggest that memory T cells expressing high amounts of IL-7R drive colitis and are maintained and expanded with IL-7. The studies presented here were undertaken to better understand the contribution of IL-7R in inflammatory bowel disease in which colitis was induced with a bacterial trigger rather than with adoptive transfer. Methods We examined the contribution of IL-7R on inflammation and disease development in two models of experimental colitis: Helicobacter bilis (Hb)-induced colitis in immune-sufficient Mdr1a /  mice and in T- and B-cell-deficient Rag2 /  mice. We used pharmacological blockade of IL-7R to understand the mechanisms involved in IL-7R-mediated inflammatory bowel disease by analyzing immune cell profiles, circulating and colon proteins, and colon gene expression. Results Treatment of mice with an anti-IL-7R antibody was effective in reducing colitis in Hb-infected Mdr1a /  mice by reducing T-cell numbers as well as T-cell function. Down regulation of the innate immune response was also detected in Hb-infected Mdr1a /  mice treated with an anti-IL-7R antibody. In Rag2 /  mice where colitis was triggered by Hb-infection, treatment with an anti-IL-7R antibody controlled innate inflammatory responses by reducing macrophage and dendritic cell numbers and their activity. Conclusions Results from our studies showed that inhibition of IL-7R successfully ameliorated inflammation and disease development in Hb-infected mice by controlling the expansion of multiple leukocyte populations, as well as the activity of these immune cells. Our findings demonstrate an important function of IL-7R-driven immunity in experimental colitis and indicate that the therapeutic efficacy of IL-7R blockade involves affecting both adaptive and innate immunity.
%K IL-7R
%K Colitis
%K Mdr1a /  mice
%K Rag2 /  mice
%K Helicobacter bilis
%U http://www.journal-inflammation.com/content/9/1/39