[HTML][HTML] The islet-resident macrophage is in an inflammatory state and senses microbial products in blood

ST Ferris, PN Zakharov, X Wan, B Calderon… - Journal of Experimental …, 2017 - rupress.org
ST Ferris, PN Zakharov, X Wan, B Calderon, MN Artyomov, ER Unanue, JA Carrero
Journal of Experimental Medicine, 2017rupress.org
We examined the transcriptional profiles of macrophages that reside in the islets of
Langerhans of 3-wk-old non-obese diabetic (NOD), NOD. Rag1−/−, and B6. g7 mice. Islet
macrophages expressed an activation signature with high expression of Tnf, Il1b, and MHC-
II at both the transcript and protein levels. These features are common with barrier
macrophages of the lung and gastrointestinal tract. Moreover, injection of lipopolysaccharide
induced rapid inflammatory gene expression, indicating that blood stimulants are accessible …
We examined the transcriptional profiles of macrophages that reside in the islets of Langerhans of 3-wk-old non-obese diabetic (NOD), NOD. Rag1−/−, and B6. g7 mice. Islet macrophages expressed an activation signature with high expression of Tnf, Il1b, and MHC-II at both the transcript and protein levels. These features are common with barrier macrophages of the lung and gastrointestinal tract. Moreover, injection of lipopolysaccharide induced rapid inflammatory gene expression, indicating that blood stimulants are accessible to the macrophages and that these macrophages can sense them. In NOD mice, the autoimmune process imparted an increased inflammatory signature, including elevated expression of chemokines and chemokine receptors and an oxidative response. The elevated inflammatory signature indicates that the autoimmune program was active at the time of weaning. Thus, the macrophages of the islets of Langerhans are poised to mount an immune response even at steady state, while the presence of the adaptive immune system elevates their activation state.
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