The distribution of receptors for the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 in the developing human fetus

Interleukin-6 receptor oc (IL-6R) and interleukin-8 receptor (IL-8RB) are w idely expressed in adult human and murine tissues. Little is known about th e expression of these receptors and the function of their ligands in the de veloping human fetus. Objectives: To determine the tissue distribution and cellular expression of IL-6R and IL-8RB in the developing human fetus. Meth ods: Reverse transcription-PCR and immunohistochemical staining were perfor med on brain, spinal cord, eye, heart, lung, liver, spleen, adrenal, kidney , intestine, and placenta from fetuses of 8 and 16+/-2 weeks post-conceptio n. Results: IL-6R and IL-8RB mRNA were detected in all tissues tested at bo th time points. Immunoreactivity to anti-IL-6R antibody was present on neur ons, and in neuropil of the brain, as well as in bone marrow, bronchi, hepa tocytes, zona glomerulosa of the adrenal, glomerular cells in kidney, splee n, and placental trophoblasts. Cell-specific expression for IL-8RB in the c entral nervous system was localized to specific groups of neurons and astro cytes in the brain and spinal cord, including the neural retina. In somatic organs IL-8RB was detected in bone marrow, myocardiocytes, bronchiolar epi thelial cells, hepatocytes, cells of the zona glomerulosa and the zona fasc iculata of the adrenal, the collecting system of the kidney, enterocytes of the bowel and in placental cells. Conclusion: The widespread expression of these cytokine receptors suggests nonhematopoietic role for their ligand i n the developing fetus. (C) 2000 Elsevier Science Ireland Ltd. All rights r eserved.