Purified interleukin 5 supports the terminal differentiation and proliferation of murine eosinophilic precursors.

Abstract

Using a clonal culture system, we investigated the hemopoietic effects of purified recombinant IL-5 obtained from conditioned media of transfected Xenopus oocytes. IL-5 alone acted on untreated bone marrow cells and supported the formation of a small number of colonies, all of which were predominantly eosinophilic. However, it did not support colony formation by spleen cells from 5-FU-treated mice, in which only primitive stem cells had survived, while IL-3 and G-CSF did. Eosinophil-containing colonies were formed from these cells in the presence of IL-5 and G-CSF together. In contrast, G-CSF alone did not support any eosinophil colonies. The eosinophilopoietic effect of IL-5 was dose-dependent, and was neutralized specifically by anti-IL-5 antibody. To exclude the possibility of interactions with accessory cells in the same culture dish, we replated a small number (200 cells/dish) of enriched hemopoietic progenitors, obtained from blast cell colonies, which were formed by cultivation of spleen cells from 5-FU-treated mice in the presence of IL-3 or G-CSF. From these replated blast cells, eosinophil colonies were induced in dishes containing IL-5 but not in those containing G-CSF alone. From these findings, it was concluded that IL-5 did not act on primitive hemopoietic cells, but on blast cells induced by IL-3 or G-CSF. IL-5 specifically facilitated the terminal differentiation and proliferation of eosinophils. In this respect, the role of IL-5 in eosinophilopoiesis seems to be analogous to erythropoietin, which promotes the terminal differentiation and amplification of erythroid cells. Moreover, IL-5 maintained the viability of mature eosinophils obtained from peritoneal exudate cells of the mice infected with parasites, indicating mature functional eosinophils carried IL-5 receptors. The synergistic effects of IL-5 and colony-stimulating factors on the expansion of eosinophils is supposed to contribute to the urgent mobilization of eosinophils at the time of helminthic infections and allergic responses.

Eosinophilia is attenuated in experimental colitis induced in IL-5 deficient mice

“…7 In addition, IL-5 stimulates the production of eosinophils in cultures of human bone marrow, 8 acts as a chemo-attractant for mature murine eosinophils and induces superoxide anion production. 9 Much less however is known about the activity of IL-5 in vivo. This paper explores the role of this cytokine in the DSS-induced mouse model of acute ulcerative colitis.…”

Vaccine-Induced Immunity againstHelicobacter pyloriInfection Is Impaired in IL-18-Deficient Mice

“…In any case, eosinophilic cells may contribute to protection (67,68). However, it should be remembered that another cytokine, IL-5, is better known to play a key regulatory role for eosinophilic cells (31)(32)(33)69). Thus, in H. pylori infection, IL-5 might be even more critical than IL-18 for the tissue eosinophilia.…”

IL-5 links adaptive and natural immunity specific for epitopes of oxidized LDL and protects from atherosclerosis

“…IL-5 is mainly produced by Th2 cells and mast cells. As an eosinophil differentiation and maturation factor (40,41), it is widely studied for its role in asthma and allergies, as well as in host defense from intestinal parasites. Interestingly, patients with asthma have been reported to have decreased atherosclerotic disease (42).…”