Role of IL-5 in IL-2-induced eosinophilia. In vivo and in vitro expression of IL-5 mRNA by IL-2.
We recently demonstrated in vivo that IL-5 was an important mediator of eosinophilia in mice with parasite infections. In this study, we examined whether or not IL-5 was actually responsible for the eosinophilia induced by injection of human rIL-2. Mice administered hIL-2 developed eosinophilia during the course of the series of injections. This eosinophilia could be suppressed by a single injection of mAb against murine IL-5. The number of eosinophilic precursors increased more in the spleen cells of the IL-2-treated mice in comparison to the control mice, although in bone marrow precursors showed little change. Similarly, the number of granulocytic precursors increased markedly in the spleen cells of IL-2-treated mice. In vitro polymerase chain reaction amplification of cDNA subfragments corresponding to IL-5 mRNA (reverse transcription-polymerase chain reaction), followed by Southern blot analysis, revealed enhancement of IL-5 mRNA expression in spleen cells 3 days after starting the human IL-2 injections. We also observed enhanced murine IL-5 mRNA expression in spleen cells stimulated with IL-2 in vitro. The level of murine IL-5 mRNA expression by IL-2-stimulated spleen cells from normal mice increased at 24 h, reached a plateau after 48 h, and decreased again within 72 h of starting culture. These results indicate that the eosinophilia induced by IL-2 in vivo is presumably mediated by IL-5 released from IL-2-stimulated lymphocytes.
Yamaguchi
Y
Y
Department of Medical Biology and Parasitology, Jichi Medical School, Tochigi-Ken, Japan.
Suda
T
T
Shiozaki
H
H
Miura
Y
Y
Hitoshi
Y
Y
Tominaga
A
A
Takatsu
K
K
Kasahara
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D004802:Eosinophilia / Q000209:etiology*; D005260:Female; D006412:Hematopoietic Stem Cells / Q000187:drug effects; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000009:adverse effects / Q000494:pharmacology*; D015848:Interleukin-5 / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D015848:Interleukin-5; D012333:RNA, Messenger; D011994:Recombinant Proteins