Analysis of the survival of mature human eosinophils: interleukin-5 prevents apoptosis in mature human eosinophils.
We and other groups have previously shown that interleukin-5 (IL-5) maintained the viability of mature eosinophils in an in vitro liquid culture system. Mature eosinophils did not proliferate but their survival was maintained in the presence of IL-5. Using this culture system, we investigated the mechanism of IL-5-mediated survival. In the absence of human IL-5 (hIL-5) mature eosinophils succumbed after 4 days, while in the presence of hIL-5 they survived up to 10 days. When DNA extracts of cultured eosinophils were analyzed on an agar gel electrophoresis, marked DNA fragmentation was observed in the absence of hIL-5, while no significant DNA fragmentation was observed in the culture with hIL-5 for 48 hours. The DNA fragmentation appeared as early as 6 to 12 hours after hIL-5 deprivation. Concomitantly, IL-5 stimulated total RNA and protein synthesis, but did not induce DNA synthesis in mature eosinophils. Because cycloheximide or actinomycin D impeded the protection of apoptosis by hIL-5, some new RNA and protein synthesis appeared to be required in this phenomena. These findings indicate that IL-5 maintains survival of mature eosinophils with induction of new RNA and protein synthesis, thus leading to the inhibition of apoptosis.
Yamaguchi
Y
Y
Department of Medical Biology and Parasitology, Jichi Medical School, Tochigi-ken, Japan.
Suda
T
T
Ohta
S
S
Tominaga
K
K
Miura
Y
Y
Kasahara
T
T
D016923:Cell Death / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects / Q000302:isolation & purification; D003609:Dactinomycin / Q000494:pharmacology; D004804:Eosinophils / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D015848:Interleukin-5 / Q000494:pharmacology*; D007700:Kinetics; D012313:RNA / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology
D016207:Cytokines; D007376:Interleukin-2; D007377:Interleukin-3; D015848:Interleukin-5; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D003609:Dactinomycin; D012313:RNA; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D004247:DNA; D003513:Cycloheximide