Regulation of cytokine production in aging: use of recombinant cytokines to upregulate mitogen-stimulated spleen cells.
We investigated the production of IL-2 and IFN-gamma (Th1 type) and IL-4 (Th2 type) cytokines by mitogen-activated spleen cells from young, adult and old mice. Cytokine production was evaluated in culture supernatants by CTLL proliferation (IL-2), ELISA (IFN-gamma), CT4.S proliferation (IL-4) and in mRNA extracted from activated CD4+ cells by RT-PCR (IL-2, IFN-gamma and IL-4). Results show that the production of IL-2, as protein and mRNA, is profoundly depressed by aging, whereas that of IFN-gamma, as protein and mRNA, firstly declines and then increases with age. The production of IL-4, as protein, monotonically declines with aging whereas, as mRNA, firstly decreases and then increases above the level in young mice. Spleen cells in culture were also incubated with mitogens and with a recombinant cytokine (IL-1 beta, IL-2, IL-3, IL-4, IL-12 or IFN-gamma) at various concentrations. It was found that recombinant cytokines by and large enhance cytokine production when the level induced by mitogens only is low. This conclusion applies to IL-2 and IFN-gamma production as protein and mRNA. The addition of recombinant cytokines also increases the production of IL-4 at the protein level in spleen cells from old mice but, at the mRNA level, only in spleen cells from young mice. This finding suggests age-related changes in IL-4-specific mRNA transcription rate and post-transcriptional half-life as well as translation kinetics.
Frasca
D
D
Laboratory of Immunology, AMB-PRO-TOSS, ENEA CR Casaccia, Rome, Italy. frasca@casaccia.enea.it
Pucci
S
S
Goso
C
C
Barattini
P
P
Barile
S
S
Pioli
C
C
Doria
G
G
D000375:Aging / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis* / Q000494:pharmacology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014158:Transcription, Genetic
D016207:Cytokines; D007376:Interleukin-2; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015847:Interleukin-4; D007371:Interferon-gamma