title: Decline in the production of interleukin-3 with age in mice.
abstract: Previously, we and others have found that the ability to produce interleukin-1 (IL-1) and interleukin-2 (IL-2) declines with age in mice. The purpose of this study was to determine the influence of age on the capacity of mice to produce interleukin-3 (IL-3). Splenic cells (5 X 10(6)/ml) from young (3-4 months) and old (24-32 months) C57BL/6 mice were first assessed for their IL-3-producing capacities in response to varying doses of concanavalin A (Con A; 2-20 micrograms/ml) in a time-dependent manner. The results showed that the production of IL-3 by both young and old C57BL/6 mice was maximal on Days 3 and 4 in response to 20 micrograms/ml of Con A, and that of IL-2 was minimal (activity was less than 0.1 unit) on Day 4. Consequently, Day 4, was selected to assess the effect of age on IL-3 production by splenic cells. The results showed a twofold reduction in IL-3 production with age (P less than 0.05). Young-old splenic cell mixture experiments at ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 indicated that the decrease in IL-3 production with age was not due to an increase in suppressor cell activity. Experiments based on mixtures of nylon wool-enriched splenic T-cell and adherent cells and on anti-MAC-1 plus complement-treated spleen cells indicated that (a) adherent cells are not required for T-cell production of IL-3, unlike IL-2 production, and (b) the decrease in IL-3 production with age is due solely to alteration in IL-3-producing T cells. Finally, a strong correlation was demonstrated between the production of IL-2 and IL-3 by spleen cells of individual young and old mice (r = 0.92, P less than 0.01). That production of both IL-2 and IL-3 is affected in a similar manner by age would suggest that a single class of helper T cells may be responsible for production of both lymphokines.
authors.affiliation: Geriatric Research, Education and Clinical Center, VA Medical Center, West Los Angeles, CA 90073.
authors.forename: M P
authors.initials: MP
authors.lastname: Chang
authors.forename: M
authors.initials: M
authors.lastname: Utsuyama
authors.forename: K
authors.initials: K
authors.lastname: Hirokawa
authors.forename: T
authors.initials: T
authors.lastname: Makinodan
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D002448:Cell Adhesion; D002478:Cells, Cultured; D005260:Female; D007376:Interleukin-2 / Q000096:biosynthesis; D007377:Interleukin-3 / Q000096:biosynthesis* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000502:physiology; D013491:Suppressor Factors, Immunologic / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology; D050378:T-Lymphocytes, Regulatory / Q000502:physiology
chemical_list: D007376:Interleukin-2; D007377:Interleukin-3; D013491:Suppressor Factors, Immunologic