Aging exacerbates restraint stress-induced inhibition of antigen-specific antibody production in mice.
BACKGROUND
We have recently found that exposure to acute restraint stress suppresses antigen-specific antibody production, including IgE, in a murine model of allergic rhinitis. Although age-related alterations in immune responses are known, it remains unclear whether aging modulates the antibody production under stressful conditions. In this study, we set out to determine the effects of aging on antibody production under acute restraint stress in mice.


METHODS
Both young and aged CBA/J mice were repeatedly sensitized intranasally with phospholipase A2 (PLA2) without adjuvants. Restraint stress was applied using uniform cylinders once a week for a continuous 8h period, on 5 occasions in total. Blood samples were taken at 0, 20 and 30 days after primary sensitization, and production of PLA2-specific antibodies and levels of IL-4, IFN-gamma, IL-10 and IL-1 beta in sera were determined by ELISA.


RESULTS
Repeated intranasal sensitization with PLA2 induced PLA2-specific IgE, IgG1 and IgG2a production in aged mice. We found that exposure to restraint stress significantly inhibited production of PLA2-specific IgE, IgG1 and IgG2a in aged mice. In addition, antibody production under restraint stress decreased significantly in aged mice when compared with young mice. No IL-4, IFN-gamma, IL-10 or IL-1 beta were detected in sera from non-stressed or stressed aged mice.


CONCLUSIONS
Aging exacerbates the immunosuppressive role of acute restraint stress in antigen-specific antibody production in mice.
Ichihara
Yumiko
Y
Hygiene and Public Health, Social Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan.
Okano
Mitsuhiro
M
Nishioka
Keiko
K
Manabe
Noriko
N
Ichihara
Naoto
N
Jitsunari
Fumihiko
F
Fujiwara
Tazuko
T
Nishizaki
Kazunori
K
D000375:Aging / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D016207:Cytokines / Q000097:blood; D005260:Female; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D051379:Mice; D008808:Mice, Inbred CBA; D054467:Phospholipases A2 / Q000276:immunology*; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000276:immunology*
D016207:Cytokines; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E; D054467:Phospholipases A2