D C Powers1. 1. Geriatric Research, Education and Clinical Center, St. Louis VAMC, Missouri.
Abstract
OBJECTIVE: To investigate whether influenza A-specific cytotoxic T lymphocyte (CTL) activity is reduced in elderly compared with younger adults. DESIGN: Case series comparing outcomes in young and elderly cohorts. SETTING: Saint Louis University Division of Geriatric Medicine. PARTICIPANTS: Healthy adult outpatients and staff members aged < 50 (young) or > or = 65 (elderly) years. METHODS: Peripheral blood mononuclear cells were assayed for CTL activity by a 51chromium release assay following 1 week of in vitro stimulation with influenza A/PR/8/34 (H1N1) virus. MEASUREMENTS: Percent specific lysis of autologous and allogeneic influenza virus-infected target cells. MAIN RESULTS: Specific lysis of autologous A/PR-infected targets was significantly lower in elderly compared to young subjects (P < 0.01), and exceeded 10% in a significantly lower proportion of elderly compared with younger subjects (P < 0.05), but was not influenced by a history of vaccination within the preceding 12 months. Cytotoxic effectors were class I human leukocyte antigen (HLA)-restricted and displayed heterosubtypic cross-reactivity but were unable to lyse influenza B-infected targets. CONCLUSIONS: These results demonstrate an age-related decline of influenza A virus-specific CTL activity and suggest that CTL responses to inactivated virus vaccine are of short duration.
OBJECTIVE: To investigate whether influenza A-specific cytotoxic T lymphocyte (CTL) activity is reduced in elderly compared with younger adults. DESIGN: Case series comparing outcomes in young and elderly cohorts. SETTING: Saint Louis University Division of Geriatric Medicine. PARTICIPANTS: Healthy adult outpatients and staff members aged < 50 (young) or > or = 65 (elderly) years. METHODS: Peripheral blood mononuclear cells were assayed for CTL activity by a 51chromium release assay following 1 week of in vitro stimulation with influenza A/PR/8/34 (H1N1) virus. MEASUREMENTS: Percent specific lysis of autologous and allogeneic influenza virus-infected target cells. MAIN RESULTS: Specific lysis of autologous A/PR-infected targets was significantly lower in elderly compared to young subjects (P < 0.01), and exceeded 10% in a significantly lower proportion of elderly compared with younger subjects (P < 0.05), but was not influenced by a history of vaccination within the preceding 12 months. Cytotoxic effectors were class I human leukocyte antigen (HLA)-restricted and displayed heterosubtypic cross-reactivity but were unable to lyse influenza B-infected targets. CONCLUSIONS: These results demonstrate an age-related decline of influenza A virus-specific CTL activity and suggest that CTL responses to inactivated virus vaccine are of short duration.
Authors: Innocent N Mbawuike; Robert L Atmar; Shital M Patel; David B Corry; Patricia L Winokur; Rebecca C Brady; Wilbur H Chen; Kathryn M Edwards; C Buddy Creech; Emmanuel B Walter; Sharon E Frey; Robert B Belshe; Johannes B Goll; Heather Hill; Wendy A Keitel Journal: Vaccine Date: 2015-12-04 Impact factor: 3.641