biostudies-literatureVerschoor CPNIA NIH HHSNational Institutes of Health753767https://www.ebi.ac.uk/biostudies/studies/S-EPMC9015675biostudies-literatureUnknown2<h4>Background</h4>Influenza-specific cytolytic T lymphocytes (CTL) have a critical role in clearing the virus from the lungs, but are poorly stimulated by current inactivated influenza vaccines. Our previous work suggests that granzyme B (GrB) activity predicts protection against laboratory-confirmed influenza infection (LCII) in older adults. However, basal GrB (bGrB) activity increases with age and the frequency of GrB⁺ CTL that do not co-express perforin increases following influenza infection, thereby acting as a potential contributor to immune pathology.<h4>Objectives</h4>Using data from a 4-year randomized trial of standard- versus high-dose influenza vaccination, we sought to determine whether measurements of GrB activity alone indicate a protective vs. pathologic responFrontiers in agingGranzyme B: a double-edged sword in the response to influenza infection in vaccinated older adults.PMC9015675P30 AG067988R01 AG048023Verschoor CPHaynes LKuchel GAMcElhaney JEPawelec GLoeb MAndrew MKfalseGranzyme B: a double-edged sword in the response to influenza infection in vaccinated older adults.<h4>Background</h4>Influenza-specific cytolytic T lymphocytes (CTL) have a critical role in clearing the virus from the lungs, but are poorly stimulated by current inactivated influenza vaccines. Our previous work suggests that granzyme B (GrB) activity predicts protection against laboratory-confirmed influenza infection (LCII) in older adults. However, basal GrB (bGrB) activity increases with age and the frequency of GrB⁺ CTL that do not co-express perforin increases following influenza infection, thereby acting as a potential contributor to immune pathology.<h4>Objectives</h4>Using data from a 4-year randomized trial of standard- versus high-dose influenza vaccination, we sought to determine whether measurements of GrB activity alone indicate a protective vs. pathologic respon2021-01-01T00:00:00Z20212026-05-09T15:23:43.181Z2024-11-07T13:45:03.605ZS-EPMC90156753544115610.3389/fragi.2021.753767