Granzyme B ELISPOT assay to measure influenza-specific cellular immunity.
The immunogenicity and efficacy of influenza vaccination are markedly lower in the elderly. Granzyme B (GrzB), quantified in fresh cell lysates, has been suggested to be a marker of cytotoxic T lymphocyte (CTL) response and a predictor of influenza illness among vaccinated older individuals. We have developed an influenza-specific GrzB ELISPOT assay using cryopreserved PBMCs. This method was tested on 106 healthy older subjects (ages 50-74) at baseline (Day 0) and three additional time points post-vaccination (Day 3, Day 28, Day 75) with influenza A/H1N1-containing vaccine. No significant difference was seen in GrzB response between any of the time points, although influenza-specific GrzB response appears to be elevated at all post-vaccination time points. There was no correlation between GrzB response and hemagglutination inhibition (HAI) titers, indicating no relationship between the cytolytic activity and humoral antibody levels in this cohort. Additionally, a significant negative correlation between GrzB response and age was observed. These results reveal a reduction in influenza-specific GrzB response as one ages. In conclusion, we have developed and optimized an influenza-specific ELISPOT assay for use with frozen cells to quantify the CTL-specific serine protease GrzB, as a measure of cellular immunity after influenza vaccination.
Mayo Vaccine Research Group, USA.
Hannah M
HM
Salk
Iana H
IH
Haralambieva
Inna G
IG
Ovsyannikova
Krista M
KM
Goergen
Gregory A
GA
Poland
D000367:Age Factors; D000368:Aged; D058501:Enzyme-Linked Immunospot Assay / Q000379:methods*; D005260:Female; D053804:Granzymes / Q000097:blood / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects*; D009980:Influenza A virus / Q000276:immunology / Q000378:metabolism; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007251:Influenza, Human; D008297:Male; D008875:Middle Aged
D007252:Influenza Vaccines; C509213:GZMB protein, human; D053804:Granzymes
Cellular; Cellular immunity; Cytotoxic; Cytotoxic T lymphocytes (CTL); ELISPOT; Enzyme-linked immunospot assay; Granzyme B; Granzymes; Human; Immunity; Influenza; Influenza virus; Killer cells; Natural; Perforin; T-lymphocytes; Viruses