Granzyme B ELISPOT assay to measure influenza-specific cellular immunity.

Abstract

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.

• Authors: Hannah M Salk, Iana H Haralambieva, Inna G Ovsyannikova, Krista M Goergen, Gregory A Poland
• Journal: Journal of immunological methods (J Immunol Methods) Vol. 398-399 Pg. 44-50 (Dec 15 2013) ISSN: 1872-7905 [Electronic] Netherlands
• PMID: 24055591 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: © 2013.

Chemical References

• Influenza Vaccines
• GZMB protein, human
• Granzymes

Topics

• Age Factors
• Aged
• Enzyme-Linked Immunospot Assay (methods)
• Female
• Granzymes (blood, immunology)
• Humans
• Immunity, Cellular (drug effects)
• Influenza A virus (immunology, metabolism)
• Influenza Vaccines (administration & dosage, immunology)
• Influenza, Human
• Male
• Middle Aged