Back to Search
Start Over
Predominance of heterosubtypic IFN-γ-only-secreting effector memory T cells in pandemic H1N1 naive adults
- Publication Year :
- 2012
-
Abstract
- The 2009/10 pandemic (pH1N1) highlighted the need for vaccines conferring heterosubtypic immunity against antigenically shifted influenza strains. Although cross-reactive T cells are strong candidates for mediating heterosubtypic immunity, little is known about the population-level prevalence, frequency, and cytokine-secretion profile of heterosubtypic T cells to pH1N1. To assess this, pH1N1 sero-negative adults were recruited. Single-cell IFN-γ and IL-2 cytokine-secretion profiles to internal proteins of pH1N1 or live virus were enumerated and characterised. Heterosubtypic T cells recognising pH1N1 core proteins were widely prevalent, being detected in 90% (30 of 33) of pH1N1-naïve individuals. Although the last exposure to influenza was greater than 6 months ago, the frequency and proportion of the IFN-γ-only-secreting T-cell subset was significantly higher than the IL-2-only-secreting subset. CD8(+) IFN-γ-only-secreting heterosubtypic T cells were predominantly CCR7(-) CD45RA(-) effector-memory phenotype, expressing the tissue-homing receptor CXCR3 and degranulation marker CD107. Receipt of the 2008-09 influenza vaccine did not alter the frequency of these heterosubtypic T cells, highlighting the inability of current vaccines to maintain this heterosubtypic T-cell pool. The surprisingly high prevalence of pre-existing circulating pH1N1-specific CD8(+) IFN-γ-only-secreting effector memory T cells with cytotoxic and lung-homing potential in pH1N1-seronegative adults may partly explain the low case fatality rate despite high rates of infection of the pandemic in young adults.
- Subjects :
- Adult
Adolescent
CD8-Positive T-Lymphocytes
Cross Reactions
Hemagglutination Inhibition Tests
Middle Aged
Antibodies, Viral
Flow Cytometry
Article
Cohort Studies
Interferon-gamma
Young Adult
Influenza A Virus, H1N1 Subtype
Influenza, Human
Leukocytes, Mononuclear
Prevalence
Humans
Interleukin-2
Immunologic Memory
Pandemics
Aged
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.pmid..........b08c77b4203b55885570323b0147b620