Adults 65 years old and older have reduced numbers of functional memory T cells to respiratory syncytial virus fusion protein

Abstract

Respiratory syncytial virus (RSV) infects elderly (≥65 years) adults, causing medically attended illness and hospitalizations. While RSV neutralizing antibody levels correlate inversely with RSV-associated hospitalization in the elderly, the role of RSVspecific T cells in preventing disease in the elderly remains unclear. We examined RSV-specific humoral, mucosal, and cellular immune profiles in healthy elderly (65 to 85 years) and young (20 to 30 years) adults. RSV neutralization antibody titers in the elderly (10.5±2.2 log 2) and young (10.5±2.1 log2) were similar. In contrast, levels of RSV F protein-specific gamma interferon (IFN-γ)- producing T cells were lower in elderly (180±80 spot-forming cells [SFC]/106 peripheral blood mononuclear cells [PBMC]) than in young adults (1,250±420 SFC/106 PBMC). Higher levels of interleukin-13 (IL-13; 3,000±1,000 pg/ml) in cultured PBMC supernatants and lower frequency of RSV F-specific CD107a+ CD8+ T cells (3.0%±1.6% versus 5.0%±1.6%) were measured in PBMC from elderly than young adults. These results suggest that deficient RSV F-specific T cell responses contribute to susceptibility to severe RSV disease in elderly adults. Copyright © 2013, American Society for Microbiology. All Rights Reserved.