Altered phenotype and functionality of varicella zoster virus-specific cellular immunity in individuals with active infection

Abstract

Background Varicella zoster virus (VZV) establishes lifelong persistence and may reactivate in individuals with impaired immune function. To investigate immunologic correlates of protection and VZV reactivation, we characterized specific immunity in 207 nonsymptomatic immunocompetent and 132 immunocompromised individuals in comparison with patients with acute herpes zoster. Methods VZV-specific CD4 T cells were quantified flow cytometrically after stimulation and characterized for expression of interferon-γ, interleukin 2, and tumor necrosis factor α and surface markers for differentiation (CD127) and anergy (cytotoxic T lymphocyte antigen 4 [CTLA-4] and programmed death [PD]-1). Immunoglobulin G and A levels were quantified using an enzyme-linked immunosorbent assay. Results In healthy individuals, VZV-specific antibody and T-cell levels were age dependent, with the highest median VZV-specific CD4 T-cell frequencies of 0.108% (interquartile range, 0.121%) during adolescence. VZV-specific T-cell profiles were multifunctional with predominant expression of all 3 cytokines, CD127 positivity, and low expression of CTLA-4 and PD-1. Nonsymptomatic immunocompromised patients had similar VZV-specific immunologic properties except for lower T-cell frequencies (P