Toll-Like Receptor and Cytokine Expression Patterns of CD56+ T Cells Are Similar to Natural Killer Cells in Response to Infection with Venezuelan Equine Encephalitis Virus Replicons

• Published in: The Journal of infectious diseases 2003-11, Vol.188 (10), p.1562-1570
• Main Authors: Saikh, Kamal U., Lee, John S., Kissner, Teri L., Dyas, Beverly, Ulrich, Robert G.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; CD56 Antigen - immunology; Cricetinae; Cytokines; Cytokines - biosynthesis; Cytokines - genetics; Cytokines - immunology; Encephalitis Virus, Venezuelan Equine - genetics; Encephalitis Virus, Venezuelan Equine - immunology; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Humans; Infections; Infectious diseases; Kidney cells; Killer Cells, Natural - immunology; Killer Cells, Natural - metabolism; Killer Cells, Natural - virology; Medical sciences; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - genetics; Membrane Glycoproteins - immunology; Microbiology; Miscellaneous; Natural killer cells; Natural killer T cells; Receptors, Cell Surface - biosynthesis; Receptors, Cell Surface - genetics; Receptors, Cell Surface - immunology; Replicon; Replicon - immunology; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA - chemistry; RNA - genetics; RNA, Double-Stranded - immunology; T lymphocytes; T-Lymphocytes - immunology; T-Lymphocytes - metabolism; T-Lymphocytes - virology; Toll-Like Receptor 2; Toll-Like Receptor 3; Toll-Like Receptor 4; Toll-Like Receptors; Venezuelan equine encephalomyelitis; Virology; Viruses
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/379196

Using the natural killer (NK) cell-surface marker CD56 to study NK T cells in peripheral blood, we found that their frequency in mononuclear cells among healthy individuals was 1%–20% (average, 7.3%) and sporadically increased 4–5-fold within individuals over the course of 8 months. Infection of mononuclear cells in vitro with Venezuelan equine encephalitis virus replicon particles (VRPs) resulted in a significant increase in CD56+ T cells and in the expression of interferon-α, tumor necrosis factor (TNF)–α, and interferon-γ by CD56+ but not CD56− T cells. NK and CD56+ T cells expressed higher levels of Toll-like receptor (TLR)–3 and TLR4 after infection with VRPs, whereas only NK cells expressed inducible TNF-α and TLR2. Most of these effects were duplicated by activating mononuclear cells with double-stranded RNA. These expression patterns indicate that T cells coexpressing NK markers respond like NK cells to viral infection or double-stranded RNA, potentially fulfilling innate and adaptive immune functions