CD25 ⁺ Natural Regulatory T Cells Are Critical in Limiting Innate and Adaptive Immunity and Resolving Disease following Respiratory Syncytial Virus Infection

Abstract

Regulatory CD4

The role of Th17 and Treg responses in the pathogenesis of RSV infection

“…This was accompanied by a delayed exacerbation and a slower recovery. However, no difference in the final viral clearance was seen postinfection as it was achieved completely in both the controls and, albeit slower, in the Treg-depleted mice (34,36,37). Loebbermann et al (38) on the other hand, did describe a decrease in viral load when depleting Treg cells in mice.…”

“…When the Treg response is inhibited, delayed migration of the CD8 + T-cells out of the peripheral lymph nodes results in delayed viral clearance and increased disease severity (34). In conclusion, Treg cells by no means hinder the viral clearance of RSV and may even facilitate the process (34,36,37).…”

“…The Treg and Th17 subsets have distinct and opposing features in this context, as demonstrated by their effects on viral clearance, clinical severity, and Th2-oriented immune response (see Table 1). Specifically, the Treg immune response will ensure an efficient viral clearance and inhibition of the Th2-oriented immune response resulting in a less severe clinical picture (34,(36)(37)(38)(39). Although evidence is less conclusive than is the case for the Treg immune response, the Th17 immune response is thought to hamper an efficient viral clearance and further enhance a Th2 immune response resulting in a more severe clinical picture (50).…”

Attenuated Bordetella pertussis Vaccine Protects against Respiratory Syncytial Virus Disease via an IL-17–Dependent Mechanism

“…To monitor colonization, lungs were homogenized and plated onto Bordet-Gengou agar plates for 120 hours. Plaque-purified human RSV (strain A2) was grown in Hep2 cells in serum-free Dulbecco's modified Eagle medium media (11). Virus load was measured by plaque assay or quantitative polymerase chain reaction for RSV L-gene (12).…”

Viral infection of the lung: Host response and sequelae

“…[98][99][100] In the mouse model of RSV infection, the depletion of Treg cells leads to excessive pulmonary inflammation and lung injury during the course of infection. 97,101,102 Recently, not only Treg cells but also conventional effector T cells (both CD4 + and CD8 + T cells) have been shown to exert a ''regulatory'' function in the lung through the production of IL-10 during simian virus 5, IAV, or RSV infection. 100,103,104 The in vivo blockade of T cell-derived IL-10 results in excessive pulmonary inflammation characterized by increased accumulation of CD45 + inflammatory cells and enhanced production of proinflammatory cytokines, especially during the course of IAV or RSV infection.…”