Viruses 2012, 4(5), 833-846; doi:10.3390/v4050833
Review

Regulatory T Cells in Arterivirus and Coronavirus Infections: Do They Protect Against Disease or Enhance it?

email, email and * email
Received: 2 April 2012; in revised form: 3 May 2012 / Accepted: 7 May 2012 / Published: 15 May 2012
(This article belongs to the Special Issue Animal Arteriviruses and Coronaviruses)
View Full-Text   |   Download PDF [232 KB, updated 23 May 2012; original version uploaded 15 May 2012]
Abstract: Regulatory T cells (Tregs) are a subset of T cells that are responsible for maintaining peripheral immune tolerance and homeostasis. The hallmark of Tregs is the expression of the forkhead box P3 (FoxP3) transcription factor. Natural regulatory T cells (nTregs) are a distinct population of T cells that express CD4 and FoxP3. nTregs develop in the thymus and function in maintaining peripheral immune tolerance. Other CD4+, CD4-CD8-, and CD8+CD28- T cells can be induced to acquire regulatory function by antigenic stimulation, depending on the cytokine milieu. Inducible (or adaptive) Tregs frequently express high levels of the interleukin 2 receptor (CD25). Atypical Tregs express FoxP3 and CD4 but have no surface expression of CD25. Type 1 regulatory T cells (Tr1 cells) produce IL-10, while T helper 3 cells (Th3) produce TGF-β. The function of inducible Tregs is presumably to maintain immune homeostasis, especially in the context of chronic inflammation or infection. Induction of Tregs in coronaviral infections protects against the more severe forms of the disease attributable to the host response. However, arteriviruses have exploited these T cell subsets as a means to dampen the immune response allowing for viral persistence. Treg induction or activation in the pathogenesis of disease has been described in both porcine reproductive and respiratory syndrome virus, lactate dehydrogenase elevating virus, and mouse hepatitis virus. This review discusses the development and biology of regulatory T cells in the context of arteriviral and coronaviral infection.
Keywords: regulatory T cell; arterivirus, porcine reproductive and respiratory syndrome virus; lactate dehydrogenase-elevating virus; coronavirus
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Cecere, T.E.; Todd, S.M.; LeRoith, T. Regulatory T Cells in Arterivirus and Coronavirus Infections: Do They Protect Against Disease or Enhance it? Viruses 2012, 4, 833-846.

AMA Style

Cecere TE, Todd SM, LeRoith T. Regulatory T Cells in Arterivirus and Coronavirus Infections: Do They Protect Against Disease or Enhance it? Viruses. 2012; 4(5):833-846.

Chicago/Turabian Style

Cecere, Thomas E.; Todd, S. Michelle; LeRoith, Tanya. 2012. "Regulatory T Cells in Arterivirus and Coronavirus Infections: Do They Protect Against Disease or Enhance it?" Viruses 4, no. 5: 833-846.


Viruses EISSN 1999-4915 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert