Mardivirus Infection and Persistence in Feathers of a Chicken Model Harboring a Local Autoimmune Response

Abstract

Herpesvirus of turkey (HVT) is commonly used as a vaccine to protect chickens against Marek’s disease. Following vaccination, HVT infects feathers where it can be detected in all chicken lines examined. Unlike the parental Brown line (BL), Smyth line (SL) chickens develop vitiligo, due to autoimmune destruction of melanocytes in feathers. Previous reports showed a strong inflammatory response in Smyth chickens’ feathers at vitiligo onset, that subsided once melanocytes were destroyed, and depigmentation was complete. Here, we questioned whether the local autoimmune response in the Smyth model influences HVT infection and persistence in feathers. For this, one-day-old SL and BL chickens were vaccinated with Newcastle disease (rHVT-ND). Vitiligo was scored and HVT loads in pigmented and non-pigmented growing feathers were quantified regularly over 20 weeks. Chickens of both lines showed moderate HVT loads in feathers. At the onset of active vitiligo, the HVT load was significantly higher in SL compared to BL feathers. However, no difference in HVT loads was noticed between pigmented and non-pigmented feathers from SL chickens. Therefore, surprisingly, the inflammatory response in feathers of SL chickens did not inhibit HVT infection and persistence, but on the contrary, temporarily promoted HVT infection in feathers.

Research status of vitiligo models

“…Studies have shown that T lymphocytes, mainly cytotoxic CD8+ T cells, that infiltrate the edges of vitiligo lesions, mediate the elimination of MCs and play a necessary and sufficient role in the occurrence and development of vitiligo. While regulatory T cells (Tregs) maintain immune homeostasis and suppress inflammation, skin Resident Memory T (TRM) cells induce vitiligo relapse [14]. According to this theory, several kinds of mouse vitiligo models have been established.…”

A Special Issue on Marek’s Disease Virus—The Editors’ View

“…Three contributions highlight the value of MDV infections in chickens as a model for human diseases. Erf et al used a Mardivirus in vivo model to gain new insights into vitiligo, a chronic autoimmune disorder [ 11 ]. A genomics study by Steep et al revealed that key somatic mutations in the Ikaros cancer driver gene can contribute to MDV-induced tumorigenesis.…”