Dendritic epidermal T cells: their role in the early phase of ectromelia virus infection.
BACKGROUND
Dendritic epidermal T cells (DETCs) are bone marrow-derived T lymphocytes that express a canonical gammadelta TCR and form a dense network in the murine skin. Here, we sought to determine their role during the early phase of ectromelia virus (ECTV) infection.


METHODS
In vivo and in vitro models were established for this purpose. In the first model, C57BL/6 mice were intradermally infected into the central part of the ear pinnas with 105 PFU ECTV-Mos strain per ear. At indicated time-points, the total pinna cell population was isolated to determine the presence of DETCs and the enumeration of DETCs secreting IFN-gamma under in vitro stimulation. Purified DETCs were also analyzed for certain gene expressions by RT-PCR. In the second model, purified DETCs isolated from pinnas of uninfected C57BL/6 mice were stimulated in vitro with 5 MOI of UV-inactivated ECTV-Mos. Total RNA was isolated at indicated time-points for RT-PCR gene expression evaluation.


RESULTS
A rapid increase in DETCs number in the pinnas was observed for 24 hours post-infection. During the next 24 h the DETCs number decreased, reaching control values. Rapid but short-lasting INF-gamma secretion by purified DETCs in vitro was observed and correlated well with the expression of the beta chemokine CCL5 gene responsible for macrophage and neutrophil attraction. It was also accompanied by DETCs expression of the immunoregulatory factors TGF-beta, GM-CSF, and KGF genes important for maintaining skin integrity.


CONCLUSIONS
DETCs from mice infected with ECTV-Mos were rapidly induced to cascade the secretion of mediators that contribute to both immune protection and the control of skin integrity.
Gieryńska
Małgorzata
M
Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences - SGGW, Warsaw, Poland. malgorzata_gierynska@sggw.pl
Pawlak
Ewelina
E
Schollenberger
Ada
A
Cespedes
Irma Spohr
IS
D000818:Animals; D018946:Chemokine CCL5 / Q000276:immunology; D004481:Ectromelia virus; D004482:Ectromelia, Infectious / Q000276:immunology*; D051523:Fibroblast Growth Factor 7 / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology*; D007801:Langerhans Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology
D018946:Chemokine CCL5; C496454:Fgf7 protein, mouse; D016212:Transforming Growth Factor beta; D051523:Fibroblast Growth Factor 7; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor